Genomic Alterations of Tumors in HER2-Low Breast Cancers.

The aim of this study was to elucidate molecular profiling in HER2-low tumors based on a promising dataset. A total of 615 consecutive HER2-negative breast cancer samples were assayed. The genomic mutations in the two groups with different HER2 expression levels (HER2-0 vs. HER2-low) were compared. The mutation types obtained via next-generation targeted sequencing were correlated with the clinicopathological features of the patients with HER2-0 and HER2-low breast cancer. The results showed that there was a significantly higher percentage of receptor-positive (ER/PR) tumors and more low-level Ki-67 tumors, but a lower incidence of stage I/II tumors in the HER2-low group compared to the HER2-0 group. There was a significantly higher frequency of 17.62% (65/369) for PIK3CA_SNA in the HER2-low group than in the HER2-0 group, which had a frequency of only 9.35% (23/246) (p = 0.006). When the called gene alterations in the triple-negative breast cancer (TNBC) group were compared with those in the luminal-like breast cancer group, there was a significantly high frequency of 28.17% (140/497) for ERBB2_SNA in a luminal-like group than in the TNBC group(16.95% (20/118)).We conclude that the early detection of PIK3CA mutations is likely to be important and might help therapeutic decision making in patients with HER2-low tumors.

Clinical outcomes and patient-reported outcomes after oncoplastic breast surgery in breast cancer patients: A matched cohort study.

BACKGROUND: Surgery is the recommended treatment for breast cancer, the most common cancer in women in Taiwan and the leading cause of cancer-related deaths. Although breast-conserving surgery (BCS) has good prognosis, in some cases, BCS may cause more significant deformities and interfere with the patient's psychosocial well-being. Oncoplastic breast surgery (OBS) is the treatment option in these cases. This study aimed to determine the outcomes of OBS and BCS regardless of clinical and patient-reported esthetic outcomes. METHODS: Between 2015 and 2020, 50 patients who underwent OBS at our hospital after complete treatment were enrolled. With 1:2 matched ratios, 100 patients were enrolled in the BCS control group. Clinical outcomes were analyzed. The BREAST-Q questionnaire was then assessed 6 months after the completion of treatment for subjective patient-reported outcomes. RESULTS: Due to the matching process, no difference was noted between the two groups in terms of demographic data such as age, comorbidities, or tumor characteristics. There were no significant differences in the local recurrence rate, disease-free survival, overall survival, positive margin rate, rewide excision rate, conversion to mastectomy rate, or complication rate (major or minor) between both groups. However, the OBS group showed higher satisfaction with breasts in the BREAST-Q questionnaire ( p < 0.001). The mean follow-up time was 38.77 ± 14.70 months in the BCS group and 29.59 ± 14.06 months in the OBS group. CONCLUSION: OBS seems to be a safe and feasible surgery in breast cancer patients because clinical outcomes are compatible with BCS. Moreover, the OBS group had better patient-reported outcomes in terms of satisfaction.

Prevalent landscape of tumor genomic alterations of luminal B1 breast cancers using a comprehensive genomic profiling assay in Taiwan.

BACKGROUND: The human epidermal growth factor receptor 2 (HER2) negative luminal B1 subtype of breast cancer has been reported with a poorer outcome than luminal A in recent studies. This study aimed to investigate the molecular alterations and identify potential therapeutic targets by analyzing the genetic profiling from a cohort of luminal B1 breast cancer in Taiwan. METHODS: We enrolled patients with luminal B1 breast cancer in our study. They were classified as patients who received curative surgery and adjuvant or neoadjuvant chemotherapy as the low-risk group, and who had advanced or metastatic disease or early relapse during the follow-up time as the high-risk group. Using targeted sequencing, we evaluated genomic alterations, interpreting variants with the ESMO Scale of clinical actionability of molecular targets (ESCAT). RESULTS: A total of 305 luminal B1 breast cancer patients underwent targeted sequencing analyses. The high-risk patients reported more actionable genes and called variants than the low-risk group (P < 0.05). PIK3CA (42%), FGFR1 (25%), and BRCA1/2 (10.5%) were the most prevalent ESCAT actionable alterations in luminal B1 breast cancer. There was no difference in the prevalence of actionable mutations between these two groups, except for ERBB2 oncogenic mutations, which were more prevalent among the high-risk than the low-risk group (P < 0.05). Alterations in PTEN, ERBB2, and BRCA1/2 were associated with disease relapse events in luminal B1 breast cancer. CONCLUSIONS: PIK3CA, FGFR1, and BRCA1/2 were the most prevalent actionable alterations among Taiwanese luminal B1 breast cancer. Moreover, PTEN and BRCA1/2 was significantly associated with disease relapse.

