Body Mass Index, Weight Change, and Risk of Prostate Cancer in the Cancer Prevention Study II Nutrition Cohort

Abstract

Background: Obesity has been associated with aggressive prostate cancer. The extent of this association, which varies by stage and grade, remains unclear. The role of recent weight change had not been previously examined. Methods: We examined body mass index (BMI) and weight change in relation to incident prostate cancer by disease stage and grade at diagnosis among 69,991 men in the Cancer Prevention Study II Nutrition Cohort. Participants provided information on height and weight in 1982, and again at enrollment in 1992. During follow-up through June 30, 2003 (excluding the first 2 years of follow-up), we documented 5,252 incident prostate cancers. Cox proportional hazards models were used to estimate rate ratios (RR) and 95% confidence intervals (95% CI).

Preoperative weight change and risk of adverse outcome following radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital database

“…3,[5][6][7][8][9] Previous studies also found an association between weight loss and decreased risk of developing high-grade PC, and an association between weight gain and BCR risk and PC mortality, 3,4,10 though in these studies, weight change was evaluated over many years. One study found perioperative weight gain is associated with increased recurrence vs men with stable weights.…”

“…3,13 However, unlike another previous study that found long-term weight loss was associated with decreased risk of developing highgrade disease, we only found a marginal protective effect against positive margins in our population. 10 Differences in study designs (that is, population-based prospective cohort vs case-only RP cohort), methods of ascertaining and defining weight change, and the end point (diagnosis of high-grade disease vs recurrence after RP) make direct comparisons of the studies difficult.…”

“…In a prospective cohort of 86 404 men asked their weight in 1982 and in 1992 and followed for cancer development after 1992, men losing X11 pounds in the decade before 1992 were significantly less likely to develop high-grade PC vs men of stable weight. 10 In animals, caloric restriction (that is, weight loss) inhibits PC growth and improves survival. 11,12 Hypoth-eses for this effect include increased apoptosis and decreased insulin-like growth factor-I (IGF-I) levels.…”

Association between prostate-specific antigen and leptin, adiponectin, HbA1c or C-peptide among African-American and Caucasian men

“…This may be contributing to previously reported protective associations between prostate cancer and obesity or weight change. [28][29][30] It may be possible that insulinrelated PSA suppression is causing a delay in referral for diagnostic biopsy and lending the appearance of a protective association between obesity and prostate cancer. Alternatively, a delay in detecting prostate cancer may lead to an association between obesity and advanced-stage prostate cancer.…”

“…19,20 However, several studies report no evidence of an association, [21][22][23][24][25][26][27] while others report that BMI is associated with reduced risk of prostate cancer, particularly low-grade tumors. [28][29][30] Finally, there is evidence that prostate cancer risk changes with time following a diabetes diagnosis, from an increased risk proximal to the diabetes diagnosis to a reduction in risk, 31,32 perhaps related to diabetes treatment, disease progression or changes in prostate cancer screening practices with time following a diabetes diagnosis. 33,34 Any association between obesity and the clinical procedures used to screen or detect prostate cancer may contribute to inconsistent results across different study populations or over time.…”