Noninvasive oral cancer test to be soon available

A U.S. government-backed panel issued a statement today saying that there is not enough published evidence to recommend for or against screening for oral cancer.

Evidence is lacking on whether screening can accurately detect oral cancer and if earlier treatment of cancers found during those tests improves long-term health, according to the U.S. Preventive Services Task Force (USPSTF).

Their draft recommendation statement applies to people who do not have any signs or symptoms of oral cancer and is meant for primary care professionals screening for oral cancer. It is not a recommendation about the practices of dentists and oral health professionals, the panel noted.

The task force an independent volunteer panel of national experts in prevention and evidence-based medicine reviewed the current literature and found:

–          Inadequate evidence that the oral screening examination accurately detects oral cancer

–          Inadequate evidence that screening for oral cancer and treatment of screen-detected oral cancer improves morbidity or mortality

–          Inadequate evidence on the harms of screening; no study reported on harms from the screening test or from false-positive or false-negative test results

Seven studies (n = 49,120) examined the performance characteristics of the oral screening examination. These studies were generally conducted in settings with an increased incidence of and mortality from oral cancer (India, Taiwan) compared with U.S. rates, the panel reported. The studies also had considerable heterogeneity and demonstrated great variation in test performance characteristics. Across the seven studies, sensitivity for oral cancer or potentially malignant disorders ranged from 18% to 94.3% and specificity from 54% to 99.9%. The positive predictive value ranged from 17% to 86.6% and the negative predictive value from 73% to 99.3%.

Two studies in the U.K. looked at oral examinations performed by general dentists among older adults (age 40 years or older) at increased risk because of alcohol and tobacco use and a mixed sample with unknown risk factors. The dental examination in the high-risk sample (n = 2,027) showed a sensitivity of 74%, a specificity of 99%, and a positive predictive value of 67%, while the study of patients with unknown risk factors found a sensitivity of 71%, a specificity of 99%, and a positive predictive value of 86%.

Although the patients in the U.K. study may be similar to the U.S. population, the results of these studies were limited by an imperfect reference standard, by combining the detection of potentially malignant disorders with oral cancer and an unclear delineation of high-risk status, according to the USPSTF.