Survival Outcomes In Human Epidermal Growth Factor Receptor 2 (HER 2) Positive Breast Cancer Patients At Kenyatta National Hospital

Background: For several years, HER2-positive breast cancer was associated with poor outcomes and higher mortality rates than other breast cancer subtypes. Nevertheless, the advent of Trastuzumab has significantly changed the treatment paradigm of HER2-positive breast cancer. However, it is not an affordable treatment option in sub-Saharan African countries. Besides, there was a lack of comprehensive data about the survival outcomes of HER2-positive breast cancer patients in our setting. Hence, the present study aimed to determine the survival outcomes among HER2-positive breast cancer patients at the Oncology Department of Kenyatta National Hospital.Methods: A hospital-based retrospective cohort design was used to evaluate the survival outcomes, and associated factors among patients with HER2-positive breast cancer admitted between 2015 and 2019 at Kenyatta National Hospital. A total of 50 eligible HER2-positive breast cancer patients were included in the study. In the pre-designed data abstraction tool, the data were collected by reviewing the medical records of the patients. The data were entered and analyzed using the Statistical Package for the Social Sciences version 27 software. The mean survival time was estimated using Kaplan Meier survival analysis. Cox regression analysis was employed to estimate the predictors of mortality among HER2-positive breast cancer patients.Results: The study showed that the overall survival rate was 30%, with a significant decrease in the percentage survival rate across the five years. More than half of the study participants (26, 52%) showed cancer progression during the last follow-up period. The present study showed that the mean cancer-specific survival rate among the study patients was 26.74±18.395 months. The study showed that the mean survival time of patients aged below 60 years (32.513 months), without co-morbidities (34.40 months), and the early stage of the disease (50.639 months) was higher than their counterparts. Multivariate cox-regression analysis revealed that advanced stage (AHR=13.1, 95% CI=2.6-66.6, P=0.002 and distant metastasis (AHR=15.0, 95% CI=3.6-62.8, P≤0.001) were the significant predictors of mortality among HER2 positive breast cancer patients.Conclusions: The overall survival rate of HER 2 positive breast cancer was 30%. Advanced stage and distant metastasis were the significant predictors of mortality among HER2-positive breast cancer patients.