Exploring the effectiveness of molecular subtypes, biomarkers, and genetic variations as first-line treatment predictors in Asian breast cancer patients: a systematic review and meta-analysis.

BACKGROUND: Breast cancer incidence has been on the rise significantly in the Asian population, occurring at an earlier age and a later stage. The potential predictive value of molecular subtypes, biomarkers, and genetic variations has not been deeply explored in the Asian population. This study evaluated the effect of molecular subtype classification and the presence or absence of biomarkers and genetic variations on pathological complete response (pCR) after neoadjuvant treatment in Asian breast cancer patients. METHODS: A systematic search was conducted in MEDLINE (PubMed), Science Direct, Scopus, and Cochrane Library databases. Studies were selected if they included Asian breast cancer patients treated with neoadjuvant chemotherapy and contained data for qualitative or quantitative analyses. The quality of the included studies was assessed using the Newcastle Ottawa Scale. Following the random effects model, pooled odds ratios or hazard ratios with 95% confidence intervals for pCR were analysed using Review Manager Software. Heterogeneity between studies was assessed using Cochran's Q-test and I2 test statistics. RESULTS: In total, 19,708 Asian breast cancer patients were pooled from 101 studies. In the neoadjuvant setting, taxane-anthracycline (TA) chemotherapy showed better pCR outcomes in triple-negative breast cancer (TNBC) (p<0.0001) and human epidermal growth factor receptor 2 enriched (HER2E) (p<0.0001) than luminal breast cancer patients. Similarly, taxane-platinum (TP) chemotherapy also showed better pCR outcomes in TNBC (p<0.0001) and HER2E (p<0.0001). Oestrogen receptor (ER)-negative, progesterone receptor (PR)-negative, HER2-positive and high Ki-67 were significantly associated with better pCR outcomes when treated with either TA or TP. Asian breast cancer patients harbouring wildtype PIK3CA were significantly associated with better pCR outcomes when treated with TA in the neoadjuvant setting (p=0.001). CONCLUSIONS: In the neoadjuvant setting, molecular subtypes (HER2E and TNBC), biomarkers (ER, PR, HER2, HR, Ki-67, nm23-H1, CK5/6, and Tau), and gene (PIK3CA) are associated with increased pCR rates in Asian breast cancer patients. Hence, they could be further explored for their possible role in first-line treatment response, which can be utilised to treat breast cancer more efficiently in the Asian population. However, it needs to be further validated with additional powered studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021246295.

Study of risk factors and marker status in women with breast cancer in Brunei Darussalam.

OBJECTIVE: To investigate the associations between breast cancer staging and body mass index (BMI), menopausal status, and family history of breast cancer, as well as to assess the expression of tumor markers in women with breast cancer in Brunei Darussalam. METHODS: A retrospective cross-sectional study was carried out at The Brunei Cancer Centre. Cases of women with breast cancer between 2000 and 2013 were retrieved from the medical records section and entered into a clinical proforma. These were reviewed and analyzed using appropriate statistical methods. RESULTS: Overall, the mean age at diagnosis was 53.6 years ± 9.83. The postmenopausal women had a significantly higher risk of being diagnosed with late-onset breast cancer than premenopausal women (P = 0.022). The expressions of PR (P = 0.034), Her2 (P = 0.046), and CatD (P = 0.004) were significantly different in breast cancer staging. Other factors did not have a statistically-significant association with breast cancer staging. CONCLUSION: While most of the factors studied were not significantly different in breast cancer staging, our findings showed that it is recommended that high-risk women perform regular breast screening after the age of 40 years old. A future study highly appreciates comparing breast cancer risk factors among the Bruneian and Western populations.