title: Does residual microscopic disease after chemoradiotherapy for locally advanced rectal cancer translate into a good clinical outcome?
abstract: OBJECTIVE
  This study aimed to assess the progression-free and overall survival of patients with residual microscopic disease following neoadjuvant chemoradiotherapy and rectal resection for locally advanced rectal cancer.
  
  
  METHODS
  Two-hundred and thirty-four consecutive rectal cancer patients who had neoadjuvant chemoradiotherapy followed by radical resection (from May 2000 to April 2012) were divided according to pathological tumour response: residual microscopic disease (MIC), complete response (pCR) and partial/no response (non-CR). Data on the neoadjuvant regime, treatment-to-surgery interval, final pathology, type of operation, operative time, postoperative complications, length of hospital stay, disease recurrence and mortality were compared between the groups.
  
  
  RESULTS
  There were 13 (5.5%) MIC patients, 48 (20.5%) with pCR and 173 (73.9%) with non-CR group. The groups were demographically comparable. MIC patients had more retrieved lymph nodes compared with the non-CR and pCR patients (median 13 compared with 8 and 10, respectively, P = 0.0086). The 5-year overall survival rates were 93.4% for the pCR and MIC patients vs 82.1% for the non-CR patients (P = 0.0324). The 5-year progression-free survival was 85.2% for the pCR and MIC patients vs 73.8% for the non-CR patients (P = 0.086).
  
  
  CONCLUSIONS
  We have identified and assessed a new pathological subgroup of rectal cancer patients who had residual microscopic disease after neoadjuvant therapy. The survival analysis aligned them closely with pCR patients.
authors.affiliation: Division of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Geva
authors.affiliation: Division of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: H
authors.initials: H
authors.lastname: Davidovics
authors.affiliation: Division of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Soyfer
authors.affiliation: Division of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Pelles-Avraham
authors.affiliation: Division of Surgery, Tel Aviv Sourasky Medical Center, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: J M
authors.initials: JM
authors.lastname: Klausner
authors.affiliation: Division of Oncology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Inbar
authors.affiliation: Division of Surgery, Tel Aviv Sourasky Medical Center, affiliated to the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: H
authors.initials: H
authors.lastname: Tulchinsky
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D000368:Aged; D059248:Chemoradiotherapy; D015331:Cohort Studies; D016208:Databases, Factual; D013505:Digestive System Surgical Procedures; D005260:Female; D006801:Humans; D007902:Length of Stay; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D018365:Neoplasm, Residual; D061646:Operative Time; D011183:Postoperative Complications / Q000453:epidemiology; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology / Q000628:therapy*; D012007:Rectum / Q000601:surgery*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
keywords: Rectal cancer; neoadjuvant; pathological complete response; residual microscopic disease