Neoadjuvant chemotherapy combo well-tolerated in poor-risk rectal cancer

Neoadjuvant chemotherapy with capecitabine and oxaliplatin in potentially operable patients with poor-risk rectal cancer was well-tolerated and showed “promising” anti-tumor activity, according to the results of a phase-2 study.

“Most patients who had locally advanced rectal cancer at presentation were able to proceed to total mesorectal excision with microscopically complete resection,” researchers wrote.

The phase-2 study enrolled 105 patients with poor-risk rectal cancer without metastatic disease as defined by high-resolution MRI. Patients were given neoadjuvant capecitabine plus oxaliplatin followed by six weeks of 54 Gy of chemoradiotherapy. Patients then underwent total mesorectal excision followed by an additional 12 weeks of postoperative adjuvant capecitabine.

The primary endpoint was pathological complete response. Patients were followed for a median of 55 months.

Patient objective response rate was high: 74% after neoadjuvant treatment, 89% after chemoradiotherapy. Ninety-five patients were able to proceed with total mesorectal excision; 93 of these patients had microscopically clear resection margins and 21 had complete pathological response. PFS at three years was 68%; OS was 83%.

“The safety profile of this chemotherapy combination seems to be consistent with findings of randomized trials of capecitabine and oxaliplatin in advanced colorectal cancer, for which it is a well-established treatment option,” the researchers wrote.

Chua YJ. Lancet Oncol. 2010;doi:10.1016/S1470-2045(09)70381-X.