[Progress report about the 1st Workshop on Local Excision of Rectal Cancer]

To determine the significance of local excision (LE) of rectal cancer and discuss oncologic results, a 1st Workshop on LE of rectal cancer was held at the Department of General und Abdominal Surgery, Johannes Gutenberg-University Mainz, Germany. The option of broadening the indication for local excision after neoadjuvant radiochemotherapy (nRCT) of rectal cancer was to be assessed. Local excision of "low risk" T 1 carcinomas was rated as oncologically adequate therapy with good functional results and low complication rates. Transanal endoscopic microsurgical (TEM) resection was the preferrred technique. Pre-requisite for the achievement of low recurrence rates (5 %) is an R0 resection with a safety margin of at least 1 mm (R < or = 1 mm) without tumor fragmentation, because otherwise possible tumor cell displacement and RX resection may not allow an assessment of the resection margin. "high risk" tumors or T 2 carcinomas were not considered an indication for local excision. To identify additional histological risk factors for the oncological outcome (sm-level, tumor budding, mucinous component, perineural infiltration, etc.) the initiation of a multi-center register study (LERC = local excision of rectal cancer) was suggested and is now in preparation. If the finding after TEM resection is not a "low risk" T 1 carcinoma, but a "high risk" situation or a T 2 tumor, immediate reoperation is advised resulting in similar outcomes as compared to primary conventional surgery. A literature analysis of LE after neoadjuvant RCT of T 2/3 rectal cancers showed a local recurrence rate of 0 % for ypT 0 and of 5 % for ypT 1 findings (studies with small patient collectives and short follow-up periods). The lymph node status of T 2 / 3 carcinomas after nRCT is unclear. More advanced/primary not resectable tumors (T 3 / 4) showed lymph node metastases in 5 % for ypT 0 and in 12 % for ypT 1 findings after nRCT, suggesting that for earlier T categories lower rates can be expected. On the basis of these favourable results a prospective multi-center study will be initiated. A study protocol will be established during the 2nd Workshop on LE of rectal cancer in Mainz.