Analysis of microsatellite instability in endometrial cancer: The significance of minimal microsatellite shift / 北京大学学报(医学版)

OBJECTIVE@#To analyze the differences and characteristics of microsatellite instability (MSI) in endometrial cancer (EMC), by using colorectal cancer (CRC) as control.@*METHODS@#In the study, 228 cases of EMC were collected. For comparative analysis, 770 cases of CRC were collected. Mismatch repair (MMR) expression was detected by immunohistochemistry (IHC), and microsatellite instability (MSI) was analyzed by PCR and capillary electrophoresis fragment analysis (MSI-PCR). MSI-PCR was detected using five mononucleotide repeat markers: BAT-25, BAT-26, NR-21, NR-24, and MONO-27.@*RESULTS@#In EMC, we found 27.19% (62/228) of deficient mismatch repair (dMMR) using IHC, significantly higher than CRC (7.79%, 60/770). Meanwhile, subclonal expression of MMR protein was found in 4 cases of dMMR-EMC and 2 cases of dMMR-CRC. According to the criteria of major micro-satellite shift, we found 16.23% (37/228) of MSI-high (MSI-H), 2.63% (6/228) of MSI-low (MSI-L), and 81.14% (185/228) of microsatellite stability (MSS) in EMC using MSI-PCR. The discor-dance rate between MMR-IHC and MSI-PCR in EMC was 11.84% (27/228). In CRC, we found 8.05% (62/770) of MSI-H, 0.13% (1/770) of MSI-L, and 91.82% (707/770) of MSS. The discordance rate between MMR-IHC and MSI-PCR in CRC was only 0.52% (4/770). However, according to the criteria of minimal microsatellite shift, 12 cases of EMC showed minimal microsatellite shift including 8 cases of dMMR/MSS and 4 cases of dMMR/MSI-L and these cases were ultimately evaluated as dMMR/MSI-H. Then, 21.49% (49/228) of EMC showed MSI-H and the discordance rate MMR-IHC and MSI-PCR in EMC decreased to 6.58% (15/228). No minimal microsatellite shift was found in CRC. Compared with EMC group with major microsatellite shift, cases with minimal microsatellite shift showed younger age, better tumor differentiation, and earlier International Federation of Gynecology and Obstetrics (FIGO) stage. There were significant differences in histological variant and FIGO stage between the two groups (P < 0.001, P=0.006).@*CONCLUSION@#EMC was more prone to minimal microsatellite shift, which should not be ignored in the interpretation of MSI-PCR results. The combined detection of MMR-IHC and MSI-PCR is the most sensitive and specific method to capture MSI tumors.

Pathological Types,Expression of Mismatch Repair Protein,Human Epidermal Growth Factor Receptor 2,and Pan-TRK,and Eostein-Barr Virus Infection in Patients With Colorectal Cancer Resected in Tibet / 中国医学科学院学报

Objective To study the pathological types,expression of mismatch repair protein,human epidermal growth factor receptor 2(HER2),and Pan-TRK,and Epstein-Barr virus(EBV)infection in patients with colorectal cancer resected in Tibet. Methods A total of 79 patients with colorectal cancer resected in Tibet Autonomous Region People's Hospital from December 2013 to July 2021 were enrolled in this study.The clinical and pathological data of the patients were collected.The expression of mismatch repair protein,HER2,and Pan-TRK was detected by immunohistochemical(IHC)staining,and detection of HER2 gene by fluorescence in situ hybridization(FISH)in the patients with HER2 IHC results of 2+ or above.EBV was detected by in situ hybridization with EBV-encoded small RNA. Results A total of 79 colorectal cancer patients were included in this study,with the male-to-female ratio of 1.26:1 and the mean age of(57.06±12.74)years(24-83 years).Among them,4 patients received preoperative neoadjuvant therapy.Colonic cancer and rectal cancer occurred in 57(57/79,72.15%,including 31 and 26 in the right colon and left colon,respectively)and 22(22/79,27.85%)patients,respectively.The maximum diameter of tumor varied within the range of 1-20 cm,with the mean of(6.61±3.33)cm.Among the 79 colorectal cancer patients,75(75/79,94.94%)patients showed adenocarcinoma.Lymph node metastasis occurred in 12(12/21,57.14%)out of the 21 patients with severe tumor budding,13(13/23,56.52%)out of the 23 patients with moderate tumor budding,and 2(2/31,6.45%)out of the 31 patients with mild tumor budding,respectively.The lymph node metastasis rate showed differences between the patients with severe/moderate tumor budding and the patients with mild tumor budding(all P<0.001).The IHC staining showed that mismatch repair protein was negative in 10(10/65,15.38%)patients,including 5 patients with both MSH2 and MSH6 negative,4 patients with both MLH1 and PMS2 negative,and 1 patient with MSH6 negative.Pan-TRK was negative in 65 patients.The IHC results of HER2 showed 0 or 1+ in 60 patients and 2+ in 5 patients.FISH showed no positive signal in the 5 patients with HER2 IHC results of 2+.The detection with EBV-encoded small RNA showed positive result in 1(1/65,1.54%)patient. Conclusions Non-specific adenocarcinoma of the right colon is the most common in the patients with colorectal cancer resected in Tibet,and 15% of the patients showed mismatch repair protein defects.EBV-associated colorectal carcer is rare,Pan-TRK expression and HER2 gene amplification are seldom.The colorectal cancer patients with moderate and severe tumor budding are more likely to have lymph node metastasis.

