Leslie K. Dennis

Epidemiologic association between prostatitis and prostate cancer

OBJECTIVES To quantify the relationship between prostatitis and prostate cancer by pooling previous epidemiologic studies of this association. METHODS A comprehensive search for articles published through 2000 was performed, blinded reviews of each study were conducted, data were abstracted, and all such studies were pooled. RESULTS In this meta-analysis, an increased risk was seen among men with a history of prostatitis (odds ratio = 1.6), particularly with population-based case-control studies (odds ratio = 1.8). Increased relative risk estimates were also seen among men with a history of syphilis and a history of gonorrhea. CONCLUSIONS These associations with prostate cancer suggest that infections may represent one mechanism through which prostate cancer develops. However, causality is unclear, because recall bias and detection bias cannot be ruled out. Future cohort studies of prostate cancer should examine sexually transmitted infections, as well as other infections, as potential risk factors.

Meta-analysis of measures of sexual activity and prostate cancer.

We conducted a meta-analysis of the association between prostate cancer and aspects of sexual activity. The data suggest an elevated relative risk (RR) of prostate cancer among men with a history of sexually transmitted infections. This was observed with both random- and fixed-effects models (RR = 1.4; 95% CI = 1.2–1.7; N = 17 studies; heterogeneity P = 0.14), especially for syphilis (RR = 2.3; 95% CI = 1.3–3.9; N = 6; heterogeneity P = 0.47). Risk of prostate cancer is also associated with increasing frequency of sexual activity (RR = 1.2 for an increase of three times per week; 95% CI = 1.1–1.3; N = 12). However, these studies are heterogeneous (P < 0.001). Increasing number of sexual partners is also associated with prostate cancer (RR = 1.2 for an increase of 20 partners; 95% CI = 1.1–1.3; N = 16; heterogeneity P = 0.11). The data do not support associations with multiple marriages, age at first intercourse, or age at first marriage. These results indicate an association between prostate cancer and sexually transmitted infections, suggesting that infections may represent one mechanism through which prostate cancer develops. The mechanism through which frequency of sexual activity may be related to prostate cancer is unclear.

Epidemiology of intracranial meningioma.

Intracranial meningiomas arise from the meninges and typically have benign histologic findings. They constitute approximately 20% of all intracranial tumors. Their incidence increases with age, and they affect women more commonly than men. The annual incidence per 100,000 people ranges from two to seven for women and from one to five for men. Since the first study was published in 1970, only eight major epidemiologic studies have been done that attempted to identify risk factors for meningioma. Ionizing radiation and head trauma have emerged as the most promising etiologic risk factors. In these studies, radiation doses as low as 1–2 Gy have been associated with increased risk. The role of dental radiographs has been suggested in some studies but not supported in others. An explanation for the apparent excess of meningiomas in women remains obscure. The potential effects of endogenous or exogenous sex hormones on tumor induction or growth remain unexplored in epidemiologic studies. More should be learned about the risk factors for meningioma in search of opportunities for prevention.

The Risk of Developing Arm Lymphedema Among Breast Cancer Survivors: A Meta-Analysis of Treatment Factors

BackgroundAs more women survive breast cancer, long-term complications that affect quality of life, such as lymphedema of the arm, gain greater importance. Numerous studies have attempted to identify treatment and prognostic factors for arm lymphedema, yet the magnitude of these associations remains inconsistent.MethodsA PubMed search was conducted through January 2008 to locate articles on lymphedema and treatment factors after breast cancer diagnosis. Random-effect models were used to estimate the pooled risk ratio.ResultsThe authors identified 98 independent studies that reported at least one risk factor of interest. The risk ratio (RR) of arm lymphedema was increased after mastectomy when compared with lumpectomy [RR = 1.42; 95% confidence interval (CI) 1.15–1.76], axillary dissection compared with no axillary dissection (RR = 3.47; 95% CI 2.34–5.15), axillary dissection compared with sentinel node biopsy (RR = 3.07; 95% CI 2.20–4.29), radiation therapy (RR = 1.92; 95% CI 1.61–2.28), and positive axillary nodes (RR = 1.54; 95% CI 1.32–1.80). These associations held when studies using self-reported lymphedema were excluded.ConclusionsMastectomy, extent of axillary dissection, radiation therapy, and presence of positive nodes increased risk of developing arm lymphedema after breast cancer. These factors likely reflected lymph node removal, which most surgeons consider to be the largest risk factor for lymphedema. Future studies should consider examining sentinel node biopsy versus no dissection with a long follow-up time post surgery to see if there is a benefit of decreased lymphedema compared with no dissection.

The Sensitivity of Medicare Claims Data for Case Ascertainment of Six Common Cancers

BACKGROUND Although Medicare claims data have been used to identify cases of cancer in older Americans, there are few data about their relative sensitivity. OBJECTIVES To investigate the sensitivity of diagnostic and procedural coding for case ascertainment of breast, colorectal, endometrial, lung, pancreatic, and prostate cancer. SUBJECTS Three hundred and eighty nine thousand and two hundred and thirty-six patients diagnosed with cancer between 1984 and 1993 resided in one of nine Surveillance Epidemiology and End Results (SEER) areas. MEASURES The sensitivity of inpatient and Part B diagnostic and cancer-specific procedural codes for case finding were compared with SEER. RESULTS The sensitivity of inpatient and inpatient plus Part B claims for the corresponding cancer diagnosis was 77.4% and 91.2%, respectively. The sensitivity of inpatient claims alone was highest for colorectal (86.1%) and endometrial (84.1%) cancer and lowest for prostate cancer (63.6%). However, when Part B claims were included, the sensitivity for diagnosis of breast cancer was greater than for other cancers (93.6%). Inpatient claim sensitivity was highest for earlier years of the study, and, because of more complete data and longer follow up, the highest sensitivity of combined inpatient and Part B claims was achieved in the late 1980s or early 1990s. CONCLUSIONS Medicare claims provide reasonably high sensitivity for the detection of cancer in the elderly, especially if inpatient and Part B claims are combined. Because the study did not measure other dimensions of accuracy, such as specificity and predictive value, the potential costs of including false positive cases need to be assessed.

