Obesity suppresses tumor attributable PSA, affecting risk categorization

Body mass weighted prostate-specific antigen levels, new markers to predict locally advanced prostate cancer after prostatectomy

BACKGROUND

Prostate-specific antigen (PSA) remains the most useful marker for screening, risk categorization, and follow-up in patients with prostate cancer. In the obese population, several studies have revealed that obesity may not only inversely interfere with the concentration of PSA, but also increase the risk of prostate cancer. Thus, we considered using the body mass weighted PSA levels, presented as serum PSA concentration multiplied by body weight or body mass index (BMI), instead of traditional PSA concentration, as potential markers to predict locally advanced prostate cancer after prostatectomy.

METHODS

We retrospectively collected and analyzed data acquired from a single institute at which robot-assisted laparoscopic radical prostatectomy was performed. A total of 174 patients underwent radical prostatectomy, and the collected data included age, PSA level, body weight, BMI, and pathology results.

RESULTS

A total of 174 patients were diagnosed with adenocarcinoma of the prostate by needle biopsy, and most (N = 165) were considered to have localized disease on preoperative multiparameter magnetic resonance imaging. After prostatectomy, 73% (N = 127) of the patients remained in the localized disease group (group A) and 27% (N = 47) of the patients were reclassified to the locally advanced prostate cancer (group B). The value of PSA was higher in group B (16.9 vs 11.2 ng/dL; p = 0.062), but there was no statistically significant difference between the two groups. After using the numerical values of PSA × body weight and PSA × BMI, a statistically significant difference emerged between the two groups ( p = 0.0198 in PSA × BW; p = 0.0110 in PSA × BMI).

CONCLUSION

The body mass-weighted PSA levels, instead of the traditional PSA concentration, may be better markers for predicting non-organ-confined disease after surgery. It may also be useful in screening and risk categorization.

Ductal variant prostate carcinoma is associated with a significantly shorter metastasis-free survival

BACKGROUND

Ductal adenocarcinoma is an uncommon prostate cancer variant. Previous studies suggest that ductal variant histology may be associated with worse clinical outcomes, but these are difficult to interpret. To address this, we performed an international, multi-institutional study to describe the characteristics of ductal adenocarcinoma, particularly focussing on the effect of presence of ductal variant cancer on metastasis-free survival.

METHODS

Patients with ductal variant histology from two institutional databases who underwent radical prostatectomies were identified and compared with an independent acinar adenocarcinoma cohort. After propensity score matching, the effect of the presence of ductal adenocarcinoma on time to biochemical recurrence, initiation of salvage therapy and the development of metastatic disease was determined. Deep whole-exome sequencing was performed for selected cases (n = 8).

RESULTS

A total of 202 ductal adenocarcinoma and 2037 acinar adenocarcinoma cases were analysed. Survival analysis after matching demonstrated that patients with ductal variant histology had shorter salvage-free survival (8.1 versus 22.0 months, p = 0.03) and metastasis-free survival (6.7 versus 78.6 months, p < 0.0001). Ductal variant histology was consistently associated with RB1 loss, as well as copy number gains in TAP1, SLC4A2 and EHHADH.

CONCLUSIONS

The presence of any ductal variant adenocarcinoma at the time of prostatectomy portends a worse clinical outcome than pure acinar cancers, with significantly shorter times to initiation of salvage therapies and the onset of metastatic disease. These features appear to be driven by uncoupling of chromosomal duplication from cell division, resulting in widespread copy number aberration with specific gain of genes implicated in treatment resistance.

