MD Anderson-led research published in the journal Cancer is shedding light on the risk of second primary malignancies, a leading cause of long-term mortality in patients diagnosed with head and neck cancers.
The study, led by Erich M. Sturgis, M.D., professor in the Department of Head and Neck Surgery, sought to determine the impact of secondary primary cancers in relation to the original cancer site and explore potential factors that may affect this risk.
"As we've improved treatment for head and neck cancers, one area that remains a problem is that our patients, who have typically been exposed to years of tobacco and often alcohol, are now at risk for other cancers related to those exposures," Sturgis said.
Researchers identified 2,230 patients diagnosed with squamous cell carcinoma of the head and neck, or more specifically, cancers of the oropharynx (middle part of throat) and non-oropharynx (mouth or voice-box). Statistical models were employed to calculate the 3-year and 5-year rates of secondary primary cancers.
The median follow-up period for all patients who were still alive was 33.1 months (36.1 months for patients with oropharynx disease and 28.4 months for patients with non-oropharynx disease).
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Smoking vs. HPV exposure
Of the 2,230 patients in the study, 236 developed a second cancer and those with oropharynx cancer were found to have a lower 3-year and 5-year rate (5% and 9%, respectively) than those with non-oropharynx cancer (8% and 16%, respectively).
In explaining the differences in outcomes, Sturgis said the greatest likelihood is that non-oropharynx cancers are strongly associated with tobacco exposure, leading this group to be at risk for additional cancers in the lung, for example. Whereas oropharynx cancers were largely believed to result from prior HPV exposure, this group was characterized by less tobacco use and saw fewer tobacco-related cancers at second sites.
"As a clinician, these findings help us understand how we should follow our patients after we've treated them for a head and neck cancer," Sturgis said. "We may have, in the patient with a heavy smoking history, a significant interest after we've cured their initial cancer, in following them and looking for a second lung cancer."
A full version of the study can be viewed here.
Also, on Cancerwise, a Q&A with Erich Sturgis addresses the connection between HPV and head and neck cancers.