[Prognosis and complications of local excision for rectal cancer after neoadjuvant chemoradiotherapy]

Objective: To investigate the prognosis and postoperative complications of local excision for rectal cancer after neoadjuvant chemoradiotherapy (nCRT). Methods: A descriptive case series study was carried out. Patient inclusion criteria: (1) patients who underwent local excision by transanal endoscopic microsurgery (TEM) after nCRT; (2) magnetic resonance evaluated tumor regression grade (mrTRG) as 1, 2 after nCRT;(3) American Society of Anesthesiologists class I to III. Patient exclusion criteria: (1) with multiple primary colorectal cancers; (2) with other malignant tumors within five years; (3) with emergency surgicery indications like digestive tract obstruction, perforation or bleeding. Clinicopathological and follow-up data of rectal cancer patients with obvious tumor regression after nCRT who underwent local excision in Peking Union Medical College Hospital from January 2010 to August 2019 were retrospectively collected. Outcome measures included disease-free survival (DFS), short-term postoperative complications, and at postoperative 1-year during follow up, gas continence, fecal continence, and quality of life (using the EORTC QLQ-CR29 scale, higher score indicated worse quality of life) at postoperative 1-year. Results: A total of 40 patients were included in this study. There were 27 males and 13 females with an average age of (66.7±12.3) years. Preoperative rectal ultrasound and other imaging examinations indicated that the tumor was located in the anterior wall in 16 cases, the lateral wall in 12 cases, and the posterior wall in 12 cases. The distance between the lower margin of the tumor and the anal verge was (4.3±1.2) cm before nCRT and (5.1±0.9) cm after nCRT. According to mrTRG, 31 cases were assessed as mrTRG 1 and 9 cases as mrTRG 2. All the patients received local extended excision of rectal cancer using TEM platform. A total of 19 cases(47.5%) suffered from complications within one month postoperatively. Clavien-Dindo grade I complications happened in 14 cases, grade II in 3 patients, and grade III in 2 cases, who all were healed by conservative treatment. Except that 2 patient presented severe low anterior resection syndrome (LARS) at 1 year postoperatively, no severe anal dysfunction was found in this cohort patients. EORTC QLQ CR29 scale results for quality of life showed that at 1 year after TEM excision, except taste (Z=-1.968, P=0.049), anxiety (Z=-3.624, P<0.001) and skin irritation (Z=-2.420, P=0.023) were worse than the situation before neoadjuvant therapy, there were no statistically significant differences in other assessment results between pre-operation and post-operation (all P>0.05). Postoperative pathological results indicated complete tumor regression (pTRG0) in 17 cases, moderate remission (pTRG1) in 13, and mild remission (pTRG2) in 10. During the follow-up of (49.1±29.6) months, 3 patients had local recurrence and 4 had distant metastasis (3 patients with liver metastasis and 1 patient with lung metastasis followed by liver metastasis). No death was found and the 5-year disease-free survival (DFS) was 84.3%. Conclusions: Local excision through TEM following nCRT not only can be adopted as an important means to accurately determine complete clinical remission (cCR), but also has high therapeutic value for rectal cancer patients presenting cCR or near cCR, with little impact on defecatory function and quality of life. However, the morbidity of complication of TEM excision after nCRT is relatively high and there is a risk of recurrence and metastasis. Therefore, it is still necessary to strictly select the indications of local excision.