|
|
||||||||
RESEARCH AND PRACTICE |
At the time of the study, Lisa C. Richardson was with the Department of Medicine, University of Florida, Gainesville. Lili Tian is with the Department of Statistics and Abraham G. Hartzema is with the Department of Pharmacy Health Care Administration, University of Florida, Gainesville. Lydia Voti, Lora E. Fleming, and Jill MacKinnon are with the Florida Cancer Data System, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, Fla. Isildinha Reis is with the Division of Biostatistics, Sylvester Comprehensive Cancer Center, and the Department of Epidemiology and Public Health, University of Miami Miller School of Medicine, Miami.
Correspondence: Requests for reprints should be sent to Lisa C. Richardson, MD, MPH, Division of Cancer Prevention and Control, National Center for Chronic Disease Prevention and Health Promotion, 4770 Buford Hwy, NE, Mail Stop K-55, Atlanta, GA 30341 (e-mail: lfr8{at}cdc.gov).
| ABSTRACT |
|---|
|
|
|---|
Objectives. We examined the roles of teaching hospitals, insurance status, and race/ ethnicity in womens receipt of adjuvant therapy for regional-stage breast cancer.
Methods. Data were taken from the Florida Cancer Data System for cases diagnosed from July 1997 to December 2000. We evaluated the impact of health insurance status and hospital type on use of adjuvant therapy (after adjustment for age, race/ethnicity, and marital status). Interaction terms for hospital type, insurance status, and race/ethnicity were entered in each model.
Results. Teaching facilities diagnosed 12.5% of the cases; however, they cared for a disproportionate percentage (21.3%) of uninsured and Medicaid-insured women. Among women who received adjuvant chemotherapy only, those diagnosed in teaching hospitals were more likely than those diagnosed in nonteaching hospitals to receive therapy regardless of insurance status or race/ethnicity. Among women who received chemotherapy with or without hormonal therapy, Hispanics were more likely than White non-Hispanic women to receive therapy, whereas women with private insurance or Medicare were less likely than uninsured and Medicaid-insured women to receive this type of therapy.
Conclusions. Teaching facilities play an important role in the diagnosis and treatment of regional-stage breast cancer among Hispanics, uninsured women, and women insured by Medicaid.
| INTRODUCTION |
|---|
|
|
|---|
Many factors have been shown to predict use of chemotherapy in regional-stage breast cancer, including age,79 race/ethnicity,7,10 and socioeconomic factors (education, income, and health insurance status).5,11,12 Some studies indicate that African American women are more likely than White women to undergo chemotherapy, but these differences disappear after control for breast cancer stage.7,12 In a study of women diagnosed with breast cancer in the Metropolitan Detroit area, Bradley and colleagues found that women insured by Medicaid (a proxy measure for lower socioeconomic status) were less likely to receive appropriate treatment than women with other types of insurance, regardless of their race/ethnicity.13 Other researchers have reported that race/ethnicity11,14 and type of health insurance5,11 predict breast cancer treatment as well. Defining the separate roles of race/ethnicity and socioeconomic status in breast cancer treatment and survival has proven very difficult, because minority women tend to have lower incomes and lower educational attainment than do White women, and they are also less likely to have health insurance.15,16
Health insurance plays a critical role in access to medical care. Health care for the uninsured and those insured by Medicaid has become more challenging as more health care providers no longer accept these patients.1719 Safety-net providers exist for primary care, but uninsured and Medicaid-insured patients access to expensive specialty care is limited.15,17 For such patients, teaching hospitals are safety-net care providers.
Our preliminary analyses of Florida Cancer Data System (FCDS) data from July 1997 through December 2000 revealed that uninsured women and those insured by Medicaid were more likely than women with private insurance to receive adjuvant therapy for regional-stage breast cancer.20 In an effort to explain these findings, we asked the following questions: What is the role of teaching hospitals in providing care for regional-stage breast cancers? How did the receipt of adjuvant therapy for regional-stage breast cancers differ by race/ethnicity and insurance status among the women in our study?
