Kenneth W. Kizer, MD, MPH
Colorectal cancer mortality rates have been on the decline in California for both men and women since the mid-1990s, but for one group—Hispanic men—rates have remained essentially unchanged, and a new study suggests that lower rates of screening may be the chief driver of this disparity.
Data compiled by the National Cancer Institute revealed that only 46.2% of Hispanic men in the United States and 44.9% in California were screened for colorectal cancer (CRC) in 2014, compared with 67.6% and 72.4%, respectively, of white men in the US as a whole and in California.
To learn more about what may account for these differences, researchers with the UC Davis Institute for Population Health Improvement (IPHI) examined California Cancer Registry data collected between 1990 and 2012 to analyze CRC incidence and mortality trends. Over that period, 23,157 Hispanic men and 114,944 white men were diagnosed with CRC in the state.
These data showed that Hispanic men diagnosed with CRC tended to be of younger age and less educated, be uninsured or have public insurance like Medicaid, reside in areas of low socioeconomic status, and were less likely to have a primary healthcare provider.
Both groups experienced similar trends in survival and stage at diagnosis over the 22-year span covered by the study; however, white men had substantially reduced colorectal cancer incidence and death across all age groups. For example, researchers found that overall CRC mortality declined by 46% for white men between 1990 and 2012 but by only 3.5% among Hispanic men.
California has a larger proportion of Hispanics speaking a language other than English at home than the US as a whole, and “Hispanics are less likely to be screened, insured, and use healthcare than other ethnic groups in California,” explained senior study author and IPHI Director Kenneth W. Kizer, MD, MPH, in a statement.
"In fact, screening rates among Mexican and South and Central American Hispanic men, the main Hispanic subgroups in California, are the lowest of any race/ethnic group in the country. Tailoring interventions to the needs of these specific populations is important to create effective prevention strategies and improve health,” he continued.
The study also found that the number of both white and Hispanic men aged younger than 50 with colorectal cancer, although small compared with other age groups, increased significantly. Current recommendations for screening do not begin until age 50, but these findings raise questions about whether screening for colon cancer, especially among higher risk groups, should begin earlier, Kizer noted.
One potential explanation the authors cited for why CRC incidence and mortality declined more rapidly in whites than Hispanics, is that Hispanic men overall, as well as those residing in California, were less likely than their white counterparts to have endoscopy screening, despite evidence of its efficacy as a screening tool.
The researchers did note that incidence of CRC in Hispanic men was lower in 2012 than in any year prior over the time period studied, and future analyses will be required to determine whether this trend continues and results in lower mortality for this population. Additionally, studies have shown that rates of age-recommended screening in Hispanic men in the United States did rise from 42% in 2003, to 59% in 2009.
“Despite these positive signs, more effective strategies aimed at both Hispanics and their healthcare providers are needed to increase CRC screening among Hispanic men and reduce their CRC burden,” the authors concluded.
Among the barriers which may play a role in lower uptake of screening among Hispanic men in California, the authors noted, are cultural values, access to healthcare, and limited language proficiency. They pointed to recent research reporting success with the use of bilingual navigators embedded in the community and using more culturally sensitive printed materials.
Martinsen RP, Morris CR, Pinheiro PS, et al. Colorectal cancer trends in California and the need for greater screening of Hispanic men [published online ahead of print July 28, 2016]. Am J Prev Med. DOI: 10.1016/j.amepre.2016.05.019.