Circulating cell-free DNA methylation patterns as non-invasive biomarkers to monitor colorectal cancer treatment efficacy without referencing primary site mutation profiles.

This study investigates methylation patterns in circulating cell-free DNA (ccfDNA) for their potential role in colorectal cancer (CRC) detection and the monitoring of treatment response. Through methylation microarrays and quantitative PCR assays, we analyzed 440 samples from The Cancer Genome Atlas (TCGA) and an additional 949 CRC samples. We detected partial or extensive methylation in over 85% of cases within three biomarkers: EFEMP1, SFRP2, and UNC5C. A methylation score for at least one of the six candidate regions within these genes' promoters was present in over 95% of CRC cases, suggesting a viable detection method. In evaluating ccfDNA from 97 CRC patients and 62 control subjects, a difference in methylation and recovery signatures was observed. The combined score, integrating both methylation and recovery metrics, showed high diagnostic accuracy, evidenced by an area under the ROC curve of 0.90 (95% CI = 0.86 to 0.94). While correlating with tumor burden, this score gave early insight into disease progression in a small patient cohort. Our results suggest that DNA methylation in ccfDNA could serve as a sensitive biomarker for CRC, offering a less invasive and potentially more cost-effective approach to augment existing cancer detection and monitoring modalities, possibly supporting comprehensive genetic mutation profiling.

Internal hernia caused by exposed structures after laparoscopic lateral lymph node dissection for rectal cancer: A case report.

Internal hernias secondary to exposed structures after lateral lymph node dissection (LLND) for rectal cancer are rare. A 53-year-old man who underwent laparoscopic ultra-low anterior resection and bilateral LND presented to our emergency department with sudden-onset severe abdominal pain and vomiting. Computed tomography demonstrated a closed loop obstruction of the intestine in the right lateral pelvic cavity and a significantly dilated small bowel in the abdominal cavity. Laparoscopic surgery revealed small bowel migration into the space between the right ureter and umbilical artery. The herniated bowel was laparoscopically reduced, and the small bowel exhibited no ischemic changes. Meanwhile, the hernial orifice was left unrepaired. The patient was discharged on the seventh postoperative day without complications. An internal hernia caused by exposed structures after lymphadenectomy should be a differential diagnosis in patients who have undergone LLND for rectal cancer and then present with severe abdominal pain and vomiting.

Genomically Stable Gastric Cancer Characterized by Hypomethylation in Wnt Signal Cascade.

INTRODUCTION: Gastric cancer is divided into four subtypes by their molecular features linked with genetic alterations, e.g., Epstein-Barr virus (EBV), microsatellite instability-high (MSI-high), chromosomal instability (CIN), and genomically stable (GS), called as TCGA classification. In this study, we tried to clarify the epigenetic features of the four GC subtypes according to aberrant methylation status in 23 loci. METHODS: A total of 98 gastric cancers and their normal gastric mucosa samples were included in this study. We divided gastric cancers into TCGA subtypes which were determined in line with MSI-high, EBV, CIN, to GS by their molecular features. The 13 loci of polymorphic microsatellite sequences were used to determine loss of heterogeneity for the detection of CIN. The MSI status was determined by three mononucleotide repeat markers. Infection of EBV was determined by recovering EBV BNRF1 sequence from genomic DNA collected from gastric cancers. Methylation status of 23 loci was investigated by the combined bisulfite restriction analysis. Status of other findings, e.g., KRAS mutations, HER2 expression status, and infection of helicobacter pylori were confirmed. RESULTS: Gastric cancers were divided into MSI (13%), EBV (7%), CIN (53%), and GS (27%). By histological classification, poorly differentiated adenocarcinoma was more in tumors categorized in MSI-high, and GS and signet-ring cell carcinoma (sig) were more in GS. Among the 23 loci investigated their methylation status, 18 loci were significantly hypermethylated in caner tissues. An unsupervised clustering divided gastric cancers into two clusters and revealed that most GS tumors clustered together in a cluster that exhibited lower methylation levels, distinct from the other subtypes. The inter-variable clustering revealed that a cluster contained the three loci (SFRP2-region 1/2 and APC) belonging to the Wnt signal cascade (Wnt-associated loci). The mean methylation score of Wnt-associated loci was the lowest in GS tumors (MSI-high: 2.7 [95% confidence interval, 2.3-2.9]; EBV: 2.1 [1.2-3.1]; CIN: 2.4 [2.2-2.7]; GS: 1.3 [0.8-0.7]). In contrast, the mean methylation score of the other 15 loci was significantly higher in MSI-high, while that in GS was as same as that in EBV or CIN (MSI-high: 10.4 [8.3-12.4]; EBV: 5.7 [1.7-9.7]; CIN: 4.4 [3.6-5.1]; GS: 3.4 [2.2-4.6]). Additionally, the lower methylation score of Wnt-associated loci was observed only in sig tumors. CONCLUSIONS: GS subtype tumors have the potential to possess distinct signatures in DNA hypomethylation profiles in Wnt signaling pathway, especially in sig.

