Occult Primary Head and Neck Squamous Cell Carcinoma: Utility of Discovering Primary Lesions

Intraoperative Pathology Consultation in Patients With p16-Positive Unknown Primary Squamous Cell Carcinoma

Importance

Current guidelines recommend intraoperative frozen section(s) during diagnostic surgery for squamous cell carcinoma for unknown primary tumors (SCCUP).

Objective

To determine the utility of intraoperative pathology consultation during transoral robotic surgery (TORS) in localizing primary tumors and influencing need for adjuvant therapy.

Design, Setting, and Participants

A retrospective case series including 47 adult patients with human papillomavirus (HPV)-associated SCCUP who underwent TORS/oropharyngectomy between January 2016 and February 2023 was carried out at a single tertiary care hospital. The analysis took place on May 13, 2024.

Exposures

Nodal stage, tonsillectomy history, extranodal extension (ENE).

Main Outcomes and Measures

Intraoperative pathology consultation and final pathology results were compared with surgical outcomes, including margin revision, need for second procedure and/or radiation with or without chemotherapy.

Results

This study included 47 adult patients. Mean (range) age was 61 (41-79) years; patients were mostly men (37 [79%]). Overall, primary tumors were identified in 37 patients (79%), including all cases with positive nodes involving more than 1 neck level. Patients whose primary tumor was not found tended to have tobacco use history (8/10 vs 13/37 [35%]; difference, 45%; 95% CI, 16%-74%) and absence of ENE (8/10 vs 15/37 [41%]; difference, 39%; 95% CI, 10%-68%). Primary tumor was identified intraoperatively in 18 of 37 patients (49%). SCCs identified intraoperatively were significantly larger than SCCs found on permanent sections only: mean (SE), 1.2 (0.13) cm vs 0.5 (0.1) cm (difference, 0.7 cm; 95% CI, 0.53-1.94). The sensitivity, specificity, positive predictive value, and negative predictive value of intraoperative consultation was 49% (95% CI, 33%-64%), 100% (95% CI, 100%-100%), 100%, and 34% (95% CI, 19%-53%), respectively. Margins were revised in 11 of 18 patients (61%) whose primary tumor was identified intraoperatively (during original procedure) and in 3 of 19 patients (16%) whose primary tumor was identified on permanent pathologic findings only (during a second procedure) (11/18 [61%] vs 3/19 [16%]; difference, 45%; 95% CI, 17%-73%). However, there was no significant difference in the use of adjuvant radiotherapy with or without chemotherapy or need for a second procedure based on intraoperative primary tumor localization.

Conclusion and Relevance

In this case series study, the sensitivity and negative predictive value of intraoperative pathology consultation among 47 patients was less than 50%. Given the lack of influence on the need for radiotherapy with or without chemotherapy or second procedure, the practical utility of routine intraoperative frozen section requires further scrutiny.

Primary Tumour Detection in Carcinoma of Unknown Primary with Transoral Robotic Surgery (TORS) Tongue Base Mucosectomy: A Meta-analysis

BACKGROUND

Head and neck carcinoma of unknown primary (CUP) represents a challenging diagnostic process when standard work-up fails to identify the primary tumour site. The aim of this systematic review and meta-analysis was to evaluate the diagnostic utility and complication profile of transoral robotic surgery (TORS) tongue base mucosectomy (TBM) in the management of CUP.

PATIENTS AND METHODS

An electronic database search was performed in the EMBASE, MEDLINE, PubMed and Cochrane databases. A meta-analysis of proportions was performed to obtain an estimate of the overall proportion for the detection and complication rates.

RESULTS

Nine studies representing 235 patients with CUP who had TORS TBM were included in the final analysis. The overall pooled tumour detection rate was 66.2% [95% confidence interval (CI) 56.1-75.8]. The incidence of tumour detection in human papilloma virus (HPV)-positive cases (81.5%, 95% CI 60.8-96.4) was significantly higher than HPV-negative cases (2.3%, 95% CI 0.00-45.7). Weighted overall complication rate was 11.4% (95% CI 7.2-16.2). The majority were grade I or II (80%) according to the Clavien-Dindo classification.

CONCLUSIONS

This meta-analysis suggests TORS to be safe and effective in localising the primary tumour site in patients with CUP. While the current data supports the use of TORS in patients who are HPV positive, larger numbers of HPV-negative cases are required to determine the true diagnostic effect with TORS before any valid conclusions can be inferred in this particular subgroup. Further research should focus on high quality prospective trials with stringent methodological work-up to minimise heterogeneity and allow for more accurate statistical analysis.

