Short-term survival in breast cancer: the experience of the University of Malaya Medical Centre

Abstract

Objective: To study the impact of various clinicopathological factors on short-term survival in a cohort of breast cancer patients treated at the University of Malaya Medical Centre (UMMC).

Methods: All cases of breast cancer treated at UMMC from January 1999 to June 2001, except for stage IV disease, were included in the study. Survival analysis was carried out using Kaplan-Meier for univariate analysis and Cox regression for multivariate analysis. The log-rank test was used to test the significance of differences between the different survival curves.

Results: A total of 385 patients were included. The mean patient age at presentation was 50.3 years (SD, 11.4); 198 (51.4%) patients had lymph node-positive disease, and 187 (48.6%) had node-negative disease. The mean follow-up period was 18.7 months (SD, 8.8). The Malay ethnic group, tumours of larger size, node-positive disease, more than five positive lymph nodes, oestrogen receptor (ER) negativity and the presence of lymphovascular invasion were significant prognostic factors for shorter recurrence-free survival (RFS) in the univariate analysis. In the multivariate analysis, ER negativity was the only independent adverse prognostic factor for RFS. For overall survival (OS), tumours of larger size, node-positive disease, more than five positive lymph nodes, ER negativity and high grade tumours were associated with significantly shorter OS. However, more than five positive lymph nodes was the only independent prognostic factor for shorter OS in the multivariate analysis. Further multivariate analysis of the patients with node-positive disease showed that the Malay ethnic group, ER negativity and more than five positive lymph nodes were independent prognostic factors for shorter RFS. On the other hand, ER negativity and more than five positive lymph nodes were independent negative prognostic factors for OS in this subgroup of patients.

Conclusion: The evaluation of various prognostic factors would provide useful information on disease progression in local patients, especially for the planning of adjuvant therapies and follow-up protocols. Differences in the pattern of breast cancer among the different ethnic groups in Malaysia warrant further studies.