We aimed to reveal the prevalence and pattern of human papillomavirus (HPV) infection and p53 mutations among Japanese head and neck squamous cell carcinoma (HNSCC) patients in relation to clinicopathological parameters. Human papillomavirus DNA and p53 mutations were examined in 493 HNSCCs and its subset of 283 HNSCCs. Oropharyngeal carcinoma was more frequently HPV-positive than non-oropharyngeal carcinoma (34.4% vs 3.6%, P < 0.001), and HPV16 accounted for 91.1% of HPV-positive tumors. In oropharyngeal carcinoma, which showed an increasing trend of HPV prevalence over time (P < 0.001), HPV infection was inversely correlated with tobacco smoking, alcohol drinking, p53 mutations, and a disruptive mutation (P = 0.003, <0.001, <0.001, and <0.001, respectively). The prevalence of p53 mutations differed significantly between virus-unrelated HNSCC and virus-related HNSCC consisting of nasopharyngeal and HPV-positive oropharyngeal carcinomas (48.3% vs 7.1%, P < 0.001). Although p53 mutations were associated with tobacco smoking and alcohol drinking, this association disappeared in virus-unrelated HNSCC. A disruptive mutation was never found in virus-related HNSCC, whereas it was independently associated with primary site, such as the oropharynx and hypopharynx (P = 0.01 and 0.03, respectively), in virus-unrelated HNSCC. Moreover, in virus-unrelated HNSCC, G:C to T:A transversions were more frequent in ever-smokers than in never-smokers (P = 0.04), whereas G:C to A:T transitions at CpG sites were less frequent in ever-smokers than in never-smokers (P = 0.04). In conclusion, HNSCC is etiologically classified into virus-related and virus-unrelated subgroups. In virus-related HNSCC, p53 mutations are uncommon with the absence of a disruptive mutation, whereas in virus-unrelated HNSCC, p53 mutations are common, and disruptive mutagenesis of p53 is related with oropharyngeal and hypopharyngeal carcinoma.

Our data suggest that preoperative CRT may improve the survival of surgically treated patients with external auditory canal SCC and that definitive CRT may be equivalent to surgical resection.

The clinical significance of human papillomavirus (HPV) in neck node metastasis from cancer of unknown primary (CUP) is not well established. We aimed to address the relationship of HPV status between node metastasis and the primary tumor, and also the relevance of HPV status regarding radiographically detected cystic node metastasis in head and neck squamous cell carcinoma (HNSCC) and CUP. HPV DNA was examined in 68 matched pairs of node metastasis and primary tumor, and in node metastasis from 27 CUPs. In surgically treated CUPs, p16 was examined immunohistochemically. When tonsillectomy proved occult tonsillar cancer in CUP, HPV DNA and p16 were also examined in the occult primary. Cystic node metastasis on contrast-enhanced computed tomography scans was correlated with the primary site and HPV status in another series of 255 HNSCCs and CUPs with known HPV status. Node metastasis was HPV-positive in 19/37 (51%) oropharyngeal SCCs (OPSCCs) and 10/27 (37%) CUPs, but not in non-OPSCCs. Fluid was collected from cystic node metastasis using fine needle aspiration in two OPSCCs and one CUP, and all fluid collections were HPV-positive. HPV status, including the presence of HPV DNA, genotype, and physical status, as well as the expression pattern of p16 were consistent between node metastasis and primary or occult primary tumor. Occult tonsillar cancer was found more frequently in p16-positive CUP than in p16-negative CUP (odds ratio (OR), 39.0; 95% confidence interval (CI), 1.4–377.8; P = 0.02). Radiographically, cystic node metastasis was specific to OPSCC and CUP, and was associated with HPV positivity relative to necrotic or solid node metastasis (OR, 6.2; 95% CI, 1.2–45.7; P = 0.03). In conclusion, HPV status remains unchanged after metastasis. The occult primary of HPV-positive CUP is most probably localized in the oropharynx. HPV status determined from fine needle aspirates facilitates the diagnosis of cystic node metastasis.

Background:Cancer stem cells (CSCs) are responsible for treatment failure. However, their identification and roles in resistance are not well established in head and neck squamous cell carcinoma (HNSCC).Methods:Three HNSCC cell lines (FaDu, Detroit562 and BICR6) were treated with cisplatin or radiation. Cell surface antigens were analysed by LyoPlate, a novel cell surface antigen array. The expression levels of antigens highly expressed after treatments were further compared between cisplatin-resistant Detroit562 cells and its parental line. Association of the candidate antigen with CSCs properties, namely sphere formation and in vivo tumourigenicity, was also examined.Results:CD10, CD15s, CD146 and CD282 were upregulated across the treated cell lines, while the increased expression of CD10 was prominent in the cisplatin-resistant cell line. Isolation mediated by FACS revealed that the CD10-positive subpopulation was more refractory to cisplatin, fluorouracil and radiation than the CD10-negative subpopulation. It also showed an increased ability to form spheres in vitro and tumours in vivo. Moreover, the CD10-positive subpopulation expressed the CSC marker OCT3/4 at a higher level than that in the CD10-negative subpopulation.Conclusions:CD10 is associated with therapeutic resistance and CSC-like properties of HNSCC. CD10 may serve as a target molecule in the treatment of refractory HNSCC.

Radiation therapy has been long utilized as localized cancer treatment. Recent studies have also demonstrated that it has a distant effect by the enhanced immunity, but it rarely occurs. The purpose of this study was to investigate whether X-ray irradiation combined with anti-PD-L1 and anti-CTLA-4 antibodies (P1C4) provides a higher probability of this distant effect as well as enhanced local antitumor efficacy for osteosarcoma. LM8 mouse osteosarcoma cells were inoculated into both legs of C3H mice assigned to one of four groups, namely no treatment (No Tx), P1C4, X-ray irradiation (RAD) to the leg of one side, and combination (COMB) groups. Survival and treatment-related immune molecular changes were analyzed. Administration of P1C4 produced a tumor growth delay on day 30 in 18% of the mice. In contrast, combination therapy produced the strongest tumor growth inhibition not only at the irradiated tumor but also at unirradiated tumor in 67% of the mice. Accordingly, lung metastasis in the COMB group was strongly reduced by 98%, with a significant survival benefit. Unirradiated tumor in mice in the COMB group significantly recruited CD8 + tumor-infiltrating lymphocytes with a moderate reduction of Treg, producing a significant increase in the CD8/ Treg ratio. These results suggest that radiation enhances the efficacy of P1C4 treatment against distant metastasis as well as local control in osteosarcoma. Our data suggest that radiation therapy combined with dual checkpoint blockade may be a promising therapeutic option for osteosarcoma.