Human papillomavirus circulating tumor DNA: a diagnostic tool in squamous cell carcinoma of unknown primary-a pilot study

Introduction

Neck mass is the most common presentation of human papillomavirus-related (HPV-related) oropharyngeal squamous cell carcinoma (OPSCC). Recently, circulating tumor HPV-DNA (ctHPVDNA) assays have been developed to detect active OPSCC. This pilot study investigates the diagnostic accuracy of ctHPVDNA in establishing HPV status for known vs. unknown OPSCC presenting as a neck mass.

Methods

A single-institution pilot study was conducted on all patients with OPSCC presenting as a neck mass between 2021 and 2022. The diagnostic accuracy of ctHPVDNA was compared to that of standard diagnostic procedures used to obtain HPV status according to the American Society of Clinical Oncology (ASCO) guideline for squamous cell carcinoma of unknown primary (SCCUP). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ctHPVDNA were calculated.

Results

A total of 27 patients were included; 70.4% were current or former smokers, 48.1% (N = 13) had identifiable primaries, and 51.9% (N = 14) had SCCUP. Four patients with known primaries required operative direct laryngoscopy with biopsy (DLB) to establish HPV status. Two patients with SCCUP underwent diagnostic transoral robotic surgery (TORS) to establish HPV status and localize the primary. Twelve patients underwent therapeutic TORS and neck dissection. The gold standard for HPV status was based on final histopathologic p16 or HPV in situ hybridization (ISH) staining during workup/treatment. ctHPVDNA had 95.8% sensitivity, 100% specificity, 100% PPV, and 75% NPV in predicting HPV-positive OPSCC in the whole sample. Binary logistic regression model using ctHPVDNA results to predict HPV-positive OPSCC was significant (-2 log likelihood = 5.55, χ2 = 8.70, p <.01, Nagelkerke's R squared = .67). Among patients with identifiable primaries, all patients had HPV-positive tumors on final pathology, and ctHPVDNA was positive in 100%. In the unknown primary patients, ctHPVDNA had 90.9% sensitivity, 100% specificity, 100% PPV, and 75% NPV.

Discussion

ctHPVDNA demonstrated good diagnostic accuracy for both known and unknown primaries. Incorporation of ctHPVDNA into the diagnostic algorithm for SCCUP may reduce the need for multiple procedures to establish HPV status.

Clinical practice guidelines for management of head and neck squamous cell carcinoma of unknown primary: an AGREE II appraisal

IMPORTANCE

Squamous cell carcinoma without a known primary is an uncommon form of head and neck cancer that requires multidisciplinary collaboration for effective management.

OBJECTIVE

To evaluate the quality of clinical practice guidelines (CPG) using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument.

DESIGN

A systematic literature search was performed to identify CPGs pertaining to the diagnosis and treatment of head and neck squamous cell carcinoma of unknown primary (HNSCCUP). Data were abstracted from guidelines meeting inclusion criteria and appraised by four independent reviewers in the six domains of quality defined by the AGREE II.

SETTING

Online database.

PARTICIPANTS

None.

EXPOSURE

None.

MAIN OUTCOME(S) AND MEASURE(S)

Quality domain scores and intraclass correlation coefficients (ICC) were calculated across domains to qualify inter-rater reliability.

RESULTS

Seven guidelines met inclusion criteria. Two guidelines achieved a score of > 60% in five or more AGREE II quality domains to gain designation as 'high'-quality content. One "average-quality" guideline authored by the ENT UK Head and Neck Society Council achieved a score of > 60% in three quality domains. The remaining four CPGs demonstrated low-quality content, with deficits most pronounced in domains 3 and 5, suggesting a lack of rigorously developed and clinically applicable information.

CONCLUSIONS AND RELEVANCE

As the diagnosis and treatment of head and neck cancer continues to evolve, identification of high-quality guidelines will become increasingly important. The authors recommend consulting HNSCCUP guidelines from the National Institute for Health and Care Excellence (NICE) or the American Society of Clinical Oncology (ASCO).

TRIAL REGISTRATION

None.