Mismatch repair gene germline mutations in patients with prostate cancer / 浙江大学学报·医学版

OBJECTIVES@#To investigate the prevalence of pathogenic germline mutations of mismatch repair (MMR) genes in prostate cancer patients and its relationship with clinicopathological characteristics.@*METHODS@#Germline sequencing data of 855 prostate cancer patients admitted in Fudan University Shanghai Cancer Center from 2018 to 2022 were retrospectively analyzed. The pathogenicity of mutations was assessed according to the American College of Medical Genetics and Genomics (ACMG) standard guideline, Clinvar and Intervar databases. The clinicopathological characteristics and responses to castration treatment were compared among patients with MMR gene mutation (MMR+ group), patients with DNA damage repair (DDR) gene germline pathogenic mutation without MMR gene (DDR+MMR－ group) and patients without DDR gene germline pathogenic mutation (DDR－ group).@*RESULTS@#Thirteen (1.52%) MMR+ patients were identified in 855 prostate cancer patients, including 1 case with MLH1 gene mutation, 6 cases with MSH2 gene mutation, 4 cases with MSH6 gene mutation and 2 cases with PMS2 gene mutation. 105 (11.9%) patients were identified as DDR gene positive (except MMR gene), and 737 (86.2%) patients were DDR gene negative. Compared with DDR－ group, MMR+ group had lower age of onset (P<0.05) and initial prostate-specific antigen (PSA) (P<0.01), while no significant differences were found between the two groups in Gleason score and TMN staging (both P>0.05). The median time to castration resistance was 8 months (95%CI: 6 months-not achieved), 16 months (95%CI: 12-32 months) and 24 months (95%CI: 21-27 months) for MMR+ group, DDR+MMR－ group and DDR－ group, respectively. The time to castration resistance in MMR+ group was significantly shorter than that in DDR+MMR－ group and DDR－ group (both P<0.01), while there was no significant difference between DDR+MMR－ group and DDR－ group (P>0.05).@*CONCLUSIONS@#MMR gene mutation testing is recommended for prostate cancer patients with early onset, low initial PSA, metastasis or early resistance to castration therapy.

Neoadjuvant immunotherapy for colorectal cancer / 中华胃肠外科杂志

Immunotherapy has been one of the hot topics in the field of colorectal cancer research in recent years. Patients with microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) are the main beneficiaries of immunotherapy. The response rate of patients with dMMR/MSI-H colorectal cancer receiving neoadjuvant immunotherapy is nearly 100%, of which the pathological complete response rate approximately accounts for 60%-67%. The prospect of neoadjuvant immunotherapy in dMMR or MSI-H colorectal cancer patients, especially in the rectal cancer patients, lies in achieving sustainable clinical complete response so as to achieve organ preservation and avoid adverse effects on reproductive, sexual, bowel and bladder function after surgery and radiotherapy. Studies have shown that part of the colorectal cancer patients of microsatellite stability (MSS) or mismatch repair proficient (pMMR) can respond to neoadjuvant immunotherapy in combination with other treatment methods such as radiotherapy and chemotherapy. In pMMR or MSS colorectal cancer, optimizing neoadjuvant immunotherapy regimens and finding effective efficacy prediction biomarkers are important research directions. In neoadjuvant immunotherapy, overcoming primary and secondary resistance and identifying the pseudoprogression and hyperprogression of neoadjuvant immunotherapy are clinical challenges that require attention. This paper comprehensively reviews the research progress, controversies,challenges and future research directions of neoadjuvant immunotherapy (mainly immune checkpoint inhibitors) in colorectal cancer.

A robust microsatellite instability detection model for unpaired colorectal cancer tissue samples / 中华医学杂志(英文版)