| METHODS |
|---|
|
|
|---|
The population eligible for this study consisted of 11 175 women with primary cases of regional-stage breast cancer (defined, according to Surveillance and End Results Registry [SEER] summary stage classification, as breast cancers that extend directly from the breast and breast cancers in which the lymph nodes are positive23) diagnosed between July 1, 1997, and December 31, 2000. Lymph nodes were positive in more than 90% of the cases. FCDS collects data on all cancer-directed treatment administered in the first 4 to 12 months of a breast cancer diagnosis. All treatment modalities are included, regardless of sequence, degree of completeness, and whether treatment was performed at the reporting hospital or elsewhere.21
Definitions
FCDS codes chemotherapy as follows: 0 = no chemotherapy; 1 = chemotherapy, not otherwise specified; 2 = chemotherapy, single agent; 3 = chemotherapy, multiple agents (combination regimen); 7 = patient or patients guardian refused chemotherapy; 8 = chemotherapy recommended, unknown whether administered; 9 = unknown whether chemotherapy administered. Hormonal therapy (including oral medications such as tamoxifen) is coded similarly: 0 = no hormonal therapy; 1= hormonal therapy (including hormonal therapy not otherwise specified and therapy with antihormones); 2 = endocrine surgery (surgical removal of the ovaries); 3 = combination of 1 and 2; 7 = patient or patients guardian refused hormonal therapy; 8 = hormonal therapy recommended, unknown whether administered; and 9 = unknown.
To examine "adjuvant treatment received" versus "no adjuvant treatment received," we created 2 dichotomous outcome variables: (1) adjuvant therapy with chemotherapy alone and (2) "any adjuvant therapy," which includes chemotherapy alone, hormonal therapy alone, or the 2 therapies together. Like other researchers,10,24 we recoded the FCDS codes 1, 2, 3, and 8 as "therapy received"; we recoded 0 and 7 as "no therapy received"; and we coded 9 as "unknown."
More than 95% of the women in our data set received all or a portion of their therapy at the reporting hospital (the hospital that reported the case to the state cancer registry). The reporting hospital was usually the hospital where the case was diagnosed. For the sake of simplicity, we use the terms "diagnosed in," "treated in," and "reported from" interchangeably.
Data Analysis
Age at diagnosis was employed as a continuous variable. Race and ethnicity were combined into a race/ethnicity variable and cases were assigned to mutually exclusive categories: White non-Hispanic, Black non-Hispanic, and Hispanic. Because of the small number of American Indian/Alaska Native and Asian and Pacific Islander cases (n = 64), these cases were excluded.
Health insurance status was collapsed into 5 categories: uninsured (including uninsured and self-paying), privately insured (including private insurance; managed care; insured, type unknown; and CHAMPUS and military), Medicare-insured (including Medicare, Veterans Affairs, Indian Health Service, and Public Health Service), Medicaid-insured (Medicaid and welfare), and unknown. The 139 women insured by CHAMPUS and military insurance were included with the privately insured because these insurance types reimbursed providers on a fee-for-service basis. Marital status was defined as single (never married or marriage annulled), married (including common-law marriages), separated or divorced, widowed, and unknown.
We categorized reporting facilities into 2 broad categories: American Association of Medical College (AAMC)recognized training programs versus all other facilities. AAMC is a nonprofit organization representing the nations 125 accredited medical schools and nearly 400 major hospital-based teaching programs.25 There are 8 AAMC-recognized teaching hospitals (3 accredited medical schools and 5 major hospital-based programs) and 197 nonteaching hospitals in Florida.
We fitted 2 multivariate logistic regression models to estimate the odds of a patients receiving adjuvant therapy versus not receiving adjuvant therapy. The model included the following covariates: age at diagnosis, race/ ethnicity, marital status, health insurance status, and type of hospital (teaching vs nonteaching).
Interaction terms between insurance status and marital status; race/ethnicity and teaching hospital; and teaching hospital and health insurance were tested for both outcomes. Interaction terms were included in the final model if they were statistically significant at the 5% level. We estimated odds ratios (ORs) with corresponding 95% confidence intervals (CIs); ORs were considered significant if the corresponding 95% CI did not include 1.0. We used SAS statistical software, version 9.0 (SAS Institute Inc, Cary, NC), for data analysis.
| RESULTS |
|---|
|
|
|---|
The demographic, insurance, and treatment characteristics of the study population are shown in Table 1
. Mean age at diagnosis was 61 years (range, 21104 years). Hispanic women and Black non-Hispanic women accounted for approximately 20% of the study population. Five percent of the study population were uninsured, 51.8% had private insurance, 36.3% were covered by federal insurance (Medicare), and 3.4% were covered by state-sponsored insurance (Medicaid). Approximately 12.5% of the cases were diagnosed in teaching hospitals. Approximately 50% were treated with chemotherapy only and 57% with combined therapy within the first 4 to 12 months after diagnosis.
