Harms of cervical cancer screening in the United States and the Netherlands.

We studied harms related to cervical cancer screening and management of screen-positive women in the United States (US) and the Netherlands. We utilized data from four US integrated health care systems (SEARCH), the US National Health Interview Survey, New Mexico state, the Netherlands national histopathology registry, and included studies on adverse health effects of cervical screening. We compared the number of Papanicolaou (Pap) smear tests, abnormal test results, punch biopsies, treatments, health problems (anxiety, pain, bleeding and discharge) and preterm births associated with excisional treatments. Results were age-standardized to the 2007 US population. Based on SEARCH, an estimated 36 million Pap tests were performed in 2007 for 91 million US women aged 21-65 years, leading to 2.3 million abnormal Pap tests, 1.5 million punch biopsies, 0.3 million treatments for precancerous lesions, 5 thousand preterm births and over 8 million health problems. Under the Netherlands screening practice, fewer Pap tests (58%), abnormal test results (64%), punch biopsies (75%), treatment procedures (40%), preterm births (60%) and health problems (63%) would have occurred. The SEARCH data did not differ much from other US data for 2007 or from more recent data up to 2013. Thus compared to the less intensive screening practice in the Netherlands, US practice of cervical cancer screening may have resulted in two- to threefold higher harms, while the effects on cervical cancer incidence and mortality are similar. The results are also of high relevance in making recommendations for HPV screening. Systematic collection of harms data is needed for monitoring and for better incorporation of harms in making screening recommendations.

The association between health literacy and cancer-related attitudes, behaviors, and knowledge.

Using a multidimensional assessment of health literacy (the Cancer Message Literacy Test-Listening, the Cancer Message Literacy Test-Reading, and the Lipkus Numeracy Scale), the authors assessed a stratified random sample of 1013 insured adults (40-70 years of age). The authors explored whether low health literacy across all 3 domains (n =111) was associated with sets of variables likely to affect engagement in cancer prevention and screening activities: (a) attitudes and behaviors relating to health care encounters and providers, (b) attitudes toward cancer and health, (c) knowledge of cancer screening tests, and (d) attitudes toward health related media and actual media use. Adults with low health literacy were more likely to report avoiding doctor's visits, to have more fatalistic attitudes toward cancer, to be less accurate in identifying the purpose of cancer screening tests, and more likely to avoid information about diseases they did not have. Compared with other participants, those with lower health literacy were more likely to say that they would seek information about cancer prevention or screening from a health care professional and less likely to turn to the Internet first for such information. Those with lower health literacy reported reading on fewer days and using the computer on fewer days than did other participants. The authors assessed the association of low health literacy with colorectal cancer screening in an age-appropriate subgroup for which colorectal cancer screening is recommended. In these insured subjects receiving care in integrated health care delivery systems, those with low health literacy were less likely to be up to date on screening for colorectal cancer, but the difference was not statistically significant.

Fracture risk in older, long-term survivors of early-stage breast cancer.

OBJECTIVES: To examine the effect of breast cancer and its treatment on fracture risk in older breast cancer survivors. DESIGN: A 10-year prospective cohort study beginning 5 years after a diagnosis of breast cancer for survivors and match date for comparison women. SETTING: Six integrated healthcare systems. PARTICIPANTS: Women aged 65 and older (1,286 survivors, 1,286 comparison women, mean age 77.7 in both groups, white, non-Hispanic: survivors, 81.6%; comparison women, 85.2%) who were alive and recurrence free 5 years after a diagnosis of early-stage breast cancer and matched on age, study site, and enrollment year to a comparison cohort without breast cancer. MEASUREMENTS: Cox proportional hazards models were used to estimate the association between fracture risk and survivor-comparison status, adjusting for drugs and risk factors associated with bone health. A subanalysis was used to evaluate the association between tamoxifen exposure and fracture risk. RESULTS: No difference was observed in fracture rates between groups (hazard ratio (HR) = 1.1, 95% confidence interval (CI) = 0.9-1.3). The protective effect of tamoxifen was not statistically significant (HR = 0.9, 95% CI = 0.6-1.2). CONCLUSION: Long-term survivors of early-stage breast cancer diagnosed at age 65 and older are not at greater risk of osteoporotic fractures than age-matched women without breast cancer. There appears to be no long-term protection from fractures with tamoxifen use.

Cancer research network: using integrated healthcare delivery systems as platforms for cancer survivorship research.