BACKGROUND@#Microsatellite instability (MSI) is a key biomarker for cancer immunotherapy and prognosis. Integration of MSI testing into a next-generation-sequencing (NGS) panel could save tissue sample, reduce turn-around time and cost, and provide MSI status and comprehensive genomic profiling in single test. We aimed to develop an MSI calling model to detect MSI status along with the NGS panel-based profiling test using tumor-only samples.@*METHODS@#From January 2019 to December 2020, a total of 174 colorectal cancer (CRC) patients were enrolled, including 31 MSI-high (MSI-H) and 143 microsatellite stability (MSS) cases. Among them, 56 paired tumor and normal samples (10 MSI-H and 46 MSS) were used for modeling, and another 118 tumor-only samples were used for validation. MSI polymerase chain reaction (MSI-PCR) was performed as the gold standard. A baseline was built for the selected microsatellite loci using the NGS data of 56 normal blood samples. An MSI detection model was constructed by analyzing the NGS data of tissue samples. The performance of the model was compared with the results of MSI-PCR.@*RESULTS@#We first intersected the target genomic regions of the NGS panels used in this study to select common microsatellite loci. A total of 42 loci including 23 mononucleotide repeat sites and 19 longer repeat sites were candidates for modeling. As mononucleotide repeat sites are more sensitive and specific for detecting MSI status than sites with longer length motif and the mononucleotide repeat sites performed even better than the total sites, a model containing 23 mononucleotide repeat sites was constructed and named Colorectal Cancer Microsatellite Instability test (CRC-MSI). The model achieved 100% sensitivity and 100% specificity when compared with MSI-PCR in both training and validation sets. Furthermore, the CRC-MSI model was robust with the tumor content as low as 6%. In addition, 8 out of 10 MSI-H samples showed alternations in the four mismatch repair genes ( MLH1 , MSH2 , MSH6 , and PMS2 ).@*CONCLUSION@#MSI status can be accurately determined along the targeted NGS panels using only tumor samples. The performance of mononucleotide repeat sites surpasses loci with longer repeat motif in MSI calling.

Correlation of NTRK genetic fusions with mismatch repair protein deletion in patients with colorectal cancer / 中华病理学杂志

Objective: To investigate the relationship between the expression of four mismatch repair proteins (MLH1, MSH2, MSH6 and PMS2) and NTRK genetic fusions in colorectal cancer. Methods: The paraffin-embedded tissue blocks of 830 cases of colorectal cancer were collected at the Affiliated Drum Tower Hospital, Nanjing University Medical School, China, from 2015 to 2019. Immunohistochemical and fluorescence in situ hybridization(FISH) method were used respectively to detect the expression of mismatch repair proteins and the break-apart of NTRKs; and the relationship between the expression of mismatch repair proteins and the NTRK genetic fusions was analyzed. Results: The overall mismatch repair protein deficiency (dMMR) rate was 9.88% (82/830), the mismatch repair proteins proficiency (pMMR) rate was 90.12%(748/830). The total deficiency rate of MLH1 protein was 9.04% (75/830), hPMS2 protein deficiency rate was 9.04% (75/830), MSH2 protein deficiency rate was 2.53% (21/830), MSH6 protein deficiency rate was 4.10% (34/830), the deficiency rate of synchronous MLH1 and PMS2 were 8.67% (72/830) and the deficiency rate of synchronous MSH2 and MSH6 were 2.17% (18/830). The dMMR group was associated with tumor location, different histological subgroups, tumor differentiation, AJCC stage and N stage (P<0.05). There were six cases (7.32%) carrying NTRK fusion by FISH among the 82 cases of dMMR, but only seven cases (0.94%) carrying NTRK fusion among the 748 cases of PMMR. The NTRKs translocation by FISH in all 13 cases were further confirmed by next generation sequencing. Among the clinicopathological characteristics, only differentiation showed significant difference between NTRK fusion positive and negative groups (P<0.05). More importantly, NTRK fusion was enriched in dMMR group (7.32% vs. 0.94%). Conclusion: In dMMR colorectal cancer group, the prevalence of NTRK fusion is higher than that in pMMR group.

Neoadjuvant immunotherapy in microsatellite stability or mismatch repair proficient colorectal cancer / 中华胃肠外科杂志

Immunotherapy has become an important treatment option for microsatellite instability-high (MSI-H) and mismatch repair deficient (dMMR) colorectal cancer. From late-line to first-line treatment, and even in neoadjuvant setting for early stage colorectal cancer, promising efficacy was observed with immunotherapy. In microsatellite stability (MSS) or mismatch repair proficient (pMMR) colorectal cancer, the researches of neoadjuvant immunotherapy have been conducted constantly. This paper focuses on the recent researches and progress of neoadjuvant immunotherapy for MSS or pMMR colorectal cancer. Neoadjuvant immunotherapy alone led to a good pathological response in a subset of patients. Studies of induction or consolidation immunotherapy before or after neoadjuvant chemoradiotherapy or concurrent immunotherapy during radiotherapy showed higher pathological complete remission (pCR) rates as compared to standard chemoradiotherapy. Studies on sequential dual immunotherapy after radiochemotherapy and targeted therapy combined with neoadjuvant immunotherapy are ongoing. At present, most of these are pilot studies with small sample size. More researches and long-term follow-up are needed to prove the efficacy of neoadjuvant immunotherapy in MSS or pMMR colorectal cancer.

