The Study: Do you remember how many patients with a locoregional breast cancer recurrence have occult distant metastases? C’mon, it was 27%! With that in mind, the final results of the CALOR trial are out in JCO. This trial randomized women with a locoregionally recurrent breast cancer to chemo versus observation after resection. Of note, receptor studies were done on the recurrent tumors, and radiation was required if there was either a positive margin or no history of prior radiation. Chemo was a dealer’s choice multidrug regimen for at least 3 months. At 10 years, patients with ER-negative tumors receiving chemo saw a 20% absolute increase in overall survival (OS) from 53% to 73% and double the rate of being breast cancer free from 34% to 70%. In comparison, those with ER-positive tumors had no benefit in any outcome.
Bottom Line: Patients with ER-negative locoregional breast cancer recurrence derive a significant benefit from chemotherapy after definitive local therapy while patients with ER-positive disease should probably stick with endocrine therapy +/- CDK inhibition.