Deaths from mouth and throat cancer have dropped since the early 1990s, according to a new study - but only among people with at least a high school education.

Researchers said that may be due to higher rates of smoking and other oral cancer risks among less educated, poorer Americans, and because they’re also less likely to have access to timely health care.

Similar trends have been shown in rates of death from lung and breast cancers, for example, they added.

“We have a lot more to do in terms of (the fact that) socioeconomic status probably is a really significant factor in mortality from oral and oropharyngeal cancers,” said Dr. Joseph Califano, who studies those cancers at the Johns Hopkins University School of Medicine in Baltimore but wasn’t involved in the new research.

“Clearly access to health care to detect cancer in early stages is very important.”

The study, led by Dr. Amy Chen at the Emory University School of Medicine in Atlanta, included mouth and throat cancer data from 1993 through 2007 in 26 states. Among adults age 25 to 64, there were about 19,300 deaths during that period.

Cancer deaths declined during the 1990s and 2000s by two to five percent every year, on average, researchers found.

By the end of the study period, the cancers killed three out of every 100,000 white men, six out of every 100,000 black men, and one each of every 100,000 white and black women annually.

But when Chen and her colleagues broke those findings down by education level, they found the downward trends only held up among black people with at least a high school education, and only among whites who’d completed some college.

That throat and mouth cancers are the latest type of cancer to show such a socioeconomic pattern is one more reason to make education a priority, Chen told Reuters Health.

“Investment in education is very important not only for the health status of the population, but also for the economic status of the population,” she added.

Chen said that smoking, alcohol abuse and the human papillomavirus (HPV) have all been linked to mouth and throat cancers - and smoking especially is known to be more common among poorer people with less education. Those same people are also less likely to have insurance or to see a primary care doctor regularly, which may mean that cancers are further along by the time they’re caught.

Mouth and throat cancer symptoms include persisting sore throat or ear pain, trouble swallowing and a lump in the throat that lasts more than a couple weeks, Chen said. “Anything like that should be checked out and made sure it’s not something as dire as throat cancer.”

Among the 4,000 cases of cancers in sites known to be associated with HPV, like the throat, tonsils and tongue, death rates only dropped significantly among more-educated black men, the study found.

Those rates increased among white men and some white women, especially the less educated, Chen and her colleagues reported in Archives of Otolaryngology-Head & Neck Surgery this week.

Chen highlighted the importance of using protection during sexual contact, including oral sex, and said that vaccinating both boys and girls against HPV may help bring down this rate - but probably not for some years.

“The incubation period, and the indolent phase of these cancers is a long time,” she said. “We’re talking about sexual behaviors that could have occurred 20 or 30 years before the incident cancer.”

Califano cautioned that researchers haven’t established whether the vaccine can definitely prevent mouth and throat cancers, saying there are still many questions about how oral sex and cancer are linked.

“It’s a really interesting study,” he concluded. “It probably opens more questions than it answers.”

SOURCE:  Archives of Otolaryngology-Head & Neck Surgery, online November 21, 2011