ABSTRACT
Background: Cardiotoxicity as a result of anthracycline chemotherapy has been linked to increased morbidity and mortality in breast cancer patients. There is a need for early detection through risk factor identification. To date, no large multicenter study has been conducted to describe the incidence, risk factors and clinical and demographic profiles of breast cancer patients with anthracycline-induced cardiotoxicity (AIC) in the Philippines. Methods: This was a nationwide multicenter retrospective cohort study among adult breast cancer patients who underwent anthracycline chemotherapy from 2015 to 2020 in 10 sites in the Philippines. Baseline characteristics and possible risk factors for AIC were retrieved from medical records and cancer registries. AIC was defined as a reduction of left ventricular ejection fraction (LVEF) by > 10% from baseline to a value of < 53% or the development of overt left ventricular systolic dysfunction or heart failure (HF). Odds ratios from logistic regression were computed to determine risk factors associated with AIC using STATA-15.0 software. Results: Out of 341 patients included, 33 had AIC, accounting for an incidence of 9.68%. Nine patients (2.6%) had clinical HF. AIC patients had a mean age of 53.91 ± 10.84 years. Breast cancer AIC patients were significantly older and had lower body mass index (BMI) than those without AIC. AIC patients had significantly more comorbidities, especially hypertension and atrial fibrillation. Multivariate analysis showed that patients with any preexisting comorbidity are approximately 12.37 times as likely to have AIC, while those with concurrent chemotherapy are 0.07 times or 93% less likely to have AIC. Conclusion: Among adult breast cancer patients undergoing anthracycline chemotherapy, we determined a high incidence of cardiotoxicity at 9.68%. Having preexisting comorbidities gave patients 12 times increased odds of developing anthracycline cardiotoxicity. The presence of concurrent non-anthracycline chemotherapy showed an inverse association with the development of AIC which we attribute largely to patient selection in a retrospective study. The significantly higher propensity for AIC development in patients with preexisting comorbidities may warrant closer monitoring and control of patient comorbidities such as hypertension among patients undergoing anthracycline chemotherapy.
ABSTRACT
BACKGROUND: Breast cancer remains to be the leading cause of malignancy among women and survival rates vary worldwide. Molecular and immunohistochemical (NC) profiling of breast cancer has emerged to improve treatment, which led to 6 different breast cancer subtypes luminal-A, luminal-B, Her-2 enriched, basal-like, daudin low, and normal breast. Essentially, this guides clinicians as to the choice of treatment and prognostication of disease. This study evaluates the characteristics of the different IHC subtypes of breast cancer among Filipinos as to pattern of recurrence and time to progression (TIP) within their 1st 2 years of follow-up.METHODS: This is a retrospective cohort study, approved by the University of the Philippines Manila Research Ethics Board (UPMREB). Study population included breast cancer patients enrolled in the DOH-BCMAP and managed at the medical oncology clinics of the Philippine General Hospital (PGH) and Jose R. Reyes Memorial Medical Center (JRRMMC) from 1 May 2011 to 31 December 2013. Patients' demographics, disease and treatment profile were gathered from the medical charts. Patients were grouped into 12 different IHC subtypes utilizing only IHC staining results of Her2neu, ER and PR. Disease progression/ relapse and time to progression (UP) were primary outcomes analyzed and compared between subtypes using SPSS.RESULTS: There were 368 eligible patients; 50% were >50 years old, 48% postmenopausal, 34% stage IIA, and 94% had invasive ductal carcinoma. About 88% completed their chemotherapy regimen, mostly AC-T. At 1 to 2 years follow-up, 18% had disease progression, mostly distant metastasis, with HER2neu(-)/ER(-)/PR(-), HER2(+), and HER2neu(-)/ER(+)/PR(+) subtypes having the most number of disease progression. The HER2neu(-)/ER(-)/PR(-) subtype had the shortest median TTP (11 months 9sd). HER2(+) subtype had median TTP of 14±8 sd, while HER2neu(-)/ER(+)/PR(+) had median TTP at 11.6±7.41 sd. The median TTPs among the different IHC subtypes were statistically comparable. CONCLUSION: Filipinas with non-metastatic breast cancer after surgery and mainly on adjuvant chemotherapy started to develop disease progression/ relapse within the first 2 years of follow-up; 82% had no relapse. At these early years of follow-up, the median TTPs among the different breast cancer IHC subtypes who went into relapse were comparable, although HER2neu(+) regardless of ER/PR subtype tended to have more disease progression, followed by HER2neu(-)/ ER(-)/ regardless of PR subtype, and then HER2neu(-)/ ER(+)/ regardless of PR subtype. IHC resultant HER2neu(+) regardless of ER/PR and HER2neu(-)/ER(-)/PR(-/+) subtypes can serve as early prognosticators of breast cancer relapse.
