Risk factors for locoregional relapse after transoral robotic surgery for human papillomavirus-related oropharyngeal squamous cell carcinoma

Transoral Robotic Surgery in the Multidisciplinary Care of Patients With Oropharyngeal Squamous Cell Carcinoma: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for the use of transoral robotic surgery (TORS) in the multidisciplinary management of oropharyngeal squamous cell cancer (OPC).

METHODS

ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. The literature search included studies published between January 1, 2002, and August 31, 2024, and comprised systematic reviews, meta-analyses, randomized controlled trials, and observational studies. Outcomes of interest include overall and disease-free survival, functional outcomes, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

A total of 58 publications were identified to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations address the evaluation and workup of patients with human papillomavirus (HPV)-positive OPC, the role of TORS, patient selection, adjuvant therapy, HPV-negative OPC, and use of TORS in salvage or recurrent setting.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Transoral Robotic Surgery for Oropharyngeal Squamous Cell Carcinoma of the Tonsil versus Base of Tongue: A Systematic Review and Meta-Analysis

Simple Summary

Transoral Robotic Surgery (TORS) has become widely adopted for the surgical removal of oropharyngeal squamous cell carcinoma (OPSCC). However, it is currently unknown if TORS has equal efficacy and outcomes in patients with tonsillar or base of tongue (BOT) OPSCC. Therefore, we performed a systematic review, including articles describing the surgical management of OPSCC with TORS that compared margin status, complications, and recurrence between tonsil and BOT. BOT OPSCC had a higher rate of positive margins compared to tonsillar OPSCC. However, no differences were seen in the recurrence or postoperative hemorrhage rates of BOT and tonsillar OPSCC. While a higher rate of positive margins was seen in BOT OPSCC when compared to tonsillar OPSCC, this did not translate to a higher recurrence rate in the BOT group. Future research on which subset of patients with BOT is more likely to have positive margins is warranted to improve the utility of TORS further.

Abstract

Transoral Robotic Surgery (TORS) has become widely adopted for the surgical removal of oropharyngeal squamous cell carcinoma (OPSCC), with the most common locations being in the tonsil and base of tongue (BOT). However, it is currently unknown if TORS has equal efficacy and outcomes in patients with tonsillar or BOT OPSCC. Therefore, the aim of this study was to compare the margin status and recurrence rates of tonsillar and BOT OPSCC after TORS. Per PRISMA guidelines, PubMed, Scopus, and CINAHL were systematically searched from inception to 2/28/2022. Articles including the surgical management of OPSCC with TORS that compared margin status, complications, and recurrence between tonsil and BOT were included. Meta-analyses of proportions and odds ratios were performed. A total of 28 studies were included, comprising 1769 patients with tonsillar OPSCC and 1139 patients with BOT OPSCC. HPV positivity was seen in 92.3% of tumors. BOT OPSCC had a higher rate of positive margins compared to tonsillar OPSCC (28.1% [95%CI 15.1–43.3] vs. 7.5% [95%CI 3.3–13.3]). No differences were seen in recurrence between BOT and tonsillar OPSCC (OR 1.1 [95%CI 0.8–1.5], p = 0.480). In addition, no differences in postoperative hemorrhage were seen between tonsillar and BOT OPSCC (10.7% [95%CI 6.1–16.5] vs. 8.8% [95% CI 1.5–21.3]). While a higher rate of positive margins was seen in BOT OPSCC when compared to tonsil OPSCC, this did not translate to a higher recurrence rate in the BOT group. Future research on which subset of patients with BOT is more likely to have positive margins is warranted to improve the utility of TORS further.

Current considerations for radiotherapy in HPV-associated head and neck cancer

Human papillomavirus (HPV)-mediated oncogenesis confers increased sensitivity to radiotherapy and HPV head and neck cancer is associated with improved patient outcomes. As such, management of HPV-related head and neck cancer requires a multidisciplinary approach that balances maximizing locoregional control with minimizing treatment-related toxicity. We highlight considerations in radiation dose and target delineation, as well as considerations for chemoradiation, postoperative radiotherapy, and single modality, definitive radiotherapy.

Treatment De-intensification for HPV-associated Oropharyngeal Cancer: A Definitive Surgery Paradigm

Human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV+OPSCC) constitutes the majority of head and neck diagnoses within the United States. Patients with HPV+OPSCC have biologically and demographically distinct disease, leading to high cure rates after standard treatments. This long survivorship period coupled with the toxicity of standard treatments makes de-intensification strategies an urgent research question. Surgery has generally been avoided for HPV+OPSCC as historical surgical techniques were invasive and morbid. With the advent of minimally invasive transoral techniques, definitive surgical options are becoming more popular. Minimally invasive surgery offers unique opportunities in a de-intensification paradigm, including more detailed patient selection, radiation volume reduction, and radiation dose de-intensification. Nevertheless, careful patient selection must be exercised as surgical defects may lead to quality of life decrements beyond what is gained through de-intensification. Ongoing phase III efforts will help clarify the patient cohorts best suited for surgically oriented de-intensification.