|
Next we modeled the odds of receiving chemotherapy alone, accounting for the covariates shown in Table 1
. Age at diagnosis was the most significant predictor of receiving chemotherapy; with each 1-year increase in age, starting at age 50, the odds of receiving chemotherapy decreased by 5% (OR = 0.95, 95% CI = 0.95, 0.96; Table 2
). Marital status remained significant in the presence of other factors, with married women and separated or divorced women approximately 33% to 34% more likely than single women to receive chemotherapy.
|
Health insurance coverage affected the odds of receiving chemotherapy by hospital type. In teaching facilities, the odds of receiving chemotherapy for women insured by private insurance, Medicare, or Medicaid did not statistically differ from the odds for uninsured women (Table 2
). However, although the difference was not statistically significant, Medicare-insured women had lower odds (OR = 0.60; 95% CI = 0.35, 1.03) of receiving chemotherapy than uninsured women, and Medicaid-insured women had twice the odds (OR = 2.08; 95% CI = 0.99, 4.40) of receiving chemotherapy compared with uninsured women. In nonteaching facilities, women insured by Medicaid had lower odds of receiving chemotherapy than uninsured women, although the difference was not statistically significant (OR = 0.73; 95% CI = 0.48, 1.09); privately insured women and women insured by Medicare were almost 30% less likely than uninsured women to receive chemotherapy.
Next we examined receipt of "any adjuvant therapy" (chemotherapy alone or with hormonal therapy; Table 3
). In comparison to the logistic model for receipt for chemotherapy alone, only 1 interaction term (race/ ethnicity x hospital type) was significant (P = .01). The odds of receiving combined therapy decreased by 3% with each 1-year increase in age (OR = 0.97: 95% CI = 0.9, 0.98). Marital status remained significant in the overall model: married, separated, or divorced women were 32% more likely than single women to receive "any adjuvant therapy." Health insurance status remained a significant predictor of receipt of any adjuvant therapy: women insured by private insurance or Medicare were less likely than uninsured women to receive therapy (OR = 0.71; 95% CI = 0.56, 0.90 vs OR = 0.74; 95% CI = 0.57, 0.96).
|
| DISCUSSION |
|---|
|
|
|---|
We found that among women whose regional-stage breast cancer was diagnosed in teaching hospitals, Medicaid-insured and uninsured women had the highest likelihood of receiving chemotherapy. Women covered by private insurance or Medicare were less likely to receive chemotherapy in this setting. For combined systemic therapy, health insurance remained significant in the overall model predicting receipt of treatment, with Medicaid-insured women and uninsured women receiving similar treatment. Osteen and colleagues33 reported similar findings; however, they did not control for possible confounders of the relationship between chemotherapy use and teaching hospitals. Other investigators have reported results contrary to ours, finding privately insured women more likely than uninsured women or those covered by state-sponsored health insurance to receive chemotherapy.5,31,32
We also found that treatment differed for different racial/ethnic groups depending on hospital type. As a group, Hispanics have the highest proportions of uninsured persons in the United States, increasing their risk of receiving inadequate care.16 In our study, Hispanic women diagnosed in teaching hospitals were as likely as White non-Hispanic women diagnosed in teaching hospitals to receive systemic therapy. However, in nonteaching hospitals, the situation for Hispanic women was dramatically different: they were 42% less likely than White non-Hispanic women to receive systemic therapy. In contrast to Hispanic women, Black non-Hispanic women diagnosed in teaching hospitals were less likely than White non-Hispanic women diagnosed in teaching hospitals to receive combined systemic therapy.
In our sample, almost 80% of the Hispanic women were diagnosed in 3 counties, and those treated in teaching facilities were reported by 3 hospitals. These results may reflect the effect of community and targeted social support resources within the teaching facilities treating these women. For example, in areas where Spanish speakers were concentrated, translators might be more readily available to Spanish-speaking women, facilitating their understanding and acceptance of adjuvant therapy. Black non-Hispanic women may not have had similar social support resources, given their lack of geographic concentration. Alternatively, the differences within teaching facilities between Hispanics and Black non-Hispanics, compared with White non-Hispanics, may reflect the fact that the Black non-Hispanic women may have had more comorbid conditions, since these women are more likely to experience toxicity,34 and that these comorbid conditions may have resulted in lower use of chemotherapy.