Agreement of medicare claims and tumor registry data for assessment of cancer-related treatment

BACKGROUND Although health claims data are increasingly used in evaluating variations in patterns of cancer care and outcomes, little is known about the comparability of these data with tumor registry information. OBJECTIVES To evaluate the agreement between Medicare claims and tumor registry data in measuring patterns of diagnostic and therapeutic procedures for older cancer patients. RESEARCH DESIGN Analysis of a database linking Surveillance, Epidemiology and End Results (SEER) registry data and Medicare claims in patients aged > or =65 years with cancer. SUBJECTS 361,255 Medicare patients with invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancer diagnosed between 1984 and 1993. MEASURES Concordance of SEER files with corresponding Medicare claims. RESULTS Medicare claims generally identified patients who underwent resection and radical surgery according to SEER (ie, concordance > or =85%-90%) but less likely biopsy or local excision (ie, concordance < or =50%). In some instances, claims also categorized patients as having more invasive surgery than was listed in SEER and also provided incremental information about the use of surgical treatment after 4 months. SEER files and, to a lesser degree, Medicare claims identified radiation therapy not included in the other data source, and Medicare files also captured a significant number of patients with codes for chemotherapy. CONCLUSIONS Medicare files may be appropriate for studies of patterns of use of surgical treatment, but not for diagnostic procedures. The potential benefit of Medicare claims in identifying delayed surgical intervention and chemotherapy deserves further study.

Analysis of recent trends in prostate cancer incidence and mortality

There is debate over whether the recent increases seen in prostate cancer are due to lead‐time bias from screening, or identification of clinically insignificant lesions.

Intravenous glucose after out‐of‐hospital cardiopulmonary arrest A community‐based randomized trial

Question: Does the common practice of infusing small amounts of glucose after cardiopulmonary arrest worsen neurologic outcome? Design and setting: A community-based randomized trial in Seattle, WA. Paramedics treated all patients with out-of-hospital cardiac arrest in a standard fashion except that the intravenous infusion did or did not contain glucose; ie, patients received either usual treatment, with 5% dextrose in water (D5W), or alternative, with half normal saline (0.45S). Outcomes: The main outcome was awakening, defined as the patient having comprehensible speech or following commands as determined by chart review. Other outcomes were survival to hospital admission and to discharge. Results: Over 2 years, paramedics randomized 748 patients. The type of fluid administered was not significantly related to awakening (16.7% for D5W versus 14.6% for 0.45S), admission (38.0% for D5W versus 39.8% for 0.45S), or discharge (15.1% for D5W versus 13.3% for 0.45S). As in previous studies, patients whose arrest had likely been on a cardiac basis with initial rhythms of ventricular fibrillation or asystole had admission blood glucose levels significantly related to awakening: mean = 309 mg/dl for never awakening and 251 mg/dl for awakening. Of note, the relation between glucose and awakening was reversed in the remaining patients, who had electromechanical dissociation or noncardiac mechanisms of arrest. Conclusion: Current practices of using limited amounts of glucose-containing solutions after cardiopulmonary arrest do not need to be changed. Blood glucose level on admission is a prognostic indicator but depends on the type of arrest.

Pesticides and hypospadias: a meta-analysis.

OBJECTIVE To use meta-analytic techniques to synthesize the findings of the current body of published literature regarding the risk of hypospadias resulting from parental exposure to pesticides. MATERIALS AND METHODS A search of Pub Med for original research published in English from January 1966 through March 2008 identified 552 studies, 90 of which were reviewed in detail. Nine studies met all study inclusion criteria. Two reviewers independently abstracted data from each included study. Any disagreements were resolved by consensus. Pooled risk ratios (PRRs) and confidence intervals (CIs) were calculated using both random and fixed effects models, along with statistical tests of homogeneity. RESULTS Elevated but marginally significant risks of hypospadias were associated with maternal occupational exposure (PRR of 1.36, CI=1.04-1.77), and paternal occupational exposure (PRR of 1.19, CI=1.00-1.41). Subgroup analyses provided insights into needed designs for future studies. Notably, exposure assessment using a job-exposure matrix resulted in slightly higher estimated risk than agricultural occupation in fathers; but this effect was reversed in mothers, suggesting the importance of indirect and residential pesticide exposures in this group. CONCLUSIONS Despite potential exposure misclassification, which would tend to diminish observed associations, the previous literature indicates a modestly increased risk of hypospadias associated with pesticide exposure.

Meta‐analysis for combining relative risks of alcohol consumption and prostate cancer

Prostate cancer has become the most common cancer among men in the United States, but little is known about factors associated with prostate cancer incidence.