Temporal changes in mammographic breast density and breast cancer risk among women with benign breast disease.

INTRODUCTION: Benign breast disease (BBD) and high mammographic breast density (MBD) are prevalent and independent risk factors for invasive breast cancer. It has been suggested that temporal changes in MBD may impact future invasive breast cancer risk, but this has not been studied among women with BBD. METHODS: We undertook a nested case-control study within a cohort of 15,395 women with BBD in Kaiser Permanente Northwest (KPNW; 1970-2012, followed through mid-2015). Cases (n = 261) developed invasive breast cancer > 1 year after BBD diagnosis, whereas controls (n = 249) did not have breast cancer by the case diagnosis date. Cases and controls were individually matched on BBD diagnosis age and plan membership duration. Standardized %MBD change (per 2 years), categorized as stable/any increase (≥ 0%), minimal decrease of less than 5% or a decrease greater than or equal to 5%, was determined from baseline and follow-up mammograms. Associations between MBD change and breast cancer risk were examined using adjusted unconditional logistic regression. RESULTS: Overall, 64.5% (n = 329) of BBD patients had non-proliferative and 35.5% (n = 181) had proliferative disease with/without atypia. Women with an MBD decrease (≤ - 5%) were less likely to develop breast cancer (Odds Ratio (OR) 0.64; 95% Confidence Interval (CI) 0.38, 1.07) compared with women with minimal decreases. Associations were stronger among women ≥ 50 years at BBD diagnosis (OR 0.48; 95% CI 0.25, 0.92) and with proliferative BBD (OR 0.32; 95% CI 0.11, 0.99). DISCUSSION: Assessment of temporal MBD changes may inform risk monitoring among women with BBD, and strategies to actively reduce MBD may help decrease future breast cancer risk.

Relation of Quantitative Histologic and Radiologic Breast Tissue Composition Metrics With Invasive Breast Cancer Risk.

Background: Benign breast disease (BBD) is a strong breast cancer risk factor, but identifying patients that might develop invasive breast cancer remains a challenge. Methods: By applying machine-learning to digitized hematoxylin and eosin-stained biopsies and computer-assisted thresholding to mammograms obtained circa BBD diagnosis, we generated quantitative tissue composition metrics and determined their association with future invasive breast cancer diagnosis. Archival breast biopsies and mammograms were obtained for women (18-86 years of age) in a case-control study, nested within a cohort of 15 395 BBD patients from Kaiser Permanente Northwest (1970-2012), followed through mid-2015. Patients who developed incident invasive breast cancer (ie, cases; n = 514) and those who did not (ie, controls; n = 514) were matched on BBD diagnosis age and plan membership duration. All statistical tests were 2-sided. Results: Increasing epithelial area on the BBD biopsy was associated with increasing breast cancer risk (odds ratio [OR]Q4 vs Q1 = 1.85, 95% confidence interval [CI] = 1.13 to 3.04; P trend = .02). Conversely, increasing stroma was associated with decreased risk in nonproliferative, but not proliferative, BBD (P heterogeneity = .002). Increasing epithelium-to-stroma proportion (ORQ4 vs Q1 = 2.06, 95% CI =1.28 to 3.33; P trend = .002) and percent mammographic density (MBD) (ORQ4 vs Q1 = 2.20, 95% CI = 1.20 to 4.03; P trend = .01) were independently and strongly predictive of increased breast cancer risk. In combination, women with high epithelium-to-stroma proportion and high MBD had substantially higher risk than those with low epithelium-to-stroma proportion and low MBD (OR = 2.27, 95% CI = 1.27 to 4.06; P trend = .005), particularly among women with nonproliferative (P trend = .01) vs proliferative (P trend = .33) BBD. Conclusion: Among BBD patients, increasing epithelium-to-stroma proportion on BBD biopsies and percent MBD at BBD diagnosis were independently and jointly associated with increasing breast cancer risk. These findings were particularly striking for women with nonproliferative disease (comprising approximately 70% of all BBD patients), for whom relevant predictive biomarkers are lacking.

