Chemotherapy for isolated locoregional recurrence of breast cancer (CALOR) a randomised trial

SUMMARY:It has been well recognized that patients with Breast Cancer with Isolated LocoRegional Recurrences (ILRR), without evidence of distant metastasis, are at a high risk of developing subsequent distant metastasis and may have poor outcomes, in spite of surgical resection of the ILRR. The role of systemic chemotherapy following surgery in this patient population has remained unclear although hormonal intervention in ER positive patients demonstrated disease free survival benefit. To address this question, three cooperative groups, The International Breast Cancer Study Group (IBCSG), Breast International Group (BIG) and NSABP collaborated and conducted this study to find out whether adjuvant chemotherapy improves the outcome of patients with ILRR following surgical resection. In this multicenter trial, 162 patients were randomly assigned to receive chemotherapy (N=85) or no chemotherapy (N=77). Eligible patients had histologically proven first ILRR resected and radiotherapy was recommended for all patients, but was mandated for those with microscopically involved surgical margins. All patients with ER or PR positive recurrent tumors received endocrine therapy and patients randomized to the chemotherapy group received at least two standard cytotoxic drugs (investigators choice) for 3-6 months. Both treatment groups were well balanced, and hormone receptor status was positive in 68% of the patients belonging to each group. The primary endpoint was Disease Free Survival and secondary endpoints included Overall Survival. The five year Disease Free Survival in the adjuvant chemotherapy group was 69% compared with 57% in the no chemotherapy group (HR=0.59, P=0.046). The five year overall survival was also significantly longer in the chemotherapy group compared to the no chemotherapy group (88% vs 76%, HR=0.41, P=0.024). With regards to the chemotherapy benefit based on hormone receptor status, patients with hormone receptor negative ILRR, had a longer Disease Free Survival with adjuvant chemotherapy (P=0.046). The authors concluded that adjuvant chemotherapy significantly improves Disease Free and Overall Survival in Breast Cancer patients with ILRR. This benefit is even more so, in those with ER negative ILRR. Adjuvant chemotherapy should therefore be considered in this patient population. Aebi S, Gelber S, Anderson SJ, et al. The Lancet Oncology 2014;15:156-163