Body mass index as a classifier to predict biochemical recurrence after radical prostatectomy in patients with lower prostate-specific antigen levels

Obesity and biochemical recurrence in clinically localised prostate cancer: a systematic review and meta-analysis of 86,490 patients

BACKGROUND

The association of obesity with biochemical recurrence (BCR) after treatment of clinically localised prostate cancer (PC) shows inconsistent results. Our aim was to systematically review all evidence evaluating obesity as a prognostic factor for BCR.

METHODS

We searched PubMed, Web of Science and Scopus, from inception to June 1, 2021. Cohort studies reporting BCR among PC patients stratified by body mass index (BMI) were included. To assess the quality of the selected studies, we used the Newcastle-Ottawa scale (NOS). Risk of BCR among obese patients (BMI ≥ 30 kg/m²) was compared with normal weight (BMI < 25), pooling individual hazard ratios (HR) in random-effect meta-analysis. Associations for continuous BMI per 5 kg/m² were also calculated. Subgroup analyses were conducted to assess reasons for heterogeneity and causal criteria were formally evaluated.

RESULTS

We identified 46 cohort studies including 86,490 PC patients. A total of 14,719 (17.1%) patients developed BCR. There was no consistent definition of BCR. Obesity was associated with BCR (HR: 1.25, 95% CI: 1.11-1.39, I²: 70.3%), and there was a 10% increase (95% CI: 4-15%, I²: 66.3%) in BCR per 5 kg/m² increase in BMI. The heterogeneity was high but decreased in the subgroup of highest-quality NOS score and when the BMI was measured by the researchers (I²: 0.0%). The association was consistent in patients receiving radical prostatectomy but not in patients receiving other therapies.

CONCLUSIONS

Obesity showed a moderate, consistent relationship with biochemical recurrence after radical prostatectomy. Measurement of BMI and BCR was variable, highlighting the need for standardised clinical guidelines. Preventive weight control programs may have a role in reducing BCR for clinically localised PC patients.

Effect of obesity on the prognosis and recurrence of prostate cancer after radical prostatectomy: a meta-analysis

Background

Obesity has been found to be closely related to the increased risk of fatal prostate cancer (PCa), however there remains no evidence that further clarifies the relationship between obesity and the postoperative recurrence and poor prognosis of PCa. In this study, a systematic review and meta-analysis were performed to systematically evaluate the effect of obesity on the prognosis and recurrence of PCa after radical prostatectomy (RP).

Methods

A literature search of the PubMed, Web of Science, and Embase databases was performed covering articles published between January 2013 and January 2020. Articles regarding the correlation between body mass index (BMI) and the prognosis and recurrence of PCa following RP were included in the meta-analysis. Two investigators independently screened the literature and extracted relevant data including publication information, key results, number of cancer cases, and multivariable-adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Meta-analysis was performed using RevMan 5.3 and Stata 16.0 software, and forest plots, funnel plots, and sensitivity analysis were also conducted.

Results

A total of 14 articles were included, all of which were analyzed for clinicopathological characteristics. Eight articles reported the biochemical recurrence (BCR) with prostate-specific antigen (PSA) as the predictor, and six articles reported the positive surgical margins (PSM). The meta-analysis showed that obese PCa patients had more postoperative recurrence and poor prognosis compared with the normal weight PCa patients, and the difference was statistically significant (OR =1.25, 95% CI: 1.10, 1.43). BCR exhibited no significant difference between obese and non-obese PCa patients after surgery (OR =1.2, 95% CI: 0.96, 1.46), and there were also no notable differences in PSM between the groups (OR =1.16, 95% CI: 0.99, 1.36). Subgroup analysis showed that obese PCa patients in the Americas (95% CI: 1.11, 1.37) and Europe (95% CI: 1.11, 1.78) were more likely to have surgical recurrence and poor prognosis (OR =1.40). Obese patients in the Americas were also more likely to have BCR after surgery (95% CI: 1.07, 1.36).

Conclusions

Obesity easily leads to poor prognosis and recurrence of PCa after RP.

The influence of nutritional factors on prostate cancer incidence and aggressiveness

There is an increasing evidence for a link between nutrition, lifestyle and prostate cancer (PCa) development and/or progression of disease. The objective of this study was to examine the association between dietary factors and PCa incidence and aggressiveness in a case-control study. After the analysis of the anatomic pathology, subjects were classified in patients with PCa (n = 157) and controls (n = 158). Clinical data including Gleason score, PSA values and biopsy results, were compiled. Frequencies of food consumption and sociodemographic data were also obtained. The results showed that physical activity was significantly higher in control (p < .022). It was also found that some nutritional habits offer a protective effect among studied subjects, like high nuts (p = .041) and fish (p = .041) intakes. Moreover, there was a significant reduction in risk (p = .029) in cases with a higher fruits and vegetables intakes. A decreased risk of aggressive PCa was associated with fruits, vegetables, legumes and fish intakes. However, these relationships were not statistically significant when data were adjusted for covariates. In conclusion, this study found an inverse association between PCa risk and the intake of fruits and vegetables, fish and nuts. The results suggested that a diet with higher intakes of these foods as Mediterranean diet may lower the risk of PCa in the studied population. As dietary factors are modifiable, identifying food groups or dietary patterns that modulate the risk of PCa and its aggressiveness can offer effective and practical strategies for its primary prevention.