Prevalence of BRCA1, BRCA2, and PALB2 genomic alterations among 924 Taiwanese breast cancer assays with tumor-only targeted sequencing: extended data analysis from the VGH-TAYLOR study.

BACKGROUND: The homologous recombination (HR) repair pathway for DNA damage, particularly the BRCA1 and BRCA2 genes, has become a target for cancer therapy, with poly ADP-ribose polymerase (PARP) inhibitors showing significant outcomes in treating germline BRCA1/2 (gBRCA1/2) mutated breast cancer. Recent studies suggest that some patients with somatic BRCA1/2 (sBRCA1/2) mutation or mutations in HR-related genes other than BRCA1/2 may benefit from PARP inhibitors as well, particularly those with PALB2 mutations. The current analysis aims to evaluate the prevalence of genetic alterations specific to BRCA1, BRCA2, and PALB2 in a large cohort of Taiwanese breast cancer patients through tumor-targeted sequencing. METHODS: A total of 924 consecutive assays from 879 Taiwanese breast cancer patients underwent tumor-targeted sequencing (Thermo Fisher Oncomine Comprehensive Assay v3). We evaluated BRCA1, BRCA2, and PALB2 mutational profiles, with variants annotated and curated by the ClinVAR, the Oncomine™ Knowledgebase Reporter, and the OncoKB™. We also conducted reflex germline testing using either whole exome sequencing (WES) or whole genome sequencing (WGS), which is ongoing. RESULTS: Among the 879 patients analyzed (924 assays), 130 had positive mutations in BRCA1 (3.1%), BRCA2 (8.6%), and PALB2 (5.2%), with a total of 14.8% having genetic alterations. Co-occurrence was noted between BRCA1/BRCA2, BRCA1/PALB2, and BRCA2/PALB2 mutations. In BRCA1-mutated samples, only p.K654fs was observed in three patients, while other variants were observed no more than twice. For BRCA2, p.N372H was the most common (26 patients), followed by p.S2186fs, p.V2466A, and p.X159_splice (5 times each). For PALB2, p.I887fs was the most common mutation (30 patients). This study identified 176 amino acid changes; 60.2% (106) were not documented in either ClinVAR or the Oncomine™ Knowledgebase Reporter. Using the OncoKB™ for annotation, 171 (97.2%) were found to have clinical implications. For the result of reflex germline testing, three variants (BRCA1 c.1969_1970del, BRCA1 c.3629_3630del, BRCA2 c.8755-1G > C) were annotated as Pathogenic/Likely pathogenic (P/LP) variants by ClinVar and as likely loss-of-function or likely oncogenic by OncoKB; while one variant (PALB2 c.448C > T) was not found in ClinVar but was annotated as likely loss-of-function or likely oncogenic by OncoKB. CONCLUSION: Our study depicted the mutational patterns of BRCA1, BRCA2, and PALB2 in Taiwanese breast cancer patients through tumor-only sequencing. This highlights the growing importance of BRCA1/2 and PALB2 alterations in breast cancer susceptibility risk and the treatment of index patients. We also emphasized the need to meticulously annotate variants in cancer-driver genes as well as actionable mutations across multiple databases.

Prevalence of PIK3CA mutations in Taiwanese patients with breast cancer: a retrospective next-generation sequencing database analysis.

Background: Breast cancer is the most common cancer type that affects women. In hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is the most frequently mutated gene associated with poor prognosis. This study evaluated the frequency of PIK3CA mutations in the Taiwanese breast cancer population. Methodology: This is a retrospective study; patient data were collected for 2 years from a next-generation sequencing database linked to electronic health records (EHRs). The primary endpoint was the regional prevalence of PIK3CA mutation. The secondary endpoints were to decipher the mutation types across breast cancer subtype, menopausal status, and time to treatment failure after everolimus (an mTOR inhibitor) or cyclin-dependent kinase 4/6 (CDK4/6) inhibitor treatment. Results: PIK3CA mutations were identified in 278 of 728 patients (38%). PIK3CA mutations were reported in 43% of patients with HR-/HER2+ subtype and 42% of patients with HR+/HER2- postmenopausal status. A lower prevalence of PIK3CA mutations was observed in triple-negative (27%) and HR+/HER2- premenopausal patients (29%). The most common mutation was at exon 20 (H1047R mutation, 41.6%), followed by exon 9 (E545K mutation, 18.9% and E542K mutation, 10.3%). Among patients treated with CDK4/6 inhibitors, the median time to treatment failure was 12 months (95% CI: 7-21 months) in the PIK3CA mutation cohort and 16 months (95% CI: 11-23 months) in the PIK3CA wild-type cohort, whereas patients receiving an mTOR inhibitor reported a median time to treatment failure of 20.5 months (95% CI: 8-33 months) in the PIK3CA mutation cohort and 6 months (95% CI: 2-9 months) in the PIK3CA wild-type cohort. Conclusion: A high frequency of PIK3CA mutations was detected in Taiwanese patients with breast cancer, which was consistent with previous studies. Early detection of PIK3CA mutations might influence therapeutic decisions, leading to better treatment outcomes.

