Incidence of second malignancies for prostate cancer

PLoS One. 2014 Jul 21;9(7):e102596. doi: 10.1371/journal.pone.0102596. eCollection 2014.

Abstract

Introduction: There is a need to assess risk of second primary cancers in prostate cancer (PCa) patients, especially since PCa treatment may be associated with increased risk of second primary tumours.

Methods: We calculated standardized incidence ratios (SIRs) for second primary tumours comparing men diagnosed with PCa between 1980 and 2010 in the Canton of Zurich, Switzerland (n = 20,559), and the general male population in the Canton.

Results: A total of 1,718 men developed a second primary tumour after PCa diagnosis, with lung and colon cancer being the most common (15 and 13% respectively). The SIR for overall second primary cancer was 1.11 (95%CI: 1.06-1.17). Site-specific SIRs varied from 1.19 (1.05-1.34) to 2.89 (2.62-4.77) for lung and thyroid cancer, respectively. When stratified by treatment, the highest SIR was observed for thyroid cancer (3.57 (1.30-7.76)) when undergoing surgery, whereas liver cancer was common when treated with radiotherapy (3.21 (1.54-5.90)) and kidney bladder was most prevalent for those on hormonal treatment (3.15 (1.93-4.87)). Stratification by time since PCa diagnosis showed a lower risk of cancer for men with PCa compared to the general population for the first four years, but then a steep increase in risk was observed.

Conclusion: In the Canton of Zurich, there was an increased risk of second primary cancers among men with PCa compared to the general population. Increased diagnostic activity after PCa diagnosis may partly explain increased risks within the first years of diagnosis, but time-stratified analyses indicated that increased risks remained and even increased over time.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Colonic Neoplasms / diagnosis
  • Colonic Neoplasms / epidemiology
  • Colonic Neoplasms / secondary
  • Humans
  • Incidence
  • Lung Neoplasms / diagnosis
  • Lung Neoplasms / epidemiology
  • Lung Neoplasms / secondary
  • Male
  • Middle Aged
  • Neoplasms, Second Primary / diagnosis
  • Neoplasms, Second Primary / epidemiology*
  • Prostate / pathology*
  • Prostatic Neoplasms / diagnosis
  • Prostatic Neoplasms / epidemiology*
  • Switzerland / epidemiology

Grant support

The authors have no support or funding to report.