Concordance of acquired mutations between metastatic lesions and liquid biopsy in metastatic colorectal cancer.

AIM: To evaluate whether PCR-reverse sequence-specific oligonucleotide can examine the concordance between liquid biopsy and metastatic lesions with acquired resistance. MATERIALS & METHODS: We examined acquired mutations in chemoresistant lesions and blood obtained from four patients with RAS wild-type metastatic colorectal cancer who underwent treatment with anti-epidermal growth factor receptor antibodies. RESULTS: In one patient, metastatic lesions harbored diverse acquired mutations in KRAS in all seven metastases; the two acquired mutations were detectable in blood collected after the patient acquired resistance. None of the other patients exhibited liquid biopsy mutations, except one, with a BRAF mutation confirmed in primary tumor and peritoneal dissemination. CONCLUSION: Liquid biopsy based on PCR-reverse sequence-specific oligonucleotide is a successful procedure for capturing acquired mutations with precise information on the RAS mutational spectrum.

Laparoscopic Synchronous Resection for Descending Colon Cancer and Tailgut Cyst.

A 67-year-old woman underwent polypectomy for a tumor at the descending colon. Pathologically, the tumor was diagnosed as adenocarcinoma with an invasion of 2000 µm. Computed tomography showed a swollen paracolic lymph node and a mass lesion in the presacral space. Magnetic resonance imaging revealed a multio-cular cystic lesion. On diagnosis of descending colon cancer and tailgut cyst, she underwent synchronous lapa-roscopic resection. Histopathologically, the colon cancer was diagnosed as pT1bN1M0, pStage IIIa. The pre-sacral cystic lesion was diagnosed as a nonmalignant tailgut cyst with negative surgical margin. The patient is currently doing well without recurrence at 28 months.

Clinical and epigenetic features of colorectal cancer patients with somatic POLE proofreading mutations.

BACKGROUND: Mutations in the POLE gene result in an ultra-hypermutated phenotype in colorectal cancer (CRC); however, the molecular characterisation of epigenetic alterations remains unclear. We examined the genetic and epigenetic profiles of POLE-mutant CRC to elucidate the clinicopathological features of the associated genetic and epigenetic alterations. RESULTS: Tumour tissues (1,013) obtained from a cohort of patients with CRC were analysed to determine associations between the proofreading domain mutations of POLE with various clinicopathological variables, microsatellite instability (MSI) status, BRAF and KRAS mutations, and the methylation status of key regions of MLH1, MGMT, and SFRP2 promoters by calculating the methylation scores (range 0-6). Only four cases (0.4%) exhibited pathogenic POLE hotspot mutations (two p.P286R [c.857C > G], one p.V411L [c.1231G > C], and p.S459F [c.1376C > T] each), which were mutually exclusive to BRAF and KRAS mutations and MSI. CRC patients were divided into four subgroups: patients with POLE mutations (POLE, 0.4%, n = 4), patients with both MSI and extensive methylation in MLH1 (MSI-M, 2.9%, n = 29), patients with MSI but no extensive methylation in MLH1 (MSI-U, 3.6%, n = 36), and patients without MSI (non-MSI, 93.2%, n = 944). The POLE group was younger at diagnosis (median 52 years, P < 0.0001), with frequent right-sided tumour localisation (frequency of tumours located in the right colon was 100%, 93.1%, 36.1%, and 29.9% in POLE, MSI-M, MSI-U, and non-MSI, respectively; P < 0.0001), and was diagnosed at an earlier stage (frequency of stages I-II was 100%, 72.4%, 77.8%, and 46.6% in POLE, MSI-M, MSI-U, and non-MSI, respectively, P < 0.0001). The mean methylation score in POLE was not different from that in MSI-U and non-MSI, but the methylation signature was distinct from that of the other subgroups. Additionally, although the examined number of POLE-mutant tumours was small, the number of CD8-positive cells increased in tumours with partial methylation in the MLH1 gene. CONCLUSIONS: CRC patients with POLE proofreading mutations are rare. Such mutations are observed in younger individuals, and tumours are primarily located in the right colon. Diagnosis occurs at an earlier stage, and distinct epigenetic alterations may be associated with CD8 cell infiltration.

