title: Prognostic impact of synchronous second primary malignancies on the overall survival of patients with metastatic prostate cancer.
abstract: OBJECTIVE
  We determined the prognostic impact of a synchronous second primary malignancy on overall survival in patients with metastatic prostate cancer. Identifying features that stratify the risk of overall survival is critical for judiciously applying definitive therapy.
  
  
  METHODS
  We retrospectively analyzed the records of 582 consecutive patients with prostate cancer diagnosed with metastasis between May 7, 1998 and August 27, 2011. Patient age, body mass index, ECOG performance status, Charlson comorbidity index, prostate specific antigen, T and N stages, Gleason and ASA® scores, progression to castration resistant prostate cancer, prior local treatments and synchronous second primary malignancies at metastasis were assessed. A synchronous second primary malignancy was defined as a cytologically or histologically proven solid malignancy. Cox proportional hazards regression analysis was done to estimate overall survival by second primary type and evaluate predictive variables.
  
  
  RESULTS
  A total of 164 patients (28.1%) had a synchronous second primary malignancy, of which colorectal (9.1%), stomach (7.3%) and lung (7.1%) cancers were the most prevalent types. During a median followup of 34.1 months patients without a synchronous second primary malignancy had a significantly higher overall survival rate than those with lung or stomach cancer. However, men without a second malignancy had outcomes comparable to those in men with colorectal cancer. Clinical stage T4 or greater, ASA score 1 or greater and lung or stomach cancer were independent predictors of overall mortality.
  
  
  CONCLUSIONS
  A substantial proportion of patients with metastatic prostate cancer present with a synchronous second primary malignancy. Definitive therapy targeting prostate cancer may confer a limited survival benefit in patients with synchronous lung or stomach cancer.
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyo Chul
authors.initials: KC
authors.lastname: Koo
authors.affiliation: Biostatistics Collaboration Laboratory, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hanna
authors.initials: H
authors.lastname: Yoo
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Ki Hong
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sang Un
authors.initials: SU
authors.lastname: Park
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Kyung Seok
authors.initials: KS
authors.lastname: Han
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Koon Ho
authors.initials: KH
authors.lastname: Rha
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung Joon
authors.initials: SJ
authors.lastname: Hong
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Choul
authors.initials: SC
authors.lastname: Yang
authors.affiliation: Department of Urology, Urological Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: chung646@yuhs.ac.
authors.forename: Byung Ha
authors.initials: BH
authors.lastname: Chung
mesh_terms: D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis; D016609:Neoplasms, Second Primary / Q000401:mortality*; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000401:mortality* / Q000473:pathology*; D012189:Retrospective Studies; D012306:Risk; D015996:Survival Rate
keywords: mortality; multiple primary; neoplasm metastasis; neoplasms; prognosis; prostatic neoplasms