Risk factors for breast cancer development by tumor characteristics among women with benign breast disease.

BACKGROUND: Among women diagnosed with invasive breast cancer, 30% have a prior diagnosis of benign breast disease (BBD). Thus, it is important to identify factors among BBD patients that elevate invasive cancer risk. In the general population, risk factors differ in their associations by clinical pathologic features; however, whether women with BBD show etiologic heterogeneity in the types of breast cancers they develop remains unknown. METHODS: Using a nested case-control study of BBD and breast cancer risk conducted in a community healthcare plan (Kaiser Permanente Northwest), we assessed relationships of histologic features in BBD biopsies and patient characteristics with subsequent breast cancer risk and tested for heterogeneity of associations by estrogen receptor (ER) status, tumor grade, and size. The study included 514 invasive breast cancer cases (median follow-up of 9 years post-BBD diagnosis) and 514 matched controls, diagnosed with proliferative or non-proliferative BBD between 1971 and 2006, with follow-up through mid-2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained using multivariable polytomous logistic regression models. RESULTS: Breast cancers were predominantly ER-positive (86%), well or moderately differentiated (73%), small (74% < 20 mm), and stage I/II (91%). Compared to patients with non-proliferative BBD, proliferative BBD with atypia conferred increased risk for ER-positive cancer (OR = 5.48, 95% CI = 2.14-14.01) with only one ER-negative case, P-heterogeneity = 0.45. The presence of columnar cell lesions (CCLs) at BBD diagnosis was associated with a 1.5-fold increase in the risk of both ER-positive and ER-negative tumors, with a 2-fold increase (95% CI = 1.21-3.58) observed among postmenopausal women (56%), independent of proliferative BBD status with and without atypia. We did not identify statistically significant differences in risk factor associations by tumor grade or size. CONCLUSION: Most tumors that developed after a BBD diagnosis in this cohort were highly treatable low-stage ER-positive tumors. CCL in BBD biopsies may be associated with moderately increased risk, independent of BBD histology, and irrespective of ER status.

Risk of chemotherapy-induced febrile neutropenia in patients with metastatic cancer not receiving granulocyte colony-stimulating factor prophylaxis in US clinical practice.

OBJECTIVES: To evaluate the use of granulocyte colony-stimulating factor (G-CSF) prophylaxis in US patients with selected metastatic cancers and chemotherapy-induced febrile neutropenia (FN) incidence and associated outcomes among the subgroup who did not receive prophylaxis. METHODS: This retrospective cohort study was conducted at four US health systems and included adults with metastatic cancer (breast, colorectal, lung, non-Hodgkin lymphoma [NHL]) who received myelosuppressive chemotherapy (2009-2017). Patients were stratified by FN risk level based on risk factors and chemotherapy (low/unclassified risk, intermediate risk without any risk factors, intermediate risk with ≥ 1 risk factor [IR + 1], high risk [HR]). G-CSF use was evaluated among all patients stratified by FN risk, and FN/FN-related outcomes were evaluated among patients who did not receive first-cycle G-CSF prophylaxis. RESULTS: Among 1457 metastatic cancer patients, 20.5% and 28.1% were classified as HR and IR + 1, respectively. First-cycle G-CSF prophylaxis use was 48.5% among HR patients and 13.9% among IR + 1 patients. In the subgroup not receiving first-cycle G-CSF prophylaxis, FN incidence in cycle 1 was 7.8% for HR patients and 4.8% for IR + 1 patients; during the course, corresponding values were 16.9% and 15.9%. Most (> 90%) FN episodes required hospitalization, and mortality risk ranged from 7.1 to 26.9% across subgroups. CONCLUSION: In this retrospective study, the majority of metastatic cancer chemotherapy patients for whom G-CSF prophylaxis is recommended did not receive it; FN incidence in this subgroup was notably high. Patients with elevated FN risk should be carefully identified and managed to ensure appropriate use of supportive care.