[Successful Resection Using a Posterior Approach of a Tailgut Cyst in the Retrorectal Space].

We present the case of a Tailgut cyst occurring in the retrorectal space that was curatively resected using a posterior approach. A 40-year-old man presented to the Kochi Health Sciences Center with the chief complaint of perineal incongruity. Pelvic magnetic resonance imaging revealed a multilocular cystic lesion in the retrorectal space, with high signal intensity on T2-weighted imaging. After diagnosing a Tailgut cyst, we performed resection of the tumor using a posterior approach. The lesion was removed en bloc with the coccyx. Histopathologically, the lesion was diagnosed as a non-malignant Tailgut cyst, and the surgical margin was negative. The patient is currently doing well without recurrence at 20 months.

Heterogeneity of Epigenetic and Epithelial Mesenchymal Transition Marks in Hepatocellular Carcinoma with Keratin 19 Proficiency.

OBJECTIVE: Keratin 19 (K19) expression is a potential predictor of poor prognosis in patients with hepatocellular carcinoma (HCC). To clarify the feature of K19-proficient HCC, we traced epigenetic footprints in cultured cells and clinical materials. PATIENTS AND METHODS: In vitro, KRT19 promoter methylation was analyzed and 5-aza-2'-deoxycytidine with trichostatin A (TSA) treatment was performed. Among 564 surgically resected HCCs, the clinicopathological relevance of K19-proficent HCCs was performed in comparison with hepatocytic (HepPar-1 and arginase-1), epithelial-mesenchymal transition (E-cadherin and vimentin), biliary differentiation-associated (K7 and NOTCH-1) markers, and epigenetic markers (KRT19 promoter/long interspersed nucleotide element-1 [LINE-1] methylation status). RESULTS: KRT19 promoter methylation was clearly associated with K19 deficiency and 5-aza-2'-deoxycytidine with TSA treatment-stimulated K19 re-expression, implicating DNA methylation as a potential epigenetic process for K19 expression. After excluding HCCs with recurrence, TNM stage as IIIB or greater, preoperative therapy, transplantation, and combined hepatocellular cholangiocarcinoma, we assessed 125 of 564 HCC cases. In this cohort, K19 expression was found in 29 HCCs (23.2%) and corresponded with poor survival following surgery (p = 0.025) and extrahepatic recurrence-free survival (p = 0.017). Compared with K19-deficient HCCs, lower KRT19 promoter methylation level was observed in K19-proficient HCCs (p < 0.0001). Conversely, HCC with genome-wide LINE-1 hypermethylation was frequently observed in K19-proficient HCCs (p = 0.0079). Additionally, K19 proficiency was associated with K7 proficiency (p = 0.043), and reduced E-cadherin and HepPar-1 expression (p = 0.043 and p < 0.0001, respectively). CONCLUSIONS: K19-proficient HCC exhibited poor prognosis owing to extrahepatic recurrence, with molecular signatures differing from those in conventional cancer stem cells, providing novel insights of the heterogeneity underlying tumor development.

Detection of circulating microRNAs with Ago2 complexes to monitor the tumor dynamics of colorectal cancer patients during chemotherapy.