The association between the histopathological features and microsatellite instability in young patients with urothelial carcinoma of the bladder

SUMMARY OBJECTIVE: Bladder cancer under the age of 40 is extremely rare. Bladder cancer development involves complex and multi-stage processes, one of which is the DNA damage repair mechanism. In this retrospective study, we aimed to evaluate the histopathological features of bladder urothelial carcinoma seen in patients under 40 years of age and tumor microsatellite instability status using immunohistochemistry. METHODS: A total of 50 patients under the age of 40 with urothelial bladder carcinoma from two different centers in the same country were included. Expression of the mismatch repair proteins MLH1, MSH2, MSH6, and PMS2 was analyzed by immunohistochemistry. RESULTS: Age at the time of diagnosis ranged from 17 to 40 years old. Most tumors were non-invasive papillary urothelial carcinoma. Two cases had nuclear loss of MSH-6 and PMS-2. We observed that tumor grade, tumor stage, presence of tumor differentiation, and infiltrative growth pattern of the tumor have significant impact on prognosis, but microsatellite instability does not have an effective role in bladder carcinogenesis in young patients. CONCLUSIONS: Our results indicate that the presence of microsatellite instability is not related to the low tumor grade and stage in urothelial neoplasms in young patients, suggesting that urothelial carcinoma of the bladder in young patients may represent a genetically stable form of neoplasia.

Association of status of mismatch repair protein expression and EB virus infection with clinicopathological parameters in 886 gastric adenocarcinoma patients / 中华胃肠外科杂志

Objective: To analyze the expression of mismatch repair (MMR) protein and the EB virus infection in gastric adenocarcinoma, and to examine the association of MMR expression and EB virus infection with clinicopathological parameters. Methods: A case-control study was performed. Clinicopathological data of patients who was pathologically diagnosed as gastric adenocarcinoma, received radical gastrectomy and had complete clinicopathological data from August 2017 to April 2020 in Tianjin Medical University Cancer Institute and Hospital were retrospectively collected and analyzed. The immunohistochemistry (IHC) of MMR proteins and in situ hybridization (ISH) of Epstein-Barr virus encoded RNA (EBER) were reviewed. The associations of MMR and EBER results with clinicopathological parameters were analyzed. The main observations of the study were MMR and EBER expression, and association of MMR and EBER results with clinicopathological parameters. Results: Eight hundred and eighty-six patients were enrolled, including 98 patients who received preoperative neoadjuvant chemoradiotherapy. Of 886 patients, 613 (69.2%) were males and the median age was 60 (22-83) years; 831 (93.8%) were mismatch repair proficiency (pMMR), and 55 (6.2%) were mismatch repair deficiency (dMMR). In dMMR group, 47 cases (85.5%) had the deficiency of both MLH1 and PMS2, 1 case (1.8%) had the deficiency of both MSH2 and MSH6, 4 cases (7.3%) had the deficiency only in PMS2, 2 cases (3.6%) had the deficiency only in MSH6, and 1 case (1.8%) had the deficiency only in MSH2. The deficiency rates of PMS2, MLH1, MSH6 and MSH2 were 5.8% (51/886), 5.3% (47/886), 0.3% (3/886) and 0.2% (2/886), respectively. Among the 871 cases with EBER results, 4.9% (43/871) were positive EBER. Univariate analysis showed that dMMR was more frequently detected in female patients (χ(2)=10.962, P=0.001), cancer locating in the antrum (χ(2)=9.336,P=0.020), Lauren intestinal type (χ(2)=9.718, P=0.018), stage T3 (χ(2)=25.866, P<0.001) and TNM stage II (χ(2)=15.470, P=0.002). The ratio of dMMR was not significantly associated with age, tumor differentiation, histological type, lymph node metastasis, distant metastasis or Her-2 immunohistochemical score (all P>0.05). Compared with negative EBER, positive EBER was more frequent in male patients (χ(2)=9.701, P=0.002), cancer locating in gastric fundus and corpus (χ(2)=17.964, P<0.001), gastric cancer with lymphoid stroma (χ(2)=744.073, P<0.001) and poorly differentiated cancer (χ(2)=13.739, P=0.010). Positive EBER was not significantly associated with age, depth of invasion, lymph node metastasis, distant metastasis, TNM stage or Her-2 immunohistochemical score (all P>0.05). In addition, all dMMR cases were EBER negative, and all cases of positive EBER were pMMR. Conclusions: The positive EB virus status is mutually exclusive with dMMR, indicating that different molecular subtypes of gastric adenocarcinoma are involved in different molecular pathways in tumorigenesis and progression. The overlapping of dMMR or positive EBER status and positive Her-2 expression is found in some cases of gastric adenocarcinoma. Patients with gastric adenocarcinoma after radical surgery should be tested for MMR status if they are female, the tumor locates in gastric antrum, the TNM staging is stage II or T3, or if the Lauren classification is intestinal type. And if patients are male, the tumor locates in the gastric fundus and corpus, the cancer is lymphoid stroma, or poor differentiated, the expression of EBER should be detected. Results of our study may provide evidence for further decision-making of clinical treatment.