5-Alpha Reductase Inhibitors and the Risk of Prostate Cancer Mortality in Men Treated for Benign Prostatic Hyperplasia.

OBJECTIVE: To compare the risk of prostate cancer mortality among men treated with 5- alpha reductase inhibitors (5-ARIs) with those treated with alpha-adrenergic blockers (ABs) in community practice settings. PATIENTS AND METHODS: A retrospective matched cohort (N=174,895) and nested case-control study (N=18,311) were conducted in 4 regions of an integrated health care system. Men 50 years and older who initiated pharmaceutical treatment for benign prostatic hyperplasia between January 1, 1992, and December 31, 2007, and had at least 3 consecutive prescriptions were followed through December 31, 2010. Adjusted subdistribution hazard ratios, accounting for competing risks of death, and matched odds ratios were used to estimate prostate cancer mortality associated with 5-ARI use (with or without concomitant ABs) as compared with AB use. RESULTS: In the cohort study, 1,053 men died of prostate cancer (mean follow-up, 3 years), 15% among 5-ARI users (N= 25,388) and 85% among AB users (N=149,507) (unadjusted mortality rate ratio, 0.80). After accounting for competing risks, it was found that 5-ARI use was not associated with prostate cancer mortality when compared with AB use (adjusted subdistribution hazard ratio, 0.85; 95% CI, 0.72-1.01). Similar results were observed in the case-control study (adjusted matched odds ratio, 0.95; 95% CI, 0.78-1.17). CONCLUSION: Among men being pharmaceutically treated for benign prostatic hyperplasia, 5-ARI use was not associated with an increased risk of prostate cancer-specific mortality when compared with AB use. The increased prevalence of high-grade lesions at the time of diagnosis noted in our study and the chemoprevention trials may not result in increased prostate cancer mortality.

Validation of a Genomic Classifier for Predicting Post-Prostatectomy Recurrence in a Community Based Health Care Setting.

PURPOSE: We determined the value of Decipher®, a genomic classifier, to predict prostate cancer outcomes among patients after prostatectomy in a community health care setting. MATERIALS AND METHODS: We examined the experience of 224 men treated with radical prostatectomy from 1997 to 2009 at Kaiser Permanente Northwest, a large prepaid health plan in Portland, Oregon. Study subjects had aggressive prostate cancer with at least 1 of several criteria such as preoperative prostate specific antigen 20 ng/ml or greater, pathological Gleason score 8 or greater, stage pT3 disease or positive surgical margins at prostatectomy. The primary end point was clinical recurrence or metastasis after surgery evaluated using a time dependent c-index. Secondary end points were biochemical recurrence and salvage treatment failure. We compared the performance of Decipher alone to the widely used CAPRA-S (Cancer of the Prostate Risk Assessment Post-Surgical) score, and assessed the independent contributions of Decipher, CAPRA-S and their combination for the prediction of recurrence and treatment failure. RESULTS: Of the 224 patients treated 12 experienced clinical recurrence, 68 had biochemical recurrence and 34 experienced salvage treatment failure. At 10 years after prostatectomy the recurrence rate was 2.6% among patients with low Decipher scores but 13.6% among those with high Decipher scores (p=0.02). When CAPRA-S and Decipher scores were considered together, the discrimination accuracy of the ROC curve was increased by 0.11 compared to the CAPRA-S score alone (combined c-index 0.84 at 10 years after radical prostatectomy) for clinical recurrence. CONCLUSIONS: Decipher improves our ability to predict clinical recurrence in prostate cancer and adds precision to conventional pathological prognostic measures.

Association of body mass index and prostate cancer mortality.

