Clinicopathological Study of Primary Intraosseous Squamous Cell Carcinoma of the Jaw and a Review of the Literature.
OBJECTIVE
Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare malignant odontogenic tumor that originates from odontogenic epithelial remnants. It is often difficult to diagnose PIOSCC definitively; hence, extraction or surgical treatment is performed before the initial diagnosis in most cases. The present study examined new insights into and prognostic factors of patients with PIOSCC admitted to the authors' department.


METHODS
An extensive record review was conducted of patients who underwent radical surgery for PIOSCC from January 2001 through December 2014.


RESULTS
Of all cases of OSCC, the frequency of PIOSCC was 1.45%. The 2-year relapse-free survival (RFS) and overall survival (OS) rates were 50.0 and 41.6% in all cases, respectively. Three patients underwent surgery or tooth extraction before the initial diagnosis; in fact, intervention before initial diagnosis was found to be an important poor prognostic factor for RFS and OS. In contrast, patients who were not treated before the initial diagnosis was made did not exhibit any locoregional recurrence.


CONCLUSIONS
The treatment of PIOSCC should be similar to that for oral cancer with at least clinical stage T3N0 in the National Comprehensive Cancer Network clinical practice guidelines. In addition, cases of PIOSCC that are not treated before the initial diagnosis are more likely to obtain a good prognosis.
Assistant Professor, Department of Clinical Oral Oncology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. Electronic address: naruse12@nagasaki-u.ac.jp.
Tomofumi
T
Naruse
Senior Assistant Professor, Department of Clinical Oral Oncology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Souichi
S
Yanamoto
Assistant Professor, Department of Clinical Oral Oncology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Yuki
Y
Sakamoto
Professor, Department of Oral Pathology and Bone Metabolism, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Tohru
T
Ikeda
Associate Professor, Dentistry and Oral Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
Shin-Ichi
SI
Yamada
Professor, Department of Clinical Oral Oncology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
Masahiro
M
Umeda
D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008339:Mandibular Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008441:Maxillary Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009808:Odontogenic Tumors / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome