Local immunoreactivity and human papillomavirus (HPV) in oral precancer and cancer lesions.

A retrospective longitudinal study was performed on 20 patients with oral leukoplakia, 10 of which developed an oral squamous cell carcinoma, to assess whether any alterations in the local immunologic reactivity could be found of value in predicting the subsequent behavior of the lesions. During the major period of follow-up, the relative frequency of in situ IgA-producing plasma cells was significantly higher in biopsies from patients subsequently developing cancer than in patients showing no cancer development. Preceding the malignant transformation by 12 to 15 months, however, a remarkable shift from IgA to IgG plasma cell predominance was noticed in the biopsies of the cancer series, not detectable in the non-cancer group. HPV group specific capsid antigens were found in seven cases of the cancer series and in six of the non-cancer group. The possible diagnostic implications of these results are discussed.