Healthcare disparities exist. In particular, racial/ethnic minority populations have worse access to care and poorer quality of care for a wide range of conditions than their white counterparts 14, 17, 18
. In 2005, the Agency for Healthcare Research and Quality issued the National Healthcare Disparities Report which identified several barriers to quality healthcare encountered by minority populations 19
. Blacks, Hispanics, and Asians had worse access to care for 43% to 88% of indicators and received poorer quality of care for 21% to 53% of indicators relative to whites 19
. The reasons for these disparities are often unknown, but are likely multifactorial 17, 20, 21
. Once identified, these disparities represent interventional opportunities to improve patient treatment and subsequent outcomes.
RT represents a key component in the management of patients with local-regionally advanced BCa. RT is indicated for all patients undergoing breast conservation 1
. Post-mastectomy RT is the current standard for breast cancers with ≥ 4 axillary lymph node metastases 22
. These guidelines were established after compelling randomized clinical trial data indicated improved rates of local-regional control and survival2, 5, 6, 23
. As such, adherence to RT guidelines in advanced BCa patients is a surrogate marker of quality cancer care. We identified racial/ethnic disparities in the use of RT in advanced BCa patients with ≥10 lymph node metastases.
The racial/ethnic disparities identified on univariate logistic regression persisted on multivariate analysis controlling for potential confounders. Both black and Hispanic patients were less likely to receive RT compared to their white counterparts in the all-inclusive model. We reasoned that patients would be more likely to receive RT if they received lumpectomy as surgical treatment, as RT is a recognized component of breast conservation therapy. Post-mastectomy RT guidelines have been adopted more recently 22
. Significant statistical interactions existed among tumor size, type of surgery received, and use of RT. We therefore constructed two additional logistic regression models stratifying patients according to the type of surgical therapy received (mastectomy vs. lumpectomy). The stratified analysis allowed us to conclude that the most significant racial/ethnic disparities in use of RT occurred among black and Hispanic patients who had undergone mastectomy.
Despite the fact that post-mastectomy RT has been advocated for several decades, it can be argued that a significant proportion of patients included in the present study were diagnosed and treated prior to the advent of current guidelines. To ensure that the year of breast cancer diagnosis was not confounding the rates of RT usage, we performed additional logistic regression analyses inclusive of the years 1998 to 2005 with similar results regarding racial/ethnic disparities (data not shown).
Regardless of the racial/ethnic disparities noted, rates of RT were low for all populations (range, 46% to 54%). The reasons for this are unknown. It is possible that clinicians take a nihilistic approach to AJCC stage IIIC patients, assume that they have occult systemic disease, and eliminate consideration of RT altogether. Access to care is less likely to be the underlying cause, as reported rates of RT are higher for patients with early stage tumors receiving breast conservation. There are situations where the use of RT may be inappropriate, such as in cases of prior radiation exposure, collagen vascular disease, inability to lay flat, or unrelated patient co-morbidities. The SEER database does not allow us to capture these data fields, although it is unlikely that these factors alone could explain the overall low rates of RT seen in our study.
There are several other reasons why patients may not receive RT when indicated, which can be broadly characterized as physician factors, patient factors, and structural factors. Physicians may make different recommendations for treatment based on what they perceive the patient’s attitude towards treatment to be. In addition, there is some evidence 24
that physicians believe blacks are less likely to comply with treatment, which may influence their recommendations. In a study assessing the effect of race and sex on physicians’ recommendations for cardiac catheterization by Schulman et al, women and black patients were significantly less likely to be referred for cardiac catheterization than their male and white counterparts respectively 25
. Structural barriers such as lack of health insurance, income, transportation issues, language barriers, and family support are just some factors that may affect RT use 14
. Some researchers suggest that socioeconomic status (SES) is more predictive of treatment quality received than race or ethnicity 19, 26, 27
. Poverty, low education level, and lack of health insurance are known to contribute to poorer quality care. As highlighted in the AHRQ National Healthcare Disparities Report, blacks with higher incomes and at least some college education, and Hispanics of all income and education levels, are less likely to have health insurance than their white counterparts 19
. Unfortunately, our current analysis did not afford us the opportunity to assess individual patients’ SES with certainty. Patients also may refuse recommended treatment as a result of distrust of the medical system or the physician. Although some have shown that minority populations are more likely to refuse invasive procedures 21
, studies by Ayanian et al 28
and Canto et al 29
have demonstrated disparities in treatment even after adjusting for patient preferences or eliminating those who refused treatment, respectively. We have attempted to control for potential confounding factors that could influence our ability to detect differences between racial or ethnic groups, but this is admittedly hard to do.
We chose to examine only BCa patients with ≥ 10 lymph node metastases, rather than specifically those with ≥ 4 lymph node metastases to obtain a more uniform, homogeneous population. The prognosis for patients with AJCC stage IIIC BCa has been almost uniformly reported as poor. The racial/ethnic disparities noted with respect to receipt of RT raise the question of whether such treatment differences result in survival disparities. We intentionally chose not to examine potential differences in overall survival in the present study, so that we could better focus on treatment differences as a surrogate marker of disparities in quality of care.
We utilized use of RT as a single surrogate marker of quality cancer care, but there are certainly others 30
. Rates of breast reconstruction, and adherence to hormonal or systemic therapy guidelines are all potential surrogate markers of quality cancer care11, 30
, but these data fields are either limited or unavailable in the SEER database. While failure to adhere to RT use guidelines is not an absolute indicator of inferior care of an individual patient, such patterns across a large population of patients provides vital information that improvement is needed.