Clinicopathological features and types of microsatellite instability in 1394 patients with colorectal cancer / 南方医科大学学报

OBJECTIVE@#To explore the clinicopathological features and types of genic mutations in DNA mismatch repair (MMR) in colorectal cancer (CRC).@*METHODS@#Immunohistochemistry was used to determine the expression of MMR proteins in 1394 patients with CRC, and PCR-capillary electrophoresis (PCR-CE) was used to detect microsatellite instability (MSI) in 106 cases of defective MMR (dMMR), 46 cases of proficient MMR (pMMR) with heterogeneous expression and 147 randomly selected cases of pMMR. The relationship between the expressions of MMR proteins and the clinicopathological features of the patients was evaluated. The consistency between the results of immunohistochemistry and PCR-CE was assessed.@*RESULTS@#Immunohistochemical staining showed an incidence of dMMR of 7.6% in the patients. The main type of dMMR was co-deletion of MLH1 and PMS2, accounting for 55.7% of the total dMMR cases. The deletion of MMR proteins was significantly correlated with the patients' age, tumor location, tumor size, gross type, histological type, degree of differentiation, lymph node status and TNM stage (@*CONCLUSIONS@#The main type of dMMR is co-deletion of MLH1 and PMS2 in patients with colorectal cancer. dMMR colorectal cancer has typical clinicopathological features and a lower incidence in China than in Western countries. The results of immunohistochemistry and PCR-CE are highly consistent for detecting dMMR in colorectal cancer patients.

Extensive colectomy in colorectal cancer and hereditary nonpolyposis colorectal cancer - long-term results / Colectomia extensa em cancro colorretal e cancro colorretal hereditário sem polipose - resultados a longo prazo

ABSTRACT Background: Colorectal cancer survival is better in hereditary nonpolyposis colorectal cancer patients than in sporadic colorectal cancer patients and even for hereditary nonpolyposis colorectal cancer with colorectal cancer is not consensual that extensive colectomy is preferable to partial colectomy. This study analyzes and compares the long-term results of these two groups of patients submitted to curative subtotal colectomy or total colectomy. Methods: Between 2002 and 2018, 68 patients with colorectal cancer without familial adenomatous polyposis were submitted to a total or subtotal colectomy in a single tertiary center. The patients were divided in two groups: hereditary nonpolyposis colorectal cancer patients (with Amsterdam criteria) and sporadic colorectal cancer patients (the others). The presence of Amsterdam criteria for hereditary nonpolyposis colorectal cancer and germline mutation for mismatch repair genes was confirmed by clinical records. Results and survival were analyzed following surgery. Results: We obtained a sporadic colorectal cancer group with 31 patients and a hereditary nonpolyposis colorectal cancer group with 37 patients. The two groups differ in age but not in gender, tumor stage or surgical morbidity. The overall survival and disease-free survival were good in both groups but even better for hereditary nonpolyposis colorectal cancer group with statistical significance when comparing the two groups. Conclusion: Total or subtotal colectomy for colorectal cancer provides a good survival. These surgical procedures should be considered the first option for colorectal cancer in young hereditary non polyposis colorectal cancer patients. In those cases, they provide good long-term results, avoiding the risk of metachronous colorectal cancer and the surveillance is restricted only to the remaining need for rectum.

RESUMO Introdução: A sobrevivência do cancro colorretal é melhor em pacientes com cancro colorretal hereditário não associado a polipose do que em pacientes com cancro colorretal esporádico. Mesmo em casos de cancro colorretal hereditário sem polipose, a preferência pela colectomia total em relação à parcial não é consensual na literatura. Este estudo analisa e compara os resultados a longo prazo destes dois grupos de pacientes submetidos à colectomia curativa subtotal ou total. Métodos: Entre 2002 e 2018, 68 pacientes com cancro colorretal sem polipose adenomatosa familiar foram submetidos a colectomia total ou subtotal em um único centro terciário. Os pacientes foram divididos em dois grupos: aqueles com cancro colorretal hereditário sem polipose (de acordo com os critérios de Amsterdão) e os com cancro colorretal esporádico (os demais). Os critérios de Amsterdão para cancro colorretal hereditário sem polipose e a presença de mutação germinativa para os genes de reparação de ADN foram confirmados por consulta dos registros clínicos. Os resultados e a sobrevivência foram analisados após a cirurgia. Resultados: No presente estudo, 31 pacientes foram incluídos no grupo de cancro colorretal esporádico e 37 no grupo de cancro colorretal hereditário sem polipose. Diferenças significativas foram observadas em relação à idade, mas não ao gênero, estadio do tumor ou morbilidade cirúrgica. A sobrevivência global e a sobrevivência livre de doença foram boas em ambos os grupos, mas os resultados foram ainda melhores no grupo de cancro colorretal hereditário sem polipose, com significado estatístico. Conclusão: A colectomia total ou a colectomia subtotal para o cancro colorretal proporcionam uma boa sobrevivência e devem ser consideradas a primeira opção de tratamento em pacientes jovens com cancro colorretal hereditário sem polipose. Nestes pacientes, uma cirurgia cólica mais extensa permite a obtenção de bons resultados a longo prazo; reduz o risco de cancro colorretal metácrono e restringe a vigilância endoscópica ao reto remanescente.