Because of the different forms of circulating miRNAs in plasma, Argonaute2 (Ago2)-miRNAs and extracellular vesicles (EV-miRNAs), we examined the two forms of extracellular miRNAs in vitro and developed a unique methodology to detect circulating Ago2-miRNAs in small volumes of plasma. We demonstrated that Ago2-miR-21 could be released into the extracellular fluid by active export from viable cancer cells and cytolysis in vitro. As miR-21 and miR-200c were abundantly expressed in both metastatic liver sites and primary lesions, we evaluated Ago2-miR-21 as a candidate biomarker of both active export and cytolysis while Ago2-miR-200c as a biomarker of cytolysis in plasma obtained from colorectal cancer (CRC) patients before treatment and in a series of plasma obtained from CRC patients with liver metastasis who received systemic chemotherapy. The measurement of Ago2-miR-21 allowed us to distinguish CRC patients from subjects without CRC. The trend in ΔCt values for Ago2-miR-21 and -200c during chemotherapy could predict tumor response to ongoing treatment. Thus, capturing circulating Ago2-miRNAs from active export can screen patients with tumor burdens, while capturing them from passive release by cytolysis can monitor tumor dynamics during chemotherapy treatment.

Clinical outcomes of women with ovarian metastases of colorectal cancer treated with oophorectomy with respect to their somatic mutation profiles.

We clarified the clinical prevalence of ovarian metastases from colorectal cancers (CRCs) in 296 female patients with CRC and evaluated clinical outcomes with relation to their mutational profiles, such as BRAF/KRAS mutation and microsatellite instability (MSI) status. The female CRCs were categorised into three subsets: CRCs with ovarian metastases [6.4% (n = 19), 5-year overall survival (OS) = 24.7%], CRCs with extra-ovarian metastases only [32.4% (n = 96), 5-year OS = 34.5%] and CRCs without any recurrence or metastasis [61.2% (n = 181), 5-year OS = 91.3%]. All patients with ovarian metastases underwent oophorectomy; of these, 9 who received preoperative chemotherapy had measurable metastases to extra-ovarian sites and the ovaries. Although 5 of 9 (56%) achieved partial response or complete response at extra-ovarian sites, no patient archived objective response at ovarian sites. Regarding the mutation profiles, in CRCs with extra-ovarian metastases only, the median survival time (MST) after initial treatments to progression to stage IV or recurrence was 13 [95% confidence interval (CI): 7-16 months] in BRAF-mutant and 34 months (95% CI: 22-58 months) in BRAF wild-type (P = 0.0033). Although ovarian metastases demonstrated poor response to systemic chemotherapy in CRCs with ovarian metastases, the MST after initial treatments to progression to stage IV or recurrence was 22 (95% CI: 21-25 months) in BRAF-mutant and 38 months (95% CI: 24-42 months) in BRAF wild-type (P = 0.0398). The outcomes of patients with ovarian metastases could be improved by oophorectomy regardless of their mutation profiles.

A Case-matched Comparative Study of Laparoscopic and Open Total Proctocolectomy for Ulcerative Colitis.

The aim of this single-institution, retrospective, observational case-control study was to evaluate the safety and feasibility of laparoscopic proctocolectomy (PC) for ulcerative colitis (UC), by comparing it with a case-control series of open PC. Twenty UC patients who underwent laparoscopic PC were retrospectively compared with the open PC group of 12 patients matched for age, sex, and urgency of the operation. In the laparoscopic PC group, the operative time was significantly longer, but the amount of blood loss was significantly smaller. The open PC patients underwent an intraoperative blood transfusion significantly more often, and the serum C-reactive protein level on the first postoperative day was significantly higher in the open PC group. In the laparoscopic PC group, the rate of severe postoperative morbidities, grades 3 and 4 on the Clavien-Dindo classification, was significantly lower, and the median length of hospital stay was significantly shorter. Laparoscopic PC for patients with UC showed superior perioperative outcomes to open PC, except for longer operative time.

Aggressive multimodality treatment for advanced rectal cancer.

A case of advanced rectal cancer treated by aggressive local and systemic treatment who has survived more than 7 years from initial recurrence is presented. A 55-year-old woman was diagnosed with advanced lower rectal cancer and underwent a low anterior resection with complete removal of all regional lymph nodes and total mesorectal excision. The tumor was diagnosed as a moderately differentiated adenocarcinoma, pStage IIIB (T3, N2a, M0). Twenty-six months after the initial surgery, local recurrence in the pelvis was detected by computed tomography, and total pelvic exenteration with distal sacrectomy (TPES) was performed after systemic chemotherapy with a molecular-targeted drug. Six months after the TPES, multiple lung metastases were detected. Consequently, the patient underwent radiofrequency ablation (RFA) and chemotherapy. The disease has since been controlled for 38 months. As volume control is essential for cancer treatment, it may be important to combine appropriate local therapy with systemic therapy to metastatic or recurrent sites in order to achieve much longer disease control.

