Racial disparities in cancer survival among randomized clinical trials patients of the Southwest Oncology Group

Impact of race and ethnicity on outcomes for estrogen receptor-negative breast cancers: experience of an academic center with a charity hospital

BACKGROUND

African American women have a higher breast cancer mortality rate than Caucasian women. Estrogen receptor (ER)-negative tumors, which are more aggressive than ER-positive tumors, occur more frequently in African American women than in Caucasian women and may contribute to apparent disparities in outcomes. However, outcome results need to be controlled for socioeconomic status (SES). We evaluated the effect of race and ethnicity on outcomes of patients with ER-negative tumors by determining outcomes in African American and Caucasian women with low SES but similar access to care.

STUDY DESIGN

From a prospective database of 786 patients with stage 0 to III breast cancer, all 375 patients with ER-negative tumors were evaluated. Patients received standard definitive operations and adjuvant treatment. Compliance with treatment was more than 90%. Primary endpoints were cancer recurrence and overall survival (OS). Statistical analysis performed included Kaplan-Meier survival analysis, log-rank test, Cox proportional hazard model, Student's t-test, and chi-squared test. A p value < or = 0.05 was considered statistically significant.

RESULTS

Fifty-four percent of African American patients had ER-negative tumors versus 39% in Caucasian patients. In both groups, 69% of patients received free care or Medicaid, with a median income of $16,577 (range $15,367 to $36,788). Comparing the 2 racial and ethnic groups, mean tumor size (p = 0.19), tumor grade distribution (p = 0.32), nodal distribution (p = 0.50), stage distribution (p = 0.30), rate of mastectomy (p = 0.47), receipt of adjuvant chemotherapy (p = 0.07), and financial class distribution (p = 0.67) were not significantly different. The 5-year OS was 77% for both groups (p = 0.59). On multivariate analysis, race and ethnicity were not independent predictors of OS (p = 0.73).

CONCLUSIONS

In a predominantly indigent population, race and ethnicity had no impact on outcomes for ER-negative breast cancer.

Triple-negative breast cancers: a view from 10,000 feet

Triple-negative breast cancer is more likely to affect younger premenopausal women and despite being responsive to traditional chemotherapy, continues to carry a poor overall prognosis. Traditional protective factors for breast cancer such as multiparity and early primaparity actually increase the risk for the triple-negative variant. Unlike other breast cancers, the incidence of this disease is also much higher in African American and West African women. Among those with triple-negative disease in the United States, the mortality rates are also highest in African American women. Variations in risk factors and socioeconomic status, lack of treatment, delays in treatment, and inadequate dosing of chemotherapy are just a few of the many reasons that may explain why this incidence and survival disparity persists.

Breast cancer in Latinas: gene expression, differential response to treatments, and differential toxicities in Latinas compared with other population groups

Disparities in clinical outcomes of breast cancer have been described among different racial and ethnic groups in the U.S. Convincing data exist showing that Latina women have a lower incidence of breast cancer but a higher breast cancer-related mortality rate compared with white women. Noticeable differences in breast cancer incidence are present even within different Latina subsets with a higher incidence in second- and third-generation women compared with foreign born. An increasing amount of data exists pointing to significant differences in the genetics and biology of breast cancer in Latinas as a significant contributor to the higher mortality, including a higher incidence of triple-negative breast cancers (which do not overexpress HER-2 protein and are negative for estrogen receptors and progesterone receptors). Other social and environmental factors are likely to play a significant role as well, including a lower rate of screening mammography, variable access to medical care, among others. Recent data are inconclusive regarding differences among racial/ethnic groups in the response to chemotherapy. Data on racial/ethnic variations in the pharmacogenomics of chemotherapy, endocrine treatments, and toxicity are more limited, with some data suggesting differences in frequencies of polymorphisms of genes involved in the metabolism of some of these agents. Further studies are needed on this subject.

Population based time trends and socioeconomic variation in use of radiotherapy and radical surgery for prostate cancer in a UK region: continuous survey

OBJECTIVE

To examine variation in the management of prostate cancer in patients with different socioeconomic status.

DESIGN

Survey using UK regional cancer registry data.

SETTING

Regional population based cancer registry.

PARTICIPANTS

35 171 patients aged >or=51 with a diagnosis of prostate cancer, 1995-2006.

MAIN OUTCOME MEASURES

Use of radiotherapy and radical surgery. Socioeconomic status according to fifths of small area deprivation index.

RESULTS

Over the nine years of the study, information on stage at diagnosis was available for 15 916 of 27 970 patients (57%). During the study period, the proportion of patients treated with radiotherapy remained at about 25%, while use of radical surgery increased significantly (from 2.9% (212/7201) during 1995-7 to 8.4% (854/10 211) during 2004-6, P<0.001). Both treatments were more commonly used in least deprived compared with most deprived patients (28.5% v 21.0% for radiotherapy and 8.4% v 4.0% for surgery). In multivariable analysis, increasing deprivation remained strongly associated with lower odds of radiotherapy or surgery (odds ratio 0.92 (95% confidence interval 0.90 to 0.94), P<0.001, and 0.91 (0.87 to 0.94), P<0.001, respectively, per incremental deprivation group). There were consistently concordant findings with multilevel models for clustering of observations by hospital of diagnosis, with restriction of the analysis to patients with information on stage, and with sequential restriction of the analysis to different age, stage, diagnosis period, and morphology groups.

