The objective of the present study was to assess the current situation of oral squamous cell carcinoma (OSCC) in northern Thailand, with an emphasis on patients <40 years of age. Medical records of patients histologically diagnosed with OSCC were collected from the Cancer Registry of Maharaj Nakorn Chiang Mai Hospital, Thailand between 2001 and 2010. The clinico-demographic data of patients aged <40 years (young group) and those aged ≥40 years (old group) were compared. A total of 874 patients were included in this study, of which 4.1% were <40 years of age. The tongue was the most common cancer site in both age groups. Most patients in both age groups were diagnosed with oral cancer at stage IV. Tobacco smoking (62.3%) and alcohol consumption (52.3%) were the most common risk factors in both age groups. However, the rates of betel quid chewing (17.5%) had decreased from those found in our study in the previous decade (50.2%); these rates were not found in the young group. The 5-year survival rate was 27.4% for the old group and 56.2% for the young group. OSCC remains a serious oral health problem in northern Thailand, and it has not been resolved among young adults. (J Oral Sci 57, 327-334, 2015)

Objectives: To identify the prevalence of high-risk human papillomavirus (HPV) genotypes 16 and 18 among patients with oral squamous cell carcinoma (OSCC) in Thailand and investigate the associations of p16 expression and HPV16/18 with the demographic, clinicopathologic, and risk parameters. Materials and Methods: A total of 403 formalin-fixed paraffin-embedded OSCC specimens from four centers in four regions were obtained. p16 expression was evaluated by immunohistochemistry. The detection of HPV16/18 DNA was performed by polymerase chain reaction. Results: Of all, 172 specimens (42.7%) were presented with amplifiable extracted DNA. Among these, 62.8% were positive for p16, 8.1% were positive for HPV16/18, and 5.8% were positive for both methods. Of all HPV-positive specimens, HPV18 was detected in 57.1%; HPV16 in 14.3%; and HPV16 and 18 (co-infection) in 28.6%. The prevalence of HPV16/18 varied between centers, with the highest rate in the northern center (20.0%). There was no significant correlation between p16 expression and HPV16/18. There were no significant associations of p16 expression and/or HPV16/18 with all variables. Conclusions: The prevalence of HPV16/18 infection in OSCC geographically varied in Thailand, with the highest rate in the northern region. Poor correlation between p16 and HPV16/18 suggests p16 not be used as a surrogate marker for HPV-positive OSCC.