Multiple Primary Squamous Cell Carcinomas of the Oral Cavity
This study consists of a retrospective review of our data base of all patients treated for oral SCCA at the University of Maryland department of oral & maxillofacial surgery between November 1989 and July 2011. Of the 1329 patients treated during this time frame, 20 patients met the criteria for inclusion. These were patients that developed 3 or more primary SCCA’s of the oral cavity. Lesions were considered separate primaries if they involved different anatomic regions within the oral cavity and were more than 2 cm apart, or if they occurred more than 5 years apart. Tumors of the oral pharynx were not included.
Results: In this study, there were 14 females and 6 males (F:M ratio of 2.3:1). Nineteen patients were white and 1 was of Indian descent. The average number of primaries per patient was 3.8 (range of 3-6 primaries). The mean age at first diagnosis was 63.3 years (range 44-86 years). The mean interval between the different primaries was 31 months (range 0-228 months). The most common site involved was the gingiva, followed by the tongue, retromolar fossa, and buccal mucosa equally. The gingiva was 4 times more commonly involved than any of the other sites. The average length of time to death or last follow up since first diagnosis was 10.8 years. Of the 20 patients, half were non-smokers or quit greater than 15 years prior to the first diagnosis. Four patients quit tobacco less than 15 years prior to diagnosis;four patients were smokers and two chewed tobacco at the time of diagnosis. All patients quit smoking during the course of their treatment. Three patients had peripheral verrucous leukoplakia (PVL), and four patients had biopsy proven lichen planus. Eleven patients developed positive nodes. The average length of time to neck involvement in these patients was 66.2 months (range 0-334 months). The average length of time from neck involvement to death/last follow up was 77.5 months. At the time of this writing, 8 patients were deceased, and 2 patients have terminal disease undergoing palliative therapy/clinical trials. These patients make up 10 of the 11 patients with nodal metastasis. The other 10 are alive and continue to follow up. Review of the medical history did not show any significant trends. There was one patient with a history of plasmacytoma of the tongue that received 30 Gy of radiation to his head and neck. None of the patients were immune suppressed.
Conclusion: Multiple primary squamous cell carcinomas of the oral cavity occur more commonly in white females, and tend to favor the gingiva. The reason why these patients keep developing new primaries is unclear, and doesn’t seem to correlate with smoking, although some are associated with specific conditions such as PVL or lichen planus. Survival in these patients can be improved by close monitoring and follow up, and early expectant treatment as new dysplasias/ carcinomas develop. Development of lymph node metastasis carries a poor prognosis in these patient (<10% survival).