Performance evaluation of predictive models for detecting MMR gene mutations associated with Lynch syndrome in cancer patients in a Chinese cohort in Taiwan.

Identifying Lynch syndrome significantly impacts cancer risk management, treatment, and prognosis. Validation of mutation risk predictive models for mismatch repair (MMR) genes is crucial for guiding genetic counseling and testing, particularly in the understudied Asian population. We evaluated the performance of four MMR mutation risk predictive models in a Chinese cohort of 604 patients with colorectal cancer (CRC), endometrial cancer (EC), or ovarian cancer (OC) in Taiwan. All patients underwent germline genetic testing and 36 (6.0%) carried a mutation in the MMR genes (MLH1, MSH2, MSH6, and PMS2). All models demonstrated good performance, with area under the receiver operating characteristic curves comparable to Western cohorts: PREMM5 0.80 (95% confidence interval [CI], 0.73-0.88), MMRPro 0.88 (95% CI, 0.82-0.94), MMRPredict 0.82 (95% CI, 0.74-0.90), and Myriad 0.76 (95% CI, 0.67-0.84). Notably, MMRPro exhibited exceptional performance across all subgroups regardless of family history (FH+ 0.88, FH- 0.83), cancer type (CRC 0.84, EC 0.85, OC 1.00), or sex (male 0.83, female 0.90). PREMM5 and MMRPredict had good accuracy in the FH+ subgroup (0.85 and 0.82, respectively) and in CRC patients (0.76 and 0.82, respectively). Using the ratio of observed and predicted mutation rates, MMRPro and PREMM5 had good overall fit, while MMRPredict and Myriad overestimated mutation rates. Risk threshold settings in different models led to different positive predictive values. We suggest a lower threshold (5%) for recommending genetic testing when using MMRPro, and a higher threshold (20%) when using PREMM5 and MMRPredict. Our findings have important implications for personalized mutation risk assessment and counseling on genetic testing.

Five-year survival prognosis of young, middle-aged, and elderly adult female invasive breast cancer patients by clinical and lifestyle characteristics.

PURPOSE: Early-onset breast cancer incidence has been increasing globally and in Taiwan. However, previous studies have not comprehensively examined how clinical and lifestyle characteristics influence the 5-year survival of breast cancer diagnosed at different stages of adulthood. METHODS: We analyzed the Taiwan National Cancer Registry and Cause of Death datasets to understand how clinical factors (including tumor and treatment characteristics) and lifestyle factors (including body mass index, cigarette smoking, and alcohol consumption) were associated with the 5-year survival of 8471 young, 57,695 middle-aged, and 14,074 elderly female adult invasive breast cancer patients respectively diagnosed at age 20-39, 40-64, and ≥ 65 years between 2002 and 2015, with mortality follow-up to 2020. Poisson regression was used for obtaining the crude and adjusted 5-year survival risk ratios. RESULTS: Clinical and lifestyle characteristics were distributed differently but had mostly similar direction of association with 5-year survival for the three age groups. Receiving any treatment was associated with better survival, especially for elderly patients. Being underweight at initial cancer treatment was associated with worse survival than having normal weight, especially for elderly patients. Current smokers had worse survival than never smokers for middle-aged and elderly patients. The 5-year breast cancer-specific survival was not significantly higher for those of age 45-49 years than 40-44 years, despite the recommended starting screening age is 45 years in Taiwan. CONCLUSION: Our findings contribute to the understanding of early-onset and later-onset female breast cancer characteristics and prognosis, which may inform surveillance and treatment strategies to achieve better breast cancer prognosis.

Mismatch Repair (MMR) Gene Mutation Carriers Have Favorable Outcome in Colorectal and Endometrial Cancer: A Prospective Cohort Study.

Germline (Lynch syndrome, LS) and somatic deficiencies of mismatch repair proteins (MMRd) are linked to colorectal and endometrial cancer; however, their prognostic impact in Asian populations remains unclear. This prospective cohort study aimed to determine the prevalence and outcome of germline and somatic MMRd in cancer patients suspected of LS. Patients with colorectal or endometrial cancer suspected of LS were enrolled and underwent gene sequencing for germline MMRd (gMMRd) and immunohistochemistry staining of MMR proteins in a subset of the pathological samples (pMMRd). Among the 451 enrolled patients, 36 patients were gMMRd (+). Compared with gMMRd (-) patients, the 10-year relapse-free survival in gMMRd (+) patients was significantly higher (100% vs. 77.9%; p = 0.006), whereas the 10-year overall survival was similar (100% vs. 90.9%; p = 0.12). Among the 102 gMMRd (-) patients with available pMMR status, 13.7% were pMMRd (+). The 5-year relapse-free survival was 62.9% in gMMRd (-) pMMRd (+) patients and 35.0% in gMMRd (-) pMMRd (-) patients, both lower than gMMRd (+) patients (100%; p < 0.001). This study showed that having LS confers a favorable outcome in colorectal and endometrial cancer patients and highlights the importance of germline genetic testing following the detection of somatic MMRd.