Short-term effects of surgical weight loss after sleeve gastrectomy on sex steroids plasma levels and PSA concentration in men with severe obesity

Male obesity is known to be associated with hypogonadism, which can be reverted after surgical weight reduction. However, the evidence about how rapidly this effect rises after surgery and what consequences each procedure have on prostate function and prostatic-specific antigen (PSA) concentration is scarce. So, we evaluated total testosterone, estradiol, luteinizing hormone, follicle-stimulating hormone and PSA plasma levels in a group of 29 Caucasian obese men (BMI - 43.4 ± 8.5 kg/m²) before and one month after sleeve gastrectomy. 19 lean healthy male subjects were considered as controls. As expected, obese patients showed a high prevalence of hypogonadism (51.6%) at baseline, with reduced total testosterone compared to lean controls (10.8 ± 3.5 vs 15.7 ± 4.2 nmol/l, p < .01), higher estradiol (124.4 ± 46.5 vs 78.7 ± 39.6 pmol/l, p < .01), lower luteinizing hormone and follicle stimulating hormone (3.6 ± 1.3 and 2.5 ± 0.9 vs 5.2 ± 2.4 and 5.9 ± 3.8 U/L, respectively, p < .05) plasma levels. One month after surgery, patients showed a significant body weight reduction (-17.2 ± 6.7 kg) with increased total testosterone (from 10.8 ± 3.5 to 18.9 ± 4.9 nmol/l, p < .001), reduced estradiol (from 124.4 ± 46.5 to 96.1 ± 34.3 pmol/l, p < .05) and increased PSA (from 0.74 ± 0.38 to 1.0 ± 0.51 μg/l, p < .001). These results confirm that hypogonadism is highly prevalent in obese males, but they also show that it can be early reversed after sleeve gastrectomy, further confirming the strong indication to surgery of hypogonadal patients with severely reduced quality of life. Higher testosterone levels may be responsible for the increase of PSA observed after surgery; however, PSA concentration has to be monitored over time to avoid underrating of potential severe prostate diseases.

Oxidised low-density lipoprotein, a possible distinguishing lipid profile biomolecule between prostate cancer and benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) share common conditions such as lower urinary tract symptoms (LUTS) and dyslipidaemia. Whether an extensive lipid profile analysis could discriminate between BPH and PCa was the objective. Thirty-six (36) BPH and twenty (20) PCa outpatients of a urology clinic plus forty (40) controls without LUTS, but normal PSA, were recruited. Body mass index (BMI), lipid profile (total cholesterol [CHOL], triglycerides [TG], high-density lipoprotein [HDL], very-low-density lipoprotein [VLDL], low-density lipoprotein [LDL] and Castelli's risk index I [CR I] [TC/HDL]), oxidised LDL, apolipoprotein E, ceramide and PSA were determined. Mean ages for BPH, PCa and control were 69 ± 13, 67 ± 10 and 53 ± 7 years respectively. Most parameters apart from BMI and HDL were significantly different compared to the control group. oxLDL for BPH versus control, PCa versus control and BPH versus PCa was significant (p < 0.001, p = 0.02 and p < 0.001 respectively). Ceramide showed significant group differences. Between BPH and PCa, total cholesterol, LDL and Apo E were significantly different (p = 0.00, p = 0.01 and p = 0.03 respectively). Apo E could potentially be a discriminating biomarker. Receiver operating characteristic curves for TPSA, Apo E and oxLDL demonstrated sensitivity of 69.44 and specificity of 88.24 for oxLDL, hence more discriminatory.

Androgen deprivation therapy promotes an obesity-like microenvironment in periprostatic fat

Prostate cancer is a leading cause of morbidity and cancer-related death worldwide. Androgen deprivation therapy (ADT) is the cornerstone of management for advanced disease. The use of these therapies is associated with multiple side effects, including metabolic syndrome and truncal obesity. At the same time, obesity has been associated with both prostate cancer development and disease progression, linked to its effects on chronic inflammation at a tissue level. The connection between ADT, obesity, inflammation and prostate cancer progression is well established in clinical settings; however, an understanding of the changes in adipose tissue at the molecular level induced by castration therapies is missing. Here, we investigated the transcriptional changes in periprostatic fat tissue induced by profound ADT in a group of patients with high-risk tumours compared to a matching untreated cohort. We find that the deprivation of androgen is associated with a pro-inflammatory and obesity-like adipose tissue microenvironment. This study suggests that the beneficial effect of therapies based on androgen deprivation may be partially counteracted by metabolic and inflammatory side effects in the adipose tissue surrounding the prostate.