Transoral Robotic Surgery in the HPV Era

MRI-Based Assessment of the Pharyngeal Constrictor Muscle as a Predictor of Surgical Margin after Transoral Robotic Surgery in HPV-Positive Tonsillar Cancer

BACKGROUND AND PURPOSE

Transoral robotic surgery is an emerging strategy for treating human papillomavirus-positive cancers, but the role of MR imaging in predicting the surgical outcome has not been established. We aimed to identify preoperative MR imaging characteristics that predispose the outcome of transoral robotic surgery toward an insecure (positive or close) surgical margin in human papillomavirus-positive tonsillar squamous cell carcinoma.

MATERIALS AND METHODS

Between December 2012 and May 2019, sixty-nine patients underwent transoral robotic surgery at our institution. Among these, 29 who were diagnosed with human papillomavirus-positive tonsillar squamous cell carcinoma, did not receive neoadjuvant treatment, underwent preoperative 3T MR imaging, and had postoperative pathologic reports and were included in this retrospective study. Two neuroradiologists evaluated the preoperative MR imaging scans to determine the tumor spread through the pharyngeal constrictor muscle using a 5-point scale: 1, normal constrictor; 2, bulging constrictor; 3, thinning constrictor; 4, obscured constrictor; and 5, tumor protrusion into the parapharyngeal fat. The risk of an insecure surgical margin (involved or <1 mm) according to the MR imaging scores was predicted using logistic regression with the Firth correction.

RESULTS

The interobserver agreement for the MR imaging scores was excellent (κ = 0.955, P < .001). A score of ≥4 could predict an insecure margin with 87.5% sensitivity and 92.3% specificity (area under the curve = 0.899) and was the only significant factor associated with an insecure margin in the multivariable analysis (OR, 6.59; 95% CI, 3.11-22.28; P < .001).

CONCLUSIONS

The pre-transoral robotic surgery MR imaging scoring system for the pharyngeal constrictor muscle is a promising predictor of the surgical margin in human papillomavirus-positive tonsillar squamous cell carcinoma.

Organ Preservation and Late Functional Outcome in Oropharyngeal Carcinoma: Rationale of EORTC 1420, the "Best of" Trial

Dysphagia represents one of the most serious adverse events after curative-intent treatments with a tremendous impact on quality of life in patients with head and neck cancers. Novel surgical and radiation therapy techniques have been developed to better preserve swallowing function, while not negatively influencing local control and/or overall survival. This review focuses on the current literature of swallowing outcomes after curative treatment strategies. Available results from recent studies relevant to this topic are presented, demonstrating the potential role of new treatment modalities for early- and intermediate-stage oropharyngeal cancers. Based on this, we present the rationale and design of the currently active EORTC 1420 "Best of" trial, and highlight the potential of this study to help prioritizing either surgery- or radiation-based treatment modalities for the treatment of oropharyngeal cancer in the future.

Current Concepts in Chemotherapy for Head and Neck Cancer

This article highlights the evidence-based data to support systemic treatment options for patients with head and neck squamous cell carcinoma (HNSCC). The discovery of the human papillomavirus epidemic in HNSCC and its favorable prognosis has led to a major focus of research. Patients are stratified into clinical or pathologic risk categories and enrolled in trials comparing standard treatment paradigms with deintensification, in low-risk disease, or to intensification, in intermediate-risk or high-risk disease. Immunotherapy has proven beneficial in second-line palliative therapy and is under investigation in first-line palliative therapy and as a component of definitive, multimodality therapy for high-risk patients.

The interplay of IMRT and transoral surgery in HPV-mediated oropharyngeal cancer: Getting the balance right

Transoral surgery (TOS) and IMRT represent two primary local ablative treatment modalities for oropharyngeal cancer (OPC). The choice of one over the other represents an interplay between the chance of cure vs risk of late sequelae. HPV-mediated (HPV+) OPC patients generally have excellent outcomes, especially in TNM-8 stage I disease. Controversies exist over which treatment has a more favorable toxicity profile and equal efficacy in the management of this population. Non-randomized retrospective data show comparable oncological and functional outcomes between TOS-based vs IMRT-based treatment for this disease. Several de-intensification concepts have been explored in this subset in both primary surgery-based vs primary radiotherapy-based trials. However, no robust mature trial data are available to convincingly guide treatment selection. TOS is often presented as one of the de-intensification options although the majority of series also describe the use of adjuvant treatments which inevitably result in non-negligible toxicities. Patient selection and surgeons' training are paramount. Understanding tumor biology and the prognostic value of traditional 'adverse' features will further guide trial design for refinement of risk tailored approach. In conclusion, comparative data suggests TOS and IMRT are both effective treatment for TNM-8 stage I HPV+ OPC with similar oncological and functional outcomes. TOS as a single modality has potential advantages in mitigating radiation included toxicities. TOS should be avoided in the presence of clinically overt extranodal extension or when negative margins are unlikely to be achieved. TOS is also less ideal for cases with radiological features predicting a high risk of distant metastasis.