Understanding the Role of Human Papillomavirus in Head and Neck Cancer of Unknown Primary: A Systematic Review

This systematic review aims to provide a comprehensive understanding of the role of human papillomavirus (HPV) in head and neck cancer of unknown primary (HNCUP). HNCUP is a rare type of cancer with an unknown primary site, which makes it difficult to diagnose and treat. The review includes articles published between 2013 and 2023 that investigated the prevalence of HPV in HNCUP, its association with clinical outcomes, and its potential implications for diagnosis and treatment. The search was conducted in 11 electronic databases, and the gray literature: Cochrane, Cumed, IBECS, JAMA Network, LILACS, MEDLINE Ovid, MEDLINE-EBSCO, PubMed, Scopus, SciELO, and Taylor & Francis Online; a total of 23 studies met the inclusion criteria. The review found that HPV is present in a significant proportion of HNCUP cases, ranging from 15.5% to 100%. HNCUP incidence is increasing, and the presence of HPV was associated with improved clinical outcomes in some studies, such as overall survival and disease-free survival; but was found to have no association with outcomes in others. This may have implications for diagnostic and treatment strategies. The findings of this review suggest that further research is needed to better understand the role of HPV in HNCUP and to develop targeted therapies for this disease.

The role of transoral surgery in the diagnosis of the carcinoma of unknown origin of the head and neck

PURPOSE OF REVIEW

The aim of this article is to update readers on the most recent evidence on the role of trans oral surgery (TOS) in the diagnosis of carcinoma of the unknown primary of the head and neck.

RECENT FINDINGS

Tongue base mucosectomy has an important role in identifying the primary in patients who have had negative imaging, PET CT scans and ipsilateral tonsillectomy. In patients with bilateral nodal disease, tongue base mucosectomy should precede tonsillectomy. There are several unanswered questions that remain regarding sequencing of operations and use of intraoperative frozen section.

SUMMARY

An evidence-based approach to diagnosis is important to ensure the highest detection rates, and least morbidity, in patients with head and neck carcinoma of the unknown primary.

The additional role of [68Ga]Ga-FAPI-04 PET/CT in patients with unknown primary lesion with a negative or equivocal [18F]FDG

PURPOSE

[18F]FDG PET/CT to detect unknown primary lesions is essential for clinical management but still has limitations. [68Ga]Ga-FAPI is a tumor-stromal imaging agent that provides a promising alternative to [18F]FDG for the assessment of malignancies. We aimed to investigate whether [68Ga]Ga-FAPI PET/CT has an additional role in identifying unknown primary lesions with negative or equivocal [18F] FDG PET/CT results.

METHODS

This single-center prospective clinical study was conducted between March 2020 and March 2022 at Southwest Medical University Hospital. Patients underwent [18F]FDG PET/CT for the identification of unknown primary lesions. They underwent repeat [68Ga]Ga-FAPI PET/CT when [18F]FDG PET/CT results were negative or equivocal. Histopathological examination, surgery, or clinical follow-up (at least 3 months) for FAPI-positive lesions. The diagnostic efficacy of [68Ga]Ga-FAPI in identifying unknown primary lesions was evaluated.

RESULTS

A total of 44 participants (median age, 57 ± 12 [SD]; 22 [50%] men) were evaluated. Thirteen of the 44 patients had equivocal [18F]FDG PET/CT findings, while the diagnosis was clear on [68Ga]Ga-FAPI PET/CT. [68Ga]Ga-FAPI PET/CT also revealed primary lesions in additional 17 patients with negative [18F]FDG PET/CT findings. In fourteen of 44 patients, no primary lesion was detected by either tracer. On this basis, we analyzed 94 lymph node metastatic lesions. The mean SUVmax of lymph node metastases on [68Ga] Ga-FAPI PET/CT and [18F]FDG PET/CT were 9.2 ± 5.1, 7.9 ± 4.8 (p = 0.03) and the mean TBR were 9.1 ± 5.2, 4.9 ± 3.1 (p < 0.01), respectively.

CONCLUSION

[68Ga]Ga-FAPI PET/CT showed great potential for identifying unknown primary lesions and has the potential to improve the detection rate of unknown primary lesions with negative or equivocal for [18F]FDG findings.

TRIAL REGISTRATION

ClinicalTrial.gov. Identifier: ChiCTR2100044131.

