Regional control is preserved after dose de-escalated radiotherapy to involved lymph nodes in HPV positive oropharyngeal cancer

Human Papillomavirus-Related Non-Metastatic Oropharyngeal Carcinoma: Current Local Treatment Options and Future Perspectives

Over the last two decades, human papillomavirus (HPV) has caused a new pandemic of cancer in many urban areas across the world. The new entity, HPV-associated oropharyngeal squamous cell carcinoma (OPSCC), has been at the center of scientific attention ever since, not only due to its distinct biological behavior, but also because of its significantly better prognosis than observed in its HPV-negative counterpart. The very good treatment outcomes of the disease after primary therapy (minimally-invasive surgery, radiation therapy with or without chemotherapy) resulted in the creation of a separate staging system, reflecting this excellent prognosis. A substantial proportion of newly diagnosed HPV-driven OPSCC is diagnosed in stage I or II, where long-term survival is observed worldwide. Deintensification of the primary therapeutic methods, aiming at a reduction of long-term toxicity in survivors, has emerged, and the quality of life of the patient after treatment has become a key-point in many clinical trials. Current treatment recommendations for the treatment of HPV-driven OPSCC do not differ significantly from HPV-negative OPSCC; however, the results of randomized trials are eagerly awaited and deemed necessary, in order to include deintensification into standard clinical practice.

Management of HPV-Related Squamous Cell Carcinoma of the Head and Neck: Pitfalls and Caveat

Head and neck squamous cell carcinomas (HNSCCs) are a very heterogeneous group of malignancies arising from the upper aerodigestive tract. They show different clinical behaviors depending on their origin site and genetics. Several data support the existence of at least two genetically different types of HNSCC, one virus-related and the other alcohol and/or tobacco and oral trauma-related, which show both clinical and biological opposite features. In fact, human papillomavirus (HPV)-related HNSCCs, which are mainly located in the oropharynx, are characterized by better prognosis and response to therapies when compared to HPV-negative HNSCCs. Interestingly, virus-related HNSCC has shown a better response to conservative (nonsurgical) treatments and immunotherapy, opening questions about the possibility to perform a pretherapy assessment which could totally guide the treatment strategy. In this review, we summarize molecular differences and similarities between HPV-positive and HPV-negative HNSCC, highlighting their impact on clinical behavior and on therapeutic strategies.

Prognostic value of nodal involvement in patients with oropharyngeal carcinoma according to the HPV status

BACKGROUND AND OBJECTIVE

Different studies performed in populations with a high incidence of HPV infection have found no prognostic capacity of clinical nodal involvement (cN+) in patients with HPV-positive oropharyngeal carcinomas. The objective of this study was to assess the prognostic ability of nodal involvement in patients with oropharyngeal carcinomas according to HPV status in a cancer population with a low incidence of HPV infection.

MATERIAL AND METHODS

Retrospective study of a cohort of 420 patients with oropharyngeal carcinomas treated during the period 1990-2016 for whom information on HPV status was available.

RESULTS

14.8% of the patients included in the study had HPV-positive tumours. In relation to patients without nodal involvement (cN0), nodal involvement at diagnosis (cN+) significantly decreased the specific survival of patients with HPV-negative oropharyngeal carcinomas. Conversely, no differences in survival were found for patients with HPV-positive tumours according to the presence of nodal involvement. A history of toxic consumption did not change the absence of prognostic significance of nodal involvement for patients with HPV-positive tumours.

CONCLUSIONS

Regional involvement at the time of diagnosis is not a prognostic variable for patients with HPV-positive oropharyngeal carcinomas.

Impact of hypofractionated schemes in radiotherapy for locally advanced head and neck cancer patients

OBJECTIVE

To analyze two cohorts of locally advanced head and neck cancer (LAHNC) patients treated with two schedules of hypofractionated radiotherapy and 5 versus 3 mm clinical target volume-planning target volume (CTV-PTV) margins.

METHODS

145 patients were included. The patient cohort was divided into two groups. Group A included 97 patients treated with 69.96/54.45 grays (Gy) to the high-risk and low-risk volumes, respectively, in 33 fractions, with 5 mm margins. Group B included 48 patients treated with 66/54 Gy in 30 fractions using 3 mm margins. Toxicity was recorded according to the Common Toxicity Criteria version 3. Patient outcomes for locoregional control (LRC), disease-free survival (DFS), and overall survival (OS) were determined.

RESULTS

Median follow-up was 26 months. In terms of toxicity, acute dysphagia worsened significantly (P = 0.003) in group B, whereas acute salivary toxicity tended to significance (P = 0.071). No significant late toxicity differences were recorded. Rates of LRC at 1 and 2 years were 90.1% ± 2.6% and 84.2% ± 3.4%, respectively, with superiority for group A (P = 0.045). The statistical significance remained for the low-dose level (P = 0.007) but not for high dose (P = 0.110). Rates of DFS at 1 and 2 years were 84.9% ± 3.1% and 76.5% ± 3.9%, respectively, whereas rates of OS were 95.9% ± 1.8% and 91.6% ± 2.7%, respectively. No differences were observed between the two groups in terms of DFS (P = 0.270) and OS (P = 0.152).