Correlation of an immune-related 8-gene panel with pathologic response to neoadjuvant chemotherapy in patients with primary breast cancers.

Neoadjuvant chemotherapy (NACT)-induced pathologic complete response (pCR) is associated with a favorable prognosis for breast cancer. Prior research links tumor-infiltrating lymphocytes with breast cancer chemotherapy response, suggesting the tumor-immune microenvironment's role. The aim of this study was to evaluate the immune-related genes that exhibit associations with the response to NACT. In this study, we analyzed a total of 37 patients (aged 27-67) who received NACT as the first-line treatment for primary breast cancer, followed by surgery. This group consisted of nine patients (24.3 %) with estrogen receptor (ER)-positive/HER2-negative status, ten patients (27.0 %) with ER-positive/HER2-positive status, five patients (13.5 %) with ER-negative/HER2-positive status, and thirteen patients (35.1 %) with triple-negative breast cancer (TNBC). Among these patients, twelve (32.4 %) achieved a pCR, with eight (66.6 %) having HER2-positive tumors, and the remaining four having TNBC. To identify immune-related genes linked with pCR in subjects with breast cancer prior to NACT, we collected fresh tissues for next-generation sequencing. Patients with pCR had higher expressions of eight genes, KLRK1, IGJ, CD69, CD40LG, MS4A1, CD1C, KLRB1, and CA4, compared to non-pCR patients. The 8-gene signature was associated with good prognosis and linked to better relapse-free survival in patients receiving chemotherapy. The expression of these genes was involved in better drug response, displaying a positive correlation with the infiltration of immune cells. In conclusion, we have identified eight immune-related genes that are associated with a favorable prognosis and positive responses to drugs. This 8-gene signature could potentially provide prognostic insights for breast cancer patients undergoing NACT.

Concordance of Targeted Sequencing from Circulating Tumor DNA and Paired Tumor Tissue for Early Breast Cancer.

In this study, we evaluated the concordance of targeted sequencing between paired ctDNA and matched tumor samples from early breast cancers treated with curative intention. Molecular profiling was performed using the Oncomine Comprehensive Assay v3 and the Oncomine Breast cfDNA Assay v2. The liquid biopsy detection rate was 39% (all-stage breast cancers, n = 612). Among 246 early-stage patients assayed for both ctDNA and matched tumor, the cfDNA assay detected 73 (29.6%) and the comprehensive assay detected 201 (81.7%) breast cancers with at least one alteration (χ2 test, p = 0.001). In total, 67 (25.6%) cases tested positive on both platforms, while the cfDNA and comprehensive assays detected an additional 10 (4%) and 138 (56%) cases, respectively. The most prevalent mutant genes were TP53 (68.3%) and KRAS (53.5%), while the PIK3CA (39.4%), AKT1 (45.9%), and ERBB2 (17.1%) mutations constituted biomarkers for FDA-approved therapeutics. Our study showed that tumor tissue should be the source of actionable mutation detection for early breast cancers, considering that the concordance rate between tumor and liquid biopsy was only one-quarter.

Clinical characteristics and treatment outcomes of invasive ductal and lobular carcinoma: analyses of 54,832 taiwan cancer registry index cases.

