Long-term survival after local excision for T1 carcinoma of the rectum

Many authors have reported high rates of local recurrence after local excision for early carcinoma of the rectum, which raises the question of whether oncologic resection gives better results. This study was designed to compare the long-term recurrence rate, long-term survival, and risk factors for T1 adenocarcinoma of the rectum treated with local excision or oncologic resection.

We identified 144 patients who had T1 sessile adenocarcinoma in the lower third or middle third of the rectum. Patients who received adjuvant therapy or who had pedunculated lesions were excluded. Data included age, gender, size of lesion, histologic type of carcinoma, grade, presence of lymphovascular invasion, and depth of invasion. Outcomes were defined as five-year and ten-year cumulative probabilities of local recurrence, distant metastasis, overall survival, and cancer-free survival. The mean follow-up was 9.2 years; median follow-up was 8.1 years.

We compared 70 patients who underwent local excision with 74 patients who underwent oncologic resection. Among patients with lesions in the middle or lower third of the rectum, 1) the five-year and ten-year outcomes were significantly better for overall survival and cancer-free survival in the oncologic resection group, but there were no significant differences in local recurrence or distant metastasis; 2) the multivariate risk factors for long-term, cancer-free survival were invasion into the lower third of the submucosa, local excision, and older than aged 68 years; and 3) for lesions with invasion into the lower third of the submucosa, the oncologic resection group had lower rates of distant metastasis and better survival. Among patients with lesions in the lower third of the rectum, 1) the five-year and ten-year outcomes showed no significant differences in survival, local recurrence, or distant metastasis between the two groups; and 2) for lesions with invasion into the lower third of the submucosa, the oncologic resection group showed a trend of improved survival, which was not statistically significant, possibly because of low statistical power from the small sample size.

Patients who undergo local excision or oncologic resection for T1 carcinoma in the lower two-thirds of the rectum have a high incidence of local recurrence and distant metastasis. To improve the cure rate, the rate of recurrence must decrease. A randomized, controlled study is needed to determine whether adjuvant therapy may be beneficial.