title: Delayed versus immediate surgery following short-course neoadjuvant radiotherapy in resectable (T3N0/N+) rectal cancer.
abstract: OBJECTIVE
  Preoperative short-course radiotherapy (SCRT) followed by surgery has shown advantage over surgery alone in patients with resectable rectal carcinoma (RC); however, the importance of the timing of surgery after SCRT has not been well defined. This study aimed to investigate the effect of this duration on treatment outcomes.
  
  
  METHODS
  Patients who underwent surgery after SCRT (25 Gy/500 cGy/daily/5fr, monday-friday) for resectable and infraperitoneal rectal adenocarcinoma (T3N0/(+)) were included into the study. Patients were divided into two groups in terms of the timing of surgery: delayed surgery (>4 weeks) or immediate surgery (<4 weeks).
  
  
  RESULTS
  A hundred and thirty-six patients were included in the study. Median time between RT and surgery was 4 ± 5.7 (1-58) weeks, where 68% (n = 93) patients underwent delayed surgery (≥4 weeks). The two groups did not differ in terms of surgical margin positivity, pathological tumor regression, N downstaging, or T downstaging (p > 0.05 for all). However, the number of positive lymph nodes was higher in the immediate surgery group [median 3 (0-18) vs. 1 (0-17), p = 0.009]. Median follow-up time was 36 ± 9 (6-93) months. Delayed surgery group had significantly longer mean overall survival (p = 0.038); however, the two groups did not differ in terms of local recurrence, mean time to local recurrence, or mean disease-free survival.
  
  
  CONCLUSIONS
  Our findings seem to support the benefit of a longer time interval between radiotherapy and surgery after short-course neoadjuvant radiotherapy in resectable rectal cancer in terms of overall survival. However, there is a need to better define patient characteristics that might benefit from delayed surgery.
authors.affiliation: Department of Radiation Oncology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Esra
authors.initials: E
authors.lastname: Kaytan-Saglam
authors.affiliation: Department of General Surgery, Koc University School of Medicine, Istanbul, Turkey.
authors.forename: Emre
authors.initials: E
authors.lastname: Balik
authors.affiliation: Department of Medical Oncology, Istanbul Bilim University, 34349, Istanbul, Turkey. saglam@istanbul.edu.tr.
authors.forename: Sezer
authors.identifier: http://orcid.org/0000-0001-8954-5792
authors.initials: S
authors.lastname: Saglam
authors.affiliation: Department of Radiation Oncology, Memorial Sisli Hospital, Istanbul, Turkey.
authors.forename: Züleyha
authors.initials: Z
authors.lastname: Akgün
authors.affiliation: Department of Radiation Oncology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Kamuran
authors.initials: K
authors.lastname: Ibis
authors.affiliation: Department of General Surgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Metin
authors.initials: M
authors.lastname: Keskin
authors.affiliation: Department of Radiation Oncology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Nergis
authors.initials: N
authors.lastname: Dagoglu
authors.affiliation: Department of Pathology, Koc University School of Medicine, Istanbul, Turkey.
authors.forename: Yersu
authors.initials: Y
authors.lastname: Kapran
authors.affiliation: Department of Pathology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
authors.forename: Mine
authors.initials: M
authors.lastname: Gulluoglu
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Delayed surgery; Immediate surgery; Rectal cancer; Short-course neoadjuvant radiotherapy