Tumour location is not an independent prognostic factor for survival following a diagnosis of breast cancer

Previous studies of patients with breast cancer have examined tumour location as a prognostic factor for survival with contradictory results. The current population-based study with 356 women examines the effect of tumour location and other important prognostic factors on survival. Univariate analyses indicated that central location (P < 0.001), a larger pathological tumour size (P = 0.003), number of positive lymph nodes (P < 0.001), younger age at diagnosis (P = 0.003), a more advanced TNM stage (P < 0.001), a higher grade (P = 0.016) and histologic type (P = 0.011) were associated with a higher risk of breast cancer death. The 10-year survival of women with central location was 33%, compared to 73% for medial and 71% for lateral (P < 0.001). However, the differences among tumour locations were markedly reduced after adjustment separately for early (P = 0.39) and advanced (P = 0.56) TNM stages, which also confirmed the results of multivariate analysis that the location does not influence survival after adjustment for other important clinicopathological characteristics.