UF Researchers Discover Racial Disparities In Oral Cancer Treatment And Survival

August 3, 2004

GAINESVILLE, Fla. — Black men battling oral and pharyngeal cancer in Florida don’t live as long as their white counterparts and are less likely to undergo the surgery necessary to optimally treat the disease, a University of Florida study reveals.

“What we found is that African-American males in Florida died 44 percent earlier than did white males, and were also more likely to receive only radiation therapy and not surgery than were whites,” said Scott Tomar, an associate professor in the division of public health services and research at UF’s College of Dentistry.

The study, published in this month’s edition of Cancer Causes and Control, is one of the nation’s first state-specific reports of racial disparities in treatment and survival of the deadly disease. On average, black men in the study died a year sooner after diagnosis than white men – a finding consistent with national data showing that white men are twice as likely as black men to survive five years after diagnosis, Tomar said.

“Our study is unique in that it looks at state-specific data for oral and pharyngeal cancer treatment and mortality,” Tomar said. “This eliminates a great amount of regional variation in the data. Previous studies that have attempted to look at issues of racial disparities have used samples of people from around the country, and they mixed geographic differences with racial differences, making it difficult to understand what might be happening differently for blacks than for whites.”

Nearly 30,000 people are diagnosed with oral cancer in the United States every year, according to the National Cancer Institute. Although the number of cancer cases in general has steadily declined during the past 10 years, black men historically have been disproportionately represented in the number of new cases, and their survival rates are dismal compared with those of white men and of women of both races.

Florida was of particular interest to Tomar because of its disproportionate burden of oral and pharyngeal cancers – it has one of the highest incidence rates in the country and the fifth highest mortality rate. So high, in fact, that Floridians suffer more than double the number of deaths caused by oral and pharyngeal cancers than that of the top four states combined, Tomar said.

“Clearly, oral cancer is a major issue in this state,” Tomar said.

UF researchers wanted to know how Florida stacked up on the issue of racial disparities in treatment and survival of oral cancers. To find out, they examined data gathered by the Florida Cancer Data System on oral and pharyngeal cancer diagnosis, treatment and mortality for more than 27,000 Floridians between 1988 and 1998.

The researchers compared data only on black and white patients; individuals of other races were excluded from the study sample. The study’s final sample size of 21,481 people included 19,331 white men and women and 2,150 black men and women.

Analysis of the data revealed twice as many cases of oral and pharyngeal cancers diagnosed in men as in women. Most occurred in people 51 to 74 with the median age 65 – although blacks were significantly younger and poorer than whites at the time of diagnosis. Anatomic location of the cancer differed greatly between whites and blacks; more than half of the black patients were diagnosed with aggressive pharyngeal cancers compared with about 39 percent of whites.

The study’s most compelling evidence: The cancers among blacks were twice as likely to have spread by the time of diagnosis. However, regardless of tumor location or whether the cancer had metastasized, blacks consistently were less likely to undergo surgery than were whites.

Differences in survival rates were even more striking, with blacks having a median survival time of 360 days compared with 649 days for whites. Although the incidence rate for both black and white men became nearly equal over the study’s 10-year period, the disparity in survival time did not significantly change.

Although the study did not associate cancer incidence with causes, Tomar said established risk factors for the development of oral and pharyngeal cancers include tobacco and alcohol use. National Cancer Institute statistics show more than 80 percent of all oral cancers occur in cigarette smokers. Add alcohol use into the mix and the risk for oral cancer increases to 15 times that of non-users of tobacco and alcohol.

“As far as the differences in incidence between black and white males, there is some evidence that it may be due to difference in these behavioral risk factors like use of tobacco and alcohol,” Tomar said. “On the other hand, the patterns of use of some of these substances, nationally as well as here in Florida, really wouldn’t explain the huge differences in incidence seen historically.”

Alice M. Horowitz, an education specialist with the National Institutes of Health’s National Institute of Dental and Craniofacial Research, said, “Educating the public about the risk factors of oral cancers and teaching them to ask for oral cancer exams is key to the prevention and early diagnosis of oral and pharyngeal cancers. Clearly, we need to do a better job of training health-care providers of all types to do oral examinations, and we need the public to become educated enough to demand them.”

Tomar said he agrees that public education would go a long way in the fight against oral and pharyngeal cancers because early detection can result in cure rates as high as 90 percent. However, he said he also wants to determine why Floridians experience such enormous racial differences in treatment and survival regardless of how early or at what stage the oral cancer is detected.

“There is this difference in how people are treated and that contributes to the huge racial disparity in survival. Unfortunately, we just don’t know why there are those differences.” Tomar said. “Our next line of investigation is to begin to tease out some of the answers.”