[A case of appendix cancer treated as cancer of unknown primary origin].

A 57-year-old man initially presented with chief complaints of abdominal distension and anorexia. Positron emission tomography- computed tomography (PET-CT) scan showed ascites and multiple peritoneal metastases with abnormal uptake of fluorodeoxyglucose (FDG). The patient underwent endoscopy, biopsy, and cytology and was diagnosed with adenocarcinoma of unknown primary origin. He was treated with systematic chemotherapy, including carboplatin/paclitaxel (CBDCA/ PTX) and gemcitabine regimens. However, progressive disease (PD) complicated by intestinal obstruction was indicated. He was referred to our department for management. We performed surgery to resolve the intestinal obstruction and confirm the diagnosis. Appendix cancer was diagnosed intraoperatively. He was administered a modified fluorouracil plus Leucovorin and oxaliplatin(mFOLFOX6) /panitumumab regimen following surgery. The tumor had a good response to treatment, and the primary lesion was resected. After resection , the tumor was controlled by systemic chemotherapy for six months. However, the patient unfortunately died owing to arrhythmia. Most patients with cancer of unknown primary origin have a very poor prognosis because it is difficult to select appropriate treatment. Laparotomy can be effective in making a definitive diagnosis, as in the case described here.

[A successful multimodality therapy for a case of recurrent rectal cancer with KRAS mutation].

A man in his 50s underwent high anterior resection for rectosigmoid cancer in January 2010. The primary tumor was diagnosed as a moderately differentiated adenocarcinoma with KRAS mutation, pStage III a. In May 2011, the patient had a recurrent lung tumor detected by computed tomography(CT); the tumor was resected using video-assisted thoracoscopic surgery. However, additional recurrent lung tumors arose, and radiofrequency ablation (RFA) was performed to treat these in February 2012. After RFA therapy, capecitabine was administered as adjuvant chemotherapy. Unfortunately, 10 months later, positron emission tomography (PET) /CT suggested a new recurrence in a left lateral lymph node. Although the pelvic lymph node was surgically removed immediately, a new lung recurrence was found on CT three months after the surgery. RFA was again used to treat this lung lesion. After the second RFA, the patient is doing well without any evidence of recurrence. We describe a case of recurrent rectal cancer successfully treated with multimodality therapy. The combination of appropriate local therapy with systemic chemotherapy is an essential strategy to treat advanced colorectal cancer, especially in patients with KRAS mutation when anti-EGFR antibodies are not effective.

Intussusception due to rectal adenocarcinoma in a young adult: a case report.

An intussusception due to colonic adenocarcinoma has sometimes been reported. However, to the best of our knowledge, reports of intussusception due to rectal adenocarcinoma are extremely rare. In this report, the case of a young man with rectal adenocarcinoma causing intussusception is described. A 24-year-old man visited a hospital complaining of abdominal pain, and an upper rectal cancer was diagnosed by colonoscopy. Computed tomography showed intussusception caused by a large tumor in the pelvis and absence of distant metastases. Locally advanced rectal cancer causing intussusception was diagnosed, and a low anterior resection was performed. Intraoperatively, repair of the invagination could not be accomplished easily; therefore, the repair was abandoned. Instead, the tumor was removed en bloc to avoid dissemination of the cancer. Histopathologically, the tumor was diagnosed as a poorly differentiated adenocarcinoma, pStage IIA. The patient has no evidence of recurrence at 10 mo after the operation.

[A case of intrahepatic cholangiocarcinoma with peritoneal dissemination treated successfully with surgical resection and adjuvant chemotherapy].

