Evaluation of the eighth TNM classification on p16-positive oropharyngeal squamous cell carcinomas in the Netherlands and the importance of additional HPV DNA testing.

Background: Oropharyngeal squamous cell carcinomas (OPSCCs) are traditionally caused by smoking and excessive alcohol consumption. However, in the last decades high-risk human papillomavirus (HPV) infections play an increasingly important role in tumorigenesis. HPV-driven OPSCCs are known to have a more favorable prognosis, which has led to important and marked changes in the recently released TNM-8. In this 8th edition, OPSCCs are divided based on p16 immunostaining, with p16 overexpression as surrogate marker for the presence of HPV. The aims of this study are to evaluate TNM-8 on a Dutch consecutive cohort of patients with p16-positive OPSCC and to determine the relevance of additional HPV DNA testing. Patients and methods: All OPSCC patients without distant metastases at diagnosis and treated with curative intent at VU University Medical Center (2000-2015) and Erasmus Medical Center (2000-2006) were included (N = 1204). HPV status was determined by p16 immunostaining followed by HPV DNA PCR on the p16-immunopositive cases. We compared TNM-7 and TNM-8 using the Harrell's C index. Results: In total, 388 of 1204 (32.2%) patients were p16-immunopositive. In these patients, TNM-8 had a markedly better predictive prognostic power than TNM-7 (Harrell's C index 0.63 versus 0.53). Of the 388 p16-positive OPSCCs, 48 tumors (12.4%) were HPV DNA-negative. This subgroup had distinct demographic, clinical and morphologic characteristics and showed a significantly worse five-year overall survival compared with the HPV DNA-positive tumors (P < 0.001). Conclusions: TNM-8 has a better predictive prognostic power than TNM-7 in patients with p16-positive OPSCC. However, within p16-positive OPSCCs, there is an HPV DNA-negative subgroup with distinct features and a worse overall survival, indicating the importance to perform additional HPV DNA testing when predicting prognosis and particularly for selecting patients for de-intensified treatment regimens.

Epidemiologic associations of HPV-positive oropharyngeal cancer and (pre)cancerous cervical lesions.

Human papillomavirus (HPV)-induced oropharyngeal squamous cell carcinoma (OPSCC) remains increasing worldwide. We aimed to investigate if the HPV-prevalence of OPSCC in the Netherlands is rising as well, also in female patients. In addition, we evaluated the association between HPV-positive OPSCC and suspicious Pap results of the cervix in these female patients. Patients with OPSCC treated in the period 2000-2015 at the VU University Medical Center Amsterdam, were included (n = 926). The presence of an oncogenic HPV infection was determined by p16-immunostaining, followed by a high-risk HPV general primer 5+/6+ DNA PCR on the p16-immunopositive cases. A review of pathology reports in all female patients (n = 305) was undertaken to identify cytological signs of HPV-related (pre)cancer of the cervix. In total 281 of 926 (30.3%) OPSCCs were HPV-positive. Moreover, a significant increase in the prevalence of HPV-positive OPSCCs was observed from 14.0% in 2000 to 48.1% in 2015 (p < 0.001). Among the female patients with an HPV-positive OPSSC (n = 70), the results of cervical smears were available in 56 of 70 patients (80.0%). Of the female patients with HPV-positive OPSCC, 9 of 56 (16.1%) patients had a vaginal cuff Papanicolaou (Pap) test ≥3b in their medical history compared to 7 of 168 (4.2%) in the HPV-negative group (p = 0.003). In conclusion, a continuous increase in the HPV-attributable fraction of OPSCC was demonstrated in the period 2000-2015 in the Amsterdam region. HPV-positive OPSCC has a significant association with a history of suspicious Pap results of the cervix in female patients.

Different prognostic models for different patient populations: validation of a new prognostic model for patients with oropharyngeal cancer in Western Europe.

