Assessing Survival Times of Breast Cancer Patients Using Type I Generalized Half Logistic Survival Model
P. O. Awodutire *
Department of Statistics, Federal Polytechnic of Oil and Gas, Bonny, Nigeria.
A. K. Olapade
Department of Mathematics, Obafemi Awolowo University, Ile - Ife, Nigeria.
O. A. Kolawole
Department of Surgery, Ladoke Akintola University of Technology Teaching Hospital, Osogbo, Nigeria.
O. R. Ilori
Department of Community Medicine, Ladoke Akintola University of Technology Teaching Hospital, Ogbomoso, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
In Nigeria, Breast Cancer is the most common malignancy among women. Unfortunately, many breast cancer patients present for treatment late. A Type I Generalized Half Logistic Survival Model was applied to a secondary data of eighty nine breast cancer patients collected from Ladoke Akintola University of Technology Teaching Hospital Osogbo. The study was focused on the 1-year survival of breast cancer patients from the day of presentation. Patient who were diagnosed with breast cancer from 2009 to 2014, were recorded. Age, stage of presentation, average years of breastfeeding, neoadjuvant treatment offered, age at menarche and use of contraceptives were the variables used in the study. The median survival time is 471 days. The contributions of the prognostic factors were assessed. The result showed that age at menarche and stage of presentation were significant at 0.05 level of significance while age of patients, average years of breastfeeding, use of contraceptives and neoadjuvant application were insignificant. Also, the accelerator factor between the early presented Breast Cancer patients and the late presented Breast Cancer patients was determined. The derived model was compared with the results of some common existing survival models, and this revealed that the type I generalized half-logistic survival model clearly demonstrates superiority over these other models.
Keywords: Model, survival, half logistic distribution, breast cancer.