INTRODUCTION: Much progress has been made in cancer survivorship research, but there are still many unanswered questions that can and need to be addressed by collaborative research consortia. METHODS: Since 1999, the National Cancer Institute-funded HMO Cancer Research Network (CRN) has engaged in a wide variety of research focusing on cancer survivorship. With a focus on thematic topics in cancer survivorship, we describe how the CRN has contributed to research in cancer survivorship and the resources it offers for future collaborations. RESULTS: We identified the following areas of cancer survivorship research: surveillance for and predictors of recurrences, health care delivery and care coordination, health care utilization and costs, psychosocial outcomes, cancer communication and decision making, late effects of cancer and its treatment, use of and adherence to adjuvant therapies, and lifestyle and behavioral interventions following cancer treatment. CONCLUSIONS: With over a decade of experience using cancer data in community-based settings, the CRN investigators and their collaborators are poised to generate evidence in cancer survivorship research. IMPLICATIONS FOR CANCER SURVIVORS: Collaborative research within these settings can improve the quality of care for cancer survivors within and beyond integrated health care delivery systems.

Neighborhood socioeconomic status and use of colonoscopy in an insured population--a retrospective cohort study.

BACKGROUND: Low-socioeconomic status (SES) is associated with a higher colorectal cancer (CRC) incidence and mortality. Screening with colonoscopy, the most commonly used test in the US, has been shown to reduce the risk of death from CRC. This study examined if, among insured persons receiving care in integrated healthcare delivery systems, differences exist in colonoscopy use according to neighborhood SES. METHODS: We assembled a retrospective cohort of 100,566 men and women, 50-74 years old, who had been enrolled in one of three US health plans for ≥1 year on January 1, 2000. Subjects were followed until the date of first colonoscopy, date of disenrollment from the health plan, or December 31, 2007, whichever occurred first. We obtained data on colonoscopy use from administrative records. We defined screening colonoscopy as an examination that was not preceded by gastrointestinal conditions in the prior 6-month period. Neighborhood SES was measured using the percentage of households in each subject's census-tract with an income below 1999 federal poverty levels based on 2000 US census data. Analyses, adjusted for demographics and comorbidity index, were performed using Weibull regression models. RESULTS: The average age of the cohort was 60 years and 52.7% were female. During 449,738 person-years of follow-up, fewer subjects in the lowest SES quartile (Q1) compared to the highest quartile (Q4) had any colonoscopy (26.7% vs. 37.1%) or a screening colonoscopy (7.6% vs. 13.3%). In regression analyses, compared to Q4, subjects in Q1 were 16% (adjusted HR = 0.84, 95% CI: 0.80-0.88) less likely to undergo any colonoscopy and 30%(adjusted HR = 0.70, CI: 0.65-0.75) less likely to undergo a screening colonoscopy. CONCLUSION: People in lower-SES neighborhoods are less likely to undergo a colonoscopy, even among insured subjects receiving care in integrated healthcare systems. Removing health insurance barriers alone is unlikely to eliminate disparities in colonoscopy use.

Age, comorbidity, and breast cancer severity: impact on receipt of definitive local therapy and rate of recurrence among older women with early-stage breast cancer.

BACKGROUND: The definitive local therapy options for early-stage breast cancer are mastectomy and breast-conserving surgery followed by radiation therapy. Older women and those with comorbidities frequently receive breast-conserving surgery alone. The interaction of age and comorbidity with breast cancer severity and their impact on receipt of definitive therapy have not been well-studied. STUDY DESIGN: In a cohort of 1,837 women aged 65 years and older receiving treatment for early-stage breast cancer in 6 integrated health care delivery systems in 1990-1994 and followed for 10 years, we examined predictors of receiving nondefinitive local therapy and assessed the impact on breast cancer recurrence within levels of severity, defined as level of risk for recurrence. RESULTS: Age and comorbidity were associated with receipt of nondefinitive therapy. Compared with those at low risk, women at the highest risk were less likely to receive nondefinitive therapy (odds ratio = 0.32; 95% CI, 0.22-0.47), and women at moderate risk were about half as likely (odds ratio = 0.54; 95% CI, 0.35-0.84). Nondefinitive local therapy was associated with higher rates of recurrence among women at moderate (hazard ratio = 5.1; 95% CI, 1.9-13.5) and low risk (hazard ratio = 3.2; 95% CI, 1.1-8.9). The association among women at high risk was weak (hazard ratio = 1.3; 95% CI, 0.75-2.1). CONCLUSIONS: Among these older women with early-stage breast cancer, decisions about therapy partially balanced breast cancer severity against age and comorbidity. However, even among women at low risk, omitting definitive local therapy was associated with increased recurrence.

