Validation of local p16 testing for determination of human papilloma virus status eligibility on a low risk oropharyngeal cancer trial - A Trans-Tasman Radiation Oncology Group study

Concurrent Cetuximab-based bioradiotherapy versus Cisplatin-based Chemoradiotherapy in the Definitive Management of Favourable Biology Human Papillomavirus-associated Oropharyngeal Squamous Cell Carcinoma: Systematic Review and Meta-analysis

Replacing cisplatin with cetuximab concurrently during radiotherapy has been one of the strategies of treatment de-escalation in human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC). However, until recently, there were limited data on the efficacy and safety of such an approach. A systematic search of the literature was carried out to identify prospective randomised controlled trials comparing definitive cisplatin-based chemoradiotherapy (CT-RT) versus cetuximab-based bioradiotherapy (BRT) in HPV-positive OPSCC. Overall survival and locoregional control were primary outcomes of interest; rates of acute and late toxicities (≥grade 3) were secondary end points. Outcome data were aggregated using a random-effects model as per Cochrane methodology including risk of bias assessment and expressed as hazard ratio or risk ratio as appropriate with respective 95% confidence intervals. Data from five randomised controlled trials involving 1560 patients with HPV-positive OPSCC were aggregated in the meta-analysis. Cetuximab-based BRT was associated with a significantly increased risk of death (hazard ratio = 2.83, 95% confidence interval 1.22-6.57; P = 0.02) and locoregional relapse (hazard ratio = 2.78, 95% confidence interval 1.77-4.39; P < 0.0001) compared with cisplatin-based CT-RT. Cisplatin was associated with higher rates of acute ≥grade 3 toxicity in terms of acute kidney injury, dry mouth, febrile neutropenia, hearing impairment, nausea and vomiting, whereas dermatitis and acneiform rash were more common with cetuximab. There were no significant differences in overall rates of late ≥grade 3 toxicity (risk ratio = 0.63, 95% confidence interval = 0.36-1.10; P = 0.10). In conclusion, there is moderate-certainty evidence that cetuximab-based BRT leads to inferior efficacy outcomes compared with cisplatin-based CT-RT in the definitive curative-intent management of HPV-associated OPSCC.

Prognostic stratification of HPV-associated oropharyngeal cancer based on CD103+ immune cell abundance in patients treated on TROG 12.01 and De-ESCALaTE randomized trials

BACKGROUND

High CD103+ intratumoral immune cell (ITIC) abundance is associated with better prognosis in unselected patients with human papilloma virus-associated oropharyngeal squamous cell carcinoma (HPV-associated OPSCC) treated with cisplatin and radiotherapy (CIS/RT). Substituting cetuximab (CETUX) for CIS with RT in HPV-associated OPSCC resulted in inferior efficacy. Our aim was to determine whether quantification of CD103 ITIC could be used to identify a population of HPV-associated OPSCC with superior prognosis.

PATIENTS AND METHODS

We pooled data from the TROG 12.01 and De-ESCALaTE randomized trials that compared CETUX/70GyRT with CIS/70GyRT in low-risk HPV-associated OPSCC: American Joint Committee on Cancer 7 stage III (excluding T1-2N1) or stage IV (excluding N2b-c if smoking history >10 pack-years and/or distant metastases), including all patients with available tumor samples. The primary endpoint was failure-free survival (FFS) in patients receiving CETUX/RT comparing CD103+ ITIC high (≥30%) versus low (<30%). High and low CD103 were compared using Cox regression adjusting for age, stage and trial.

RESULTS

Tumor samples were available in 159/182 patients on TROG 12.01 and 145/334 on De-ESCALaTE. CD103+ ITIC abundance was high in 27% of patients. The median follow-up was 3.2 years. The 3-year FFS in patients treated with CETUX/RT was 93% [95% confidence interval (CI) 79% to 98%] in high CD103 and 74% (95% CI 63% to 81%) in low CD103 [adjusted hazard ratio = 0.22 (95% CI 0.12-0.41), P < 0.001]. The 3-year overall survival in patients treated with CETUX/RT was 100% in high CD103 and 86% (95% CI 76% to 92%) in low CD103, P < 0.001. In patients treated with CIS/RT, there was no significant difference in FFS.