OBJECTIVES: Inconsistent evidence exists on whether obesity is associated with an increased risk of prostate cancer death post-radical prostatectomy. We examined data from three large health plans to evaluate if an increased body mass index (BMI) at prostate cancer diagnosis is related to prostate cancer mortality SUBJECTS AND METHODS: This population-based case-control study included 751 men with prostate cancer who underwent radical prostatectomy. Cases were men who died due to prostate cancer (N=323) and matched controls (N=428). We used multivariable logistic regression models to assess the association between BMI at diagnosis and prostate cancer mortality, adjusted for Gleason score, PSA, tumour characteristics, and matching factors. RESULTS: Study subjects were classified into the following BMI (kg/m2) categories: healthy (18.5-24.9), overweight (25-29.9) and obese (≥30). Nearly 43% of the participants had a BMI ≥25 at diagnosis. A higher fraction of cases (30%) were obese compared to controls (22%). Overall, obese men had more than a 50% increase in prostate cancer mortality (adjusted odds ratio=1.50 [95% CI, 1.03-2.19]) when compared to men with healthy BMI. After stratifying by Gleason score, the odds of mortality generally rose with increasing BMI. The strongest effect was observed in the Gleason score 8+ category (2.37, 95% CI: 1.11-5.09). These associations persisted after adjusting for PSA at diagnosis and other tumour characteristics. CONCLUSIONS: These results suggest that BMI at diagnosis is strongly correlated with prostate cancer mortality, and that men with aggressive disease have a markedly greater odds of death if they are overweight or obese.

Use of intravenous bisphosphonates in patients with breast, lung, or prostate cancer and metastases to bone: a 15-year study in two large US health systems.

PURPOSE: The purpose of this paper is to document the use of intravenous (IV) bisphosphonates for prevention of skeletal-related events (SREs) in patients with bone metastases (BM) due to breast cancer (BC), lung cancer (LC), or prostate cancer (PC). METHODS: Using data from two large US health systems, we identified all patients aged ≥ 18 years with primary BC, LC, or PC and newly diagnosed BM between 1/1/1995 and 12/31/2009. Starting with the diagnosis of BM, we reviewed medical and administrative records for evidence of receipt of IV bisphosphonates (zoledronic acid or pamidronate) and occurrence of SREs. Initiation of IV bisphosphonates prior to occurrence of an SRE was designated "primary prophylaxis"; use following an SRE was designated "secondary prophylaxis". RESULTS: We identified a total of 1,193 patients with newly diagnosed BM, including 400 with BC, 332 with LC, and 461 with PC. Use of IV bisphosphonates was substantially higher in BC (55.8 % of all patients) than in LC (14.8 %) or PC (20.2 %). Use of IV bisphosphonates was fairly evenly split between primary and secondary prophylaxis in BC (26.3 vs. 29.5 %, respectively) and PC (10.6 vs 9.5 %); in LC, however, primary prophylaxis was much less common than secondary prophylaxis (4.8 vs 9.9 %). CONCLUSIONS: Almost one half of all patients with BM due to BC, and substantially more with LC and PC, do not receive IV bisphosphonates. Among patients receiving such therapy, treatment often is not initiated until after the occurrence of an SRE. Our study suggests that IV bisphosphonates may be substantially underutilized in patients with BM due to these common cancers.

Natural history of skeletal-related events in patients with breast, lung, or prostate cancer and metastases to bone: a 15-year study in two large US health systems.