Baseline and follow-up laboratory monitoring of cardiovascular medications.

BACKGROUND: Laboratory monitoring of medications is typically used to establish safety prior to drug initiation and to detect drug-related injury following initiation. It is unclear whether black box warnings (BBWs) as well as evidence- and consensus-based clinical guidelines increase the likelihood of appropriate monitoring. OBJECTIVE: To determine the proportion of patients newly initiated on selected cardiovascular medications with baseline assessment and follow-up laboratory monitoring and compare the prevalence of laboratory testing for drugs with and without BBWs and guidelines. METHODS: This cross-sectional study included patients aged 18 years or older from a large multispecialty group practice who were prescribed a cardiovascular medication (angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, amiodarone, digoxin, lipid-lowering agents, diuretics, and potassium supplements) between January 1 and July 31, 2008. The primary outcome measure was laboratory test ordering for baseline assessment and follow-up monitoring of newly initiated cardiovascular medications. RESULTS: The number of new users of each study drug ranged from 49 to 1757 during the study period. Baseline laboratory test ordering across study drugs ranged from 37.4% to 94.8%, and follow-up laboratory test ordering ranged from 20.0% to 77.2%. Laboratory tests for drugs with baseline laboratory assessment recommendations in BBWs were more commonly ordered than for drugs without BBWs (86.4% vs 78.0%, p < 0.001). Drugs with follow-up monitoring recommendations in clinical guidelines had a lower prevalence of monitoring (33.1% vs 50.7%, p < 0.001). CONCLUSIONS: Baseline assessment of cardiovascular medication monitoring is variable. Quality measurement of adherence to BBW recommendations may improve monitoring.

Impact of health information technology interventions to improve medication laboratory monitoring for ambulatory patients: a systematic review.

Medication errors are a major source of morbidity and mortality. Inadequate laboratory monitoring of high-risk medications after initial prescription is a medical error that contributes to preventable adverse drug events. Health information technology (HIT)-based clinical decision support may improve patient safety by improving the laboratory monitoring of high-risk medications, but the effectiveness of such interventions is unclear. Therefore, the authors conducted a systematic review to identify studies that evaluate the independent effect of HIT interventions on improving laboratory monitoring for high-risk medications in the ambulatory setting using a Medline search from January 1, 1980 through January 1, 2009 and a manual review of relevant bibliographies. All anticoagulation monitoring studies were excluded. Eight articles met the inclusion criteria, including six randomized controlled trials and two pre-post intervention studies. Six of the studies were conducted in two large, integrated healthcare delivery systems in the USA. Overall, five of the eight studies reported statistically significant, but small, improvements in laboratory monitoring; only half of the randomized controlled trials reported statistically significant improvements. Studies that found no improvement were more likely to have used analytic strategies that addressed clustering and confounding. Whether HIT improves laboratory monitoring of certain high-risk medications for ambulatory patients remains unclear, and further research is needed to clarify this important question.

Delayed radiotherapy for breast cancer patients in integrated delivery systems.

OBJECTIVE: To identify factors associated with delayed radiotherapy (RT) in older women with early-stage breast cancer. METHODS: We studied 541 women age >or=65 years diagnosed with early-stage breast cancer in 1990-1994 at 5 integrated healthcare delivery systems and treated with breast-conserving surgery and RT, but not chemotherapy. We examined whether demographic, tumor, or treatment characteristics were associated with RT delays of >8 weeks postsurgery using chi(2) tests and multivariable logistic regression. RESULTS: Seventy-six women (14%) had delayed RT, with a median delay of 14 weeks. Even though they had insurance and access to care, nonwhite and Hispanic women were much more likely than white women to have delayed RT (odds ratio = 3.3; 95% confidence interval = 1.7, 10) in multivariable analyses that controlled for demographic and clinical variables. CONCLUSIONS: Timely RT should be facilitated through physician and patient education, navigation, and notification programs to improve quality of care. Queues for RT appointments should be evaluated on an ongoing basis to ensure adequate access. Future research should examine modifiable barriers to RT timeliness and whether delays impact long-term outcomes.

Survivorship research based in integrated healthcare delivery systems: the Cancer Research Network.

