Regional Disparities in Breast Cancer Outcomes and the Process of Care
By Wong, Jan H | |
Proquest LLC |
Mortality from breast cancer in eastern
D ISPARITIES IN BREAST CANCER outcomes by race and ethnicity arewell recognized in the United States.1 Black women consistently experience the poorest breast cancer-specific survival, whereas white and Japanese women enjoy the best breast cancer-specific survival.2 The outcome of Native Hawaiians, Native Americans, and Latinas, although better than blacks, was inferior to white and Japanese women.2 The variability in outcomes among different race/ethnic groups is accepted to be multifactorial in origin. Factors implicated in the inferior outcomes observed in black women include more advanced stage at diagnosis,3 a lower proportion of hormone receptor-positive tumors,4 variability in the delivery of care,5 and socioeconomic factors.6
The interaction of race, ethnicity, socioeconomic status, and the delivery of care and its impact on outcome in breast cancer is complex. Adjustments for prognostic predictors reduces ethnic differences in breast cancer survival, but the lack of early detection, late stage at diagnosis, and limited access to health care remain important predictors of worse breast cancer survival.2 Geographic variations in breast cancer outcomes have been observed with conflicting evidence on the impact of a rural versus urban residence.7 Most studies have focused on socioeconomic factors to explain any apparent geographic variations in breast cancer outcomes.
Methods
Data Source
This study used data of female patients with breast cancer diagnosed within the 100 counties of
Patients
Female patients with the diagnosis of breast cancer, both invasive and noninvasive, were identified within the CCR. Demographic, pathologic data, and vital status at the time of last follow-up were requested from the CCR. Demographic data included the county in which the individual was diagnosed along with race/ ethnicity and age at diagnosis. Pathologic data included tumor size, pathologic T stage, pathologic N stage, and pathologic stage grouping at diagnosis, estrogen receptor status, and progesterone receptor status. Although currently a required reporting element, human epidermal growth factor receptor 2 status (HER-2/neu) during this time period was not required to be reported to the CCR. The date of surgery and the date of initiation of chemotherapy were requested. Individuals in whom the date of initiation of chemotherapy was absent were presumed not to have received adjuvant chemotherapy.
Statistical Analysis
Patients were stratified based on the county of diagnosis into one of two groups: ENC or RNC. Patient, tumor, and treatment characteristics were evaluated and compared between patients diagnosed in ENC and those diagnosed in RNC. Patients who were of undetermined stage or Stage IVat diagnosis were excluded from adjuvant chemotherapy analysis. The Student's t test was used to compare the means of continuous variables. The x2 test was used for univariate comparisons of categorical variables. Survival was calculated by themethod of Kaplan-Meier10 with significance assessed by the log-rank test. A Cox proportional hazard model was used to identify significant predictors of survival. Statistical analyses were performed using NCSS statistical software (
Results
Patient and Tumor Characteristics
During the 4-year period between
Of the total number of women diagnosed with breast cancer in
Adjuvant Systemic Chemotherapy
Adjuvant chemotherapy was not documented to have been received by the majority of women diagnosed with early-stage (non-Stage IV) breast cancer. However, there was no statistically significant difference in the delivery of adjuvant systemic chemotherapy in women diagnosed in ENC and RNC. Because the early delivery of systemic chemotherapy is associated with improved outcomes,12 we examined the time from surgery to delivery of adjuvant chemotherapy. Approximately 81 per cent of women in RNC received adjuvant chemotherapy within 90 days of surgery, whereas only 78.7 per cent of women in ENC received adjuvant chemotherapy within the same timeframe (P 4 0.02).
Survival
The survival of women with breast cancer diagnosed in ENC was significantly worse than the survival of women diagnosed in RNC (Fig. 2, P 4 0.003). White women experienced a 9-month improvement in median survival when compared with black women (Table 2). As anticipated, women who were estrogen receptorpositive and progesterone receptor-positive had significantly better breast cancer survival than women who were hormone receptor-negative.
The administration of adjuvant chemotherapy was significantly associated with improved survival. The median survival of patients who did not receive adjuvant chemotherapy was 32.9 months, whereas those patients who did receive adjuvant chemotherapy had a median survival of 46.6 months (P < 0.001). Furthermore, patients who received chemotherapy in a timely fashion (90 days of surgery or less) fared significantly better than women who did not (45.9 vs. 31.6 months, P < 0.001).
A Cox proportional hazard model demonstrated that race/ethnicity, estrogen receptor status, and the timely delivery of adjuvant chemotherapy remained statistically significant predictors of outcome (Table 3). However, the region of diagnosis (ENC vs. RNC) was no longer predictive of survival.