PURPOSE: To document the risk of skeletal complications in patients with bone metastases from breast cancer (BC), lung cancer (LC), or prostate cancer (PC) in routine clinical practice. METHODS: We used data from two large US health systems to identify patients aged ≥18 years with primary BC, LC, or PC and newly diagnosed bone metastases between January 1, 1995 and December 31, 2009. Beginning with the date of diagnosis of bone metastasis, we estimated the cumulative incidence of skeletal-related events (SREs) (spinal cord compression, pathologic fracture, radiation to bone, bone surgery), based on review of medical records, accounting for death as a competing risk. RESULTS: We identified a total of 621 BC, 477 LC, and 721 PC patients with newly diagnosed bone metastases. SREs were present at diagnosis of bone metastasis in 22.4, 22.4, and 10.0 % of BC, LC, and PC patients, respectively. Relatively few LC or PC patients received intravenous bisphosphonates (14.8 and 20.2 %, respectively); use was higher in patients with BC, however (55.8 %). In BC, cumulative incidence of SREs during follow-up was 38.7 % at 6 months, 45.4 % at 12 months, and 54.2 % at 24 months; in LC, it was 41.0, 45.4, and 47.7 %; and in PC, it was 21.5, 30.4, and 41.9 %. More than one half of patients with bone metastases had evidence of SREs (BC: 62.6 %; LC: 58.7 %; PC: 51.7 %), either at diagnosis of bone metastases or subsequently. CONCLUSIONS: SREs are a frequent complication in patients with solid tumors and bone metastases, and are much more common than previously recognized in women with BC.

Immunohistochemical expression of ERG in the molecular epidemiology of fatal prostate cancer study.

BACKGROUND: Gene fusions between the ERG transcription factor and the androgen-regulated gene TMPRSS2 occur in a subset of prostate cancers and contribute to transformation of prostatic epithelial cells. Prior reports have used fluorescence in situ hybridization (FISH) or quantitative PCR (QPCR) to determine the presence of TMPRSS2-ERG fusions or ERG expression, respectively. Recently, several groups have reported on immunohistochemistry (IHC) to measure ERG expression, which is much more readily performed in clinical practice. However, the prior studies examining ERG expression by IHC had small sample sizes or they failed to clarify the association of ERG protein expression with important clinico-pathological features or prostate cancer-specific mortality. METHODS: To address these deficits, we evaluated ERG expression by IHC in 208 radical prostatectomy samples from the Kaiser Permanente Molecular Epidemiology of Fatal Prostate Cancer (MEFPC) study, a case-control study of prostate cancer-specific mortality. RESULTS: Nuclear ERG expression was seen in neoplastic prostate epithelia in 49 of the samples (23.7%). ERG expression in tumor cells was associated with higher tumor stage (OR = 2.0, 95% confidence interval 1.0-4.0, P value = 0.04). ERG immunoreactivity was positively associated with prostate cancer-specific mortality, although the confidence interval was wide (OR = 1.9, 95% confidence interval 0.88-4.0, P value = 0.10). CONCLUSIONS: Our results demonstrate that ERG protein expression is readily quantifiable with an existing commercial antibody. Evaluating ERG protein expression may improve our ability to identify the subset of more aggressive, invasive prostate cancers.

Screening colonoscopy and risk for incident late-stage colorectal cancer diagnosis in average-risk adults: a nested case-control study.

BACKGROUND: The effectiveness of screening colonoscopy in average-risk adults is uncertain, particularly for right colon cancer. OBJECTIVE: To examine the association between screening colonoscopy and risk for incident late-stage colorectal cancer (CRC). DESIGN: Nested case-control study. SETTING: Four U.S. health plans. PATIENTS: 1039 average-risk adults enrolled for at least 5 years in one of the health plans. Case patients were aged 55 to 85 years on their diagnosis date (reference date) of stage IIB or higher (late-stage) CRC during 2006 to 2008. One or 2 control patients were selected for each case patient, matched on birth year, sex, health plan, and prior enrollment duration. MEASUREMENTS: Receipt of CRC screening 3 months to 10 years before the reference date, ascertained through medical record audits. Case patients and control patients were compared on receipt of screening colonoscopy or sigmoidoscopy by using conditional logistic regression that accounted for health history, socioeconomic status, and other screening exposures. RESULTS: In analyses restricted to 471 eligible case patients and their 509 matched control patients, 13 case patients (2.8%) and 46 control patients (9.0%) had undergone screening colonoscopy, which corresponded to an adjusted odds ratio (AOR) of 0.29 (95% CI, 0.15 to 0.58) for any late-stage CRC, 0.36 (CI, 0.16 to 0.80) for right colon cancer, and 0.26 (CI, 0.06 to 1.11; P = 0.069) for left colon/rectum cancer. Ninety-two case patients (19.5%) and 173 control patients (34.0%) had screening sigmoidoscopy, corresponding to an AOR of 0.50 (CI, 0.36 to 0.70) overall, 0.79 (CI, 0.51 to 1.23) for right colon late-stage cancer, and 0.26 (CI, 0.14 to 0.48) for left colon cancer. LIMITATION: The small number of screening colonoscopies affected the precision of the estimates. CONCLUSION: Screening with colonoscopy in average-risk persons was associated with reduced risk for diagnosis of incident late-stage CRC, including right-sided colon cancer. For sigmoidoscopy, this association was seen for left CRC, but the association for right colon late-stage cancer was not statistically significant.