CONCLUSIONS

After a diagnosis of prostate cancer, men from lower socioeconomic groups were substantially less likely to be treated with radical surgery or radiotherapy. The causes and impact on survival of such differences remain uncertain.

Racial differences in PSA screening interval and stage at diagnosis

OBJECTIVES

This study examined PSA screening interval of black and white men aged 65 or older and its association with prostate cancer stage at diagnosis.

METHODS

SEER-Medicare data were examined for 18,067 black and white men diagnosed with prostate cancer between 1994 and 2002. Logistic regression was used to assess the association between race, PSA screening interval, and stage at diagnosis. Analysis also controlled for age, marital status, comorbidity, diagnosis year, geographic region, income, and receipt of surgery.

RESULTS

Compared to whites, blacks diagnosed with prostate cancer were more likely to have had a longer PSA screening interval prior to diagnosis, including a greater likelihood of no pre-diagnosis use of PSA screening. Controlling for PSA screening interval was associated with a reduction in blacks' relative odds of being diagnosed with advanced (stage III or IV) prostate cancer, to a point that the stage at diagnosis was not statistically different from that of whites (OR=1.12, 95% CI=0.98-1.29). Longer intra-PSA intervals were systematically associated with greater odds of diagnosis with advanced disease.

CONCLUSIONS

More frequent or systematic PSA screening may be a pathway to reducing racial differences in prostate cancer stage at diagnosis, and, by extension, mortality.

Pap test and HIV testing behaviors of South Carolina women 18-64 years old

BACKGROUND

Pap tests are used to detect abnormal cell growth in the cervix. Early detection of precancerous cells increases the likelihood of treatment success. In fact, the Pap test is one of only a few cancer screening procedures that can prevent cancer by virtue of identifying and intervening upon abnormal precancerous cells in the early stages. There has been a growing prevalence of cervical cancer among HIV-positive women. Early diagnosis is essential to improving survival outcomes of women living with HIV/AIDS. The purpose of this study was to describe Pap test behaviors among women in South Carolina and examine its relationship with HIV testing.

METHODS

Behavioral Risk Factor Surveillance System (BRFSS) data from 2008 were analyzed. Chi-square tests and logistic regression analyses were performed to describe Pap test behaviors among our sample (n=3,404) of non-Hispanic White and non-Hispanic Black women (18–64 years old).

RESULTS

The majority of participants (97%) reported ever having a Pap test. Participants who reported never having a Pap test were 50% less likely to have ever been tested for HIV.

CONCLUSIONS

The participants in our study met the Healthy People 2010 target of ever having a Pap test. However, less than half of participants (42%) had ever been tested for HIV. A larger proportion of women who have had a Pap test had also been tested for HIV.

PRACTICE IMPLICATIONS

Our findings suggest that offering women an HIV test during routine Pap tests may present an opportunity to increase the number of women in South Carolina who know their HIV serostatus.

Prognostic factors for response to cisplatin-based chemotherapy in advanced cervical carcinoma: a Gynecologic Oncology Group Study

PURPOSE

Cisplatin-based combination chemotherapy is considered standard treatment for advanced/recurrent cervical carcinoma; however, the majority of patients do not respond. This study was undertaken to identify the prognostic factors and develop a model predictive of (non-) response to chemotherapy.

METHODS

Four-hundred twenty-eight patients with advanced cervical cancer who received a cisplatin-containing combination in three Gynecologic Oncology Group (GOG) protocols (110, 169 and 179) were evaluated for baseline clinical characteristics and multivariate analysis was conducted to identify factors independently prognostic predictive of response using a Logistic regression model. A predictive model was developed and externally validated using an independent GOG protocol (149) data.

RESULTS

Multivariate analysis identified five factors (African-American, performance status [PS] >0, pelvic disease, prior radiosensitizer and time interval from diagnosis to first recurrence <1 year) independently prognostic of poor response. A simple prognostic index was derived based on the total number of risk factors. When patients were classified into three risk groups (low risk: 0-1 factor; mid risk: 2-3 factors; high risk: 4-5 factors), patients with 4-5 risk factors were estimated to have a response rate of only 13%, and median progression-free and overall survival of 2.8 months and 5.5 months, respectively. The accuracy of the index was supported by both internal and external datasets.

CONCLUSIONS

A simple index based on five prognostic factors may have utility in clinical practice to identify the women who are not likely to respond to the cisplatin-containing regimens. This subgroup of patients should be considered for non-cisplatin chemotherapy or investigational trials.

Socioeconomic disparities in breast cancer survival: relation to stage at diagnosis, treatment and race

BACKGROUND

Previous studies have documented lower breast cancer survival among women with lower socioeconomic status (SES) in the United States. In this study, I examined the extent to which socioeconomic disparity in breast cancer survival was explained by stage at diagnosis, treatment, race and rural/urban residence using the Surveillance, Epidemiology, and End Results (SEER) data.