CONCLUSIONS

CD103+ ITIC expression separates CETUX/RT-treated low-risk HPV-associated OPSCC into excellent and poor prognosis subgroups. The high CD103 population is a rational target for de-intensification trials.

Current Status of Human Papillomavirus-Related Head and Neck Cancer: From Viral Genome to Patient Care

Human papillomavirus (HPV) infection identified as a definitive human carcinogen is increasingly being recognized for its role in carcinogenesis of human cancers. Up to 38%–80% of head and neck squamous cell carcinoma (HNSCC) in oropharyngeal location (OPSCC) and nearly all cervical cancers contain the HPV genome which is implicated in causing cancer through its oncoproteins E6 and E7. Given by the biologically distinct HPV-related OPSCC and a more favorable prognosis compared to HPV-negative tumors, clinical trials on de-escalation treatment strategies for these patients have been studied. It is therefore raised the questions for the patient stratification if treatment de-escalation is feasible. Moreover, understanding the crosstalk of HPV-mediated malignancy and immunity with clinical insights from the proportional response rate to immune checkpoint blockade treatments in patients with HNSCC is of importance to substantially improve the treatment efficacy. This review discusses the biology of HPV-related HNSCC as well as successful clinically findings with promising candidates in the pipeline for future directions. With the advent of various sequencing technologies, further biomolecules associated with HPV-related HNSCC progression are currently being identified to be used as potential biomarkers or targets for clinical decisions throughout the continuum of cancer care.

Randomised trial of radiotherapy with weekly cisplatin or cetuximab in low risk HPV associated oropharyngeal cancer (TROG 12.01) - a Trans-Tasman Radiation Oncology Group study

BACKGROUND

The excellent prognosis of patients with low risk HPV associated oropharyngeal squamous cell carcinoma has led to concerns about overtreatment and excessive toxicity with radiotherapy and cisplatin, leading to interest in de-intensification trials. We investigated whether cetuximab, an EGFR targeting antibody, when combined with radiotherapy would result in a decrease in symptom burden and toxicity with similar efficacy when compared to weekly cisplatin.

METHODS

XXXX, a randomised, multicentre trial involving 15 sites in XXXX enrolled patients with HPV associated oropharyngeal squamous cell carcinoma, AJCC 7^th edition Stage III (excluding T1-2N1) or stage IV (excluding T4 and/or N3 and/or N2b-c if smoking history >10 pack years and/or distant metastases). Patients were randomised (1:1) to receive radiotherapy (70Gy in 35 fractions) with either weekly cisplatin, 7 doses of 40mg/m² or cetuximab, loading dose of 400mg/m² followed by 7 weekly doses of 250 mg/m². The primary outcome was symptom severity assessed by the MD Anderson Symptom Inventory Head and Neck Symptom Severity Scale from baseline to 13 weeks post completion of radiotherapy using the area under the curve (AUC). Trial was registered on ClinicalTrials.gov: XXXX RESULTS: Between 17^th June 2013 and 7^th June 2018, 189 patients were enrolled, with 92 on cisplatin arm and 90 on cetuximab included in the main analysis. There was no difference in the primary endpoint of symptom severity; difference in AUC cetuximab - cisplatin was 0.05 (95%CI: -0.19, 0.30), p= 0.66. The T-score (mean number of ≥ grade 3 acute adverse events) was 4.35 (SD 2.48) in the cisplatin arm and 3.82 (SD 1.8) in the cetuximab arm, p= 0.108. The 3 -year failure-free survival rates were 93% (95% CI: 86-97%) in the cisplatin arm and 80% (95% CI: 70-87%) in the cetuximab arm (hazard ratio = 3.0 (95% CI: 1.2-7.7); p=0.015.

CONCLUSIONS

For patients with low risk HPV associated oropharyngeal cancer, radiotherapy and cetuximab had inferior failure-free survival without improvement in symptom burden or toxicity compared to radiotherapy and weekly cisplatin. Radiotherapy and cisplatin remains the standard of care.