Mukai H, et al. – The SELECT BC study was employed and the impact of treatment preferences in second–line chemotherapy on breast cancer prognosis was examined. For the group of patients in whom taxane was the primary chemotherapy, the study of the combination of first–line chemotherapy and second–line chemotherapy indicated that S–1 could be recommended as a second–line chemotherapy.

Methods

• 618 were assigned to 2 groups (S-1 group, 309; taxane group, 309), among HER2-negative metastatic breast cancer patients.
• 3 groups were formed for the S-1 and taxane groups: crossover group, protocol-recommended group, and other group,
• The clinicians regulated the analysis of overall survival (OS) using Cox regression with inverse probability weighting, to adjust for postrandomization confounding.

Results

• The OS of the crossover group (39.6 months) was better than that of the protocol-recommended group (35.7 months) and the other chemotherapy group (36.9 months) (vs. the protocol-recommended group, HR 0.72 [95% CI 0.52-0.98], p = 0.037; vs. the other chemotherapy group, HR 0.71 [95% CI 0.43-1.18], p = 0.183), in the taxane group.
• No statistically significant difference was observed in OS between the 3 groups in the S-1 group.