The Relationship Between Age At First Diagnosis And Treatment Outcome Of Breast Cancer In Namibia

ABSTRACT

The purpose of this study was to evaluate the relationship between age at first diagnosis and outcomes of women treated of breast cancer at Windhoek central hospital between 2009 and 2011 and to describe and compare the outcomes of young and older patients in relation to socio-demographic and clinical factors. The study was a retrospective cohort study involving a document review of 334 women diagnosed and treated of breast cancer at Windhoek central hospital between 2009 and 2011. Patients were followed up from date of diagnosis to a period of 5 years after treatment. Patients were grouped into two groups defined as young (age≤40years) and older (age>40years) for analysis. Survival rates, metastases and recurrences were compared between the younger patients and the older patients. 19% were younger patients and 81% were older patients. Good outcome was defined as 5-year survival with no metastasis or recurrence and poor outcome as either death within 5 years or development of metastasis or recurrence within 5 years after treatment. 47.6 % of the older patients and 43.1% of the young patients had good outcomes. Statistical analyses indicated that young patients had an 8% increased risk (Crude RR=1.08, 95% CI of 0.85 to 1.38) of having poor outcomes than older patients and after adjusting for potential confounders the risk was found to be just 3% (adjusted RR=1.03, 95%CI 0.9 to 1.1). There was no statistical difference (p>0.05) between the outcomes of younger patients and older patients in the study. Predictively, older patients had higher overall 5- year survival rate of 56.5% compared to 52.3% of younger patients. The disease free survival rates for the older patients and the young patients were more or less similar (43% 5-year disease free survival for the young patients and 47% for the older patients).With regards to metastasis, 39.4% of the older patients and 49.2% of the young patients had metastases within 5 years after treatment. The study did not find any differences in risks of recurrence after treatment between the young patients and the older patients (4.6% for the young and 4.5% for the older group, RR =1.03, 95CI 0.3 to 3.5). Factors such as rural residence, nulliparity, unemployment and being single were linked to poor outcomes among younger patients. Clinical factors such as non-familial breast cancer, Stage II breast cancer, hormone receptor negative tumours and chronic /other illnesses were linked to poor outcomes in younger patients as well. Treatment commencement delays were more than 70days amongst all patients in Namibia, which could have resulted in very low overall survival rates of all patients.