Medical history, body size, and cigarette smoking in relation to fatal prostate cancer.

OBJECTIVES: Prostate cancer has few known risk factors. As part of a population-based case-control study conducted in four health maintenance organizations, the authors examined the associations between fatal prostate cancer and several medical and behavioral characteristics. METHODS: Cases were 768 health plan members who died of prostate adenocarcinoma during the period 1997-2001. We randomly selected controls (929) from the health plan membership and matched them to cases on health plan, age, race, and pattern of health plan membership. We examined medical records to obtain information on potential risk factors during the 10 years before the date on which prostate cancer was first suspected; the same reference date was used for the matched controls. RESULTS: Anthropometric characteristics, as well as personal histories of benign prostatic hypertrophy, transurethral prostatectomy, cancer, diabetes, prostatitis, hypertension, and vasectomy were largely similar for cases and controls. Men who died from prostate cancer were more likely than controls to have been cigarette smokers according to the most recent smoking notation before the reference date (odds ratio 1.5, 95% confidence interval 1.1-2.0). CONCLUSIONS: The observed increase in risk associated with recent cigarette smoking is consistent with the findings of several other studies. However, in contrast with some reports, we observed no connection between fatal prostate cancer and some prior health conditions or measures of body size.

Racial differences in treatment of early-stage prostate cancer.

OBJECTIVES: To determine whether differences existed in prostate cancer treatment received by white and African American men at a health maintenance organization where access to medical care is theoretically equal for all members and, if so, to determine the reasons for these differences. METHODS: We used information from the Kaiser Permanente Northwest Tumor Registry to identify all men diagnosed with local- or regional-stage prostate cancer between 1980 and 2000. We compared the likelihood of treatment with curative intent (TCI) between the two races, adjusting for age, tumor grade, stage, and the presence of comorbid conditions. We reviewed medical records of all 79 African American men and a sample of 158 white men (matched for age, stage, grade, and year of diagnosis) to determine the reasons that men did or did not receive TCI. RESULTS: Seventy-one percent of African American men and 82% of white men were treated with curative intent (P = 0.01). African American men were not more likely than white men to refuse TCI when it was offered (10.6% versus 8.1%, respectively; P = 0.6). However, urologists offered TCI less often to African American men than to white men (85% versus 91%, respectively; P = 0.02), and this difference could not be explained by differences in age, tumor grade, stage, or presence of comorbid conditions. CONCLUSIONS: African American men were less likely to receive TCI than white men. Because all of the men were insured, economic factors did not cause this difference. Furthermore, the cause did not seem to be differences in age, tumor grade, stage, or comorbid conditions.

Screening by prostate-specific antigen and digital rectal examination in relation to prostate cancer mortality: a case-control study.

