Lack of a significant independent effect of race on survival in breast cancer.

In an analysis of 2033 patients with breast cancer from two population groups presenting to the Combined Breast Clinic of the Johannesburg and Hillbrow Hospitals, black patients were found to present with more advanced stage disease (P much less than 0.0001) and to have a poorer prognosis within each stage than whites (P less than 0.005- less than 0.001). Intrastage inhomogeniety was indicated by the finding that black patients had significantly more advanced T and N categories within stage grouping as compared to white patients (P = 0.013-P less than .001). A multivariate analysis controlling for age, T and N in nonmetastatic showed that when these factors were taken into consideration there was no significant independent effect of race on survival. The data indicate that the poorer prognosis which has been previously reported for black patients probably results from intrastage variability of disease bulk, supporting the use of the TNM rather that the stage grouping system for prognostication. Age differences also were evident when the two population groups were compared, with breast cancer in blacks appearing to present at an earlier age. Further analysis showed that these age differences were related to the age structure of the two populations and that breast cancer probably does not occur at a younger age in black subjects. Ethnic origin, does not appear to play a significant independent role in the prognosis of breast cancer in women.