title: Multiple primary malignancies in patients with prostate cancer: increased risk of secondary malignancies after radiotherapy.
abstract: BACKGROUND
  New treatment strategies for prostate cancer have recently been developed, but multiple malignancies remain a major concern. The aim of this study was to evaluate the characteristics of multiple malignancies and to analyze the risk of secondary malignancies after radiotherapy for prostate cancer.
  
  
  METHODS
  From 2000 to 2011, 150 patients with prostate cancer were treated with curative radiotherapy in our department. Patient age range was 54-92 years (median, 70 years), and the follow-up period was 4-142 months (median, 48 months). The incidence of multiple primary cancers was compared with the estimated incidence.
  
  
  RESULTS
  A total of 147 patients (98 %) survived more than 12 months (12-142 months; median, 48 months); 20/150 patients (13 %) died within 10 years. Cause of death was recurrent prostate cancer in 11 patients, other primary malignancies in 7 patients, and cardiovascular disease in 2 patients. Multiple primary cancers were present in 26 of 150 patients (17 %), including 16 subsequent malignancies (11 %) with latent periods of 13-83 months (median, 43 months). The subsequent non-prostate malignancies were lung cancer in 4 patients, urinary bladder or ureter cancer in 4, stomach cancer in 3, malignant lymphoma in 2, and other in 3. Analysis of the observed incidence of secondary malignancies compared with the estimated incidence in the general population revealed a higher incidence of ureter cancer and malignant lymphoma.
  
  
  CONCLUSIONS
  Close attention should be paid to secondary malignancies after radiotherapy for prostate cancer, including malignancies occurring within 5 years, which could be attributable to radiotherapy.
authors.affiliation: Department of Radiology, Nara Hospital, Kinki University, 1248-1 Otoda, Ikoma, 630-0293, Japan, okajima@nara.med.kindai.ac.jp.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Okajima
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Matsuura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tatebe
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Keiji
authors.initials: K
authors.lastname: Hiroi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Nishimura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000532:radiotherapy; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000473:pathology* / Q000532:radiotherapy; D009381:Neoplasms, Radiation-Induced / Q000473:pathology*; D016609:Neoplasms, Second Primary / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000532:radiotherapy; D011878:Radiotherapy / Q000009:adverse effects; D012307:Risk Factors