Anand B. Karnad, MD
Chief, Division of Hematology Oncology
Professor, Castella Foundation Endowed Chair in Aging
Chair, Protocol Review Committee for the Cancer Center Support Grant
University of Texas Health Science Center
Cancer Therapy & Research Center
San Antonio, Texas
The Hispanic population in the United States represents the fastest-growing segment of the population (expected to reach 30% of the nation’s total by 2050), and faces significant cancer health disparities: lower cancer awareness and lower screening rates leading to a higher incidence of certain cancers and higher mortality rates from at least six cancers compared with non-Hispanic whites.1,2
Yet Hispanics are dramatically underrepresented in clinical trials and findings often are not reported with participants’ ethnicity in mind.
Only 2.2% of patients enrolled in clinical trials during a 10-year period were Hispanic, according to one study.3
An analysis conducted at the University of Texas Health Science Center Cancer Therapy & Research Center (CTCR) found that only about 8% of a sampling of potentially practice-changing clinical trials provided information on the accrual of Hispanics.4
For those trials that did report ethnicity, just 3.9% of participants were Hispanic.
There are strategies that have proved successful at CTCR for boosting enrollment of Hispanics in clinical trials, and these approaches can help broaden clinical trial recruitment so that this significant segment of the nation’s population is included in the development of life-saving therapies.Disparity in Cancer Rates
It is important to note that the Hispanic population is heterogeneous; it is made up of different immigration patterns and genetic ancestry, and has been exposed to a variety of lifestyle practices and environmental factors.
Therefore, it is not surprising that within the Hispanic population, incidence patterns of different cancers can vary up to 5-fold based on country of origin. The Hispanic population also faces obesity-related health disparities and other inequalities—leading to a dire need for cancer health disparity research in this population.
Cancers that are disproportionately common in the Hispanic population include:1,2
double the incidence in Hispanics compared with non-Hispanic whites, with a higher mortality rate
2 to 2.5 times more common in Hispanic women
4 to 5 times higher among Hispanics from South or Central America
substantially higher among Puerto Rican immigrants and in Hispanic populations as a group
a higher incidence of leukemia, retinoblastoma, osteosarcoma, and germ cell tumors.
Genetic factors (ancestry informative markers), environmental factors (physical activity, obesity, diet, tobacco, and alcohol), and cultural factors (machismo and fatalism), may explain some of the cancer health disparity, but there is paucity of data for causality in many common cancers including for some of the devastating epidemics of cancer in this population (eg, liver cancer).
Hispanics have the highest incidence of lack of health insurance compared with any other ethnic group and this socioeconomic factor drives a significant burden of their health disparity.Need for Clinical Trial Enrollment
Cancer clinical trials, the invaluable research engine that drives the translation of new knowledge from discovery in the laboratory to the bedside of the patient and ultimately to practice-changing interventions that save lives, are now dramatically altering the landscape and natural history of cancer. There are several hundred new agents for the treatment of cancer that are in various phases of testing and thousands of cancer clinical trials are being conducted all over the world.
Participation in clinical trials by minority populations is essential if we are to overcome cancer health disparity and reduce the burden of cancer in these populations. Although there has been a national agenda for Latino cancer prevention and control published in 2005, and up-to-date statistics on Hispanic cancers in the United States published in 2012, there has not been a concerted effort to focus on Hispanic participation in and accrual to cancer clinical trials.