BACKGROUND: Integrated healthcare delivery systems present unique opportunities for cancer survivorship research. The National Cancer Institute funds the Cancer Research Network (CRN) to leverage these capabilities for all types of cancer research, including survivorship. METHODS: The authors gathered information from a recent CRN funding application, Survivorship Interest Group materials, the CRN website, and published articles. CRN studies were selected to illustrate diverse topics and a variety of data-collection approaches. RESULTS: The 14 systems that participate in the CRN provide care for approximately 10.8 million individuals of all ages and racial/ethnic backgrounds, for whom approximately 38,000 new cancer diagnoses were made in 2005. CRN systems have the ability to use existing data and collect new data on patients, providers, and organizations through well established research centers staffed by independent scientists. Of the 45 funded and 2 pending CRN grant applications as of November 30, 2007, 21 include aspects related to cancer survivorship. These studies have examined clinical trial participation, patterns of care, age and racial/ethnic disparities, diffusion of clinical trial findings, treatment outcomes, surveillance, and end-of-life and palliative care. Breast, colorectal, lung, ovarian, and prostate cancers have been the focus of these studies. Results of these studies have been published widely in leading journals. CONCLUSIONS: Completed and ongoing CRN survivorship studies provide a strong foundation for future studies. Scientists from all institutional affiliations are welcome to approach the CRN with ideas and are encouraged to allow ample time to establish collaborative relationships and design rigorous studies.

Mortality impact of less-than-standard therapy in older breast cancer patients.

BACKGROUND: The purpose of this study was to compare the rates of all-cause and breast cancer-specific mortality after breast-conserving surgery (BCS) only, BCS plus radiation therapy (RT), mastectomy, and the receipt of adjuvant tamoxifen in a large population-based cohort of older women with early-stage disease. STUDY DESIGN: This cohort study was conducted within six US integrated health-care delivery systems. Automated administrative databases, medical records, and tumor registries were used to identify women aged 65 years or older who received BCS or mastectomy to treat stage I or II breast cancer diagnosed from January 1, 1990, through December 31, 1994. We compared cause-specific 10-year mortality rates across treatment categories by fitting Cox proportional hazards models adjusted for demographics and tumor characteristics. RESULTS: We identified 1,837 women having operations for stage I or II breast cancer. Compared with women receiving mastectomy, those receiving BCS without RT were twice as likely to die of breast cancer (adjusted hazards ratio [HR]=2.19, 95% confidence interval [CI], 1.51 to 3.18). Breast cancer mortality rates were similar between women receiving BCS plus RT and women receiving mastectomy (adjusted HR=1.08, 95% CI, 0.79 to 1.48). In the subset of 886 chemotherapy-naive women treated with tamoxifen, those treated with tamoxifen for less than 1 year had a substantially higher breast cancer mortality rate than those exposed 5 years or more (adjusted HR=6.26, 95% CI, 3.10 to 12.64). CONCLUSIONS: Our findings indicate that older women receiving BCS alone have higher rates of breast cancer death than those receiving BCS + RT or mastectomy and that the survival benefit from tamoxifen increases with increasing duration of treatment.

Under utilization of surveillance mammography among older breast cancer survivors.

BACKGROUND: Annual surveillance mammography is recommended for follow-up of women with a history of breast cancer. We examined surveillance mammography among breast cancer survivors who were enrolled in integrated healthcare systems. METHODS: Women in this study were 65 or older when diagnosed with early stage invasive breast cancer (N = 1,762). We assessed mammography use during 4 years of follow-up, using generalized estimating equations to account for repeated measurements. RESULTS: Eighty-two percent had mammograms during the first year after treatment; the percentage declined to 68.5% in the fourth year of follow-up. Controlling for age and comorbidity, women who were at higher risk of recurrence by being diagnosed at stage II or receiving breast-conserving surgery (BCS) without radiation therapy were less likely to have yearly mammograms (compared to stage I, odds ratio [OR] for stage IIA 0.72, confidence interval [CI] 0.59, 0.87, OR for stage IIB 0.75, CI 0.57, 1.0; compared to BCS with radiation, OR 0.58, CI 0.43, 0.77). Women with visits to a breast cancer surgeon or oncologist were more likely to receive mammograms (OR for breast cancer surgeon 6.0, CI 4.9, 7.4, OR for oncologist 7.4, CI 6.1, 9.0). CONCLUSIONS: Breast cancer survivors who are at greater risk of recurrence are less likely to receive surveillance mammograms. Women without a visit to an oncologist or breast cancer surgeon during a year have particularly low rates of mammography. Improvements to surveillance care for breast cancer survivors may require active participation by primary care physicians and improvements in cancer survivorship programs by healthcare systems.

