Racial/ethnic disparities for leukemias in Puerto Rico and the United States of America, 2015-2019

BACKGROUND

Leukemia is a cancer of the early-forming cells. Over the past decade, leukemia racial/ethnic disparities have been documented in the United States of America (USA). Although the Puerto Rican population in the USA represents the second-largest Hispanic population in the nation, most of the existing studies do not include Puerto Rico. We compared the incidence and mortality rates for leukemia and its subtypes in Puerto Rico and four racial/ethnic groups in the USA.

METHODS

We used data from the Puerto Rico Central Cancer Registry and the Surveillance, Epidemiology, and End Results Program (2015-2019). The racial/ethnic groups studied were non-Hispanic whites (NHW), non-Hispanic blacks (NHB), Hispanics (USH), and Asian/Pacific Islanders (NHAPI) living in the USA and the Puerto Rico population. We calculated the incidence and mortality rates. The relative risk of developing or dying due to leukemia was also calculated.

RESULTS

Compared with Puerto Rico, NHW [standardized incidence rate (SIR) = 1.47; 95%CI = 1.40-1.53; standardized mortality rates (SMR) = 1.55; 95%CI = 1.45-1.65)] and NHB (SIR = 1.09; 95%CI = 1.04-1.15; SMR = 1.27; 95%CI = 1.19-1.35) had higher incidence and mortality rates; but lower than the NHAPI (SIR = 0.78; 95%CI = 0.74-0.82; SMR = 0.83; 95%CI = 0.77-0.89); and similar to USH. However, we found differences among leukemia subtypes. For example, NHAPI and USH had lower risk of developing chronic leukemias than Puerto Rico. We found a lower risk to develop acute lymphocytic leukemia in NHB than in Puerto Rico.

CONCLUSIONS

Our study provides a better understanding of leukemia's racial/ethnic disparities and fills a knowledge gap by examining the incidence and mortality rates in Puerto Rico. Future studies are needed to better understand the factors influencing the differences found in the incidence and mortality of leukemia among different racial/ethnic groups.

Invasive cancer incidence - Puerto Rico, 2007-2011

Cancer is a leading cause of morbidity and death in Puerto Rico. To set a baseline for identifying new trends and patterns of cancer incidence, Puerto Rico Central Cancer Registry staff and CDC analyzed data from Puerto Rico included in U.S. Cancer Statistics (USCS) for 2007-2011, the most recent data available. This is the first report of invasive cancer incidence rates for 2007-2011 among Puerto Rican residents by sex, age, cancer site, and municipality. Cancer incidence rates in Puerto Rico were compared with those in the U.S. population for 2011. A total of 68,312 invasive cancers were diagnosed and reported in Puerto Rico during 2007-2011. The average annual incidence rate was 330 cases per 100,000 persons. The cancer sites with the highest cancer incidence rates included prostate (152), female breast (84), and colon and rectum (43). Cancer incidence rates varied by municipality, particularly for prostate, lung and bronchus, and colon and rectum cancers. In 2011, cancer incidence rates in Puerto Rico were lower for all cancer sites and lung and bronchus, but higher for prostate and thyroid cancers, compared with rates within the U.S.

POPULATION

Identifying these variations can aid evaluation of factors associated with high incidence, such as cancer screening practices, and development of targeted cancer prevention and control efforts. Public health professionals can monitor cancer incidence trends and use these findings to evaluate the impact of prevention efforts, such as legislation prohibiting tobacco use in the workplace and public places and the Puerto Rico Cessation Quitline in decreasing lung and other tobacco-related cancers.