Discussion
Mortality from breast cancer has been declining since 1990 in the United States.13 Although less than whites, breast cancer death rates have declined in most race/ethnic groups in
A number of tumor factors and patient characteristics are recognized to be associated with survival in breast cancer. These include advanced stage at diagnosis, the absence of estrogen and progesterone receptors, 15 and the overexpression of Her2/neu.4, 16 To confirm the validity of our data set, a preliminary analysis of the study population was performed and confirmed with the exception of Her2/neu status, which was not part of our data set, that these recognized prognostic factors including race/ethnicity have significant prognostic significance. As expected, black women fared worse than white women, and T stage, N stage, stage grouping as well as hormone receptor status were all significantly associated with breast cancer survival.
Of the recognized breast cancer subtypes, the triple negative subtype tends to confer a significantly worse prognosis.4 Triple negative breast cancer is approximately three times more likely to be found in black women with breast cancer.4 Although Her2/neu status was not part of the data set, it is likely that the majority of women who were both estrogen- and progesterone receptor-negative were also Her2/neu-negative. The finding that more women were hormone receptornegative and likely triple negative is consistent with the overrepresentation of black women in ENC because triple negative breast cancer is known to more prevalent in that population of women.17
The reasons for the overrepresentation of blacks in patients with breast cancer in ENC are unclear. Despite broad differences in the percent of blacks living in the individuals counties of ENC, blacks represent a similar percentage (22.8%) of the entire population of ENC as of RNC (22.0%).8 No discernible difference between black women diagnosed in ENC and black women diagnosed in RNC could be identified in recognized prognostic factors suggesting that the overrepresentation of black women in ENC contributes to, but cannot alone explain, the disparate outcomes observed. This overrepresentation of black women warrants further investigation.
An unanticipated observation was that patients in ENC had similar pathologic T stage, pathologic N stage, and pathologic stage grouping to those in RNC. Relative to their black counterparts, however, white women present with earlier pathologic T stage, pathologic N stage, and pathologic stage grouping (data not shown).6, 11 This finding, along with the observation that race/ethnicity remains statistically associated with breast cancer survival in a multivariate analysis, is consistent with other reports that black women present with a more advanced stage of breast cancer than white women18 and that race/ethnicity impacts stage at diagnosis and survival.2
Adjuvant systemic chemotherapy has repeatedly been demonstrated to improve survival in women at risk for developing recurrent disease.19, 20 We were unable to discern a difference in the percentage of women receiving adjuvant chemotherapy in ENC when compared with RNC. However, when we examined the time to delivery of adjuvant systemic chemotherapy, women in ENC were significantly less likely to receive their adjuvant chemotherapy in a timely fashion, a variable that has been demonstrated to impact survival.12, 21 The observation that significant numbers of women in
Much of ENC is rural. Residents of rural communities tend to have lower income, less education, and no health insurance when compared with urban populations. Rural patients with cancer tend to be diagnosed at later stages of disease and have more advanced-stage illness than their urban counterparts.22 Variations in the treatment of localized breast cancer based on where the patient resides have been documented in patient undergoing breast-conserving surgery.23 Li and coworkers11 demonstrated that certain race/ethnic groups were more likely to receive inappropriate primary surgical and radiation breast cancer treatment. Bickell5 noted that women in underserved populations are less likely to receive adjuvant chemotherapy. Our findings are in keeping with these reports.
The reason(s) for the variability in the delivery of care are likely multifactorial. A previous report by Lanin and coworkers24 from our institution demonstrated a number of variables that were associated with late presentation of disease including difficulty in finding transportation to the doctor and the absence of private health insurance. Additionally, these investigators found that numerous cultural and psychological variables in the domains of healthcare use, folk beliefs, and beliefs in the treatment of breast cancer were associated with late stage at presentation as well. The coalescence of financial, logistic, and cultural issues likely contributes to the apparent disproportionate failure to receive timely systemic therapy in rural ENC relative to RNC.
Modern breast cancer treatment requires that a patient be under the sequential care of several physicians and receive a timely series of treatments. Uninsured Hispanics, non-Hispanic blacks as well as low-income individuals, a substantial subset of the breast cancer population in ENC, are recognized to be less likely to receive recommended cancer care.25-28 Our findings lend further support to this observation. Women with breast cancer in ENC may be failing to transition seamlessly through their breast cancer care. Nurse navigation has been initiated to attempt to address the transitions of care. Whether improvements in quality measures of care observed with nurse navigation programs will ultimately translate into improvements in breast cancer survival remain to be determined.29
Our report has a number of limitations. We were unable to document the local/regional care of women diagnosed with breast cancer in
Conclusions
This report demonstrates that recognized biologic factors such as estrogen receptor status and race/ethnicity are significant determinants of breast cancer outcome. However, the failure to deliver timely adjuvant chemotherapy appears to be significantly associated with breast cancer survival as well. The reasons for the failure to deliver timely adjuvant chemotherapy warrant further investigation. Specific interventions such as nurse navigation aimed at improving the seamless transition of care for vulnerable populations of women may contribute to improving breast cancer outcomes in ENC.
