Guideline-discordant androgen deprivation therapy in localized prostate cancer: patterns of use in the medicare population and cost implications.

Background Androgen deprivation therapy (ADT) in localized prostate cancer improves overall survival and is recommended by National Comprehensive Cancer Network guidelines in certain situations. However, ADT is without benefit in other situations and can actually cause harm. This study examines recent trends in the ADT use and quantifies the cost of guideline-discordant ADT. Patients and methods Patients, aged 66-80 years, in the Surveillance Epidemiology and End Results-Medicare database with non-metastatic prostate cancer diagnosed between 2004 and 2007 were included for analysis. Prostate-specific antigen, Gleason score, and stage were used to define D'Amico risk categories. Logistic regression was used to examine factors associated with guideline-discordant ADT. Annual direct cost was estimated using 2011 Medicare reimbursement for ADT. Results Of 28 654 men included, 12.4% received guideline-discordant ADT. In low-risk patients, 14.9% received discordant ADT, mostly due to simultaneous ADT with radiation. Discordant use was seen in 7.3% of intermediate and 14.9% of high-risk patients, mostly from ADT as primary therapy. The odds of receiving guideline-discordant ADT decreased over time (2007 versus 2004; OR 0.69; 95% CI 0.62-0.76). The estimated annual direct cost from discordant ADT is $42 000 000. Conclusion Approximately one in eight patients received ADT discordant with published guidelines. Elimination of discordant use would result in substantial savings.

Renal cell carcinoma.

Renal cell carcinoma (RCC) continues to be a frustrating tumor for clinicians to manage and treat. Progress has been made in the identification of risk factors, particularly dietary risk factors. An increased risk has been seen with frequent consumption of fried meat and poultry. Citrus fruits, vitamin C, beta-carotene, and alpha-tocopherol have demonstrated a protective effect against RCC. Other factors that have been associated with the risk of RCC are smoking (which doubles the risk), obesity, hypertension, and exposure to asbestos and petroleum products. Response rates for systemic treatment of RCC continue to hover at about 20%; however, some nonchemotherapy treatments may provide palliation with few side effects. In addition, lower dose combinations of interleukin-2 and interferon alfa may be as beneficial as higher dose regimens, but with less toxicity. Molecular prognostic factors, including proliferation markers, karyometric analyses, oncogenes, and cell adhesion molecules and proteases are areas of intense investigation and may provide mechanisms for identifying patients who require more (or less) aggressive treatment.

Biomarkers of essential fatty acid consumption and risk of prostatic carcinoma.

Animal studies have suggested that omega-6 fatty acids found in vegetable oils may promote prostate cancer. Our goal was to use erythrocyte membrane and adipose tissue fatty acid composition as biomarkers to investigate whether essential fatty acids modulated prostate cancer risk. An outpatient clinic-based study of 89 cases and 38 controls was conducted in North Carolina between July 1989 and December 1991. Cases were recruited from a university-based urology outpatient clinic. Eligible cases were more than 45 years of age and had histological confirmation of a prostate cancer diagnosis within 1 year of entry into the study. Controls were histologically confirmed free of prostate cancer. Erythrocyte membranes from venous blood and adipose tissue fatty acids from s.c. fat samples were analyzed in batches using capillary gas chromatography. Unconditional logistic regression analysis was used to calculate odds ratios for the association of each fatty acid with prostate cancer while controlling for potential confounders. Linoleic acid consumption was positively associated with prostate cancer risk. The odds ratios comparing the first and fourth quartiles of linoleic acid consumption were 3.54 (95% confidence interval, 1.0-12.53) with P trend < 0.04 for erythrocyte membranes, and 2.47 (95% confidence interval, 0.66-9.26) with P trend < 0.08 for adipose tissue. These data suggest that linoleic acid consumption may increase prostate cancer risk, which is consistent with results from animal experiments. Linoleic acid is found in vegetable oils used in cooking and in cereals, snack foods, and baked goods. Our data failed to demonstrate consistently a protective effect of marine omega-3 fatty acids on prostate cancer.

Correlation between biomarkers of omega-3 fatty acid consumption and questionnaire data in African American and Caucasian United States males with and without prostatic carcinoma.

Results from animal studies suggest that omega-3 fatty acids from marine sources are protective against cancer. To determine whether adipose tissue and erythrocyte membrane fatty acid composition could serve as biomarkers of essential fatty acid consumption in subjects with prostate cancer, we compared fish consumption, which was estimated using a food frequency survey, to the omega-3 fatty acid content of adipose tissue and erythrocyte membranes. The study was conducted using 127 men who had undergone a prostate biopsy. All subjects were recruited from a university hospital urology clinic. African Americans comprised 23% of the subjects, and 70% were diagnosed with prostate cancer. We found a correlation of 0.44 with 95% confidence intervals (CIs) = 0.29-0.57 between reported fish consumption and the omega-3 fatty acid eicosapentaenoic acid composition in erythrocyte membranes and 0.38 with 95% CI = 0.21-0.53 when the dietary survey was compared to eicosapentaenoic acid in adipose tissue. The survey/biomarker correlations in cases were not significantly different from the correlations in controls. The study had 90% power to detect a 0.35 difference between correlations. These results suggest that the presence of prostate cancer does not affect the adipose tissue or erythrocyte membrane biomarkers of fatty acid consumption, and that erythrocyte membranes are as useful as biomarkers as is adipose tissue. Our findings corroborate previous studies that found that tissue biomarkers can reflect past fatty acid consumption and support the use of biomarkers in case-control studies using cancer patients.

Essential fatty acid consumption and risk of breast cancer.

Animal and ecological studies of essential fatty acids suggest that omega-3 fatty acids found in fish oils and omega-6 fatty acids found in vegetable oils may be playing a role in the etiology of breast cancer. Essential fatty acids may modulate breast cancer risk by interacting with prostaglandins, which have immunosuppressive and platelet aggregative capabilities. The fatty acid composition of adipose tissue reflects the dietary consumption of essential fatty acids over a period of years. Biochemical techniques have been used in epidemiological studies to accurately estimate fatty acid consumption. However, analytical epidemiology studies that have used biochemical measurements of adipose tissue fatty acid composition, have not supported a relationship between consumption of these essential fatty acids and breast cancer risk.