Previous research examining the accuracy of cancer registry data found that data collected from services provided in hospitals are more complete than data from freestanding clinics or doctors offices.35,36 One possible explanation for our finding that women diagnosed in teaching hospitals were more likely to receive adjuvant treatment for regional-stage breast cancer is that data from teaching hospitals may, in theory, be more complete, because chemotherapy is administered in the hospital-based clinics. However, we found no studies supporting or refuting this possibility, and because most women diagnosed in nonteaching hospitals were treated within those hospitals as well, this is an unlikely explanation.
Another possible explanation for this finding is that the teaching hospitals may indeed be providing the recommended standard of care to their breast cancer patients,29,37 consistent with recent reports that the mission of teaching hospitals is to be innovators and first adopters of new treatments and technologies.38 This mission benefits the underserved women who are most likely to be treated in these hospitals.
Malin et al.35 reviewed studies that used data from cancer registries to examine quality of treatment, and these studies found, as we did, that women treated in teaching hospitals were more likely than those treated in non-teaching hospitals to receive adjuvant therapy. Our findings about age and treatment are also consistent with those of others, in that the odds of receiving chemotherapy decreased with increasing age at diagnosis.610,31,32,3941 With the addition of hormonal therapy, the proportion of women assigned to adjuvant therapy increased, but the associations remained the same. Our results confirmed others observations that the use of combined therapy decreases with increasing age.10,31,32 Although we were not able to address comorbidity as a cause of decreased use of adjuvant therapy for regional-stage breast cancer, others have reported that age remains an independent determinant of treatment after comorbidity is accounted for.7,9,42
Our study had several other limitations that may affect the interpretation of our results. First, accuracy and completeness of data decreases when women receive treatment in an outpatient setting.33,35 We attempted to enrich our data by linking FCDS registry data with discharge data from hospitals and ambulatory care facilities in Florida. This linkage did not have an impact on the completeness of data on chemotherapy or hormonal therapy. In addition, we were unable to examine doctorpatient interactions or patient preferences for treatment, which are known to affect treatment decisions.31,4245
Another concern is potential misclassification of treatment outcomes because of lack of data about patients estrogen and progesterone receptor status, since these markers predict response to hormonal therapy.1,2,46 Older women were more likely to receive combined therapy, consistent with the finding that older women are more likely to have estrogen receptorpositive breast cancer, which is responsive to hormonal therapy.47 We also noted that Black non-Hispanic women had the highest likelihood of receiving chemotherapy only, consistent with reports of Black women having a higher likelihood of estrogen receptornegative breast cancer.48 This probably explains the smaller increase in use of "any adjuvant therapy" for Black non-Hispanic women than for White non-Hispanic women, given their expected negative estrogen receptor status.
Our results may not be generalizable to other states and other health care systems operating at the local level; multiple studies have shown significant geographic variation in medical resources and medical care (including number of specialists and number of hospitals capable of providing state-of-the-art cancer care).29 Our results reflect practice patterns in Florida between July 1997 and December 2000. We used health insurance status as a proxy for socioeconomic statusan imperfect proxy at best.13 Given the different populations served by teaching and nonteaching facilities, our findings may be subject to residual confounding by socioeconomic factors that we were not able to measure.
Despite its limitations, our study has several strengths and adds to our knowledge of how hospital type interacts with health insurance status and race/ethnicity to influence the treatment of regional-stage breast cancer. The sample size was large enough to allow us to make definitive conclusions about the patterns of care in a diverse population and to examine a number of potentially confounding variables. We were able to examine interactions between hospital type and health insurance status and race/ethnicity that affected the outcome of treatment for women with regional-stage breast cancer. Though health insurance is a powerful predictor of access to health care, its effect can be modified by other factors, such as whether a health care facility associated with a teaching program is available to the patient.11,16,26 We were able to examine teaching hospitals as a source of care, highlighting the positive impact these hospitals have on breast cancer care for medically under-served women in Florida.
