Oncological outcome after MRI-based selection for neoadjuvant chemoradiotherapy in the OCUM Rectal Cancer Trial.

BACKGROUND: It is not clear whether all patients with rectal cancer need chemoradiotherapy. A restrictive use of neoadjuvant chemoradiotherapy (nCRT) based on MRI findings for rectal cancer was investigated in this study. METHODS: This prospective multicentre observational study included patients with stage cT2-4 rectal cancer, with any cN and cM0 status. Carcinomas in the middle and lower third that were 1 mm or less from the mesorectal fascia, all cT4 tumours, and all cT3 tumours of the lower third were classified as high risk, and these patients received nCRT followed by total mesorectal excision (TME). All other carcinomas with a minimum distance of more than 1 mm from the mesorectal fascia and those in the upper third were classified as low risk; these patients underwent TME alone (no nCRT). Patients were followed for at least 3 years. Outcomes were the rates of local recurrence, distant metastasis and survival. RESULTS: Among 545 patients included, 428 were treated according to the study protocol: 254 (59·3 per cent) had TME alone and 174 (40·7 per cent) received nCRT and TME. Median follow-up was 60 months. The 3- and 5-year local recurrence rates were 1·3 and 2·7 per cent respectively, with no differences between the two treatment protocols. Patients with disease requiring nCRT had higher 3- and 5-year rates of distant metastasis (17·3 and 24·9 per cent respectively versus 8·9 and 14·4 per cent in patients who had TME alone; P = 0·005) and worse disease-free survival compared with that in patients who did not need nCRT (3- and 5-year rates 76·7 and 66·7 per cent, versus 84·9 and 76·0 per cent in the TME-alone group; P = 0·016). CONCLUSION: Restriction of nCRT to high-risk patients achieved good results.

Long-term results of transanal endoscopic microsurgery after endoscopic polypectomy of malignant rectal adenoma.

BACKGROUND: There is no consensus on the treatment and prognosis of malignant rectal polyps. The aim of the present study was to determine the role of transanal endoscopic microsurgery (TEM) after endoscopic complete polypectomy of malignant rectal adenomas with long-term follow-up. METHODS: Of 105 patients with pT1 rectal carcinoma in 32 patients TEM followed complete endoscopic polypectomy while 73 had primary TEM. Local recurrence (LR), distant metastasis, overall and cancer-specific survival were determined by the Kaplan-Meier method. RESULTS: Median follow-up was 9.1 years. In 32 patients with TEM following complete polypectomy no residual cancer was found. LR occurred in 3/28 (11%) patients with low-risk carcinoma (pT1 G1/2/X, L0/X, R0) and in 1/4 (25%) with high-risk carcinoma (pT1 G3/4 or L1). After primary TEM with complete resection (minimal distance >1 mm) LR occurred in 6/60 (10%) with low-risk carcinoma. After incomplete TEM resection (minimal distance ≤1 mm) LR occurred in 3/8 (38%) patients with low-risk and in 1/5 (20%) patients with high-risk carcinoma. Grading was the only significant risk factor for LR after endoscopic polypectomy followed by TEM (p = 0.002). At all outcomes did not differ between postpolypectomy TEM and primary TEM. CONCLUSIONS: Patients with malignant rectal polyps removed by endoscopic polypectomy have a substantial risk of LR even if TEM of polyp site is cancer free. Risk of LR depends on tumor characteristics. In low-risk carcinoma long-term follow-up is necessary. The high LR rate in patients with high-risk rectal carcinoma restricts the use of TEM alone.