Sphincter-Sparing Surgery in Early-Stage Rectal Cancer

PHOENIX—Conservative, sphincter-sparing surgery followed by chemotherapy plus radiotherapy appears effective in selected patients with early-stage rectal cancer, Anthony Russell, MD, said at the American Society for Therapeutic Radiology and Oncology meeting.

Five-year survival among the 65 patients in this phase I/II trial (RTOG 89-02) is 78%, with median survival not yet reached, said Dr. Russell, a radiation oncologist with Radiological Associates of Sacramento.

Eligible patients had clinically mobile, distal rectal cancers located below the pelvic peritoneal reflection, 4 cm or less in largest diameter and occupying 40% or less of the rectal circumference. Patients with overt lymph node or hematogenous metastases were excluded. These were all patients for whom sphincter conservation would not have been feasible by conventional surgery (anterior resection).

Surgery was accomplished by transanal excision (with or without sphincterotomy) or by a trans-sacral or transcoccy-geal approach. Surgery was intended to remove, en bloc, the primary cancer by transmural excision of the rectal wall.

Based on stage, grade, and adequacy of surgical margins, patients were assigned to one of three postsurgical groups: observation or adjuvant fluorouracil with one of two different dose levels of locoregional radiation. Of the 65 patients enrolled, 51 received adjuvant chemotherapy plus radiation therapy.

With minimum follow-up exceeding 5 years in all groups, 11 patients have failed: 3 had a locoregional recurrence; 3 had distant failure; and 5 had both locoregional and distant failure.

Locoregional failure correlated with stage: 4% for T1 cancers; 16% for T2 disease; and 23% for T3 disease. Distant failure by stage was 4%, 12%, and 31% for T1, T2, and T3 disease, respectively. Of patients receiving adjuvant therapy, 27% had acute grade 3-4 toxicities (primarily grade 3), and 10% had late grade 3-4 toxicities (mostly grade 3).

“These results should provide an incentive for patients to participate in screening because early diagnosis leads to a high cure rate for rectal cancer and offers the opportunity for conservative, sphincter-sparing treatment.” He noted that the majority of cancers detected in this study could be found by DRE.

Dr. Russell said that in the future this treatment approach may be improved by more sensitive tests to detect extrarectal spread before surgery and by use of more prolonged or intensive systemic treatment for high-risk patients.