Women with regional-stage breast cancer who receive adjuvant treatment after surgery and radiation therapy have better survival rates than do women who are not treated in this manner.3,46 Our examination of interactions between health insurance, race/ ethnicity, and teaching hospitals highlights the important role teaching hospitals have in delivering treatment for regional-stage breast cancer among the uninsured, the underinsured, and minority women. Academic health centers, public and private, have assumed up to 40% of the care of uninsured persons in their communities over the last decade.28 The influx of uninsured patients into teaching hospitals has occurred in communities with a high penetration of managed care organizations into the health care marketplace.18,28
It is heartening to find that teaching hospitals in Florida have been able to continue to provide evidence-based care for medically underserved women. In an environment of threatened cuts to Medicaid and decreased funding to teaching hospitals, our findings provide support for maintaining or increasing funding to these health care facilities because of the significant amount of care they provide to minority, uninsured, and Medicaid-insured women that is compatible with published clinical guidelines. Ultimately, delivery of appropriate breast cancer treatment based on stage at diagnosis3,46 will lessen health disparities among medically under-served women.
| Acknowledgments |
|---|
We would like to thank Mary Ann Shumate for her tireless assistance during the study, Edward Trapido for his encouragement, and all of the local cancer registry staff across Florida who report to the FCDS.
Human Participant Protection
The Florida Department of Health and the institutional review boards of the University of Florida and the University of Miami approved the protocol for this study.
| Footnotes |
|---|
Contributors
L. C. Richardson originated the study, obtained funding, designed the study and analyses, supervised all aspects of the studys implementation, and led the writing of the article. L. Tian assisted with the studys design and developed the analysis plan. L. Voti assisted with the creation of the analysis database and with data analyses. A. G Hartzema assisted with the design and implementation of the study. I. Reis assisted with the data analyses. L. E. Fleming assisted with the implementation of the study and with analysis plans and contributed to the writing. J. MacKinnon assisted with the implementation of the study and creation of the analysis database. All authors participated in interpreting the results and in critically reviewing drafts of the article.
Accepted for publication January 22, 2005.
| References |
|---|
|
|
|---|
2. NIH consensus conference. Treatment of early-stage breast cancer. JAMA. 1991;265:391395.
3. Systemic treatment of early breast cancer by hormonal, cytotoxic, or immune therapy. 133 randomised trials involving 31,000 recurrences and 24,000 deaths among 75,000 women. Early Breast Cancer Trialists Collaborative Group. Lancet. 1992;339:115.[Web of Science][Medline]
4. Goldhirsh A, Glick JH, Gelber RD, Coates AS, Senn HJ. Meeting highlights: International Consensus Panel on the Treatment of Primary Breast Cancer. J Clin Oncol. 2001;19:38173827.
5. Bickell NA, Aufses AH Jr, Chassin MR. The quality of early-stage breast cancer care. Ann Surg. 2000; 232:220224.[CrossRef][Web of Science][Medline]
6. Lash TL, Silliman RA, Guadagnoli E, Mor V. The effect of less than definitive care on breast carcinoma recurrence and mortality. Cancer. 2000;89: 17391747.[CrossRef][Web of Science][Medline]
7. Du X, Goodwin JS. Patterns of use of chemotherapy for breast cancer in older women: findings from Medicare claims data. J Clin Oncol. 2001;19: 14551461.
8. Bouchardy C, Rapiti E, Fioretta P, et al. Under-treatment strongly decreases prognosis of breast cancer in elderly women. J Clin Oncol. 2003;21:35803587.
9. Silliman RA, Guadagnoli E, Weitberg AB, Mor V. Age as a predictor of diagnosis and initial intensity in newly diagnosed breast cancer patients. J Gerontol. 1989;44: M4650.
10. Du XL, Key CR, Osborne C, Mahnken JD, Goodwin JS. Discrepancy between consensus recommendations and actual community use of adjuvant chemotherapy in women with breast cancer. Ann Intern Med. 2003; 138:9098.
11. Breen N, Wesley MN, Merrill RM, Johnson K. The relationship of socio-economic status and access to minimum expected therapy among female breast cancer patients in the National Cancer Institute Black-White Survival Study. Ethn Dis. 1999;2:111125.
12. Muss HB, Hunter CP, Wesley M, et al. Treatment plans for black and white women with stage II node-positive breast cancer. The National Cancer Institute Black/White Cancer Survival Study Experience. Cancer. 1992;70:24602467.[CrossRef][Web of Science][Medline]
13. Bradley CJ, Given CW, Roberts C. Race, socioeconomic status, and breast cancer treatment and survival. J Natl Cancer Inst. 2002;94:490496.
