Primary intraosseous carcinoma of the jaw: pooled analysis of world literature and report of two new cases.

Primary intraosseous carcinoma (PIOC) is a rare malignant neoplasm of the jaw. These tumours are believed to arise from the odontogenic epithelium and hence are also referred to as odontogenic carcinoma. A detailed search was made for squamous cell PIOC of the jaw in English literature using Medline Cancer CD. The data obtained were transferred onto dBase software. Two detailed case reports of patients treated at Regional Cancer Centre, Trivandrum during 1996 and 1997 were also included. A pooled analysis was carried out. Survival analysis was carried out using Kaplan-Meier method and log-rank statistics were used for comparing survival. A total of 35 cases were analysed, of which 33 were from published literature. The mean age of the patients at the time of diagnosis was 52.3 years with male to female ratio being 2.5:1. Posterior mandible was the predominant site. The median follow-up time was 28 months. Overall survival at 5 years was 37.8% (95% CI; 14.8-61.0) while the corresponding disease free survival was 29.8% (95% CI; 9.2-54.1). Primary intraosseous carcinoma is a rare tumour of jawbones, characterized by progressive swelling of the jaw, pain and loosening of tooth. The tumour is locally aggressive and metastasizes to regional nodes. The overall and disease free survival is poor with almost 50% patients failing loco-regionally within the first 2 years of follow-up.