[Prognostic analysis of local excision following neoadjuvant therapy for rectal cancer: a single-center study]

Objective: To investigate the complications, along with their diagnosis and management, that follow local excision for rectal cancer after neoadjuvant therapy. Methods: The clinical data of 53 patients with rectal cancer who underwent local resection after neoadjuvant treatment in Peking Union Medical College Hospital from January, 2010 to December, 2024 were retrospectively collected for this descriptive case series study. Indications for local resection were: (1) age ≥ 18 years; (2) American Society of Anesthesiologists (ASA) classification I-III; (3) pathologically confirmed rectal adenocarcinoma; (4) distance from the lower edge of the tumor to the anal edge of less than 8 cm; and (5) use of preoperative neoadjuvant therapy. Contraindications of local resection were: (1) multiple primary colorectal cancer and (2) intestinal obstruction, intestinal perforation, or and gastrointestinal bleeding that required emergency surgery. There were 36 males and 17 females, and the median age was 62 (26-85) years. After neoadjuvant therapy, the median distance from the tumor to the anal margin was 4.5 (range, 2.2-6.9) cm. The main outcome measures included: surgical details, pathological findings, postoperative complications, anorectal function, and oncological outcomes (recurrence and survival). Results: Surgical methods included transanal endoscopic microsurgery (TEM) in 47 cases, transanal minimally invasive surgery (TAMIS) in 3 cases, and traditional transanal local resection in 3 cases. Of the 53 patients, 29 (54.7%) had pathological complete response (pCR), namely pT0 stage; 8 cases were pT1, 15 cases were pT2, and 1 case was pT3. Twenty-four cases (45.3%) had 33 complications. Clavien-Dindo grade I-II accounted for 97.0% (32/33), including 14 cases (26.4%) of wound dehiscence. Low anterior resection syndrome (LARS) occurred in 7 cases (13.2%), including 5 minor cases and 2 major cases. Postoperative fever occurred in 7 cases (13.2%); urinary retention occurred in 3 cases (5.7%); and diarrhea occurred in 1 case (1.9%). Clavien Dindo grade III was observed in only 3.0% (1/33) of patients, which was a rectovaginal fistula. Among the 14 patients with wound dehiscence, 7 cases only suffered anal pain and were cured after symptomatic analgesic treatment. Five cases suffered anal pain with hematochezia but improved after treatment with essential diet, hemostasis, intravenous antibiotics, pain relief, and sitz bath. Two cases of secondary perianal infection were treated with intravenous antibiotics, local drainage, parenteral nutrition support, and symptomatic treatment, and the wounds healed within 2 months. One patient with rectovaginal fistula underwent transverse colostomy. After six months, the fistula healed and stoma reversal was performed. Seven patients with LARS received anal lifting exercise and defecation reflex training, and anal function recovered to the preoperative level after 1 year. Other complications improved after symptomatic treatment, pain relief, or catheter replacement. The median follow-up time was 60 months. Local recurrence occurred in 4 patients (7.5%) and distant metastasis occurred in 12 patients (22.6%). Seven patients (13.2%) died. The 5-year disease-free survival rate was 75.5%, and the 5-year overall survival rate was 86.8%. Conclusions: Local excision for rectal cancer following neoadjuvant therapy has a high incidence of complications, mainly wound-related, due to the decline of rectal wound healing ability after radiotherapy. However, most of the complications were relieved after symptomatic treatment, and the risk was controllable.