14. Roetzheim RG, Gonzalez EC, Ferrante JM, Pal N, Van Durme DJ, Krischer JP. Effects of health insurance and race on breast carcinoma treatments and outcomes. Cancer. 2000;89:22022213.[CrossRef][Web of Science][Medline]
15. Duncan RP, Vogel WB, Porter CK, Garvin CW. The Florida Health Insurance Study. January 2000. Available at: http://www.fdhc.state.fl.us/Publications/TechnicalReports/index.shtml. Accessed February 3, 2004.
16. Rhodes JA. The uninsured in America2002: estimates for the civilian noninstitutionalized population under age 65. Available at: http://www.meps.ahrq.gov/papers/st19/stat19.htm. Accessed December 29, 2003.
17. Felland, L, Felt-Lisk S, McHugh M. Health care access for low-income people: significant safety net gaps remain. Issue Brief No. 84, Center for Studying Health System Change. June 2004. Available at: http://www.hschange.org/CONTENT/682. Accessed October 15, 2005.
18. Cunningham PJ, Grossman JM, St Peter RF, Lesser CS. Managed care and physicians provision of charity care. JAMA. 1999;282:10871092.
19. Woodwell DA, Cherry DK. National Ambulatory Medical Care Survey: 2002 summary. Adv Data Vital Health Stat. August 26, 2004;no. 346:144.
20. Richardson L, Hartzema A, Voti L, MacKinnon J, Fleming L, Trapido E. Chemotherapy for regional stage breast cancer in Florida [abstract]. Proc Am Soc Clin Oncol. 2003;22:535. Abstract 2154.
21. Florida Cancer Data System. Available at: http://www.fcds.med.miami.edu/info/index.html. Accessed February 3, 2004.
22. Hotes JL, Wu XC, McLaughlin CC, et al., eds. Cancer in North America, 19962000. Volume One: Incidence. Springfield, Ill: North American Association of Central Cancer Registries; May 2003.
23. Shambaugh EM, Weiss MA, eds. SEER summary staging manual1977: codes and coding instructions. Bethesda, Md: National Cancer Institute; 1997. NIH publication NO 97-4969.
24. Mariotto A, Feuer EJ, Harlan LC, Wun L-M, Johnson KA, Abrams J. Trends in the use of adjuvant multi-agent chemotherapy and tamoxifen for breast cancer in the United States: 19751999. J Natl Cancer Inst. 2002;94:16261634.
25. American Association of Medical Colleges. Available at: http://www.aamc.org. Accessed February 3, 2003.
26. Institute of Medicine. Coverage matters: insurance and health care. October 11, 2001. Available at: http://www.iom.edu/report.asp?id=4662. Accessed July 27, 2004.
27. Silliman RA, Troyan SL, Guadagnoli E, Kaplan SH, Greenfield S. The impact of age, marital status, and physicianpatient interactions on the care of older women with breast carcinoma. Cancer. 1997;80: 13261334.[CrossRef][Web of Science][Medline]
28. Blumenthal D, Thier SO. A shared responsibility: academic health centers and the provision of care to the poor and uninsured. A report to the Commonwealth Fund, Task Force on Academic Health Centers. April 2001. Available at: http://www.cmwf.org. Accessed February 3, 2003.
29. Blumenthal D, Thier SO. Health care at the cutting edge: the role of academic health centers in the provision of specialty care. A report to the Commonwealth Fund, Task Force on Academic Health Centers. July 2000. Available at: http://www.cmwf.org. Accessed July 26, 2004.
30. Osteen RT, Karnell LH. The National Cancer Database report on breast cancer. Cancer. 1994;73: 19942000.[CrossRef][Web of Science][Medline]
31. Mandelblatt JS, Hadley J, Kerner JF, et al. for the Outcomes and Preferences for Treatment in Older Women Nationwide Study (OPTIONS) Research Team. Patterns of breast carcinoma treatment in older women. Cancer. 2000;89:561573.[CrossRef][Web of Science][Medline]
32. White J, Morrow M, Moughan J, et al. Compliance with breast-conservation standards for patients with early-stage breast carcinoma. Cancer. 2003;97: 893904.[CrossRef][Web of Science][Medline]
33. Osteen RT, Winchester DP, Hussey DH, et al. Insurance coverage of patients with breast cancer in the 1991 Commission on Cancer Patient Care Evaluation Study. Ann Surg Oncol. 1994;1(6):462467.[Abstract]
34. Ayanian JZ, Kohler BA, Abe T, Epstein AM. The relation between health insurance coverage and clinical outcomes among women with breast cancer. N Engl J Med. 1993;329:326331.