PURPOSE: Invasive lobular cancer (ILC) is the second most common histology type of breast cancer followed by invasive ductal carcinoma (IDC). This study aimed to investigate the characteristic, treatment strategies, and clinical outcomes of ILC based on a national population-based cancer registry. METHODS: This study recruited 2671 ILC and 52,215 IDC patients diagnosed between 2011 and 2017 using the Taiwan Cancer Registry (TCR). Correlations between ILC and IDC subgroups were assessed using 1:4 propensity score matching and compared using the χ2 test. Disease free survival(DFS) and overall survival(OS) were estimated using the Kaplan-Meier method with the log-rank test. The risk of disease relapse and mortality were assessed using Cox proportional hazards model. RESULTS: ILC patients had larger tumor sizes, more positive axillary lymph node involvement, lower tumor grade, and higher cancer stage than IDC patients. After matching, ILC patients had a significantly higher rate of receiving mastectomy (58.93% and 53.85%) and positive surgical margin regardless of surgery type. ILC exhibited a significantly higher rate of distant metastasis than IDC(3.67% and 2.93%), but no difference in local recurrence rate, DFS or OS between the two groups. Higher cancer stage, higher grade, and mastectomy were risk factors for disease relapse and cancer-specific mortality. The hormone receptor-positive and HER2 over-expression subtypes were found to be associated with a reduced risk of disease relapse, while only PR positivity was associated with a decreased risk of mortality. (all P-values < 0.05). CONCLUSION: ILC patients had a higher mastectomy rate, higher surgical margin rate and distant metastasis rate than IDC patients. There is no significant difference in DFS or OS between ILC and IDC patients. Mastectomy was associated with poor outcomes regardless of ILC or IDC.

The association of trastuzumab with atrial fibrillation and heart failure in breast cancer patients in routine clinical practice: a population-based propensity score matching and competing risk model analysis.

PURPOSE: Trastuzumab, a potent anti-human epidermal growth factor receptor 2 (HER2) monoclonal antibody, is conditionally reimbursed by the Taiwan National Health Insurance (NHI) for HER2-positive breast cancer (BC). Trastuzumab-induced cardiotoxicity studies have well characterized heart failure (HF) but fewer addressed arrhythmia, particularly the association of potential life threatening atrial fibrillation (Af) is poorly characterized. We aimed to study the trastuzumab-related risk of Af and HF using the claimed data of Taiwan NHI. METHODS: A nationwide retrospective cohort of patients with BC from the Taiwan NHI reimbursement database from January 2007 to December 2016 was analyzed. Propensity score matching and competing risk model analysis were used for adjusting confounding concurrent medication or comorbidities and competing events. The HF study was used to validate the method used. RESULTS: For Af, 12,472 trastuzumab users were matched with 12,472 non-trastuzumab users. For HF, 12,241 trastuzumab users and 12,241 non-users were enrolled. We found that trastuzumab users had significantly worse HF-free survival but not Af-free survival than non-trastuzumab users. In the competing risk analysis, the use of trastuzumab did not increase the risk of Af (hazard ratio [HR] 0.76, P = 0.0006) but was associated with HF (HR 1.19, P = 0.0052). The risk trends among stratifications by comorbidities and concurrent medication remained in similar directions for both Af and HF. CONCLUSION: Trastuzumab in real-world practice was associated with an increased risk of HF, but was not associated with an increased risk of Af in BC patients. Trastuzumab-induced arrhythmogenic effects may be masked by concurrent heart-protecting measures, more prominent roles of comorbidities or concurrent medications under real-world settings. Further studies are required.

Long-Term Complications and Patient-Reported Outcomes After Alloplastic Breast Reconstruction.

BACKGROUND: The most widely used method for breast reconstruction in Taiwan is alloplastic breast reconstruction, and traditionally, it can be categorized into immediate or delayed, single-stage or 2-stage procedures. We evaluated clinical outcomes and analyzed patients' self-reported satisfaction and quality of life after alloplastic breast reconstruction based on a previous preliminary study. PATIENT AND METHODS: The patients who underwent primary alloplastic breast reconstruction after mastectomy were recruited in 2006 to 2020 at a single institute in Taiwan. The assessment of clinical outcomes was conducted by retrospective chart review and risk analysis. The patients also completed the BREAST-Q, a condition-specific patient-reported outcome measure, at least 6 months after treatment. RESULTS: A total of 237 patients with 247 reconstructed breasts were enrolled in this study. The demographics showed that 205 (83%) were reconstructed using a 2-stage tissue expander-based procedure and 42 (17%) were 1-stage direct-to-implant reconstructions. The mean follow-up time was 79.5 months. The clinical assessment revealed that the overall complication rate was 34%, with infection being the most common (21 patients; 8%). According to risk analysis, smoking (odds ratio, 7.626; 95% confidence interval, 1.56-37.30; P = 0.012), and nipple-sparing mastectomy (odds ratio, 3.281; 95% confidence interval, 1.54-6.99; P = 0.002) were significant risk factors for overall complications. The questionnaire response rate was 38% (94 of 247), at least 6 months after treatment. The total mean score was 69.78. CONCLUSIONS: At a single institute in Taiwan from 2006 to 2020, alloplastic breast reconstruction, either single- or 2-stage, have acceptable complication rate and good postoperative satisfaction based on patient-reported outcomes. Both patient- and surgery-related factors presented as significant risk factors. Precise patient selection and comprehensive discussion between the patient and physician may play the important role to achieve optimal aesthetic outcomes.

