Clinical Citations: What effect can visual screening have on oral cancer mortality?

In India, oral cancer is the most common form of cancer and of cancer-related death in men. Researchers in Trivandrum, India, determined that visual screening for oral cancer reduces mortality in high-risk persons. In fact, they estimated that screening can prevent 37,000 oral cancer deaths worldwide annually.

A total of 191,873 healthy persons aged 35 years or older participated in a cluster-randomized controlled trial over 9 years. Seven intervention groups were randomized to 3 rounds of oral visual inspection by trained health care workers in 3-year intervals, and another 6 groups included controls who received standard care.

Patients who were screen-positive, defined as having 1 or more lesions, were examined by dentists and oncologists. Patients with normal or benign lesions were advised to have repeated screening; those with oral precancerous lesions received surgical excision when possible; and those with invasive cancer were referred to surgery, radiotherapy, or chemotherapy.

There were 205 oral cancer cases and 77 oral cancer deaths in the intervention groups, compared with 158 oral cancer cases and 87 oral cancer deaths in the control group. In the intervention group, 70 of the oral cancer deaths were in users of tobacco, alcohol, or both, compared with 85 deaths in the control group.

In a related editorial, Mignogna and Fedele argued that the data from the Indian study can be interpreted in 2 ways. They raised concerns about possible weaknesses in the study's methodology, including potential imbalance in restricted-block randomization, the inclusion of nonmedical health care workers, the length of time between screenings, and a lack of clarity regarding diagnostic criteria.

They added, however, that given that oral cancer is almost always preceded by visible changes in the oral mucosa, which can be readily seen in a visual examination, the study data confirm a strong correlation between visual screening and prevention. Mignogna and Fedele urge health organizations worldwide to make a commitment to screening as an inexpensive, straightforward approach to oral cancer prevention.