Transoral robotic surgery versus nonrobotic resection of oropharyngeal squamous cell carcinoma

The aim of this study is to evaluate the impact of transoral robotic surgery (TORS) compared to nonrobotic surgery (NRS) on overall survival in oropharyngeal squamous cell carcinoma (OPSCC). We performed a retrospective study of patients with HPV+ and HPV- OPSCC undergoing TORS or NRS with neck dissection using the National Cancer Database from the years 2010-2016. Among patients with OPSCC in our cohort, 3167 (58.1%) patients underwent NRS and 2288 (41.9%) underwent TORS. TORS patients demonstrated better overall survival than NRS patients (HPV+ patients: aHR 0.74, p = 0.02; HPV- patients: aHR 0.58, p < 0.01). Subsite analysis showed TORS was correlated with improved survival in base of tongue (BoT) primaries for both HPV+ (aHR 0.46, p = 0.01) and HPV- (aHR 0.42, p = 0.01) OPSCC. Compared to NRS, TORS is associated with improved overall survival for HPV+ and HPV- OPSCC, as well as greater overall survival for BoT primaries.

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.

Human papillomavirus oropharynx carcinoma: Aggressive de-escalation of adjuvant therapy

BACKGROUND

Aggressive dose de-escalated adjuvant radiation therapy (RT) in patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC).

METHODS

Patients with HPV(+)OPSCC on a phase II clinical trial of primary surgery and neck dissection followed by dose de-escalated RT (N = 79) were compared with a cohort of patients who received standard adjuvant therapy (N = 115). Local recurrence-free, regional recurrence-free, distant metastases-free survival, and progression-free survival (PFS) were assessed.

RESULTS

Of 194 patients, 23 experienced progression at a median of 1.1 years following surgery (interquartile range [IQR] 0.7-2.0; range 0.3-5.4); 10 patients in the de-escalated cohort and 13 patients in the standard cohort. The 3-year PFS rate for the de-escalated cohort was 87%, and in the standard cohort was 90% (hazard ratio [HR] 1.18, 95% confidence interval (CI) [0.50-2.75]).

CONCLUSION

Patients with HPV(+)OPSCC who undergo surgical resection and neck dissection and meet criteria for adjuvant therapy can undergo aggressive dose de-escalation of RT without increasing risk of progression locally, regionally or at distant sites.

Phase II Evaluation of Aggressive Dose De-Escalation for Adjuvant Chemoradiotherapy in Human Papillomavirus-Associated Oropharynx Squamous Cell Carcinoma

PURPOSE

The purpose of this study was to determine if dose de-escalation from 60 to 66 Gy to 30 to 36 Gy of adjuvant radiotherapy (RT) for selected patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma could maintain historical rates for disease control while reducing toxicity and preserving swallow function and quality of life (QOL).

PATIENTS AND METHODS

MC1273 was a single-arm phase II trial testing an aggressive course of RT de-escalation after surgery. Eligibility criteria included patients with p16-positive oropharyngeal squamous cell carcinoma, smoking history of 10 pack-years or less, and negative margins. Cohort A (intermediate risk) received 30 Gy delivered in 1.5-Gy fractions twice per day over 2 weeks along with 15 mg/m2 docetaxel once per week. Cohort B included patients with extranodal extension who received the same treatment plus a simultaneous integrated boost to nodal levels with extranodal extension to 36 Gy in 1.8-Gy fractions twice per day. The primary end point was locoregional tumor control at 2 years. Secondary end points included 2-year progression-free survival, overall survival, toxicity, swallow function, and patient-reported QOL.

RESULTS

Accrual was from September 2013 to June 2016 (N = 80; cohort A, n = 37; cohort B, n = 43). Median follow-up was 36 months, with a minimum follow-up of 25 months. The 2-year locoregional tumor control rate was 96.2%, with progression-free survival of 91.1% and overall survival of 98.7%. Rates of grade 3 or worse toxicity at pre-RT and 1 and 2 years post-RT were 2.5%, 0%, and 0%. Swallowing function improved slightly between pre-RT and 12 months post-RT, with one patient requiring temporary feeding tube placement.

CONCLUSION

Aggressive RT de-escalation resulted in locoregional tumor control rates comparable to historical controls, low toxicity, and little decrement in swallowing function or QOL.

Primary surgery for human papillomavirus-associated oropharyngeal cancer: Survival outcomes with or without adjuvant treatment

OBJECTIVES

Human papillomavirus-associated (HPV+) oropharyngeal squamous cell carcinoma (OPSCC) is a unique form of head and neck cancer with improved prognosis. We assessed survival for stage I patients with low- or intermediate-risk pathologic features with surgery alone compared with surgery with adjuvant radiation (RT) or chemoradiation (CRT).