Prognostic factors of synchronous endometrial and ovarian endometrioid carcinoma / 부인종양

OBJECTIVE: Gynecologists occasionally encounter synchronous endometrial and ovarian endometrioid carcinoma (SEO-EC) patients who show favorable prognosis than locally advanced or metastatic disease patients. This study aimed to elucidate prognostic factors of SEO-EC and identify patients who have a sufficiently low risk of recurrence without receiving adjuvant chemotherapy. METHODS: We retrospectively reviewed 46 patients with pathologically confirmed SEO-EC who underwent surgery at the National Cancer Center Hospital between 1997 and 2016. Immunohistochemical evaluation of DNA mismatch repair (MMR) protein expression were performed for both endometrial and ovarian tumors. Patient outcomes were analyzed according to clinicopathologic factors. RESULTS: From the multivariate analysis, cervical stromal invasion indicated a worse prognosis for progression-free survival (hazard ratio [HR]=6.85; 95% confidence interval [CI]=1.50–31.1) and overall survival (HR=6.95; 95% CI=1.15–41.8). Lymph node metastasis and peritoneal dissemination did not significantly affect survival. MMR deficiency was observed in 13 patients (28.3%), with both endometrial and ovarian tumors showing the same MMR expression status. MMR deficiency was not significantly associated with survival. Of 23 patients with lesions confined to only the uterine body and adnexa, only 2 had recurrence in the group receiving adjuvant therapy, while none of the 10 patients who did not receive adjuvant therapy had recurrence. CONCLUSION: SEO-EC patients with tumors localized to the uterine body and adnexa lesions had a low risk for recurrence and may not require adjuvant therapy. SEO-EC may have prognostic factors different from those of endometrial and ovarian cancer.

Frequency of Variants in DNA-Repair Genes in a Southwest Colombian Population / Frecuencia de las variantes en genes de reparación del ADN en una población del suroccidente de Colombia

Objective To describe the frequency of mutations in DNA-repair genes in a southwestern Colombian population. Methods We have designed an observational study, including 162 people from all ages from southwest Colombia. We have extracted and collected their DNA in filters. We have immersed the DNA in a phosphate buffer along with DNeasy package (Thermo Fisher Scientific, Waltham, MA, USA). The preparation process was with the TruSeq Exome Library Prep (Illumina, Inc. San Diego, CA, USA), then the obtained libraries were normalized with TruSeq Rapid Exome (Illumina, Inc. San Diego, CA, USA). We sequenced the full exome and identified the variants associated with 12 genes (ataxia telangiectasia mutated [ATM], BRCA1 DNA repair associated [BRCA1], BRCA2 DNA repair associated [BRCA2], checkpoint kinase 2 [CHEK2], epithelial cell adhesion molecule [EPCAM], homeobox protein Hox-B13 [HOXB13], mutS homolog 1, 2 and 6 [MLH1, MSH2, MSH6], nibrin [NBN], PMS1 homolog 2, mismatch repair system component [PMS2], and tumor protein p53 [TP53]). Descriptive statistics were performed with the R software (The R Foundation for Statistical Computing, Vienna, Austria). Results A total of 7,315,466 pieces of data were sequenced in this population. The most frequently mutated genes were ATM (1,221 pieces of data; 13.2%), BRCA1 (1,178 pieces of data; 12.8%), BRCA2 (1,484 pieces of data; 16.12%), and NBN (965 pieces of data; 10.42%). The most common single nucleotide polymorphisms (SNPs) in these 12 genes were the following: BRCA2 (rs169547, rs206075, rs206076); ATM (rs659243, rs228589); TP53 (rs1625895, rs1042522, rs1642785); PMS2 (rs2228006, rs1805319); NBN (rs709816); and MSH6 (rs3136367) Conclusion The BRCA2, ATM, BRCA1 and NBN DNA-repair genes were the most frequently mutated in this southwestern Colombian Population