BACKGROUND: The potential role of prostate cancer screening in reducing mortality is uncertain. To examine whether screening with the prostate-specific antigen (PSA) test or digital rectal examination is associated with reduced prostate cancer mortality, we conducted a population-based case-control study in 4 health maintenance organizations. METHODS: Cases were 769 health plan members who died because of prostate adenocarcinoma during the years 1997-2001. We randomly selected 929 controls from the health plan membership and matched them to cases on health plan, age, race, and membership history. Medical records were used to document all screening tests in the 10 years before and including the date on which prostate cancer was first suspected. RESULTS: Among white participants, 62% of cases and 69% of controls had a least 1 screening PSA test or digital rectal examination (odds ratio = 0.73; 95% confidence interval = 0.55-0.97). The corresponding proportions for blacks were 59% and 61% (1.0; 0.59-1.4). Most screening tests were digital rectal examinations; therefore, in the subgroup with no history of PSA screening, the association between digital rectal screening and prostate cancer mortality was similar to the overall association (0.65 [0.48-0.88] among whites; 0.86 [0.53-1.4] among blacks). Very few men received screening PSA without screening digital rectal examination (6% of cases and 7% of controls among whites). CONCLUSIONS: Digital rectal screening was associated with a reduced risk of death due to prostate cancer in our population. Because of several data limitations, this study could not accurately estimate the effect of PSA screening separate from digital rectal examination.

The incidence of colorectal cancer following a negative screening sigmoidoscopy: implications for screening interval.

BACKGROUND & AIMS: Current guidelines recommend a 5-year interval for colorectal cancer (CRC) screening by sigmoidoscopy. However, the optimal screening interval is uncertain. We estimated the annual incidence of distal and proximal CRC in the first 5 years following a negative sigmoidoscopy examination to gauge the potential benefit of rescreening in <5 years. METHODS: A cohort of 72,483 participants in the Colon Cancer Prevention program of Kaiser Permanente of Northern California (KP) was defined using computerized databases. Men and women aged 50 years and older who had a negative screening flexible sigmoidoscopy examination between 1994 and 1996 and were considered not to be at high risk for developing CRC were included. Subjects were censored at the time of diagnosis (for cases), death, termination of KP membership, or subsequent colon examination. RESULTS: Thirty cases of distal and 80 cases of proximal CRC occurred. Age-adjusted incidence rates of distal CRC ranged from a low of 2.8 per 100,000 person-years in the first year of follow-up to a high of 13.0 per 100,000 in the fourth year (rate difference, 10.2; 95% confidence interval, 1.1-19.3). However, for the entire follow-up period, incidence of distal CRC remained much lower than age-adjusted rates of 70.6 in the general population (Surveillance, Epidemiology, and End Results registry). The incidence of proximal CRC was also decreased modestly over population rates of disease. CONCLUSIONS: Screening by sigmoidoscopy more frequently than every 5 years would likely lead, at best, to only modest improvements as compared with a 5-year screening interval.

Prostate cancer screening and mortality: a case-control study (United States).

OBJECTIVE: We performed a case-control study at Kaiser Permanente Northwest to assess the association between digital rectal examination (DRE) and prostate-specific antigen (PSA) testing, separately and together, and prostate cancer mortality. METHODS: We identified 171 KPNW members who died as a result of prostate cancer from 1992 to 1999 and 342 randomly-selected KPNW members matched to the cases on age, sex, and length of plan membership. History of screening was determined from medical records and laboratory databases for cases and controls. RESULTS: DRE and/or PSA screening at any time up to and including the case diagnosis date had taken place among 69.0% of cases and 74.6% of controls. After using logistic regression analysis to adjust for matching variables and a provider diagnosis of benign prostatic hypertrophy (BPH), we found an inverse association between receipt of a prostate cancer screening test and prostate cancer mortality (odds ratio (OR): 0.70, 95% confidence interval (CI): 0.46 - 1.1). Most of the screening tests were DREs, and it was not possible to assess the separate influence of PSA screening. CONCLUSIONS: The results of this study suggest that men who have been screened for prostate cancer have a reduced risk of dying as a result of this disease.