Oral cancer accounts for 2 percent of reported malignancies and 1.2 percent of cancer-related deaths in the United States. Oral cancer screening (OCS), recommended by the American Dental Association since 2010, can help to diagnose the cancer early, and this can significantly improve survival rates. If caught early, the five-year survival rate of oral cancer is 82.8 percent, but once the cancer metastasizes, that rate drops to 28 percent. Researchers at Brigham and Women's Hospital led a study to examine OCS rates among those who had been to the dentist within two years, looking at whether sociodemographic factors such as income or race predicted differences in these rates. The team found that a significantly higher proportion of minority and low-income individuals reported that they had not received an OCS exam despite a recent dental visit. The results of this study are published in The American Journal of Preventive Medicine.
"We wanted to look specifically at the population that has access to dental care and report having access to a dentist," said first author Avni Gupta, a research scientist at the Brigham's Center for Surgery and Public Health. "Our results indicate that the selection of patients for screening isn't based on the high-risk profile for oral cancer, but on sociodemographic characteristics. This is not appropriate. All patients should be receiving oral cancer screenings, but providers aren't screening these groups, and this may be why they are presenting with more advanced cancer."
The study looked at civilian, non-institutionalized individuals, aged 30-and-over, that had visited a dentist in the last two years. In three data cycles, from 2011 to 2016, patients self-reported if they had ever had an intra-oral or extra-oral exam, noninvasive procedures that can easily and safely be performed in an out-patient setting by a qualified health professional.
The intra-oral exam, in which a health professional pulls on the tongue and feels around the mouth to detect any premalignant lesions, was the primary outcome of the study. The extra-oral exam, in which the health professional feels the patient's neck, was a secondary outcome. The patient survey described the intra-oral exam and extra-oral exam in detail so that a patient could easily identify the two types of screenings.
The team found that only 37.6 percent of people who had seen a dental professional reported receiving an intra-oral cancer screening exam while only 31.3 percent reported receiving an extra-oral exam. Adjusting for different risk factors, the team found that OCS rates were much lower among racial minorities, lower-income groups, and those who were uninsured or publicly insured. These disparities were independent of the two major risk factors for oral cancer, smoking and alcohol consumption.
The largest limitation of the study was the use of self-reported data that is subject to recall bias. However, this would only impact the study if these biases had greater influence on some sociodemographic groups than others.
Gupta said that while the previous studies have indicated disparities in access to dental care, she hopes that this study shows that providing access is not enough to get rid of the gaps in OCS rates between different sociodemographic groups.
"Just providing access is not enough - it matters what type of care patients are able to access," Gupta said. "We talk a lot about disparities in medical care, but the quality of dental care services is important, too. We need to better understand the barriers that dental care providers face in order to ensure that patients get the same level and quality of care regardless of sociodemographic factors."