Long-term Oncological Outcomes of T1 Rectal Cancer according to the Therapeutic Modalities

Choi, Pyong Wha; Yu, Chang Sik; Jung, Sang Hun; Kim, Dae Dong; Hong, Dong Hyun; Kim, Hee Cheol; Kim, Jin Cheon

Abstract

PURPOSE
Recent studies have showed a 7~15% lymph node metastasis rate in T1 rectal cancer. Surgical options for T1 rectal cancer are radical resections, local excisions, and local excisions with adjuvant radiotherapy. Outcomes according to the type of surgery are variable. The present study was performed to assess outcomes of T1 rectal cancer according to therapeutic modalities and to provide guidelines for appropriate treatment of T1 rectal cancer.
METHODS
A retrospective study of 117 patients with T1 rectal cancer who underwent surgery between June 1989 and December 2002 at Asan Medical Center was conducted. Radical resections, local excisions, and local excisions with adjuvant radiotherapy were performed as therapeutic modalities. Adjuvant radiotherapy after local excision was performed in patients with sm2 or sm3 cancers, lympho-vascular invasion (+), poorly differentiated cancer, and resection margin (+) or because of a patient's refusal to undergo a radical resection.
RESULTS
Twenty-five (21.3%) patients were treated by local excision, 14 (12.0%) by adjuvant radiotherapy after local excision, and 78 (66.7%) by radical resection. The distance from the anal verge was significantly longer in the radical resection group than in the local excision group (7.8+/-3.4 vs. 4.9+/-2.1 cm; P<0.001). There was no significant difference by age, sex, or pathologic findings between the three groups. There was one local recurrence in the local excision group, one distant metastasis in the local excision with adjuvant radiotherapy group, and two distant metastases in the radical resection group. The 5-year cancer-specific survival and disease-free survival rates were as follows; local excision group, 94.1 and 95.8%, respectively; local excision with adjuvant radiotherapy group, 100 and 92.8%, respectively; radical resection group, 98.3 and 98.6%, respectively. There were no significant differences in survival between the groups.
CONCLUSIONS
Oncological outcomes of T1 rectal cancer patients were comparable among the surgical options. Adjuvant radiotherapy is recommended after local excision in patients with risk factors, such as sm2 or sm3 cancer, poorly differentiated cancer, and positive lympho-vascular invasion.