Objetivo Describir la frecuencia de las mutaciones en los genes de reparación del ADN en una población del suroccidente de Colombia. Métodos Diseñamos un estudio observacional que incluyó a 162 personas del suroccidente de Colombia de todas las edades. Hemos extraído y recogido el ADN en filtros. Los sumergimos en tampón fosfato junto con el paquete DNeasy (Thermo Fisher Scientific, Waltham, MA, EEUU). El proceso de preparación fue realizado con TruSeq Exome Library Prep (Illumina, Inc. San Diego, CA, EEUU); luego, las bibliotecas obtenidas se normalizaron con TruSeq Rapid Exome (Illumina, Inc. San Diego, CA, USA). Secuenciamos el exoma completo e identificamos las variantes asociadas a doce genes (ataxia telangiectasia mutated [ATM], BRCA1 DNA repair associated [BRCA1], BRCA2 DNA repair associated [BRCA2], checkpoint kinase 2 [CHEK2], epithelial cell adhesion molecule [EPCAM], homeobox protein Hox-B13 [HOXB13], mutS homolog 1, 2 and 6 [MLH1, MSH2, MSH6], nibrin [NBN], PMS1 homolog 2, mismatch repair system component [PMS2], y tumor protein p53 [TP53]). La estadística descriptiva se realizó en el programa R (The R Foundation for Statistical Computing, Viena, Austria). Resultados Un total de 7.315.466 datos fueron secuenciados en esta población. Los genes más frecuentemente mutados fueron el ATM, con 1.221 datos (13,2%), el BRCA1, con 1.178 datos (12,8%), el BRCA2, con 1.484 datos (16,12%) y el NBN, con 965 datos (10,42%). Los polimorfismos de un solo nucleótido (PSN) más comunes en estos 12 genes fueron los siguientes: BRCA2 (rs169547, rs206075, rs206076); ATM (rs659243, rs228589); TP53 (rs1625895, rs1042522, rs1642785); PMS2 (rs2228006, rs1805319); NBN (rs709816) y MSH6 (rs3136367) Conclusión Los genes de reparación de ADN BRCA2, ATM, BRCA1 NBN fueron los más frecuentemente mutados en esta población del suroccidente de Colombia.

Consensus on the detection of microsatellite instability in colorectal cancer and other related solid tumors in China / 中华肿瘤杂志

Microsatellite instability (MSI) which resulted from the deficiency of DNA mismatch repair (MMR), is an important clinical significance in the related solid tumors, such as colorectal cancer and endometrial cancer. There are several methods to detect MSI status, including immunohistochemistry for MMR protein, multiplex fluorescent polymerase chain reaction (PCR) for microsatellite site and MSI algorithm based on next generation sequencing (NGS). The consensus elaborates the definition and clinical significance of MSI as well as the advantages and disadvantages of the three detection methods. Through this expert consensus, we hope to promote the screening which based on MSI status in malignant tumors and improve the acknowledge of clinicians about various testing methods. Thereby, they could interpret the results more accurately and provide better clinical services to patients.

Associations of Genetic Variations in Mismatch Repair Genes MSH3 and PMS1 with Acute Adverse Events and Survival in Patients with Rectal Cancer Receiving Postoperative Chemoradiotherapy / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Mismatch repair (MMR) deficiency plays a critical role in rectal cancer. This study aimed to explore the associations between genetic variations in seven MMR genes and adverse events (AEs) and survival of patients with rectal cancer treated with postoperative chemoradiotherapy (CRT). MATERIALS AND METHODS: Fifty single nucleotide polymorphisms in seven MMR (MLH1, MLH3, MSH2, MSH3, MSH6, PMS1 and PMS2) genes were genotyped by Sequenom MassARRAY method in 365 patients with locally advanced rectal cancer receiving postoperative CRT. The associations between genotypes and AEs were measured by odds ratios and 95% confidence intervals (CIs) by unconditional logistic regression model. The associations between genetic variations and survival were computed by the hazard ratios and 95% CIs by Cox proportional regression model. RESULTS: The most common grade ≥ 2 AEs in those 365 patients, in decreasing order, were diarrhea (44.1%), leukopenia (29.6%), and dermatitis (18.9%). Except 38 cases missing, 61 patients (18.7%) died during the follow-up period. We found MSH3 rs12513549, rs33013 and rs6151627 significantly associated with the risk of grade ≥ 2 diarrhea. PMS1 rs1233255 had an impact on the occurrence of grade ≥2 dermatitis. Meanwhile, PMS1 rs4920657, rs5743030, and rs5743100 were associated with overall survival (OS) time of rectal cancer. CONCLUSION: These results suggest that MSH3 and PMS1 polymorphisms may play important roles in AEs prediction and prognosis of rectal cancer patients receiving postoperative CRT, which can be potential genetic biomarkers for rectal cancer personalized treatment.

Síndrome de Lynch: aspectos genéticos, clínicos y diagnósticos / Lynch syndrome: genetic, clinical and diagnostic aspects

Esta revisión tiene como objetivo dar a conocer los aspectos genéticos, clínicos y diagnósticos del síndrome de Lynch, además de brindar la información más relevante acerca de la asesoría genética en estos pacientes y las recomendaciones actuales para su seguimiento.

This review aims to present the genetic, clinical and diagnostic aspects of Lynch syndrome, as well as providing the most relevant information about genetic counseling in these patients and the current recommendations for their surveillance.

Serrated neoplasia pathway as an alternative route of colorectal cancer carcinogenesis

In the past two decades, besides conventional adenoma pathway, a subset of colonic lesions, including hyperplastic polyps, sessile serrated adenoma/polyps, and traditional serrated adenomas have been suggested as precancerous lesions via the alternative serrated neoplasia pathway. Major molecular alterations of sessile serrated neoplasia include BRAF mutation, high CpG island methylator phenotype, and escape of cellular senescence and progression via methylation of tumor suppressor genes or mismatch repair genes. With increasing information of the morphologic and molecular features of serrated lesions, one major challenge is how to reflect this knowledge in clinical practice, such as pathologic and endoscopic diagnosis, and guidelines for treatment and surveillance.

