Transanal endoscopic microsurgical excision of pT2 rectal cancer: results and possible indications.

Purpose: In previous studies, local excision was predominantly established for "low-risk" pT1 rectal cancer. The results obtained with T2 tumors are unclear; recurrence rates of 0 to 67 percent were reported. This study was designed to determine the value of local excision for T2 rectal carcinomas, prognostic factors, and the need for reoperation.

Methods: After local excision of 649 patients with rectal tumors, pT2 carcinoma was found in 44 patients. In general, immediate reoperation was recommended; however, 24 patients declined further surgery or were not reoperated because of comorbidities. The results were analyzed separately for local R0 resection of low-risk carcinomas and for prognostically unfavorable criteria (R1/RX/R < or = 1mm/G3-4/L1/V1). Reoperation was performed within four weeks. Recurrences also were divided by previous local R0 resection of low-risk tumors as well as by unfavorable results and were analyzed in a long-term, follow-up study. Patients with palliative therapy were excluded, and follow-up was obtained in 90 percent (20 transanal endoscopic microsurgical excision alone, 17 transanal endoscopic microsurgical excision and reoperation).

Results: Local recurrence rates after local R0 resection alone of low-risk T2 carcinomas were 29 percent, whereas patients with unfavorable criteria developed recurrences in 50 percent. After immediate reoperation, the local recurrence risk in patients without lymph node filiae was significantly reduced to 7 percent.

Conclusions: Local R0 resection of low-risk pT2 carcinomas represents an inadequate therapy. In pT2N0M0 rectal carcinomas, the recurrence rate can be reduced through immediate reoperation to a level similar to primary radical surgery. An initial poor local resection result (R1/RX/R < or = 1 mm/G3-4/L1/V1) has no negative influence on further oncologic outcome.