title: High nodal positivity rates even in good clinical responders after chemoradiation of rectal cancer: is organ preservation feasible?
abstract: OBJECTIVE
  Local excision (LE) is emerging as a treatment option for rectal cancer responding well to chemoradiation. However, it does not address the mesorectal nodal burden. We aimed to identify the factors influencing nodal positivity and subsequently defined a low-risk group by including only patients at low risk.
  
  
  METHODS
  A single-centre, retrospective database analysis was carried out of patients with radically resected rectal cancer after neoadjuvant chemoradiation.
  
  
  RESULTS
  This study included 524 patients with predominantly low rectal tumours. Nodal positivity among ypT0, T1 and T2 groups was 14.7%, 28% and 30%, respectively. Multivariate analysis with stepwise logistic regression identified the following low-risk features: age ≥ 40 years, nonsignet ring cell carcinoma (SRCC) histology and pathological complete response (pCR). Sixty-nine patients fulfilling all three criteria were analysed and the nodal positivity was found to be 10.1%, which implies that, if these patients had been selected for LE, one in 10 would have had positive mesorectal nodes.
  
  
  CONCLUSIONS
  Even in patients with low-risk criteria (pCR, non-SRCC histology and age ≥ 40 years), the residual positive nodal disease burden is 10%. Whether this high incidence of residual nodal disease translates into a similar risk of locoregional recurrence if an organ-preservation strategy is adopted is unclear.
authors.affiliation: Department of Surgical Oncology, Tata Memorial Centre, Mumbai, India.
authors.forename: K C
authors.initials: KC
authors.lastname: Vallam
authors.affiliation: Department of Radiation Oncology, Tata Memorial Centre, Mumbai, India.
authors.forename: R
authors.initials: R
authors.lastname: Engineer
authors.affiliation: Department of Surgical Oncology, Tata Memorial Centre, Mumbai, India.
authors.forename: A
authors.initials: A
authors.lastname: Desouza
authors.affiliation: Department of Digestive Diseases and Clinical Nutrition, Tata Memorial Centre, Mumbai, India.
authors.forename: P
authors.initials: P
authors.lastname: Patil
authors.affiliation: Department of GI Oncology, Tata Memorial Centre, Mumbai, India. asaklani@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Saklani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D059248:Chemoradiotherapy; D003082:Colectomy / Q000379:methods*; D003131:Combined Modality Therapy; D016208:Databases, Factual; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009367:Neoplasm Staging; D059351:Organ Sparing Treatments / Q000379:methods*; D012004:Rectal Neoplasms / Q000473:pathology* / Q000628:therapy*; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult
keywords: Neoadjuvant chemoradiation; local excision; nodal response; organ preservation protocol; rectal cancer