Changing practice in systemic breast cancer adjuvant treatment in a well-defined French population.

ABSTRACT

Using the 2,208 non metastatic breast cancer diagnosed women who underwent breast surgery from the 2,432 first breast cancers recorded by the French département of Côte-d'Or cancer registry from 1982 to 1992, we described in this well-defined population, the trend in breast-cancer adjuvant treatment, and related practices with recommendations according to risk groups. Adjuvant treatment was received by 44.1% of the 2,208 women. Inflammatory tumors were systematically treated with chemotherapy. For the non-inflammatory M0 breast-cancer (2,167 women), the adjuvant treatment probability was mainly determined by the nodal involvement. After adjustment on the tumor- and host-characteristics, time period was associated with increased probability of adjuvant treatment in the whole group of patients and within each pN subgroup. In the group without nodal involvement, this increase was also associated with the SBR histologic grade. There was strong evidence of large changes in breast-cancer adjuvant treatment. Clinical practices in the Côte-d'Or region have paralleled the NIH recommendations. For node-negative breast cancers, these trends appeared despite persistent uncertainty in the definition of subgroups to treat. Over time, the SBR histologic grade became an apparent factor of treatment. This use as a treatment indicator was done without validation in any adjuvant treatment trial. The simultaneous recommendation to treat with the absence of guidelines could lead to the treating of an increasingly large group by extending the "high-risk" definition. This could be a non-optimal management of risk while putting strain on health care resources.