ABSTRACT
HPV plays a role in the development of a portion of head and neck squamous cell carcinoma (HNSCC), but only limited information on its role in southern Chinese population is available. A multicenter case-control study was conducted. HPV type, viral integration, E6/7 mRNA expression status, and TP53 mutation were determined. A total of 228 HNSCC were recruited including 137 (60.1%) oral SCC, 34 (14.9%) oropharyngeal SCC, 31 (13.6%) laryngeal SCC, 21 (9.2%) hypopharyngeal SCC, and 5 (2.2%) lip and paranasal sinus SCC. High-risk HPV infection was found in 7.5% (17/228) of HNSCC, but only a small proportion of samples had evidence of viral integration (5.3%, 12/228) or E6/7 mRNA expression (4.4%, 10/228). HPV infection with oncogenic phenotype (integration and E6/7 mRNA expression) was significantly more common in oropharyngeal SCC than controls (9/34, 26.5% vs. 0/42, 0.0%, P < 0.001). Smoking showed a significant association with HNSCC, oropharyngeal SCC, and laryngeal SCC. TP53 mutation was associated with HNSCC (P < 0.001). Older age, TP53 mutation, and HPV16 infection with oncogenic phenotypes were independently associated factors for HNSCC with odds ratios of 1.03 (1.02-1.05), 3.38 (1.71-6.66), and 9.19 (1.13-74.68), respectively. High-risk HPV infection of head and neck mucosa is not uncommon in the Hong Kong population. This study found that 26-30% of oropharyngeal carcinoma was associated with HPV infection, mostly HPV16, and that smoking which predisposes to TP53 mutations was another important risk factor.
Subject(s)
Carcinoma, Squamous Cell/virology , Head and Neck Neoplasms/virology , Papillomaviridae/isolation & purification , Papillomavirus Infections/virology , Adult , Aged , Aged, 80 and over , Asian People , Carcinoma, Squamous Cell/epidemiology , Case-Control Studies , Cross-Sectional Studies , Female , Gene Expression Profiling , Head and Neck Neoplasms/epidemiology , Hong Kong/epidemiology , Humans , Male , Middle Aged , Oncogene Proteins, Viral/biosynthesis , Oncogene Proteins, Viral/genetics , Papillomaviridae/classification , Papillomavirus Infections/epidemiology , Risk Factors , Smoking , Tumor Suppressor Protein p53/genetics , Virus Integration , Young AdultABSTRACT
AIM: The prognostic significance of KRAS, NRAS, PIK3CA and BRAF mutations was evaluated in Chinese patients with metastatic colorectal cancer (CRC). METHOD: Tumor samples from 183 patients were retrospectively tested for KRAS, NRAS, PIK3CA and BRAF mutations. Multivariate analysis was performed to determine the relationship between mutational status, drug response and survival. RESULT: Over 70% of patients received two or more lines of chemotherapy, 50% had cetuximab and 18% had bevacizumab. The prevalence of KRAS, NRAS, BRAF and PIK3CA mutations was 45, 3.2, 5 and 20%, respectively. For the entire cohort, the median overall survival was 24 months (95% confidence interval [CI] = 20.4-26.4 months). Of the genes tested, only KRAS mutation was an independent prognostic factor with a multivariate hazard ratio of 1.5 (95% CI = 1.05-2.16, P = 0.03). In the subgroup of patients who received cetuximab-based therapy in the first-line setting, KRAS mutation was associated with a lack of response to chemotherapy (28% vs 66%, chi-square, P = 0.01). Patients with KRAS mutant tumors (or KRAS wild-type tumors that harbored BRAF and/or PIK3CA mutations) tended to have lower response rates to chemotherapy and/or cetuximab (P = not significant). The number of NRAS mutant cases was too small to allow any statistical analysis. CONCLUSION: The prevalence of KRAS, NRAS, BRAF and PIK3CA mutations in this cohort is consistent with reports from non-Asian populations, and KRAS mutation has both prognostic and predictive significance in Chinese patients with metastatic CRC.
