Vitamin D, PTH, and calcium in relation to survival following prostate cancer

Research output: Contribution to journalArticle

Abstract

PURPOSE: Epidemiological studies suggest that low levels of vitamin D constitute a risk factor for prostate cancer. However, the results are conflicting, perhaps because prostate cancer is a very heterogeneous disease. More recent studies have focused on cancer progression and mortality. Vitamin D is closely related to both calcium metabolism and parathyroid hormone (PTH) levels, and all three factors have been implicated in prostate cancer.

METHODS: We examined the associations between pre-diagnostic serum levels of vitamin D (25OHD), PTH, and calcium and mortality among 943 participants within the Malmö Diet and Cancer Study, who were diagnosed with prostate cancer. The mean time from diagnosis until the end of followup was 9.1 years (SD 4.5), and the mean time from inclusion until end of follow-up was 16.6 years (SD 4.9). The analytes were divided into quartiles, and the risk of death from prostate cancer was analyzed using Cox proportional hazard analysis, yielding hazards ratios (HR) with 95 % confidence intervals. The models were adjusted for season and year of inclusion, age at baseline, age at diagnosis, body mass index (BMI), and tumor characteristics (TNM and Gleason score).

RESULTS: We observed a trend toward a lower prostate-specific mortality with 25OHD >85 nmol/L in the unadjusted analysis. This became statistically significantly in the third quartile of 25OHD (85-102 nmol/L) compared to the first (<68 nmol/L), HR 0.54 (0.34-0.85) when adjusting for age, time of inclusion, and BMI. The association was further strengthened when adjusted for age at diagnosis, Gleason score, and TNM classification with a HR in Q3 0.36 (0.22-0.60). p for trend was 0.03. Regarding calcium, there was a significantly lower HR for the second quartile (2.35-2.39 mmol/L) compared to the first (≤2.34 mmol/L) with a HR of 0.54 (0.32-0.86) in the unadjusted analysis. However, this association disappeared when adjusting for tumor characteristics. There were no associations between levels of PTH and prostate cancer mortality.

CONCLUSION: This study shows that levels of pre-diagnostic vitamin D above 85 nmol/L may improve survival in men with prostate cancer.

Details

Authors
Organisations
External organisations
  • Skåne University Hospital
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology
Original languageEnglish
Pages (from-to)669-677
JournalCancer Causes and Control
Volume27
Issue number5
Early online date2016 Mar 29
Publication statusPublished - 2016 May
Publication categoryResearch
Peer-reviewedYes

Related research output

JOHAN BRÄNDSTEDT, 2016, Lund: Lund University: Faculty of Medicine. 64 p.

Research output: ThesisDoctoral Thesis (monograph)

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