The Effect of Biological Scaffold (Biodesign) in Postmastectomy Direct-to-Implant Breast Reconstruction: A 5-Year Single-Institution Experience.

BACKGROUND: Direct-to-implant (DTI) breast reconstruction is one of the immediate implant-based breast reconstruction methods. If the amount of soft tissue (eg, muscle or fascia) is insufficient to completely cover the implant, biological scaffold or acellular dermal matrix can be safely used for implant coverage. In this study, we used an acellular porcine small intestinal submucosa (SIS) mesh (Biodesign; Cook Medical Inc, Bloomington, IN) for DTI reconstruction to explore the impact of its use on breast reconstruction results. METHODS: We retrospectively assessed cases involving DTI reconstruction at Taipei Veterans General Hospital from 2015 to 2019. Women, 18 years or older, who underwent immediate DTI reconstruction after mastectomy were included in the study. Mastectomy may have been performed because of therapeutic or prophylactic reasons. Patients who did and did not use SIS mesh for reconstruction were studied separately, and the 2 groups were compared in terms of clinical outcomes and complications. The validated, self-administered BREAST-Q Reconstruction Module version 2.0 survey was used to evaluate health-related quality of life and satisfaction among patients who underwent breast reconstruction. RESULTS: A total of 30 DTI breast reconstructions were enrolled. The mean age was 49.2 years, and the mean body mass index was 22.3 kg/m2. The mean postoperative follow-up duration was 17.1 months. Nipple-sparing mastectomy was performed for 26 cases (86.7%), and DTI breast reconstructions using SIS mesh for implant coverage were done in 14 cases (46.7%). The overall complication rate was 53.3% in 30 reconstructions, with nipple complications being the most common complication. The non-SIS and SIS-using groups had a similar overall complication rate postoperatively. As for the quality-of-life assessment, the SIS group obtained a higher score on BREAST-Q than those for whom SIS was not used. CONCLUSIONS: Porcine SIS mesh might be a safe and effective alternative to biological scaffolds in immediate 1-stage implant-based breast reconstruction to improve the quality of life after surgery.

Postoperative Sedation Duration as an Independent Risk Factor for Postoperative Pneumonia in Head and Neck Cancer Patients Undergoing Free Flap Reconstruction.

OBJECTIVE: Patients who had reconstruction for head and neck cancer usually have long duration of postoperative sedation and intensive care. This is due to the complex nature of large-area soft tissue defect surgeries and upper respiratory tract infections associated with them. Postoperative pulmonary complications are common in these patients. In this study, we analyzed the risk factors and the relationship between postoperative complications and the duration of sedation to improve the patients' recovery process after free flap reconstruction for head and neck surgery. MATERIALS AND METHODS: This was a retrospective study that included 188 patients who had head and neck surgery with free flap reconstruction in 2011 (traditional recovery group) and 2018 (early recovery group). Postoperative recovery events were compared between the 2 groups. Complications such as pneumonia, wound infection, vascular thrombosis, and bleeding were also analyzed. RESULTS: The results showed that the early recovery group had a shorter duration of sedation (P < 0.001), shorter duration of intensive care unit stay (P = 0.05), more rapid ventilator weaning (P < 0.001), and fewer pneumonia events (8.8% vs 39.1%) than the traditional recovery group. Wound- and vessel-related complications were not affected by the duration of sedation. CONCLUSIONS: Our study demonstrated that shortening the duration of postoperative sedation can effectively decrease the length of intensive care unit stay and reduce postoperative incidence of pneumonia without increasing wound- and vessel-related complications.

Prevalence of Tumor Genomic Alterations in Homologous Recombination Repair Genes Among Taiwanese Breast Cancers.

