Oral Presentation Annual Meetings of the Endocrine Society of Australia and Society for Reproductive Biology and Australia and New Zealand Bone and Mineral Society 2016

Associations of testosterone, dihydrotestosterone and estradiol with prostate, colorectal and lung cancer in older men (#115)

Yi Xian Chan 1 2 , Helman Alfonso 3 , S. A. Paul Chubb 2 4 , Graeme Hankey 2 5 , Leon Flicker 2 6 , Bu Yeap 1 2
  1. Department of Endocrinology and Diabetes, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
  2. School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia
  3. School of Public Health, Department of Epidemiology and Biostatistics, Curtin University, Perth, Western Australia, Australia
  4. Pathwest Laboratory Medicine, Fiona Stanley Hospital, Perth, Western Australia, Australia
  5. Department of Neurology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
  6. Western Australian Centre for Health and Ageing, Centre for Medical Research, University of Western Australia, Perth, Western Australia, Australia

Context

Sex hormones have been implicated in the development of several cancer types, however few studies have assessed the associations of sex hormones with the incidence of common cancers.

 

Objectives

To assess associations of testosterone (T) and its metabolites dihydrotestosterone (DHT) and estradiol (E2), with the incidence of prostate, colorectal and lung cancer in community-dwelling men aged ≥70 years.

 

Methods and participants 

T, DHT and E2 were assayed using liquid chromatography-mass spectrometry between 2001-2004 in 4248 men. Outcomes until 20th June 2013 were ascertained using electronic linkage. Analyses were performed using competing-risks models, and adjustments were made for potential confounding factors. Results are expressed as subhazard ratios (SHR).

 

Results

After exclusions, 3690 men were included in the analysis. There were 348, 137 and 107 cases of prostate, colorectal and lung cancers respectively. In the fully-adjusted analyses, T was not associated with the incidence of prostate cancer (SHR=1.00, 95% CI 0.90-1.12; p=0.939 per 1 SD increase in T). Similarly, no significant associations of free T, DHT and E2 were observed with prostate cancer incidence. Sex hormones were not associated with colorectal cancer incidence, however higher DHT was associated with an increased incidence of lung cancer (adjusted SHR=1.25, 95% CI 1.03-1.51; p=0.023 per 1 SD increase in DHT). When hormone parameters were assessed in quartiles, total and free T in the highest quartile were associated with an increased incidence of lung cancer compared to the rest of the quartiles (adjusted SHR=1.84, 95% CI 1.22-2.80; p=0.004 for total T; and adjusted SHR=1.85, 95% CI 1.19-2.88; p=0.006 for free T).

 

Conclusions

Sex hormones are not associated with incident prostate and colorectal cancer in older men. Higher T and DHT are independently associated with an increased incidence of lung cancer. Further studies warranted to investigate if a causal relationship exists.