A 72-year-old woman was diagnosed with liver dysfunction during a medical examination. An abdominal computed tomography (CT) scan showed multiple nodules in the left lobe, anterior segment, andposterior segment of the liver, leading to a diagnosis of intrahepatic cholangiocarcinoma (ICC). Extended left lobectomy and partial hepatectomy in the anterior and posterior segment with lymph node dissection was performed. At the time of the operation, small nodules on the peritoneum near the stomach were resected; these nodules were diagnosed as peritoneal disseminations of ICC. The histopathological diagnosis was moderately differentiated tubular adenocarcinoma (T4N0M1, Stage IVB). Adjuvant chemotherapy with S-1 was administered for 18 months. Thirty months after the operation, multiple lung metastases were detected by using CT, and chemotherapy with gemcitabine was initiated. Thirty-six months after chemotherapy with gemcitabine, the patient is alive and at home despite her lung metastases, which grew slightly in size. Herein, we report a long-term survival case of ICC with peritoneal dissemination that was successfully treated with surgical resection and adjuvant chemotherapy.

[A case in which dihydropyrimidine dehydrogenase deficiency was strongly suspected during adjuvant chemotherapy with capecitabine for colon cancer].

Severe toxicity in patients with a deficiency of dihydropyrimidine dehydrogenase(DPD), an enzyme that reduces fluoropyrimidine, is very rare, and reports on this condition are few. Accordingly, diagnosis is very difficult. The patient was 70-year-old man who was admitted for adjuvant chemotherapy with capecitabine(3,600mg/day)for rectal cancer. He was admitted to our hospital because of severe oral mucositis(grade 3)and hand-foot syndrome(grade 3). After hospitalization, he experienced complications with neutropenia(grade 4)and thrombocytopenia(grade 4). The patient died 25 days after the onset of chemotherapy. Despite the measurement of the DPD value in mononuclear cells of peripheral blood and urophanic uracil and dihydrouracil, we were unable to diagnose DPD deficiency. However, we suspected a partial deficiency of DPD on the basis of the clinical course.

[A case of primary adenocarcinoma of small intestine responding to XELOX chemotherapy and leading to a partial metabolic response].

We report a case of adenocarcinoma of the small intestine responding to XELOX chemotherapy, leading to a partial metabolic response(PMR). The patient was a 58-year-old male with multiple peritoneal dissemination of adenocarcinoma of the small intestine. Chemotherapy with XELOX(L-OHP 130 mg/m² on day 1 , and capecitabine 1,000 mg/m2 on days 1-14)was performed. After 4 courses, a significant tumor reduction was obtained. This case suggests that chemotherapy with XELOX is a potential regimen for small intestinal adenocarcinoma.

[A case of resected rectal cancer with hepatic node and multiple liver metastases effectively treated by preoperative modified FOLFOX6 and sLV5FU2 chemotherapy].

A 55-year-old male had complained of melena.Colonoscopy revealed a type 2 tumor at the rectum.CT demonstrated hepatic lymph nodes and multiple liver metastases(stage IV).Low anterior resection was performed(tub2, RsRa, circ, type 2, pSS, pN1, sH3, cHN1, sP0, cM0: fstage IV).The patient was treated with mFOLFOX6 and sLV5FU2 after operation.CT revealed a partial response after 14 courses of systemic chemotherapy.sLV5 FU2 therapy was converted to capecitabine because he experienced bone marrow suppression.CT showed that the liver metastases had enlarged but the hepatic lymph nodes disappeared.Right portal vein embolization was performed.After 4 weeks, right hepatectomy and hepatic lymph node dissection were performed.Preoperative chemotherapy with mFOLFOX6 seems beneficial as a neoadjuvant chemotherapy for hepatic lymph node-positive advanced colorectal cancer.

[A case of early poorly-differentiated neuroendocrine carcinoma of stomach].

A 45-year-old male was admitted to our hospital complaining of anemia. Gastric endoscopy showed a type IIa+IIc tumor at the anterior wall of the gastric angle. Based on the pathology of the biopsy specimen, poorly-differentiated adenocarcinoma was diagnosed. Computed tomography scans showed regional lymph node swelling. Distal gastrectomy with a D2 lymph node dissection was performed. On pathology, the tumor was immunohistochemically positive for chromogranin A and synaptophysin. The Ki67 index was 70%. The tumor was diagnosed as poorly-differentiated neuroendocrine carcinoma of the stomach. He was treated with S-1 and CPT-11. Neuroendocrine cell carcinoma of the stomach is rare and usually has a very poor prognosis. Thus, we are reporting this case of early poorly-differentiated neuroendocrine carcinoma of the stomach that was curatively resected and had 12-month survival without recurrence.