Gender-related factors in head and neck cancers are not as broadly proven or recognized, and this study suggests significant differences at the molecular level between male and female patients of head-neck and thyroid cancers, said Han Liang, PhD, associate professor in the department of bioinformatics and computational biology at MDACC and one of the study’s authors.
Dr. Sturgis noted that specific forms of head and neck cancers were not separated out for analysis. “Head and neck cancer is not a singular disease,” he said. “The TCGA includes oral cavity cancer, oropharynx cancers, and laryngeal cancers, and those are really three different diseases.” Dr. Liang states that although the grouping did consist primarily of tumors from the oral cavity, oropharynx, and laryngeal site—samples from the TCGA—these cancer forms were not looked at separately “due to the limited power of smaller sample size.”
There are known gender incidence differences between certain head and neck cancers, Dr. Sturgis said, although the reasons for those differences are not clearly understood. “HPV-related head and neck cancers are about four to five times more common in men than women,” he said. “Now, that may just be behavioral differences between men and women and, thus, differences in exposure. But the idea that hormonal factors and other differences between men and women influence that is certainly possible.”
To put it in context, this study is part of the greater medical movement toward precision medicine. “Currently, male and female patients with many cancer types are often treated in a similar way without explicitly considering the factor of sex,” said Dr. Liang. “While this practice may be appropriate for the cancer types in the weak sex-effect group, special consideration should be given to those in the strong sex-effect group in terms of both drug development and clinical practice.”
Otolaryngologists already take gender into account in certain instances, noted Dr. Sturgis, but on a limited basis. “You may be a little more suspicious about the possible presence of HPV-related tonsil cancer in a white man in his 50s than a white woman in her 20s, because the latter is from an unusual group for getting HPV-related tonsil cancer,” he said. “So, certainly it influences us, but the signs and symptoms are what drive the diagnostic workup.”
It is in the treatment aspect that studies such as these will ultimately come into play—but not quite yet. Both Drs. Sturgis and Weber characterize the study’s findings regarding thyroid and head and neck cancers as “not ready for prime time” when it comes to making decisions about cancer treatment. “You would need to have the specific head and neck cancers separated out but, more importantly, we really need to start gathering genetic data, meaning genomic data, on tumors prospectively, so we can compare outcomes with different treatments between tumors that have different genomic patterns,” Dr. Sturgis added.