PURPOSE: Deleterious germline BRCA1/2 mutations are among the most highly pathogenic variants in hereditary breast and ovarian cancer syndrome. Recently, genes implicated in homologous recombination repair (HRR) pathways have been investigated extensively. Defective HRR genes may indicate potential clinical benefits from PARP (poly ADP ribose polymerase) inhibitors beyond BRCA1/2 mutations. METHODS: We evaluated the prevalence of BRCA1/2 mutations as well as alterations in HRR genes with targeted sequencing. A total of 648 consecutive breast cancer samples were assayed, and HRR genes were evaluated for prevalence in breast cancer tissues. RESULTS: Among 648 breast cancers, there were 17 truncating and 2 missense mutations in BRCA1 and 45 truncating and 1 missense mutation in BRCA2, impacting 3% and 5% of the study population (collectively altered in 6%) with cooccurrence of BRCA1/2 in 7 breast cancers. On the other hand, HRR genes were altered in 122 (19%) breast cancers, while TBB (Talazoparib Beyond BRCA) trial-interrogated genes (excluding BRCA1/2) were mutated in 107 (17%) patients. Beyond BRCA1/2, the most prevalent HRR mutant genes came from ARID1A (7%), PALB2 (7%), and PTEN (6%). Collectively, 164 (25%) of the 648 Taiwanese breast cancer samples harbored at least one mutation among HRR genes. CONCLUSIONS: The prevalence of BRCA1/2 mutations was far below one tenth, while the prevalence of HRR mutations was much higher and approached one-fourth among Taiwanese breast cancers. Further opportunities to take advantage of defective HRR genes for breast cancer treatment should be sought for the realization of precision medicine.

Clinical outcomes and metastatic behavior between de novo versus recurrent HER2-positive metastatic breast cancer: A 17-year single-institution cohort study at Taipei Veterans General Hospital.

BACKGROUND: To assess the clinical outcomes and metastatic behavior between de novo versus recurrent human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) based on a single-institution database in Taiwan. METHODS: We retrospectively identified patients diagnosed between January 2000 and December 2017 with de novo stage IV or recurrent HER2-positive MBC. Several variables were recorded in patients with recurrent disease: age at diagnosis, metastatic site, hormone receptor (HR) status, HER2 status, and disease-free interval (DFI). Treatments and metastatic patterns were compared between de novo stage IV and recurrent MBC cohorts. Post-metastasis survival (PMS) was estimated using the Kaplan-Meier method with log-rank tests. Hazard ratios and 95% CIs were estimated using Cox regression analysis. RESULTS: In total, 1360 patients were diagnosed with breast cancer with HER2 overexpression. At baseline, de novo stage IV patients were older than recurrent MBC patients (median age 58 vs 53). The majority of the de novo stage IV patients were diagnosed after 2010, while most of the recurrent MBC patients were diagnosed during 2000-2009. An increased number of de novo stage IV patients underwent targeted therapy than recurrent MBC patients was also noted. PMS in patients with de novo stage IV and recurrent MBC was 79.2 months and 61.8 months, respectively, which indicated significant better survival in de novo stage IV than those with recurrent MBC disease. Longer survival was also noted in de novo stage IV and recurrent MBC with DFI >24 months than in those with recurrent MBC with DFI <24 months and in patients receiving HER2-targeted therapy after MBC diagnosis than in those not receiving the therapy. However, median PMS showed no significant difference between patients with the luminal B2 (HR-positive, HER2-negative) and HER2-enriched (HR-negative, HER2-positive) subtypes. After adjustment in multivariate analysis, a low risk of BC-specific death was observed in patients aged >50 years, those receiving HER2-targeted therapy for MBC, and those with oligometastasis, while patients with first metastases to the liver or brain showed a higher risk of BC-specific death than those without metastases. CONCLUSION: De novo and recurrent MBC have distinct characteristic, metastatic patterns and outcomes in Asian HER2-positive breast cancer patients. The age distribution and survivals between HR+/- status were different to non-Asian group. These differences should be further investigated in the future considering ethnic factor.

The clinical impacts of molecular subtyping by multigene assay on hormone receptor-positive breast cancers.

