Prospective studies of hormonal and life-style related factors and risk of cancer
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Background: Androgens are important in prostate cancer development but how circulating levels of androgens affect risk of prostate cancer of different aggressiveness is not clear. Being childless has been associated with a lower risk of prostate cancer, but it is not clear if this association is causal or a result of residual confounding. Fathering of dizygotic twins, a marker of high fertility, has not been studied in relation to risk of prostate cancer.
Another marker of life-long hormonal exposure is height, which has been associated with increased risk of cancer and cancer death. However, the association to separate cancer sites has not been consistent.
The aims of this thesis were to study hormonal factors (paper I), and proxies of hormonal factors (paper II and III), and risk of prostate cancer; as well as height and risk of cancer and cancer death by separate sites (paper IV).
Methods: Study designs were i) case-control studies, nested within the Västerbotten Intervention Project (paper I), and in Prostate Cancer database Sweden 2.0 (PCBaSe 2.0) (paper II and III), and ii) cohort study, in the Metabolic Syndrome and Cancer project (Me-Can) (paper IV).
Results, prostate cancer: In paper I, increasing levels of serum androgens were not associated with risk of prostate cancer overall or in tumor risk categories. In paper II, childless men had a lower risk of prostate cancer, overall and in all risk categories, compared to fathers, an association which was in part explained by differences in marital status and educational level. In paper III, fathers of dizygotic twins did not have an increased risk of prostate cancer, either overall or in risk categories, when compared to fathers of singletons.
Results, cancer overall: In paper IV, height was associated with an increased risk of cancer and cancer death overall in both women and men. The strongest association for cancer was to malignant melanoma in both women and men, and for cancer death to post-menopausal breast cancer in women and renal cell carcinoma in men.
Conclusions: These studies indicate that hormonal factors, when studied as serum levels or when studied using proxies of fertility, do not have a major impact on the risk of prostate cancer. The association between height and an increased risk of cancer appears robust for total cancer and cancer death, as well as for several separate cancer sites.
Place, publisher, year, edition, pages
Umeå: Umeå Universitet , 2014. , 76 p.
Umeå University medical dissertations, ISSN 0346-6612 ; 1648
prostate cancer, epidemiology, androgens, risk factors, fatherhood status, dizygotic twins, height, cohort, case-control, prospective
Urology and Nephrology Cancer and Oncology
Research subject Cancer Epidemiology
IdentifiersURN: urn:nbn:se:umu:diva-88308ISBN: 978-91-7601-029-7OAI: oai:DiVA.org:umu-88308DiVA: diva2:715361
2014-06-05, Bergasalen, Umeå Universitetssjukhus, byggnad 27, Umeå, 09:00 (Swedish)
Wolk, Alicja, Professor
Stattin, Pär, ProfessorJonsson, Håkan, DocentStocks, Tanja, Med dr
FunderSwedish Cancer Society, 11 0471Swedish Research Council, 825-2010-5950
List of papers