Diffusion of aromatase inhibitors for breast cancer therapy between 1996 and 2003 in the Cancer Research Network.

PURPOSE: Clinical trials demonstrated adjuvant aromatase inhibitor treatment is superior for decreasing breast cancer recurrence risk over adjuvant tamoxifen treatment as early as 2001. Yet clinical use for adjuvant treatment was not recommended by the American Society of Clinical Oncology until 2004. Aromatase inhibitor uptake after the first public presentation of randomized trial results but before the release of national guidelines is unclear. We evaluated diffusion of aromatase inhibitor dispensings for breast cancer treatment in integrated healthcare delivery systems across the United States. METHODS: We collected automated data for 13,245 women enrolled at seven integrated healthcare delivery systems in the Cancer Research Network. All women were aged >55 and diagnosed with estrogen receptor positive, invasive breast cancer between 1996 and 2003. We used electronic pharmacy data to identify aromatase inhibitor and tamoxifen dispensings through 2004. We evaluated the proportions of women who received hormone dispensings in two ways: (1) at any point after diagnosis to capture all use, and (2) in the two-year period following diagnosis to approximate adjuvant use. RESULTS: Over time, adjuvant aromatase inhibitor use increased whereas tamoxifen use decreased. Aromatase inhibitor dispensings within 2 years of diagnosis increased from 4.1% among women diagnosed in 2000 to 13% in 2001, 24% in 2002, and 40% in 2003. Tamoxifen use declined starting in 2001 at every system. CONCLUSION: Aromatase inhibitor use rose dramatically after 2001 while tamoxifen use decreased. It appears results from early clinical trials changed practice in these integrated healthcare systems before formal changes in national guidelines.

Mammography surveillance and mortality in older breast cancer survivors.

PURPOSE: There are more than 2,000,000 breast cancer survivors in the United States today. While surveillance for asymptomatic recurrence and second primary is included in consensus recommendations, the effectiveness of this surveillance has not been well characterized. Our purpose is to estimate the effectiveness of surveillance mammography in a cohort of breast cancer survivors with complete ascertainment of surveillance mammograms and negligible losses to follow-up. PATIENTS AND METHODS: We enrolled 1,846 stage I and II breast cancer patients who were at least 65 years old at six integrated health care delivery systems. We used medical record review and existing databases to ascertain patient, tumor, and therapy characteristics, as well as receipt of surveillance mammograms. We linked personal identifiers to the National Death Index to ascertain date and cause of death. We matched four controls to each breast cancer decedent to estimate the association between receipt of surveillance mammogram and breast cancer mortality. RESULTS: One hundred seventy-eight women died of breast cancer during 5 years of follow-up. Each additional surveillance mammogram was associated with a 0.69-fold decrease in the odds of breast cancer mortality (95% CI, 0.52 to 0.92). The protective association was strongest among women with stage I disease, those who received mastectomy, and those in the oldest age group. CONCLUSION: Given existing recommendations for post-therapy surveillance, trials to compare surveillance with no surveillance are unlikely. This large observational study provides support for the recommendations, suggesting that receipt of surveillance mammograms reduces the rate of breast cancer mortality in older patients diagnosed with early-stage disease.

Racial differences in tumor stage and survival for colorectal cancer in an insured population.

BACKGROUND: Despite declining death rates from colorectal cancer (CRC), racial disparities have continued to increase. In this study, the authors examined disparities in a racially diverse group of insured patients. METHODS: This study was conducted among patients who were diagnosed with CRC from 1993 to 1998, when they were enrolled in integrated healthcare systems. Patients were identified from tumor registries and were linked to information in administrative databases. The sample was restricted to non-Hispanic whites (n = 10,585), non-Hispanic blacks (n = 1479), Hispanics (n = 985), and Asians/Pacific Islanders (n = 909). Differences in tumor stage and survival were analyzed by using polytomous and Cox regression models, respectively. RESULTS: In multivariable regression analyses, blacks were more likely than whites to have distant or unstaged tumors. In Cox models that were adjusted for nonmutable factors, blacks had a higher risk of death from CRC (hazard ratio [HR], 1.17; 95% confidence interval [95% CI], 1.06-1.30). Hispanics had a risk of death similar to whites (HR, 1.04; 95% CI, 0.92-1.18), whereas Asians/Pacific Islanders had a lower risk of death from CRC (HR, 0.89; 95% CI, 0.78-1.02). Adjustment for tumor stage decreased the HR to 1.11 for blacks, and the addition of receipt of surgical therapy to the model decreased the HR further to 1.06. The HR among Hispanics and Asians/Pacific Islanders was stable to adjustment for tumor stage and surgical therapy. CONCLUSIONS: The relation between race and survival from CRC was complex and appeared to be related to differences in tumor stage and therapy received, even in insured populations. Targeted interventions to improve the use of effective screening and treatment among vulnerable populations may be needed to eliminate disparities in CRC.

