Association between life-course leisure-time physical activity and prostate cancer

Differential association between dairy intake patterns and incident prostate cancer: a potential dairy matrix effect

OBJECTIVE

To evaluate the association between dairy intake patterns and the risk of prostate cancer (PC), and its histological differentiation, among men from Mexico City.

METHODS

We analyzed the information from 394 incident PC cases paired by age (± 5 years) with 794 population controls. According to the Gleason score at diagnosis, cases were classified as well- (≤ 6), moderately- (= 7), and poorly differentiated PC (≥ 8). Based on a semiquantitative-food frequency questionnaire and using energy-density approach, we estimated the energy-adjusted daily intake of whole milk, cheese (fresh, Oaxaca, and Manchego), cream, and yogurt. Through a principal component analysis, we identified three dairy intake patterns: whole milk, cheese, and yogurt. The association between each dairy intake pattern and PC was evaluated from independent nonconditional logistic regression models. We also evaluated the mediator role of calcium and saturated fat intake.

RESULTS

After adjustment, a high intake of whole milk pattern was associated with a 63% increased risk of PC (ORhigh vs low: 1.63; 95% CI 1.17-2.25, p trend = 0.002); at expenses of moderately (ORhigh vs low: 1.77; 95% CI 1.09-2.85, p trend = 0.015) and poorly differentiated PC (ORhigh vs low: 1.75; 95% CI 1.05- 2.92, p trend = 0.031). The association was mainly mediated by calcium intake (proportion mediated = 1.17; p < 0.01). No associations were found between cream and yogurt intake patterns with risk of PC, and its histological grade.

CONCLUSIONS

A differential association of dairy intake patterns with risk of PC, and the poorly differentiated PC, was identified. This association seems to be determined by different dairy matrices and it is mediated by calcium content. Longitudinal studies are needed to confirm these findings and be able to identify other potential mediators in the etiology of PC.

Late puberty onset and lack of acne during adolescence reduce high-grade prostate cancer at adulthood

BACKGROUND

The interplay between pubertal events patterns (PEP) and prostate cancer (PCa) remains poorly understood. Therefore, we investigated the association of PEP with the odds of PCa, and PCa histological differentiation in men residents of Mexico city.

METHODS

In this case-control study, we analyzed the information of 371 incident prostate cancer cases and 775 controls matched on age (±5 years). High-grade prostate cancer was classified with Gleason score at diagnosis as ≥8. With information related to beard growth, age at maximum height attainment, and acne severity, the k-medoids algorithm was used to identify three mutually exclusive PEP (early, intermediate, and late). This association was evaluated using multivariable nonconditional logistic regression models.

RESULTS

Men with late PEP, characterized by age at maximum height attainment at around 23 years and no history of acne, was inversely associated with incident (odds ratio [OR]: 0.27; 95% confidence interval [CI]: 0.15-0.48, p trend <0.01) and high-grade prostate cancer (OR: 0.24; 95% CI: 0.09-0.59, p trend <0.01). Similar associations were observed even after adjusting by IGF-1 (OR: 0.19; 95% CI: 0.06-0.58) and androgens excretion (OR: 0.21; 95% CI: 0.06-0.66). Only the association between the absence of acne and prostate cancer remained significant after adjustment by these biomarkers.

CONCLUSIONS

This study suggests that pubertal characteristics might be helpful in identifying risk groups, among which, secondary prevention strategies could be applied. Also, the results agree with previous work suggesting other potential biological mechanisms involved in the etiology of prostate cancer such as the infectious and inflammatory pathways.