BACKGROUND: Multigene assays, such as MammaPrint and BluePrint, provide additional information other than conventional immunohistochemistry (IHC) to help making decision of treatment. This study aims to compare the clinical correlation between molecular subtyping (MS) versus surrogate pathological subtyping (PS). METHODS: A database from patients receiving MS evaluation in Taipei Veterans General Hospital from 2013 to 2018 was reviewed retrospectively. Patients were categorized as luminal A, luminal B, human epidermal growth factor receptor 2 (HER2) and basal type from MS results and also centrally assessed according to PS (estrogen receptor [ER], progesterone receptor [PgR], HER2, and Ki-67). The clinical correlation between two different subtyping methodologies was analyzed, and the application of chemotherapy was compared. RESULTS: From 2013 to 2018, a total of 130 patients received MS testing in our institute, and 132 tumor samples were sent for analysis. From MammaPrint, 64 (48.5%) and 55 (41.7%) samples were defined as low and high risks, respectively. The other 13 (9.8%) tumor samples were identified as late recurrence low risk. MS restratified 44 tumors as subtype shifting including 20 tumors from A to B in intrinsic subtypes and 24 tumors from B to A after MS evaluation. Chemotherapy was conducted in only one (1.3%) patient with MS-luminal A but in 87.8% (n = 43) of MS-luminal B subtypes. CONCLUSION: The MS results restratify the subtypes of hormone receptor positive breast cancer and dominate decision-making of adjuvant therapy. The role of surrogate biomarkers as an alternative tool needs further elucidation. The treatment outcome in different subtypes categorized by MS or PS will be the interesting focus of research.

Clinicopathological characteristics and treatment outcomes of luminal B1 breast cancer in Taiwan.

BACKGROUND: Hormone receptor-positive, human epidermal growth factor receptor II (HER2)-negative luminal B1 breast cancer is associated with a higher risk of disease relapse than luminal A breast cancer. Therefore, we assessed and compared the distant metastasis pattern and clinical outcomes associated with luminal B1 and luminal A breast cancer in an Asian population. METHODS: In this observational study, we assessed patients with estrogen receptor-positive, HER2-negative breast cancer who underwent surgery from 2009 to 2016. Patients were classified into luminal A or luminal B1 subsets via immunohistochemical analysis. Disease-free survival, post-metastasis survival, and overall survival were estimated; time to disease relapse and patterns of distant metastasis were compared. Risk of relapse and mortality were assessed using Cox proportional hazards model. RESULTS: Patients with luminal B1 breast cancer (n = 677) were significantly younger and had larger tumors and a higher degree of affected axillary lymph nodes, lymphovascular invasion, and tumor necrosis than those with luminal A breast cancer (n = 630). Higher rates of local recurrence and distant metastasis were observed for luminal B1 (both p < 0.05); however, no difference was observed in the specific distant metastatic sites. We observed a significant increase in disease relapse risk in luminal B1 patients compared with that in luminal A (hazard ratio: 2.157, 95% CI: 1.340-3.473, p < 0.05). Patient age, tumor size, stage, lymphovascular invasion, and receiving chemotherapy and hormone therapy were independent risk factors for metastasis and recurrence. Only the luminal B1 subtype (hazard ratio: 5.653, 95% CI: 1.166-27.409, p < 0.05) and stage (hazard ratio: 3.400, 95% CI: 1.512-7.649, p < 0.05) were identified as independent risk factors for post metastatic mortality. CONCLUSION: Luminal B1 breast cancer has aggressive tumor biology compared with luminal A breast cancer in the follow-up period. However, there was no significant difference in the disease relapse pattern between the groups.

VGH-TAYLOR: Comprehensive precision medicine study protocol on the heterogeneity of Taiwanese breast cancer patients.

Heterogeneity in breast cancer leads to diverse morphological features and different clinical outcomes. There are inherent differences in breast cancer between the populations in Asia and in western countries. The use of immune-based treatment in breast cancer is currently in the developmental stage. The VGH-TAYLOR study is designed to understand the genetic profiling of different subtypes of breast cancer in Taiwan and define the molecular risk factors for breast cancer recurrence. The T-cell receptor repertoire and the potential effects of immunotherapy in breast cancer subjects is evaluated. The favorable biomarkers for early detection of tumor recurrence, diagnosis and prognosis may provide clues for the selection of individualized treatment regimens and improvement in breast cancer therapy.

Lay abstract We describe the rationale and design for the VGH-TAYLOR study, which includes Taiwanese patients with breast cancer and with a wide spectrum of clinical scenarios covering different breast cancer subtypes and clinical settings, such as the neoadjuvant, adjuvant and metastatic settings. The gene expression profile and genetic mutations of breast cancer subjects with the primary and recurrent tumors are compared. We also explore whether immune-related gene expression and diversity have any impact on response to treatment and survival. This study aims to discover biomarkers of detection of cancer relapse, diagnosis and prognosis that may enable personalized medicine and improvement in breast cancer treatment. Clinical trial registration: NCT04626440 (ClinicalTrials.gov).

