Update on outcomes research databases in prostate cancer 2006

Self-reported Prostate Cancer Progression Status Is Accurate: A Validation Study

BACKGROUND

Studies of prostate cancer progression are important for discovering risk factors that may increase the risk of prostate cancer-specific death; however, little is known about the validity of self-reported prostate cancer progression.

METHODS

We conducted a validation study of self-reported prostate cancer progression in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial and in a prostate cancer cohort enrolled in a Fred Hutchinson Cancer Research Center (FHCRC)-based study. We calculated measures of validity for self-reported progression, including sensitivity, specificity, positive predictive value, and negative predictive value using medical records as the gold standard.

RESULTS

Our results suggest that ascertaining prostate cancer progression-related events (i.e., prostate-specific antigen elevation, recurrence, metastasis, and use of secondary treatment) through self-report may be a viable option for identifying men whose disease has progressed after diagnosis or initial therapy, particularly when multiple questions related to progression are included in the assessment (aggregate cluster of questions: sensitivity = 0.76 [PLCO]; 0.93 [FHCRC], specificity = 0.80 [PLCO]; 0.97 [FHCRC]). With an aggregate positive predictive value of 0.50 (PLCO), however, our PLCO results suggest that additional medical record verification of self-reported progression events may be necessary to rule out false positives. Most individuals reporting no evidence of progression-related events, however, were true negatives (aggregate negative predictive value = 0.92 [PLCO]; 0.98 [FHCRC]). Thus, there may be limited utility to investing resources in chart review to confirm self-reported nonevents.

CONCLUSION

Ascertaining prostate cancer progression through self-report provides an efficient and valid approach to enhancing existing cancer cohorts with updated data on progression status. See video abstract at, http://links.lww.com/EDE/B658.

Vitamin K and its analogs: Potential avenues for prostate cancer management

Epidemiological studies have demonstrated a relationship between cancer incidence and dietary habits. Especially intake of certain essential nutrients like vitamins has been shown to be beneficial in experimental studies and some clinical trials. Vitamin K (VK) is an essential nutrient involved in the blood clotting cascade, and there are considerable experimental data demonstrating its potential anticancer activity in several cancer types including prostate cancer. Previous in vitro and in vivo studies have focused mainly on anti-oxidative effects as the underlying anticancer mechanism of VK. However, recent studies reveal that VK inhibits the growth of cancer cells through other mechanisms, including apoptosis, cell cycle arrest, autophagy, and modulation of various transcription factors such as Myc and Fos. In the present review, we focus on the anticancer effect of dietary VK and its analogs on prostate cancer, with an emphasis on the signaling pathways that are activated following exposure to these compounds. This review also highlights the potential of VK and its derivatives as an adjuvant treatment in combination with other vitamins or with chemotherapeutic drugs. Based on our recent results and a review of the existing literature, we present evidence that VK and its derivatives can potentially be explored as cancer therapy, especially for prostate cancer.

Perfil epidemiológico e fatores prognósticos no tratamento cirúrgico do adenocarcinoma de próstata clinicamente localizado

OBJETIVO: Avaliar a evolução e os fatores prognósticos da prostatectomia radical. MÉTODOS: Um total de 500 pacientes foi submetido à prostatectomia radical, entre 2000 e 2006. Estádio clínico, PSA pré-operatório e escore de Gleason foram avaliados em conjunto com o estádio patológico e margens cirúrgicas. O seguimento foi feito pela monitorização do PSA e correlação com diversos critérios. RESULTADOS: Dos 500 pacientes com doença clinicamente localizada tiveram seguimento médio de 36,7 ± 18,8 meses. O tempo operatório foi de 190 ± 45 minutos e o sangramento intra-operatório de 630 mL. O PSA pré-operatório médio foi de 7,8 ± 4,5 ng/dL, com maior proporção de escore de Gleason<6 (72%) e estádio TNM pT2c (65%). As complicações pós-operatórias foram incontinência em 2% pacientes e 46% com impotência sexual. CONCLUSÃO: A chance de recorrência esteve diretamente associada com PSA=10 ng/mL, escores de Gleason maiores e inversamente proporcionais à idade dos pacientes.

Correlations of dietary patterns with prostate health

Both genetic and environmental influences may be involved in etiology of prostate health and prostate cancer. These include ethnic origin, family history, smoking, and diet. Adiposity and excess energy intake are potentially distinct risk factors and positive associations with prostate cancer risk for both were observed among case-control and cohort studies. Some epidemiological studies support an association between dietary fat, particularly saturated or animal fats, and prostate cancer risk. Of these, several suggest reduced risk with low-fat diets high in n-3 fatty acids and increased risk with high-fat diets rich in n-6 fatty acids. Others suggested association with higher meat intake, possibly due to heterocyclic amines and polycyclic aromatic hydrocarbons, produced during grilling or frying. Positive association of prostate cancer risk with dairy intake could involve alpha-methylacyl-CoA racemase activity (required for beta-oxidation of phytanic acid present in dairy products and red meat) or the suppression of vitamin D activity by calcium. Inverse associations were observed with dietary intake of plant foods. These include cereals, soy products, and fruit and vegetable sources of carotenoids. Numerous plant constituents may act synergistically in the prevention and inhibition of prostate disorders. These diet-risk associations may lead to future individualized diet recommendations based upon genetic polymorphisms.

Body size and composition and prostate cancer risk: systematic review and meta-regression analysis

The evidence that measures of obesity and stature are associated with prostate cancer is weak and inconsistent. We performed a systematic review and meta-analysis of the relationship between body mass index (BMI), height, weight, waist circumference and waist-to-hips ratio (WHR) and the risk of prostate cancer. Study-specific dose-response slopes were obtained, and random effects rate ratios (RRs) were computed from linear meta-regression models. We included 55,521 cases identified among 2,818,767 men from 31 cohort studies, and 13,232 cases and 16,317 controls from 25 case-control studies. The overall RR for BMI was 1.05 per 5 kg/m2 increment, 95% CI 1.01-1.08. For studies that reported results by stage of disease, the RRs were stronger for advanced disease (RR 1.12 per 5 kg/m2 increment, 95% CI 1.01-1.23) compared with localized disease (RR 0.96 per 5 kg/m2 increment, 95% CI 0.89-1.03), p = 0.02. Height was also positively associated with risk (RR 1.05 per 10 cm increment, 95% CI 1.02-1.09), but the evidence was weak for weight (RR 1.01 per 10 kg increment, 95% CI 0.97-1.04), waist circumference (RR 1.03 per 10 cm increment, 95% CI 0.99-1.07), and WHR (RR 1.11 per 0.1 unit increment, 95% CI 0.95-1.30). Stronger associations were observed among cohort studies compared with case-control studies for BMI (p = 0.006), height (p < 0.001) and weight (p = 0.02). This meta-analysis indicates that obesity is weakly associated with an increased risk of prostate cancer (particularly advanced stage tumors). While increased stature may also increase risk, there is little evidence for an association with central obesity.