METHODS

Women diagnosed with breast cancer during 1998-2002 in the 13 SEER cancer registry areas were followed-up to the end of 2005. The association between an area-based measure of SES and cause-specific five-year survival was estimated using Cox regression models. Six models were used to assess the extent to which SES differences in survival were explained by clinical and demographical factors. The base model estimated the hazard ratio (HR) by SES only and then additional adjustments were made sequentially for: 1) age and year of diagnosis; 2) stage at diagnosis; 3) first course treatment; 4) race; and 5) rural/urban residence.

RESULTS

An inverse association was found between SES and risk of dying from breast cancer (p < 0.0001). As area-level SES falls, HR rises (1.00 --> 1.05 --> 1.23 --> 1.31) with the two lowest SES groups having statistically higher HRs. This SES differential completely disappeared after full adjustment for clinical and demographical factors (p = 0.20).

CONCLUSION

Stage at diagnosis, first course treatment and race explained most of the socioeconomic disparity in breast cancer survival. Targeted interventions to increase breast cancer screening and treatment coverage in patients with lower SES could reduce much of socioeconomic disparity.

Medical advances and racial/ethnic disparities in cancer survival

BACKGROUND

Although advances in early detection and treatment of cancer improve overall population survival, these advances may not benefit all population groups equally and may heighten racial/ethnic differences in survival.

METHODS

We identified cancer cases in the Surveillance, Epidemiology and End Results program, who were ages > or = 20 years and diagnosed with one invasive cancer in 1995 to 1999 (n = 580,225). We used 5-year relative survival rates to measure the degree to which mortality from each cancer is amenable to medical interventions (amenability index). We used Kaplan-Meier methods and Cox proportional hazards regression to estimate survival differences between each racial/ethnic minority group relative to Whites, by the overall amenability index, and three levels of amenability (nonamenable, partly amenable, and mostly amenable cancers, corresponding to cancers with 5-year relative survival rate < 40%, 40-69%, and > or = 70%, respectively), adjusting for gender, age, disease stage, and county-level poverty concentration.

RESULTS

As amenability increased, racial/ethnic differences in cancer survival increased for African Americans, American Indians/Native Alaskans, and Hispanics relative to Whites. For example, the hazard ratios (95% confidence intervals) for African Americans versus Whites from nonamenable, partly amenable, and mostly amenable cancers were 1.05 (1.03-1.07), 1.38 (1.34-1.41), and 1.41 (1.37-1.46), respectively. Asians/Pacific Islanders had similar or longer survival relative to Whites across amenability levels; however, several subgroups experienced increasingly poorer survival with increasing amenability.

CONCLUSIONS

Cancer survival disparities for most racial/ethnic minority populations widen as cancers become more amenable to medical interventions. Efforts in developing cancer control measures must be coupled with specific strategies for reducing the expected disparities.

Racial survival disparity in head and neck cancer results from low prevalence of human papillomavirus infection in black oropharyngeal cancer patients

The burden of squamous cell carcinoma of the head and neck (SCCHN) is greater for blacks than for whites, especially in oropharyngeal cases. We previously showed retrospectively that disease-free survival was significantly greater in white than in black SCCHN patients treated with chemoradiation, the greatest difference occurring in the oropharyngeal subgroup. Oropharyngeal cancer is increasing in incidence and in its association with human papillomavirus (HPV) infection; HPV-positive oropharyngeal cancer patients have significantly better outcomes (versus HPV-negative). These collective data led to the present analyses of overall survival (OS) in our retrospective cohort and of OS and HPV status (tested prospectively in pretreatment biopsy specimens) in the phase 3, multicenter TAX 324 trial of induction chemotherapy followed by concurrent chemoradiation in SCCHN patients. Median OS in the retrospective cohort of 106 white and 95 black SCCHN patients was 52.1 months (white) versus only 23.7 months (black; P = 0.009), due entirely to OS in the subgroup of patients with oropharyngeal cancer--69.4 months (whites) versus 25.2 months (blacks; P = 0.0006); no significant difference by race occurred in survival of non-oropharyngeal SCCHN (P = 0.58). In TAX 324, 196 white patients and 28 black patients could be assessed for HPV status. Median OS was significantly worse for black patients (20.9 months) than for white patients (70.6 months; P = 0.03) and dramatically improved in HPV-positive (not reached) versus HPV-negative (26.6 months, 5.1 hazard ratio) oropharyngeal patients (P < 0.0001), 49% of whom were HPV-16 positive. Overall, HPV positivity was 34% in white versus 4% in black patients (P = 0.0004). Survival was similar for black and white HPV-negative patients (P = 0.56). This is the first prospective assessment of confirmed HPV status in black versus white SCCHN patients. Worse OS for black SCCHN patients was driven by oropharyngeal cancer outcomes, and that for black oropharyngeal cancer patients by a lower prevalence of HPV infection. These findings have important implications for the etiology, prevention, prognosis, and treatment of SCCHN.