Comprehensive molecular profiling of Taiwanese breast cancers revealed potential therapeutic targets: prevalence of actionable mutations among 380 targeted sequencing analyses.

BACKGROUND: Breast cancer is one of the leading causes of cancer-related deaths in women, and there is a demand in developing an Asian-based genetic profiling database for breast cancer in improving the treatment response. This study aimed to determine molecular alternations and identify potential therapeutic targets by analyzing the genetic profiling from a cohort of Taiwanese breast cancers using a commercialized next-generation sequencing (NGS) targeted panel. METHODS: The study population comprised a broad spectrum of breast cancer patients in Taiwan, including Group 1: planned to receive first-line surgery and followed by adjuvant therapy, or early relapse within three years, Group 2: planned to receive first-line neoadjuvant therapy and followed by surgery, and Group 3: de novo stage IV, or stage IV with recurrence beyond three years. Molecular profiles were determined using Thermo Fisher™ Oncomine™ Comprehensive Assay version 3 (TMO comprehensive assay) from Formalin-Fixed Paraffin-Embedded (FFPE) tissues. Level of actionability was evaluated with the ESMO Scale of clinical actionability of molecular targets (ESCAT). RESULTS: A total of 380 TMO comprehensive assays were conducted on 372 patients, and we presented targeted sequencing analyses of Tier I: alteration-drug match associated with improved outcome in clinical trials including ERBB2 amplification, BRCA1/2 germline mutation, PIK3CA mutation, and NTRK translocation, and Tier II: antitumor activity associated with the matched alteration-drug but lack of prospective outcome data including PTEN loss, ESR1 mutation, AKT1 mutation, and ERBB2 mutation, and Tier III: matched drug-alteration that led to clinical benefit in another tumor type including MDM2 amplification, and ERBB3 mutation. Among them, 249 (66%) showed at least one actionable alternation based on the ESCAT criteria. The most frequent impacted genes (all variants combined within each sample) were PIK3CA (38%), followed by ERBB2 (23%), ESR1 (10%), AKT1 (6%), and BRCA2 (5%), and the remaining rare variants (less than 5% of assayed cohort) were BRCA1 (3%), MDM2 (2.2%), and ERBB3 (1.1%). CONCLUSION: Targeted sequencing of actionable genes is believed to provide clinical applicability and substantial benefits for Taiwanese breast cancer patients. A valid scale of clinical actionability should be adopted for precision medicine practice under multidisciplinary molecular tumor board.

Prognostic Factors and Clinical Outcomes of Clinical Node-Negative Cutaneous Malignant Melanoma Patients: An Asian Single Institute Study.

INTRODUCTION: Cutaneous malignant melanoma is notorious for its aggressive behavior and relatively poor outcome compared with other common skin malignancies. Acral lentiginous melanoma (ALM) accounts for at least 50% of melanoma in the Asian population and has a significantly lower survival rate. However, previous studies of the prognostic factors of melanoma-specific survival were all conducted from Western institutions. Here, we performed a retrospective analysis to investigate this issue. METHODS: Fifty patients diagnosed as having clinical node-negative cutaneous malignant melanoma who underwent sentinel lymph node (SLN) biopsy at Taipei Veterans General Hospital between January 2007 and December 2018 were enrolled. Patient demographics, tumor characteristics, and lymph node characteristics were evaluated by chart review. RESULTS: Eighty-two percent of the melanoma in the sample population was ALM. Twelve patients (24.0%) presented at least 1 metastatic sentinel node, and the average number of retrieved SLNs was 3. Of the patients with positive SLNs who proceeded to completion lymph node dissection, only 2 (16.7%) had metastatic nonsentinel nodes (NSNs). The average follow-up time for all patients was 45 months. Recurrence and melanoma-specific death occurred in 21 patients (42.0%) and 15 patients (30.0%), respectively. Melanoma-specific survival was significantly lower in patients with ulcerative lesions (P = 0.005) and more metastatic SLNs (P = 0.036). The overall morbidity rate of completion lymph node dissection was 66.7%. CONCLUSIONS: The presence of ulcerations and number of metastatic SLNs were the most important prognostic factors in this ALM-dominant Asian cohort. Among patients with clinically negative nodes but positive SLNs, less than one-fourth of patients harbored metastatic NSNs. Completion lymph node dissection carries a relatively high risk of morbidity; therefore, further research regarding predictors of positive NSNs in the Asian population is necessary.