Palliative radiotherapy and chemotherapy instead of surgery in symptomatic rectal cancer with synchronous unresectable metastases: Final overall survival analysis of phase II study.

Abstract

726 Background: A palliative surgery and chemotherapy is the standard of care in stage IV rectal cancer patients with pelvic symptoms. Recently we published primary results of the single-arm phase II study on combination of short-course radiation (5x5 Gy) with an oxaliplatin-based chemotherapy started after one-week rest (NCT01157806). The study met its primary end-point with only 17.5% (95% CI 13% to 22%) of patients (pts) who needed stoma throughout the observation and 67% (95% CI 58% to 76%) of pts having significant resolution of pelvic symptoms. Here we provide the long-term follow up data after median 60 months of observation. Methods: 40 consecutive patients with symptomatic rectal cancer with unresectable distant metastases were enrolled from September 2009 to February 2011. The time of treatment failure on chemotherapy (TTF3) was measured from the start of radiation to disease progression on fluoropiridine, oxaliplatin and irinotecan. All eligible patients were assessed for KRAS/NRAS status. Due to limitations in access to targeted agents none of patients were treated with anti-angiogenic agents and anti-EGFR treatment was restricted to third line. Results: Total 40 pts were assessed for pelvic symptoms, chemotherapy response and overall survival. In the group of patients with survival reaching over 2 years we have not observed any additional local complications which were treated surgically. The patients with total symptoms’ resolution after one month had significantly longer time-to-treatment failure (TTF3) than non-responders (median 22.5 vs 5 months, p < 0.05), while patients with minor local response had intermediate TTF3. The subgroup of patients who experienced clinical complete response of rectal tumor had a median TTF3 and overall survival reaching median 40 months. Conclusions: In the palliative setting short-course radiotherapy and early chemotherapy allowed for acceptable and durable local control. Metastatic rectal cancer patients with early symptomatic response of primary tumor had significantly better prognosis. Clinical trial information: NCT01157806.