|Roni Caryn Rabin
Maryland researchers investigating throat cancer and squamous-cell cancers
of the head and neck have made a discovery that may help explain why white
cancer patients often outlive their black peers even when they have what
appear to be the same cancers.
Cases of throat and head and neck cancers have spiked in
recent years, with research suggesting a link to human papillomavirus, the
same STD responsible for most cases of cervical cancer. HPV can be spread
through oral sex, causing oropharyngeal cancer, or cancer of the throat and
Dr. Kevin J. Cullen, director of the university's
Greenebaum Cancer Center, and colleagues noticed that their white throat
cancer patients survived an average 70 months, compared with 25 months for
their black patients. "We were shocked to see this in our own institution,
where more than half of the patients we treat are African-American," said
Concurrently, the team was analyzing specimens of head and
neck tumors collected from a treatment trial - the TAX 324 study - to
determine how many tumors were linked to HPV. They found that patients with
HPV-positive tumors responded much better to treatment with chemotherapy and
radiation. And they were overwhelmingly white.
According to Cullen, one-half of white patients had HPV-positive
tumors, compared to just one black patient. "There was no difference in the
survival between black and white patients in the TAX 324 trials if you
subtracted out the HPV-positive patients," he said.
The racial gap has often been explained as a result of
late diagnosis among blacks, lack of access to care and less aggressive
treatment. In the case of oropharyngeal cancer, however, the team's research
suggests distinct biologic differences. It also suggests the racial gap in
survival for this type of cancer could reflect cultural differences between
blacks and whites, including different sexual practices.
In an accompanying editorial, Dr. Otis Brawley, medical
director of the American Cancer Society, noted that changing sexual
practices were driving up rates of head and neck cancers, and possibly
others as well. "There is a huge public health message here," he wrote.
The study, "Racial Survival Disparity in Head and Neck
Cancer Results from Low Prevalence of Human Papillomavirus Infection in
Black Oropharyngeal Cancer Patients," and the editorial, "Oropharyngeal
Cancer, Race, and the Human Papillomavirus," were published in Cancer
Prevention Research (2009;2(9):776-781 and 769-772, respectively).