35. Malin JL, Schuster MA, Kahn KL, Brook RH. Quality of breast cancer care: what do we know? J Clin Oncol. 2002;20:43814393.
36. Bickell NA, Chassin MR. Determining the quality of breast cancer care: do tumor registries measure up? Ann Intern Med. 2000;132:705710.
37. Ayanian JZ, Weissman JS. Teaching hospitals and quality of care: a review of the literature. Milbank Q. 2002;80:569593.[CrossRef][Web of Science][Medline]
38. Nattinger AB, Gottlieb MS, Veum J, Yahnke D, Goodwin JS. Geographic variation in the use of breast-conserving treatment for breast cancer. N Engl J Med. 1992;326:11021107.[Abstract]
39. Hillner BE, Penberthy L, Desch CE, McDonald MK, Smith TJ, Retchin SM. Variation in staging and treatment of local and regional breast cancer in the elderly. Breast Cancer Res Treat. 1996;40:7586.[CrossRef][Web of Science][Medline]
40. Golledge J, Wiggins JE, Callam MJ. Age-related variation in the treatment and outcomes of patients with breast carcinoma. Cancer. 2000;88:369374.[CrossRef][Web of Science][Medline]
41. Nagel G, Rohrig B, Hoyer H, Wedding U, Katenkamp D. A population-based study on variations in the use of adjuvant systemic therapy on postmenopausal patients with early stage breast cancer. J Cancer Res Clin Oncol. 2003;129:183191.[Web of Science][Medline]
42. Houterman S, Janssen-Heijnen ML, Verheij CD, et al. Comorbidity has negligible impact on treatment and complications but influences survival in breast cancer patients. Br J Cancer. 2004;90:23322337.[Web of Science][Medline]
43. Wolberg WH. Mastectomy or breast conservation in the management of primary breast cancer: psychosocial factors. Oncology. 1990;4:101104.
44. Moyer A, Salovey P. Patient participation in treatment decision making and the psychosocial consequences of breast cancer surgery. Womens Health. 1998;4:103116.[Medline]
45. Katz SJ, Lantz PM, Zemencuk JK. Correlates of surgical treatment type for women with noninvasive and invasive breast cancer. J Womens Health Gend Based Med. 2001;10:659670.[CrossRef][Web of Science][Medline]
46. Tamoxifen for early breast cancer: an overview of the randomised trials. Early Breast Cancer Trialists Collaborative Group. Lancet. 1998;351:14511467.[CrossRef][Web of Science][Medline]
47. Silliman RA, Guadagnoli E, Rakowski W, et al. Adjuvant tamoxifen prescription in women 65 years and older with primary breast cancer. J Clin Oncol. 2002;20:26802688.
48. Elledge RM, Clark GM, Chamness GC, Osborne CK. Tumor biologic factors and breast cancer prognosis among white, Hispanic, and black women in the United States. J Natl Cancer Inst. 1994;86:705712.
This article has been cited by other articles:
![]() |
A. H. Haider, D. C. Chang, D. T. Efron, E. R. Haut, M. Crandall, and E. E. Cornwell III Race and Insurance Status as Risk Factors for Trauma Mortality Arch Surg, October 1, 2008; 143(10): 945 - 949. [Abstract] [Full Text] [PDF] |
||||
![]() |
L.-A. Ho, C.-Y. Lin, T.-H. Kuo, Y.-K. Kuo, and Y.-L. Kuo Applying Deeper Learning and Confucian Values in Enhancing School Effectiveness: Empirical Results and Findings Urban Education, September 1, 2008; 43(5): 561 - 586. [Abstract] [PDF] |
||||
![]() |
E. Ward, M. Halpern, N. Schrag, V. Cokkinides, C. DeSantis, P. Bandi, R. Siegel, A. Stewart, and A. Jemal Association of Insurance with Cancer Care Utilization and Outcomes CA Cancer J Clin, January 1, 2008; 58(1): 9 - 31. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. MacKinnon, R. C. Duncan, Y. Huang, D. J. Lee, L. E. Fleming, L. Voti, M. Rudolph, and J. D. Wilkinson Detecting an Association between Socioeconomic Status and Late Stage Breast Cancer Using Spatial Analysis and Area-Based Measures Cancer Epidemiol. Biomarkers Prev., April 1, 2007; 16(4): 756 - 762. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |