title: Radiation-induced second malignancies.
abstract: BACKGROUND
  The number of patients with second malignancies is growing and they represent about one in six out of all new cancers. Second malignancies can be categorized into three major groups according to the predominant etiological factor(s): (i) treatment-related, (ii) part of a syndrome and (iii) those due to shared etiologic exposures.
  
  
  METHODS
  This article focuses on radiation-induced malignancies with illustrative cases of thyroid, rectal cancer and sarcoma.
  
  
  RESULTS
  The detection and management of radiation-induced malignancies of some case scenarios are presented. Second malignancies are detected within previous radiation field and the time intervals from previous tumor vary from 8 to 21 years.
  
  
  CONCLUSIONS
  Clinicians should aim to reduce radiation-induced malignancies by careful selection of patients and radiation techniques before radiotherapy. Subsequent vigilant follow-up and investigations can detect these radiation-induced malignancies early and, hence, result in successful treatment.
authors: Radiation Oncology Department, Allan Blair Cancer Center, Regina, SK, Canada.
authors: Shazia
authors: S
authors: Mahmood
authors: Radiation Oncology Department, Allan Blair Cancer Center, Regina, SK, Canada.
authors: Khanh
authors: K
authors: Vu
authors: Radiation Oncology Department, Allan Blair Cancer Center, Regina, SK, Canada patricia.tai@saskcancer.ca.
authors: Patricia
authors: P
authors: Tai
authors: Radiation Oncology Department, Cross Cancer Institute, Edmonton, AB, Canada.
authors: Kurian
authors: K
authors: Joseph
authors: Radiation Oncology Program, Winnipeg, MB, Canada.
authors: Rashmi
authors: R
authors: Koul
authors: Radiation Oncology Program, Winnipeg, MB, Canada.
authors: Arbind
authors: A
authors: Dubey
authors: University of Western Ontario, Radiation Oncology Department, London Health Science Center, London, ON, Canada.
authors: Edward
authors: E
authors: Yu
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000532:radiotherapy*; D000293:Adolescent; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy; D005260:Female; D006689:Hodgkin Disease / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy; D011878:Radiotherapy / Q000009:adverse effects*
keywords: Radiation-induced; re-irradiation; review; second malignancies