Hypertension is an independent predictor of survival disparity between African‐American and white breast cancer patients

Abstract

The objective of this study was to determine whether comorbidity, or pre-existing conditions, can account for some of the disparity in survival between African-American and white breast cancer patients. A historical cohort study was conducted of 416 AfricanAmerican and 838 white women diagnosed with breast cancer between 1973 and 1986, and followed through 1999 in the Kaiser Permanente Northern California Medical Care Program. Information on comorbidity, tumor characteristics and breast cancer treatment was obtained from medical records, and Surveillance, Epidemiology and End Results, Northern California Cancer Center Registry. Associations between comorbidity and survival were analyzed with multiple Cox proportional hazards regression. Over a mean follow-up of 9 years, African Americans had higher overall crude mortality than whites: 165 (39.7%) versus 279 (33.3%), respectively. When age, race, tumor characteristics and breast cancer treatment were controlled, the presence of hypertension was associated with all cause survival [hazard ratio (HR) 5 1.33, 95% confidence intervals (CI) 1.07-1.67] and it accounted for 30% of racial disparity in this outcome. Hypertension-augmented Charlson Comorbidity Index was a significant predictor of survival from all causes (HR 5 1.32, 95%CI 1.18-1.49), competing causes (HR 5 1.52, 95%CI 1.32-1.76) and breast cancer specific causes (HR 5 1.18, 95%CI 1.03-1.35). In conclusion, hypertension has prognostic significance in relation to survival disparity between African-American and white breast cancer patients. If our findings are replicated in contemporary cohorts, it may be necessary to include hypertension in the Charlson Comorbidity Index and other comorbidity measures. ' 2008 Wiley-Liss, Inc.Key words: comorbidity; breast cancer; survival; race/ethnicity; cohort African-American breast cancer patients experience shorter survival than their white counterparts, and on average present with more advanced stage and hormone receptor-negative disease at younger ages. 1 African-American ethnicity seems to be an independent predictor of poor breast cancer outcome, even after accounting for socioeconomic factors and inadequate health care access. 2 Importantly, African-American women also tend to have poorer overall health, as reflected in greater prevalence of comorbidity. 3 Furthermore, inadequately controlled comorbidities tend to adversely affect cancer treatment, as exemplified in the National Cancer Institute's Black White Cancer Survival Study, with breast cancer patients presenting with disproportionately increased rates of hypertension. 4 A recent study by Tammemagi et al. 5 reporting on outcomes among breast cancer patients followed for a median of 10 years at the Henry Ford Health System in Michigan showed that comorbidities such as hypertension and diabetes accounted for almost half of the overall survival disparity among African-American and white breast cancer patients. Thus, optimizing comorbidity measurement may help not only to uncover predictors of survival disparity ...

Prevalence, Awareness, Control, and Treatment of Hypertension and Diabetes in Korean Cancer Survivors: A Cross-Sectional Analysis of the Fourth and Fifth Korea National Health and Nutrition Examination Surveys

“…With the increasing number of cancer survivors, evaluation and management of their chronic comorbid conditions have become important issues (Ogle et al, 2000). Hypertension is the most common comorbidity in cancer survivors, with a prevalence of 20%-65% (Ogle et al, 2000;Park et al, 2006;Shin et al, 2008;Braithwaite et al, 2009). Prevalence of hypertension at the time of cancer diagnosis is similar to that in the general population, however, the much higher rate is observed after treatment such as chemotherapy (Mouhayar et al, 2011).…”

“…Inadequately controlled comorbidities tend to adversely affect health status or disability as well as cancer treatment in cancer survivors, and they have prognostic significance in relation to survival disparity (Muss et al, 1992;Hewitt et al, 2003). Although hypertension and diabetes accounted for a poorer prognosis among cancer survivors in a limited number of studies on certain types of cancers, hypertension was associated with all-cause survival disparity and poor prognosis in stomach, lung, and colon cancer (Park et al, 2006;Shin et al, 2008;Braithwaite et al, 2009), and diabetes was significantly associated with higher mortality and recurrence rates in cancer survivors (Richardson et al, 2005;Griffiths et al, 2012). Therefore, proper management of hypertension and diabetes is important for better survival and quality of life for cancer survivors.…”

“…Although some studies have examined the prevalence and factors associated with management of hypertension and diabetes in cancer survivors (Park et al, 2006;Baker et al, 2007;Braithwaite et al, 2009), little is known about the management, awareness, and control of hypertension and diabetes in cancer survivors based on populationlevel data. Therefore, this study assessed the prevalence, management, awareness, and control of hypertension and diabetes in cancer survivors, using data from the Korean National Health and Nutrition Examination …”

Comparison of hypertension management between cancer survivors and the general public

“…1 Hypertension is the most common comorbid condition in cancer survivors, with a prevalence of 20-65%. [2][3][4] Furthermore, it can lead to 30B50% of excess mortality from stroke and heart disease in cancer survivors, 2,3 as demonstrated in large-cohort studies in Korea 3 and the United States. 2 Therefore, proper management of hypertension is important for better survival and quality of life of cancer survivors who have hypertension.…”

“…Although some studies have examined the prevalence, 4,14-16 predictors [14][15][16] and outcomes 2,3 of hypertension in cancer survivors, little is known about the management perspective of hypertension specific to cancer survivors. 17 In the current study, we aimed to compare hypertension management, including antihypertensive medication adherence, frequency of blood pressure (BP) monitoring and perceived BP control between cancer survivors and the general population.…”