HPV関連中咽頭癌に対する手術療法

抄録

In recent years, a dramatic rise in the incidence of human papilloma virus (HPV)-associated oropharyngeal cancer has been reported. As compared with non-HPV associated oropharyngeal cancer, HPV-associated oropharyngeal cancer typically shows high susceptibility to radio- and chemotherapy and a better prognosis. Even after initial primary surgery, HPV-associated oropharyngeal cancers are highly curable and carry a good prognosis as compared with non-HPV associated oropharyngeal cancers. Therefore, therapy for HPV-associated oropharyngeal cancers should be selected with the goal of radical cure with good functional outcomes, minimum invasiveness and complications. If complete resection of the tumor with sufficient negative margins could be expected from surgery alone, especially minimally invasive surgery, as the primary treatment option, the treatment period would be dramatically shortened, with great merits. We retrospectively reviewed the data of 29 cases of HPV-associated oropharyngeal cancer of the lateral wall that we treated by surgical resection, focusing on the extent of invasion of the tumor, to identify factors that may affect the resected margins in surgically treated candidates. The margin positivity rate was significantly higher in cases with invasion of the soft palate, base of the tongue and pharyngeal contractile muscles. Multivariate analysis also identified presence/absence of invasion of the pharyngeal contractile muscles as a significant prognostic factor. Based on these results, we recommend that surgery not be considered as the primary treatment option in cases with tumor invasion of the pharyngeal contractile muscles.

For cases without involvement of the pharyngeal contractile muscles, if surgery is opted for instead of radiation therapy, a minimally invasive approach would be desirable. We present the case of a patient with a tumor extending caudally, who was successfully operated by the pull-through method without free flap reconstruction, and is showing a satisfactory good postoperative course.