Background: The association between human papillomavirus (HPV) and overall survival (OS) in oropharynx cancer (OPC) was retrospectively examined in TAX 324, a phase III trial of sequential therapy for locally advanced head and neck cancer. Methods: Accrual for TAX 324 was completed in 2003 and data updated through 2008. Pretherapy tumor biopsies were studied by PCR for human papillomavirus type 16 and linked to OS, progression-free survival (PFS) and demographics. Results: Of 264 patients with OPC, 111 (42%) had evaluable biopsies; 56 (50%) were HPV+ and 55 (50%) were HPV−. HPV+ patients were significantly younger (54 versus 58 years, P = 0.02), had T1/T2 primary cancers (49% versus 20%, P = 0.001), and had a performance status of zero (77% versus 49%, P = 0.003). OS and PFS were better for HPV+ patients (OS, hazard ratio = 0.20, P < 0.0001). Local–regional failure was less in HPV+ patients (13% versus 42%, P = 0.0006); at 5 years, 82% of HPV+ patients were alive compared with 35% of HPV− patients (P < 0.0001). Conclusions: HPV+ OPC has a different biology compared with HPV− OPC; 5-year OS, PFS, and local–regional control are unprecedented. These results support the possibility of selectively reducing therapy and long-term morbidity in HPV+ OPC while preserving survival and approaching HPV− disease with more aggressive treatment.

The expression of vitamin D receptors (VDR) and growth inhibition induced by 1,25-dihydroxyvitamin D₃have been noted in certain human malignant melanoma cell lines. In this study, widely disparate levels of VDR mRNA expression were demonstrated in a panel of eight human malignant melanoma cell lines. Quantitation of receptor level by ligand binding assay showed a similar pattern. Proliferation and growth curve analysis was performed in two cell lines: RPMI 7951 (high VDR) and SK-MEL-28 (low VDR). Significant growth inhibition was noted in RPMI 7951 cells at 10⁻⁹M1,25-dihydroxyvitamin D₃. SK-MEL-28 cells, which express much lower levels of VDR, did not show any growth inhibition except at extremely high concentrations of 1,25-dihydroxyvitamin D₃, namely 10⁻⁶M. These findings suggest a receptor-mediated mechanism of growth inhibition for 1,25-dihydroxyvitamin D₃and a role for this hormone in the growth of malignant melanoma cells.