Long-term results of local excision for rectal cancer

Abstract

Objective: To review the authors' experience with local excision of early rectal cancers to assess the effectiveness of initial treatment and of salvage surgery.

Summary background data: Local excision for rectal cancer is appealing for its low morbidity and excellent functional results. However, its use is limited by inability to assess regional lymph nodes and uncertainty of oncologic outcome.

Methods: Patients with T1 and T2 adenocarcinomas of the rectum treated by local excision as definitive surgery between 1969 to 1996 at the authors' institution were reviewed. Pathology slides were reviewed. Among 125 assessable patients, 74 were T1 and 51 were T2. Thirty-one patients (25%) were selected to receive adjuvant radiation therapy. Fifteen of these 31 patients received adjuvant radiation in combination with 5-fluorouracil chemotherapy. Median follow-up was 6.7 years. One hundred fifteen patients (92%) were followed until death or for greater than 5 years, and 69 patients (55%) were followed until death or for greater than 10 years. Recurrence was recorded as local, distant, and overall. Survival was disease-specific.

Results: Ten-year local recurrence and survival rates were 17% and 74% for T1 rectal cancers and 26% and 72% for T2 cancers. Median time to relapse was 1.4 years (range 0.4-7.0) for local recurrence and 2.5 years (0.8-7.5) for distant recurrence. In patients receiving radiotherapy, local recurrence was delayed (median 2.1 years vs. 1.1 years), but overall rates of local and overall recurrence and survival rates were similar to patients not receiving radiotherapy. Among 26 cancer deaths, 8 (28%) occurred more than 5 years after local excision. On multivariate analysis, no clinical or pathologic features were predictive of local recurrence. Intratumoral vascular invasion was the only significant predictor of survival. Among 34 patients who developed tumor recurrence, the pattern of first clinical recurrence was predominantly local: 50% local only, 18% local and distant, and 32% distant only. Among the 17 patients with isolated local recurrence, 14 underwent salvage resection. Actuarial survival among these surgically salvaged patients was 30% at 6 years after salvage. CONCLUSIONS The long-term risk of recurrence after local excision of T1 and T2 rectal cancers is substantial. Two thirds of patients with tumor recurrence have local failure, implicating inadequate resection in treatment failure. In this study, neither adjuvant radiotherapy nor salvage surgery was reliable in preventing or controlling local recurrence. The postoperative interval to cancer death is as long as 10 years, raising concern that cancer mortality may be higher than is generally appreciated. Additional treatment strategies are needed to improve the outcome of local excision.

Figure 1. Actuarial local control rates for T1 (solid line) and T2 (dotted line) rectal cancers. (A) Cancers treated by local excision alone. (B) Cancers treated by local excision and radiotherapy.

Figure 2. Actuarial disease-specific survival rates for T1 (solid line) and T2 (dotted line) rectal cancers. (A) Cancers treated by local excision alone. (B) Tumors treated by local excision and radiotherapy.

Figure 3. Actuarial survival of rectal cancers with (dotted line) and without (solid line) intratumoral vessel invasion identified on histopathology.

Figure 4. Local recurrence-free survival and disease-specific survival of patients with T1 rectal cancers with (high risk, dotted line) and without (low risk, solid line) adverse features on histopathology (high grade, vessel invasion, or positive margin). (A) Local recurrence. (B) Survival.

Figure 5. Actuarial survival rates of patients who developed recurrence. Each graph compares patients whose recurrence was treated by surgical resection (solid line) to patients whose recurrence was not resected (dotted line). (A) Patients with any recurrence. (B) Patients with isolated local recurrence.