MATERIALS AND METHODS

We identified patients with stage I HPV+ OPSCC (after restaging with 8th edition staging system) treated with surgery alone, adjuvant RT or CRT in the National Cancer Data Base from 2010 to 2013. We compared survival for low-risk patients (≤1 metastatic lymph nodes with no adverse features) and intermediate-risk patients (2-4 metastatic lymph nodes, microscopic extranodal extension (ENE) or lymphovascular invasion).

RESULTS

We examined 1677 patients with median follow-up of 43.9 months. In the intermediate-risk group, 4-year overall survival was 94.0% with surgery alone, 91.5% with adjuvant RT and 92.0% with adjuvant CRT (p = 0.72). There were similar rates of overall survival in the low-risk group. In multivariable models accounting for clinicopathologic differences the dose of adjuvant RT was not associated with mortality. On Cox proportional hazard modeling, adjuvant RT (HR 0.94; CI 0.43-2.08) or CRT (HR 0.96; CI 0.45-2.11) did not significantly improved survival compared with surgery alone in the intermediate-risk group (reference). Similar results were seen in the low-risk group. The composite number of pathologic risk features significantly improved risk stratification.

CONCLUSION

We provide observational evidence that adjuvant RT or CRT does not provide a survival benefit for stage I HPV+ OPSCC with low- or intermediate-risk pathologic features.

Transoral Resection of Human Papillomavirus (HPV)-Positive Squamous Cell Carcinoma of the Oropharynx: Outcomes with and Without Adjuvant Therapy

BACKGROUND

With the rise of oropharyngeal squamous cell carcinoma associated with human papillomavirus (HPV), appropriate treatment strategies continue to be tailored toward minimizing treatment while preserving oncologic outcomes. This study aimed to compare the outcomes for those undergoing transoral resection with or without adjuvant therapy for HPV-related oropharyngeal carcinoma.

METHODS

A case-match cohort analysis was performed at two institutions on patients with HPV-related oropharyngeal squamous cell carcinoma. All the subjects underwent transoral surgery and neck dissection. The patients treated with surgery alone were matched 1:1 to those treated with surgery and adjuvant therapy using two groups identified as confounders: T-stage (T1/2 or T3/4) and number of pathologically positive lymph nodes (≤4 or >4).

RESULTS

The study identified 105 matched pairs, with a median follow-up period of 42 months (range 3.1-102.3 months). The patients were staged as T1/T2 (86%) or T3/4 (14%). Each group had five patients with more than four positive lymph nodes. Adjuvant therapy significantly improved disease-free survival (hazard ratio [HR] 0.067; 95% confidence interval [CI] 0.01-0.62) and was associated with a lower risk of local and regional recurrence (risk ratio [RR] 0.096; 95% CI 0.02-0.47). No difference in disease-specific survival (HR 0.22; 95% CI 0.02-2.57) or overall survival (HR 0.18; 95% CI 0.01-2.4) was observed with the addition of adjuvant therapy. The risk of the gastrostomy tube was higher for those receiving adjuvant therapy (RR 7.3; 95% CI 2.6-20.6).

CONCLUSIONS

Transoral surgery is an effective approach for the treatment of HPV-related oropharyngeal carcinoma. The addition of adjuvant therapy appears to decrease the risk of recurrence and improve disease-free survival but may not significantly improve overall survival.

Pathologic Markers in Surgically Treated HPV-Associated Oropharyngeal Cancer: Retrospective Study, Systematic Review, and Meta-analysis

OBJECTIVE

Human papillomavirus-associated (HPV) oropharyngeal cancer is a unique clinical entity whose incidence is increasing. It is controversial whether traditional pathologic markers of aggressive head and neck cancer also apply in surgically treated HPV-associated disease.

STUDY DESIGN

Retrospective study, systematic review, and meta-analysis Data Sources: PubMed and Cochrane review.

REVIEW METHODS

PubMed and Cochrane review were searched for published articles on surgically treated HPV-associated oropharyngeal cancer. Eligible studies were included in a meta-analysis of survival using several clinicopathologic markers as predictors. Surgically treated HPV-positive oropharyngeal cancer patients at our institution were studied retrospectively and added to the meta-analysis.

RESULTS

Eight published reports, plus our retrospective series, were included in the meta-analysis. This showed significant impact on event-free survival for T stage, nodal number, perineural invasion, and lymphovascular invasion (all P < .05) but not for N stage extracapsular extension ( P = ns).

CONCLUSIONS

While many traditional clinico-pathologic markers of aggressive disease in head and neck cancer also impact survival in surgically treated HPV-associated oropharyngeal cancer, extracapsular extension may be less important.