Adherence to surveillance among patients with superficial bladder cancer.

BACKGROUND: Patients diagnosed with superficial bladder cancer who have not undergone total cystectomy are at high risk for recurrence, and bladder surveillance with cystoscopy is recommended for such patients every 3-6 months. We examined the degree to which bladder cancer patients undergo the recommended surveillance procedures and identified patient and primary care provider characteristics associated with nonadherence to these recommendations. METHODS: We used information obtained from the Surveillance, Epidemiology, and End Results (SEER) Program-Medicare-linked database to identify 6717 patients aged 65 years or older who were diagnosed with superficial bladder cancer from 1992 through 1996 and who survived for at least 3 years after diagnosis but did not have a total cystectomy. We used information obtained from Medicare claims forms to examine the frequency with which these patients had a surveillance examination of the bladder during each of five contiguous 6-month intervals from month 7 to month 36 following diagnosis. We examined characteristics of patients and their physicians that were associated with low-intensity surveillance (defined as having an examination during fewer than two of the five possible follow-up intervals). Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: Only 40% of the entire cohort had an examination during all five intervals; 1216 patients (18.1%) had low-intensity surveillance. Patient characteristics that were independently associated with low-intensity surveillance were being age 75 years or older (adjusted OR = 1.54, 95% CI = 1.35 to 1.74), nonwhite (adjusted OR = 1.94, 95% CI = 1.57 to 2.40), and having favorable tumor histology (adjusted OR = 0.59, 95% CI = 0.48 to 0.72 for poorly differentiated versus referent well-differentiated tumor grade) and high comorbidity (adjusted OR = 1.72, 95% CI = 1.30 to 2.27). Residence in an urban area or in a census tract with low median income was also associated with low-intensity surveillance. CONCLUSIONS: The actual practice of surveillance for patients with superficial bladder cancer differs substantially from the standards recommended in clinical guidelines.

Variations in lung cancer risk among smokers.

BACKGROUND: Although there is no proven benefit associated with screening for lung cancer, screening programs are attracting many individuals who perceive themselves to be at high risk due to smoking. We sought to determine whether the risk of lung cancer varies predictably among smokers. METHODS: We used data on 18 172 subjects enrolled in the Carotene and Retinol Efficacy Trial (CARET)-a large, randomized trial of lung cancer prevention-to derive a lung cancer risk prediction model. Model inputs included the subject's age, sex, asbestos exposure history, and smoking history. We assessed the model's calibration by comparing predicted and observed rates of lung cancer across risk deciles and validated it by assessing the extent to which a model estimated on data from five CARET study sites could predict events in the sixth study site. We then applied the model to evaluate the risk of lung cancer among smokers enrolled in a study of lung cancer screening with computed tomography (CT). RESULTS: The model was internally valid and well calibrated. Ten-year lung cancer risk varied greatly among participants in the CT study, from 15% for a 68-year-old man who has smoked two packs per day for 50 years and continues to smoke, to 0.8% for a 51-year-old woman who smoked one pack per day for 28 years before quitting 9 years earlier. Even among the subset of CT study participants who would be eligible for a clinical trial of cancer prevention, risk varied greatly. CONCLUSIONS: The risk of lung cancer varies widely among smokers. Accurate risk prediction may help individuals who are contemplating voluntary screening to balance the potential benefits and risks. Risk prediction may also be useful for researchers designing clinical trials of lung cancer prevention.

Association of energy intake with prostate cancer in a long-term aging study: Baltimore Longitudinal Study of Aging (United States).

OBJECTIVES: To examine the association of total energy intake and macronutrient contributors to energy with prostate cancer risk among men in the Baltimore Longitudinal Study of Aging. METHODS: In the Baltimore Longitudinal Study of Aging cohort, 444 men completed at least one food frequency questionnaire (FFQ). At their earliest FFQ completion, men were 45 to 92 years old. The total number of prostate cancer cases (n = 68) consisted of men who were diagnosed with cancer before their FFQ completion (n = 46) and those who were diagnosed after their FFQ completion (n = 22). Multiple logistic regression analysis was used to calculate the odds ratio of prostate cancer and its 95% confidence interval. RESULTS: Total energy intake was positively associated with prostate cancer. Compared with the lowest quintile of energy intake, the odds ratio for the highest quintile was 3.79 (95% confidence interval 1.52 to 9.48, P TREND = 0.002). Energy-adjusted intakes of protein, fat, and carbohydrates were not statistically significantly associated with prostate cancer risk. CONCLUSIONS: This analysis, in which we used current energy intake as a surrogate for past prediagnostic intake, suggests a higher risk of prostate cancer with increased energy intake.

Calcium intake and prostate cancer risk in a long-term aging study: the Baltimore Longitudinal Study of Aging.

OBJECTIVE: To investigate the association between prostate cancer and calcium and other nutrients thought to influence the synthesis of 1,25-dihydroxyvitamin D [1,25(OH)2D]. METHODS: We included in the analysis 454 male participants in the Baltimore Longitudinal Study of Aging who were 46 to 92 years old at the time of completion of a food frequency questionnaire. Among them, 69 men were diagnosed with prostate cancer during their lifetime. In 68% of the cases, the food frequency questionnaire was completed after the diagnosis of cancer. Multiple logistic regression analysis was used to calculate the odds ratio and 95% confidence interval of prostate cancer. RESULTS: The median calcium intake was 788 mg/day. The adjusted odds ratio of prostate cancer for the highest tertile compared with the lowest tertile of calcium intake was 0.92 (95% confidence interval 0.48 to 1.77; P(trend) = 0.89). Likewise, no significant trends were found for phosphorus, vitamin D, fructose, or animal protein intake. Dairy products, including milk, were not associated with an increased risk of prostate cancer. The adjusted odds ratio of prostate cancer was 1.26 (95% confidence interval 0.57 to 2.79; P(trend) = 0.73) for men with high dairy intakes compared with those with low dairy intakes. CONCLUSIONS: The results of this study suggest that calcium intake within moderate limits is not associated with a notably increased risk of prostate cancer.