Pathologic complete response may not represent the optimal surrogate for survival after preoperative therapy for esophageal cancer

Abstract

Background: We designed a phase II trial to examine the benefit of preoperative hyperfractionated radiation therapy (XRT) and concurrent chemotherapy for patients with locally advanced esophageal cancer (LAEC).

Aim of study: The pathologic complete response (pCR) was the primary endpoint to estimate efficacy.

Methods: Twenty-three patients with LAEC received twice-daily XRT during wk 1 and 5 and once-daily XRT during wk 2-4 (59 Gy). Cisplatin (100 mg/m(2)) was given on d 1, while 5-fluorouracil (1000 mg/m(2)) was given by continuous infusion the first and fifth weeks of the XRT.

Results: The pCR for the 19 patients undergoing esophagectomy was 16%. The study was closed at the interim analysis having not met the required minimum pCR rate of 20%. Hematologic toxicities consisted of grades III and IV neutropenia observed in 33% and 14% of patients, respectively. Grade III nausea and vomiting was seen in 38% of patients. One grade V pulmonary toxicity occurred. The median survival was 44.6 mo with 65% of patients alive at 2 yr.

Conclusions: The pCR rate in this trial did not meet the predetermined statistical minimum. With the encouraging 2-yr survival, it is not clear that pCR is a reliable surrogate endpoint to discern treatment efficacy.