CONCLUSION

The use of reduced CTV to PTV margins and dose reduction with hypofractionation schedule can improve the pattern of toxicity in LAHNC patients. This approach resulted in an increased rate of locoregional progression, particularly in low-risk regions.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:E163-E170, 2020.

Long-term recurrence-free survival after an unplanned reduction in radiotherapy for HPV-positive oropharyngeal SCC: Two cases and a review of the literature

There is currently no clear distinction between the treatment of HPV-positive and HPV-negative oropharyngeal squamous cell carcinoma (OPSCC). HPV-positive OPSCC has been demonstrated to be more radiosensitive than its HPV-negative counterpart. Despite this, patients with HPV-positive OPSCC continue to receive a full dose of radiation (70 Gy) outside clinical trials. However, this high dose comes with considerable morbidities, including severe mucositis, dysphagia, and xerostomia. We describe the cases of 2 patients with HPV-positive OPSCC who received two cycles of high-dose cisplatin at 100 mg/m² on 3 separate days, along with concurrent radiotherapy at 50 Gy in 25 fractions for one and 46 Gy in 23 fractions for the other. During treatment, both patients experienced significant acute-phase toxicities-including grade 3 mucositis, grade 3 nausea, and grade 2 dermatitis-and their treatment regimen was stopped before its planned completion. Nevertheless, after a follow-up of 75 and 78 months, respectively, neither patient exhibited any evidence of disease. Late toxicities included grade 1 xerostomia, grade 1 pharyngeal-phase dysphagia, and grade 1 dysgeusia with some foods. We conclude that de-escalating the dose of radiation for HPV-positive patients by 30% and identifying which patients can safely be treated with this level of dose reduction warrants further study.

Considerations in surgical versus non-surgical management of HPV positive oropharyngeal cancer

Given the marked difference in clinical presentation and treatment response based on human papilloma virus (HPV) status, HPV-associated oropharyngeal squamous cell carcinoma is now viewed as a distinct biologic and clinical entity. HPV-associated oropharyngeal squamous cell carcinoma has increased by nearly 7.5 % per year, from approximately 16 % in the early 1980′s to nearly 70 % today, and is believed will continue to increase dramatically in the coming years. Currently, a myriad of treatment options exist for these patients as many active clinical trials are underway which aim to identify the most appropriate interventions for this unique group of patients. This review aims to provide considerations between surgical and non-surgical management for HPV-associated oropharyngeal squamous cell carcinoma.

Predictors of overall survival in human papillomavirus-associated oropharyngeal cancer using the National Cancer Data Base

OBJECTIVES

This study identifies clinical characteristics associated with HPV-positive oropharynx squamous cell carcinoma (OPSCC) and evaluates predictors of overall survival (OS) in HPV-positive patients undergoing definitive treatment within the National Cancer Data Base (NCDB).

MATERIAL AND METHODS

The NCDB was queried for patients ⩾18years old with OPSCC and known HPV status who underwent definitive treatment: surgery, radiation (RT), chemotherapy-RT (CRT), surgery+RT, surgery+CRT (S-CRT). Cox proportional hazards model was used for multivariate analysis (MVA) to evaluate predictors of OS by HPV status.

RESULTS

3952 patients were included: 2454 (62%) were HPV-positive. Median follow up was 23.7months (range, 1.0-54.5). Unadjusted 2-year OS rates for HPV-positive vs. negative were 93.1% vs. 77.8% (p<0.001) with an adjusted hazard ratio of 0.44 (95% CI, 0.36-0.53; p<0.001). MVA identified multimodality treatment including CRT (HR, 0.42; p=0.024) and S-RT (HR, 0.30; p=0.024), but not S-CRT (HR, 0.51; p=0.086), as predictors for improved OS in HPV-positive stage III-IVB disease. Multimodality treatment including S-CRT was associated with longer OS in HPV-negative OPSCC. Nodal stage was poorly associated with OS in HPV-positive cancers. The presence of positive margins and/or extracapsular extension was associated with worse OS in HPV-negative (HR, 2.11; p=0.008) but not HPV positive OPSCC (HR, 1.61; p=0.154).

CONCLUSION

The established demographic and clinical features of HPV-positive OPSCC were corroborated in the NCDB. Population analysis suggests that AJCC staging is poorly associated with OS in HPV-positive cancer, and traditional high-risk features may be less impactful. Bimodality therapy appears beneficial in HPV-positive HNSCC.