Hormonoradiotherapie adjuvante concomitante des cancers du sein: etat de l'art. [Adjuvant treatment of breast cancer by concomitant hormonotherapy and radiotherapy: state of the art]

Combining radiation and hormone therapy has become common clinical practice in recent years for locally advanced prostate cancer. The use of such concomitant therapy in the treatment of breast disease has been very infrequently reported in the literature, but such an application seems justified given the common hormonal dependence of breast cancer and the potential synergetic effect of these two treatment modalities. As adjuvant therapy, tamoxifen is the key drug in the hormonal treatment arsenal, providing a significant improvement in both local control and global survival rates. Aromatase inhibitors are currently being evaluated in this setting, and initial results are promising. In vitro, tamoxifen does not seem to offer a protective effect against radiation. In clinical use, the few available published studies confirm the superiority of the association of radiation with tamoxifen as opposed to radiation therapy alone in decreasing local recurrences of surgically removed breast tumors. Toxicity associated with such concomitant therapy includes mainly subcutaneous and pulmonary fibroses. However, subcutaneous fibrosis and its cosmetic impact on the treated breast are frequently described side effects of radiation therapy, and their incidence may actually be reduced when tamoxifen is associated. The evidence is less controversial for pulmonary fibrosis, which is more common with the concomitant therapy. The association of radiation and aromatase inhibitors has as of yet rarely been reported. Letrozole (Femara) has a radiosensitizing effect on breast-cancer cell lines transfected with the aromatase gene. Clinical data assessing this effect in vivo are not available. The FEMTABIG study (letrozole vs. tamoxifen vs. sequential treatment) did not specify the sequence of radiation and hormonal therapy. The ATAC study comparing the adjuvant use of anastrozole (Arimidex) and tamoxifen does not provide any information on the number of patients receiving radiation concomitant with the hormonal treatment, and in addition also does not specify the sequence of radiation and hormonal treatment. The TEAM study compared exemestane (Aromasine) and tamoxifen, but specified that hormonal treatment follow the completion of radiation therapy