Transoral robotic surgery for oropharyngeal cancer: patient selection and special considerations

The increasing incidence of oropharyngeal squamous cell carcinoma (OPSCC) emphasizes the importance of optimizing treatment for the disease. Historical protocol has utilized definitive radiation and invasive open procedures; these techniques expose the patient to significant risks and morbidity. Transoral robotic surgery (TORS) has emerged as a therapeutic modality with promise. Here, the literature regarding proper patient selection and other considerations for this procedure was reviewed. Multiple patient and tumor-related factors were found to be relevant for successful use of this treatment strategy. Outcomes regarding early and advanced-stage OPSCC were analyzed. Finally, the literature regarding use of TORS in three distinct patient populations, individuals with primary OPSCC, carcinoma of unknown primary and those with recurrent OPSCC, was examined.

A comparison of oncological outcomes between transoral surgical and non-surgical treatment protocols in the management of oropharyngeal squamous cell carcinoma

Background:

The incidence of oropharyngeal squamous cell carcinoma in the Western world is increasing, with the human papillomavirus epidemic implicated in this observed trend. The optimal treatment modality is yet undetermined regarding oncological outcomes.

Methods:

This study comprised 98 patients with oropharyngeal squamous cell carcinoma, treated with either primary transoral surgery with adjuvant therapy or primary chemoradiotherapy with curative intent, between 2008 and 2012. Clinicopathological characteristics including tumour–node–metastasis stage, human papillomavirus status, treatment modality, recurrence and overall survival were collated.

Results:

Five per cent of primary surgical patients had locoregional recurrences compared with 25 per cent of primary chemoradiotherapy patients. A lower rate of locoregional recurrence was observed in the human papillomavirus positive group.

Conclusion:

This paper reports higher rates of overall survival and local control for oropharyngeal squamous cell carcinoma treated with primary surgery compared with primary chemoradiotherapy. This reflects overall lower tumour stage and higher human papillomavirus status in this group.

Treatment de-intensification strategies for head and neck cancer

Increasingly, squamous cell carcinoma of the oropharynx (OPSCC) is attributable to transformation resulting from high-risk human papillomavirus (HPV) infection. Such cancers are significantly more responsive to treatment than traditional tobacco- and alcohol-associated squamous cell cancers of the head and neck. Conventional management with definitive chemoradiation, surgery and adjuvant radiation, or radiation given with altered fractionation schemes, while effective, incurs long-term morbidity that escalates with treatment intensity and significantly impairs quality of life. Recent trials have suggested that less intensive treatment regimens may achieve similar efficacy with decreased toxicity. In this article, we review the primary strategies used for de-escalation of treatment, which include the reduction of radiation dose, substitution and/or elimination of concurrent radiosensitising chemotherapy, and the use of minimally invasive surgery. We discuss the rationale behind these approaches and the preliminary data demonstrating the success of de-escalation, as well as potential considerations raised by treatment de-intensification in HPV-associated OPSCC.

Recent Progress in Therapeutic Treatments and Screening Strategies for the Prevention and Treatment of HPV-Associated Head and Neck Cancer

The rise in human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) has elicited significant interest in the role of high-risk HPV in tumorigenesis. Because patients with HPV-positive HNSCC have better prognoses than do their HPV-negative counterparts, current therapeutic strategies for HPV⁺ HNSCC are increasingly considered to be overly aggressive, highlighting a need for customized treatment guidelines for this cohort. Additional issues include the unmet need for a reliable screening strategy for HNSCC, as well as the ongoing assessment of the efficacy of prophylactic vaccines for the prevention of HPV infections in the head and neck regions. This review also outlines a number of emerging prospects for therapeutic vaccines, as well as for targeted, molecular-based therapies for HPV-associated head and neck cancers. Overall, the future for developing novel and effective therapeutic agents for HPV-associated head and neck tumors is promising; continued progress is critical in order to meet the challenges posed by the growing epidemic.