REFERENCES
1. Edwards BK, Brown ML, Wingo PA, et al. Annual report to the nation on the status of cancer, 1975-2002, featuring populationbased trends in cancer treatment. J Natl Cancer Inst 2005;97: 1407-27.
2. Maskarinec G, Sen C, Koga K, et al. Ethnic differences in breast cancer survival: status and determinants.
3. McBride R, Hershman D, Tsai WY, et al. Within-stage racial differences in tumor size and number of positive lymph nodes in women with breast cancer. Cancer 2007;110:1201-8.
4. Carey LA, Perou CM, Livasy CA, et al. Race, breast cancer subtypes, and survival in the Carolina Breast Cancer Study. JAMA 2006;295:2492-502.
5.
6. Lantz PM, Mujahid M, Schwartz K, et al. The influence of race, ethnicity, and individual socioeconomic factors on breast cancer stage at diagnosis.
7. McLafferty S, Wang F. Rural reversal? Cancer 2009;115: 2755-64.
8.
9. Trends and disparities in specific cancermortality in easternNorth Carolina. Available at: www.ecu.edu/cs-dhs/chsrd/HealthIndicator/.../ HI_ENC41_082807.pdf. Accessed
10. Kaplan E,
11. Li CI, Malone KE, Daling JR. Differences in breast cancer stage, treatment, and survival by race and ethnicity. Arch Intern Med 2003;163:49-56.
12. Lohrisch C, Paltiel C, Gelmon K, et al. Impact on survival of time from definitive surgery to initiation of adjuvant chemotherapy for early-stage breast cancer. J Clin Oncol 2006;24:4888-94.
13. Breast cancer facts and figures 2011-2012. Available at: www.cancer.org/acs/groups/content/@epidemiologysurveilance/ documents/document/acspc-030975.pdf. Accessed
14. Hery C, Ferlay J, Boniol M, et al. Quantification of changes in breast cancer incidence and mortality since 1990 in 35 countries with Caucasian-majority populations. Ann Oncol 2008;19:1187-94.
15. Fitzgibbons PL, Page DL, Weaver D, et al. Prognostic factors in breast cancer.
16. Slamon DJ, Clark GM,
17. Swede H, Gregorio DI, Tannenbaum SH, et al. Prevalence and prognostic role of triple-negative breast cancer by race: a surveillance study. Clin Breast Cancer 2011;11:332-41.
18. Boyer-Chammard A, Taylor TH,
19.
20. Peto R, Davies C, Godwin J, et al. Comparisons between different polychemotherapy regimens for early breast cancer: meta-analyses of long-term outcome among 100,000 women in 123 randomised trials. Lancet 2012;379:432-44.
21. Biagi JJ, Raphael J, King WD, et al. The effect of delay in time to adjuvant chemotherapy (TTAC) on survival in breast cancer (BC): a systematic review and meta-analysis. J Clin Oncol 2011; 29(suppl):Abstract 1128.
22. Monroe AC, Ricketts TC, Savitz LA. Cancer in rural versus urban populations: a review.
23. Farrow DC, Hunt WC, Samet JM. Geographic variation in the treatment of localized breast cancer. N Engl J Med 1992;326: 1097-101.
24. Lannin DR,
25. Shavers VL, Brown ML. Racial and ethnic disparities in the receipt of cancer treatment. J Natl Cancer Inst 2002;94:334-57.
26. Elmore JG, Nakano CY, Linden HM, et al. Racial inequities in the timing of breast cancer detection, diagnosis, and initiation of treatment. Med Care 2005;43:141-8.
27. Ensuring Quality Cancer Care. National Cancer Policy Board,
28.
29. Weber JJ, Mascarenhas DC, Bellin LS, et al. Patient navigation and the quality of breast cancer care: an analysis of the breast cancer care quality indicators. Ann Surg Oncol 2012;19: 3251-6.
30. Fisher B, Anderson S, Bryant J, et al. Twenty-year followup of a randomized trail comparing total mastectomy, lumpectomy, and lumpectomy plus irradiation for the treatment of invasive breast cancer. N Engl J Med 2002;347:1233-41.
31. Baquet CR, Commiskey P. Socioeconomic factors and breast carcinoma in multicultural women. Cancer 2000;88(suppl): 1256-64.
32. Gordon NH. Socioeconomic factors and breast cancer in black and white Americans. Cancer Metastasis Rev 2003;22: 55-65.
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