Risk factors associated with mortality of breast cancer patients after surgery: the case of Zambia.
Date
2024
Authors
Mulope, Mulope
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Zambia
Abstract
Breast cancer (BC) has become a public health problem world-wide due to its high mortality rate among women in both developed and developing countries. Numerous studies have been conducted to determine prognostic factors for breast cancer mortality and projection of mortality in developed countries. However, little was known of how factors related to both patients care and personal attributes in the case of Zambia, with a different environmental and cultural setting. Therefore, this study identifies the factors that affects survival rates and estimates a 5-year mortality of BC patients after surgery. We conducted a retrospective study encompassing 233 women who had undergone BC surgery between 2013 and 2018, and were followed-up to the end of 2019. The data were gathered from medical records of patients from the cancer center registry at Cancer Disease
Hospital (CDH) in Lusaka, Zambia. We determined the prognostic factors of BC mortality after surgery using the Logistic regression model. The most commonly used statistic of comparison was the odds ratio (OR). Further, 5-year mortality rates for various age groups were estimated using the fitted model. A total of 54 deaths were recorded during the study period. The results of the study showed that age at surgery, marital status, HIV status, BMI, BC stage, histologic grade, Progesterone Receptor (PR) status were statistically and significantly associated with mortality of BC patients after surgery, using a multiple logistic regression model. It was also established that factors which had two response categories (positive or negative) had higher mortality rates for subjects who were found to be positive on that factor compared to subjects who were negative. For other factors such as tumor size, lymph node status, BC stage and histologic grade, the odds of death increased with the degree of severity across the levels of the factor.
Additionally, the odds of death were higher for both HIV positive and the single patients compared to the HIV negative and married ones, respectively. Further, the odds of death for obese or overweight patients were more than twice of those classified as not obese or overweight. Furthermore, the 5-year mortality of different age groups using multiple logistic regression stood at 74.1% for the younger group (≤ 35 years) and 98.9% for the older group (50 <= age). Therefore, the study recommends the need for early detection of breast cancer along with the availability and accessibility of appropriate treatment.
Keywords: Breast cancer, mortality, survival, logistic regression, prognostic, retrospective study
Description
Thesis of Master of Science Degree in Statistics.