title: Is it safe to omit neoadjuvant chemo-radiation in mucinous rectal carcinoma?
abstract: BACKGROUND
  Purpose was to compare the oncologic outcome of neoadjuvant chemoradiotherapy (nCXRT) versus postoperative chemoradiotherapy (pCXRT) for locally advanced mucinous rectal carcinoma (MRC) having curative total mesorectal excision (TME).
  
  
  METHODS
  One hundred and two patients with MRC (T3-4 and/or N1-2) of middle and lower third rectum were included. Patients were non-randomly divided into 2 groups: Group A (N = 61) had nCXRT followed by total mesorectal excision (TME) after 8-11 weeks and Group B (N = 41) had TME followed by pCXRT. Primary end points were disease free survival (DFS) and overall survival (OS). Secondary endpoints were tumor regression grade (TRG) and morbidity.
  
  
  RESULTS
  In group A, 29 patients had partial response after nCXRT, 26 patients showed no change and 6 patients had progression. TME was done in 55 patients in group A and 41 patients in group B. Six patients in group A turned to be unresectable after nCXRT due to progressive disease. Mean follow-up was 53 months. In patients received TME, Four-year DFS was higher in group A compared to group B yet not statistically significant (DFS 0.69 [95% CI 0.54-0.85] vs. 0.67 [95% CI 0.47-0.87]; P = 0.39). However, actuarial 4 years OS was comparable in both groups (0.72 [95% CI 0.59-0.91] vs. 0.70 [95% CI 0.55-0.88]; P = 0.46 in groups A and B respectively). Multivariate analysis revealed that age <40, and N2 were risk factors of recurrence.
  
  
  CONCLUSIONS
  Whilst accepting that the numbers are small, there was no statistical difference in outcome (DFS and OS) between patients receiving pre- or post-operative chemo-radiotherapy. In most MRC patients, tumor regression is not significant after nCXRT and there is considerable possibility of tumor progression during nCXRT treatment. So, nCXRT should be used with close follow-up in MRC for early detection of possible tumor progression. If the patient cannot tolerate nCXRT, it is possibly safe to do surgery followed by pCXRT. Prospective study is needed to study the value of nCXRT in MRC.
authors.affiliation: Department of Surgery, University of Alexandria, Egypt. Electronic address: khaled.madbouly@alexmed.edu.eg.
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Madbouly
authors.affiliation: Department of Surgery, University of Cairo, Egypt.
authors.forename: Abdrabou N
authors.initials: AN
authors.lastname: Mashhour
authors.affiliation: Department of Surgery, University of Mansoura, Egypt.
authors.forename: Waleed
authors.initials: W
authors.lastname: Omar
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000601:surgery / Q000628:therapy*; D000328:Adult; D000368:Aged; D059186:Chemoradiotherapy, Adjuvant / Q000009:adverse effects / Q000379:methods; D003131:Combined Modality Therapy; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000009:adverse effects / Q000379:methods; D009364:Neoplasm Recurrence, Local; D011446:Prospective Studies; D012004:Rectal Neoplasms / Q000601:surgery / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Mucinous carcinoma; Neoadjuvant chemoradiation; Rectum; Total mesorectal excision