Bayesian and Frequentist Analytical Approaches Using Log-Normal and Gamma Frailty Parametric Models for Breast Cancer Mortality

Comparative Analysis of Women's Breast Cancer Survival Time at Three Selected Government Referral Hospitals in Ethiopia's Amhara Region Using Parametric Shared Frailty Models

Background

One in five people will eventually develop cancer, and one in eleven women will lose their lives to the disease. The main aim of this study is to determinants of survival time of women with breast cancer using appropriate Frailty models.

Methods

A study involving 632 Ethiopian women with breast cancer was conducted between 2018 and 2020, utilizing medical records from Felege-Hiwot Referral Hospital, the University of Gondar, and Dessie Referral Hospital. To compare survival, the Kaplan-Meier plot (s) and Log rank test were employed; to assess mean survival, one-way analysis of variance and the t test were utilized. The factors influencing women's survival times from breast cancer were identified using the parametric shared frailty model and the accelerated failure time model.

Results

The median time to die for breast cancer patients treated at FHRH, UoGCSH, and DRH was 14.91 months, 11.14 months, and 12.32 months, respectively. The parametric model of shared frailty fit those who were statistically significant in univariate analysis. The results showed that survival of women with breast cancer was significantly influenced by age, tumor size, comorbidity, nodal status, stage, histologic grade, and type of primary treatment initiated. When comparing mean survival times between hospitals, the results showed a significant difference; patients who were treated in FHRH live significantly longer than patients treated in UoGCSH and DRH, whereas patients treated in UoGCSH have comparatively lower survival. Women with stage IV and comorbidities have 22.4% and 27.1% shorter expected survival, respectively.

Conclusion

This finding suggests that improving the availability and accessibility of radiation therapy and surgery, eliminating disparities between hospitals, raising awareness of early signs and symptoms of breast cancer and encouraging women to seek clinical help, and highlighting women with comorbidities at diagnosis are important ways to increase survival time.

Risk Factors Affecting Survival Time of Breast Cancer Patients: The case of Southwest Ethiopia

BACKGROUND

Breast cancer is one of the non-communicable diseases and the main origin of the loss of life in the world. In Ethiopia, breast cancer is the second common cancer health problem for women. The main objective of this study was to identify the potential risk factors affecting the survival time of breast cancer patients in Southwest Ethiopia.

STUDY DESIGN

A retrospective study design.

METHODS

The data were taken from the patients' medical records that registered from January 1, 2015, to  January 31, 2020. A retrospective study design was used in this study. Different shared frailty survival models were employed to analyze the dataset.

RESULTS

Out of 642 recorded breast cancer patients, 447(69.6%) cases died during the study period, and 195 (30.4%) patients lost follow-up for unknown reasons. The median time to death for breast cancer patients was 10 months, and hospitals were used as a cluster effect. The result revealed that women with no smoking habit had about 3.35 times higher survival time than patients who had a smoking habit, and as breast cancer patients age increased, the survival time decreased by 0.99. Moreover, breast cancer patients in rural areas had about 0.14 times lower survival time, compared to breast cancer patients who were urban residents.

CONCLUSIONS

Age, place of residence, treatment taken, stage, histologic grade, tumor size, oral contraceptives, and smoking habits led to a shorter survival time. To reduce the burden of breast cancer, awareness should be given to the community.