Patterns and predictors of mammography utilization among breast cancer survivors.

BACKGROUND: Improvements in cancer detection and treatment have resulted in increasing numbers of breast cancer survivors. Information regarding the use of mammography by breast cancer survivors is limited. METHODS: The use of surveillance mammography was examined over a 5-year period in a retrospective cohort of women age>or=55 years who were diagnosed with incident primary breast cancer (1996-1997) while enrolled in 1 of 4 geographically diverse integrated health systems. RESULTS: Of the 797 women included in the study, 80% (n=636) underwent mammograms during the first year after treatment for breast cancer. The percentage of women having mammograms during each yearly period decreased significantly over time. In multivariable analyses, older women with comorbid illnesses or those with late-stage disease were less likely to undergo mammograms, whereas those who underwent breast-conserving therapy (adjusted odds ratio [OR] of 1.38 [95% confidence interval (95% CI), 1.09-1.75]) were more likely to have mammograms. Women who had outpatient visits with a gynecologist (adjusted OR of 3.49 [95% CI, 2.55-4.79]), or a primary care physician (adjusted OR of 2.21 [95% CI, 1.73-2.82]) during the year were more likely to undergo mammograms in that year. CONCLUSIONS: The use of mammography among breast cancer survivors declines over time. Efforts are needed to increase awareness among healthcare providers and breast cancer survivors of the value of follow-up mammography. The current findings highlight the importance of maintaining ongoing contact with primary care physicians and gynecologists.

Building a research consortium of large health systems: the Cancer Research Network.

Critical questions about cancer prevention, care, and outcomes increasingly require research involving large patient populations and their care delivery organizations. The Cancer Research Network (CRN) includes 11 integrated health systems funded by the National Cancer Institute (NCI) to conduct collaborative cancer research. This article describes the challenges of constructing a productive consortium of large health systems, and explores the CRN's responses. The CRN was initially funded through an NCI cooperative agreement in 1999 and has since received a second 4-year grant. Leadership and policy development are provided through a steering committee, subcommittees, and an external advisory committee. The CRN includes integral and affiliated research projects supported by a Scientific and Data Resources Core. Three characteristics of the CRN intensified the general challenges of consortium research: 1) its members are large health systems with legitimate concerns about confidentiality of data about enrollees, providers, and the organization; 2) CRN research projects often generate highly sensitive data about quality of care; and therefore 3) each participating organization wants a strong voice in CRN direction. CRN experience to date confirms that a consortium of health systems with internal research capacity can address a range of important cancer research questions that would be difficult to study in other venues. The advantages and challenges of consortium research are explored, with suggestions for the development, execution, and management of multisystem population laboratories.

Disparities and survival among breast cancer patients.

BACKGROUND: Although rates of survival for women with breast cancer have improved, the survival disparity between African American and white women in the United States has increased. PURPOSE: To determine whether this survival disparity persists in an insured population with access to medical care. METHODS: In this retrospective cohort study, we extracted data from the tumor registries of six nonprofit, integrated health care delivery systems affiliated with the Cancer Research Network and assessed the survival of African American (n = 2276) and white (n = 18 879) female enrollees who were diagnosed with invasive breast cancer from January 1, 1993, through December 31, 1998. Cox proportional hazards regression was used to estimate the death rate among African American women relative to that of white women after adjustment for potential explanatory factors including stage at diagnosis, tumor characteristics, and treatment. RESULTS: Five-year survival was lower for African American women (73.8%) than for white women (81.6%). African American women were less likely to have tumor characteristics with good prognosis. Controlling for age at diagnosis, stage, grade, tumor size, and estrogen and progesterone receptor status, the adjusted hazard rate ratio for African American women was 1.34 (95% confidence interval = 1.22 to 1.46). Similar risks were found among women ages 20-49 and 50 and older. Controlling for treatment slightly lowered the hazard rate ratio to 1.31 (95% confidence interval = 1.20 to 1.43). CONCLUSIONS: Among women with invasive breast cancer, being insured and having access to medical care does not eliminate the survival disparity for African American women.