OBJECTIVE: The presence of human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC) is a major determinant in prognostic risk modelling. Recently, a prognostic model was proposed in which HPV status, comorbidity and nodal stage were the most important prognostic factors to determine high-, intermediate- and low-risk survival groups. Here, we report on the validation of this model using an independent single-institutional cohort. METHODS: A total number of 235 patients curatively treated for OPSCC in the period 2000-2011 at the MUMC (Maastricht University Medical Center, The Netherlands) were included. The presence of an oncogenic HPV infection was determined by p16 immunostaining, followed by a high-risk HPV DNA PCR on the p16-positive cases. The model variables included were HPV status, comorbidity and nodal stage. As a measure of model performance, the Harrell's Concordance index (Harrell's C-index) was used. RESULTS: The 5-year overall survival (OS) estimates were 84.6%, 54.5% and 28.7% in the low-, intermediate- and high-risk group, respectively. The difference between the survival curves was highly significant (P<0.001). The Harrell's C-index was 0.69 (95% confidence interval (CI): 0.63-0.75). CONCLUSION: In this study a previously developed prognostic risk model was validated. This model will help to personalise treatment in OPSCC patients. This model is publicly available at www.predictcancer.org.

TP53 mutation and human papilloma virus status of oral squamous cell carcinomas in young adult patients.

OBJECTIVE: Little is known about the molecular carcinogenesis of oral squamous cell carcinoma (OSCC) in young adult patients. The aim of this study was to investigate the detailed TP53 mutation and human papilloma virus (HPV) status of OSCC in patients, younger than 45 years. METHODS: TP53 mutations were determined with direct sequencing on paraffin-embedded carcinoma tissue from 31 young patients and compared with two older age OSCC reference groups: one from the same institute (N = 87) and an independent one (N = 675). Biologically active tumour HPV was detected by p16-immunohistochemistry followed by a HPV-DNA GP5 + /6 + -PCR. RESULTS: HPV16 was present in one OSCC (3%). TP53 mutations were found in 14 (45%) OSCC: five were missense and nine resulted in a truncated protein. Six of these latter were insertions or deletions of one or more nucleotides leading to frameshift, one was at a splice site and two resulted in a stop codon. The percentage of truncating mutations (64% of all mutations) was higher than that observed in the institute's reference group (44%, P = 0.23) and in the independent reference group (24%, P = 0.002). CONCLUSIONS: This study shows that TP53 mutations are common in OSCC of young adult patients; infection with biologically active HPV is rare.

Human papillomavirus detection and comorbidity: critical issues in selection of patients with oropharyngeal cancer for treatment De-escalation trials.

BACKGROUND: The presence of human papillomavirus (HPV)-infection in oropharyngeal squamous cell carcinoma (OPSCC) is a major determinant in prognostic risk modeling. However, most risk models are based on clinical trials which only include a selected patient population. The clinical significance of HPV and other prognostic factors in patients with OPSCC remains to be evaluated in a large, unselected cohort, which also includes patients with stage I/II disease and patients with severe comorbidity. PATIENTS AND METHODS: All patients diagnosed with OPSCC in 2000-2006 in two Dutch university hospitals were included. The presence of an oncogenic HPV infection was determined by p16-immunostaining, followed by a high-risk HPV general primer 5+/6+ DNA PCR on the p16-positive cases. Cox regression analysis was carried out to compare survival rates between HPV-positive and HPV-negative patients and a prognostic model was generated by recursive partitioning. RESULTS: In total, 163 of 841 (19.4%) tumors were HPV-positive. Patients with HPV-positive OPSCC had a more favorable overall survival [73.5% versus 40.9% after 5 years; P < 0.001; hazard ratio = 0.34, 95% confidence interval (CI) 0.25-0.48] compared with patients with HPV-negative OPSCC. Patients with p16-positive but HPV DNA-negative tumors showed a significantly less favorable survival than patients with p16-positive and HPV DNA-positive tumors (P < 0.001). A prognostic model was developed in which patients were classified into three risk groups according to HPV status, nodal stage and comorbidity. [Harrell's concordance index of 0.68 (95% CI 0.65-0.71)]. CONCLUSIONS: Tumor HPV status is a strong and independent prognostic factor for survival among patients with OPSCC. A prognostic risk model was proposed, based on our large, unselected cohort of patients with HPV status, comorbidity and nodal stage being the important prognostic factors. In addition, this study emphasizes the importance of performing an HPV DNA-specific test besides p16-immunostaining.