Endometrial cancer risk and survival by tumor MMR status / 부인종양

OBJECTIVE: The risk of developing endometrial cancer (EC) and/or survival following a diagnosis of EC might differ by tumor DNA mismatch repair (MMR) status. We assessed the association between tumor MMR status (classified as MMR-proficient, somatic MMR-deficient, germline MMR-deficient) and the risk of developing EC and survival following a diagnosis of EC. METHODS: We analyzed data from women who participated in the Australian National Endometrial Cancer Study (ANECS) conducted between 2005 and 2007. Risk analyses (698 cases/691 population controls) utilized sociodemographic and lifestyle information obtained from telephone interviews at recruitment. For survival analyses (728 cases), patients' clinical data was abstracted from medical records, and survival data were obtained via linkage with the Australian National Death Index. We used logistic regression analysis to evaluate the associations between tumor MMR status and EC risk, and proportional hazards models to perform survival analyses with adjustment of known prognostic factors. RESULTS: Established risk factors for EC did not differ significantly by tumor MMR status. In analyses including all EC subtypes, overall and EC-specific survival did not differ by tumor MMR status. Among women with the most common endometrioid subtype, EC-specific survival was worse for women with somatic MMR-deficient EC compared to women with MMR-proficient EC (hazard ratio [HR]=2.18; 95% confidence interval [CI]=1.19–4.01). CONCLUSION: The risk of EC is not associated with MMR status. Accurate separation of germline from somatic causes of MMR deficiency suggests that patients with endometrioid subtype somatic MMR-deficient tumors have poorer EC-specific survival than those with MMR-proficient tumors, after accounting for other prognostic factors.

Screening for Lynch syndrome using risk assessment criteria in patients with ovarian cancer / 부인종양

OBJECTIVE: Lynch syndrome is a cancer predisposition syndrome caused by germline mutation of DNA mismatch repair (MMR) genes. Lynch syndrome only causes about 0.4% of cases of ovarian cancer, which suggests that universal screening may not be cost-efficient. However, the frequency of Lynch syndrome in ovarian cancer is unclear in the Asian population. The goal of the study was to investigate a screening strategy using family history. METHODS: The subjects were 129 patients with ovarian cancer. Clinical and family history were collected using a self-administered questionnaire, and Society of Gynecologic Oncology (SGO) criteria 2007 and PREMM5 were used for risk assessment. Microsatellite instability, immunohistochemistry, and methylation of MMR genes were analyzed. RESULTS: Of the 129 cases, 25 (19.4%) met the SGO criteria, and 4 of these 25 had MSI-high and MMR deficiency. Two cases had loss of MSH2 and MSH6, indicating MSH2 mutation, and the other two had loss of MLH1 and PMS2, including one without MLH1 methylation indicating MLH1 mutation. These results show that screening using family history can detect Lynch syndrome in 12.0% (3/25) of ovarian cancer cases. The 3 cases were positive for PREMM5, but negative for Amsterdam II criteria and revised Bethesda guidelines. Genetic testing in one case with MSH2 and MSH6 deficiency confirmed the diagnosis of Lynch syndrome with MSH2 mutation. CONCLUSION: This is the first study of screening for Lynch syndrome in ovarian cancer using clinical and family history in an Asian population. This approach may be effective for diagnosis in these patients.

Expression of secreted frizzled-related protein 4 in DNA mismatch repair-deficient and mismatch repair-proficient colorectal cancers / 南方医科大学学报

OBJECTIVE@#To investigate the expressions of secreted frizzled-related protein 4 (SFRP4) in stage Ⅱ DNA mismatch repair-deficient (dMMR) and mismatch repair- proficient (pMMR) colorectal cancers and explore their clinical significance.@*METHODS@#We collected fresh stage Ⅱ colon cancer tissues with different MMR status detected by immunohistochemistry (IHC). The differentially expressed mRNAs between dMMR and pMMR tumors were identified by Affymetrix Human oeLncRNA gene chip, and the expression of SFRP4 in these cancer tissues and in colorectal cancer cell lines were detected using Western blotting and real- time quantitative PCR. The apoptosis rates of HCT116 cells with and without siRNA- mediated transient SFRP4 knockdown were determined using flow cytometry. We further investigated the expression pattern of Ki-67 and its correlation with SFRP4 expression.@*RESULTS@#Compared with pMMR colon cancer tissues or cells, both dMMR colon cancer tissues (=0.014) and cells (=0.0079) showed significantly increased expression of SFRP4, which was in negative correlation with Ki-67 (=0.041). In HCT116 cells, transient SFRP4 knockdown resulted in decreased cell apoptosis, including both early apoptosis (=0.003) and late apoptosis (=0.024).@*CONCLUSIONS@#Up-regulation of SFRP4 in dMMR stage Ⅱ colon cancer promotes apoptosis and inhibits proliferation of the cancer cells, and may improve the prognosis of dMMR colon cancer.