<span>Clinical Investigation on Multiple Primary Oral Cancers in Kochi Medical School Hospital</span>

Kitamura, Naoya

Clinical Investigation on Multiple Primary Oral Cancers in Kochi Medical School Hospital

Naoya Kitamura DDS, PhD, Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Shinya Sento , Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Mayu Takahashi , Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Jun Kunito , Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Fumito Hamada , Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Riki Tomita , Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Eri Sasabe DDS, PhD, Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Tetsuya Yamamoto DDS, PhD, Oral and Maxillofacial Surgery, Kochi Medical School, Kochi University, Nankoku-city, Kochi, Japan

Objectives: In recent years, multiple cancer cases is increasing because of the aging of the cancer patients, advances in diagnostic technology and treatment. This study was clinical retrospective evaluation of the multiple primary oral cancers with the exception of the ectopic double cancer. Patients and Methods: Six hundred and eighty-six patients with oral squamous cell carcinoma referred to our department for 32 years of 1982 – 2013 were enrolled in this study. The incidence of multiple primary oral cancer, tumor sites in the oral cavity, the interval between primary and secondary tumors, and prognosis were retrospectively investigated. In addition, multiple primary tumors was classified into synchronous (diagnosed simultaneously or within 12 months) and metachronous (diagnosed after a time interval of 12 months) cases. Results: The incidence of multiple primary oral cancers was 24/686 (3.5%). The male-to-female ratio was 1:1.7 (9 men/15 women) and the average age at the onset of the first cancer was 69.7 ± 12.2 years old. Of these patients, 17 and 7 cases had double and triple cancers, respectively (total 55 cancers). The sites of 55 multiple primary oral cancers was the tongue in 11, the lower gum in 19, the upper gum in 5, the oral floor in 8, the buccal mucosa in 11, and the lip in 1. Multiple primary oral cancers were synchronous in 6 cases, metachronous in 14 cases, and simultaneous + metachronous in 4 cases. In metachronous cases, the interval between multiple cancers was 6.9 ± 5.9 years (median: 5 years). The tumors were treated by surgery alone in 42, by chemo-radiotherapy (CRT) in 8, surgery after CRT in 3, and chemotherapy alone in 2. Twelve patients including 1 case with liver metastasis of oral cancer keep alive, and 7 and 3 patients died of other diseases such as cerebral infarction and cardiovascular disease and cancer (2 oral cancers and 1 esophageal cancer). Conclusion: These results suggest that long-standing careful screening examinations are important to improve survival in patients with oral squamous cell carcinoma.