Machine Learning Models Predict the Primary Sites of Head and Neck Squamous Cell Carcinoma Metastases Based on DNA Methylation

In head and neck squamous cell cancers (HNSCs) that present as metastases with an unknown primary (HNSC-CUPs), the identification of a primary tumor improves therapy options and increases patient survival. However, the currently available diagnostic methods are laborious and do not offer a sufficient detection rate. Predictive machine learning models based on DNA methylation profiles have recently emerged as a promising technique for tumor classification. We applied this technique to HNSC to develop a tool that can improve the diagnostic workup for HNSC-CUPs. On a reference cohort of 405 primary HNSC samples, we developed four classifiers based on different machine learning models (random forest (RF), neural network (NN), elastic net penalized logistic regression (LOGREG), support vector machine (SVM)) that predict the primary site of HNSC tumors from their DNA methylation profile. The classifiers achieved high classification accuracies (RF=83%, NN=88%, LOGREG=SVM=89%) on an independent cohort of 64 HNSC metastases. Further, the NN, LOGREG, and SVM models significantly outperformed p16 status as a marker for an origin in the oropharynx. In conclusion, the DNA methylation profiles of HNSC metastases are characteristic for their primary sites and the classifiers developed in this study, which are made available to the scientific community, can provide valuable information to guide the diagnostic workup of HNSC-CUP. This article is protected by copyright. All rights reserved.

Therapeutic strategies: Surgery for human papillomavirus-associated oropharyngeal carcinoma

Treatment of oropharyngeal cancer (OPC) has undergone considerable evolution since the discovery of human papillomavirus (HPV)-associated OPC. It is widely understood that HPV OPC affects a younger population and standard treatment offers improved oncologic outcomes compared with non-HPV OPC but can cause significant toxicities and long-term side effects. Surgery for treatment de-escalation is an active area of research. The purpose of this review is to explore surgery as it relates to the treatment of HPV OPC with a focus on the evolution of treatment, rationale for surgery, surgical techniques, outcomes, and the role of surgery in de-escalation of treatment.

Human Papillomavirus and Squamous Cell Carcinoma of Unknown Primary in the Head and Neck Region: A Comprehensive Review on Clinical Implications

Squamous cell carcinoma of unknown primary (SCCUP) is a challenging diagnostic subgroup of oropharyngeal squamous cell carcinoma (OPSCC). The incidence of SCCUP is increasing in parallel with the well-documented increase in OPSCC and is likewise driven by the increase in human papillomavirus (HPV). The SCCUP patient often presents with a cystic lymph node metastasis and undergoes an aggressive diagnostic and treatment program. Detection of HPV in cytologic specimens indicates an oropharyngeal primary tumor origin and can guide the further diagnostic strategy. Advances in diagnostic modalities, e.g., transoral robotic surgery and transoral laser microsurgery, have increased the successful identification of the primary tumor site in HPV-induced SCCUP, and this harbors a potential for de-escalation treatment and increased survival. This review provides an overview of HPV-induced SCCUP, diagnostic modalities, and treatment options.

Diagnostic performance of 18F-FDG PET/CT for the detection of occult primary tumors in squamous cell carcinoma of unknown primary in the head and neck: a single-center retrospective study

OBJECTIVE

To investigate the diagnostic performance of 18F-FDG PET/computed tomography (CT) for the detection of occult primary tumors in patients with squamous cell carcinoma of unknown primary (SCCUP) in the head and neck.

PATIENTS

From March 2016 to January 2020, 37 patients diagnosed as SCCUP before PET/CT were retrospectively reviewed. The diagnosis of SCCUP was made when an overt primary tumor location could not be found for histologically proven squamous cell cervical lymphadenopathy after a complete diagnostic workup which includes full medical history, physical examinations, flexible rhinolaryngoscopy and CT or MRI. The PET/CT images were visually assessed by two nuclear medicine radiologists. Histopathological investigations after the PET scan served as the reference standard.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for SCCUP were 71.4, 43.8, 62.5, 53.9 and 59.5%, respectively. PET/CT allowed identification of previously undetected lesions in 40.5% of the SCCUP patients. A total of 24 PET/CT scans indicated a positive result. Among them, nine were categorized into false-positive because of negative results from subsequent targeted and random biopsies. There were 13 PET/CT scans with a negative result, six of which, however, were revealed to have a primary site by subsequent random biopsies.

CONCLUSION

18F-FDG PET/CT was shown to be useful in detecting a primary tumor for SCCUP, but had limitations in terms of both false-positive cases and false-negative cases. Therefore, histopathological investigations such as targeted and random biopsy should be viewed as necessary practice irrespective of PET/CT results.

Diagnostic approaches to carcinoma of unknown primary of the head and neck

Squamous cell carcinoma in cervical lymph nodes arising from an undetected primary tumour, termed carcinoma of unknown primary (SCCUP), is a well-recognized clinical presentation within head and neck oncology. SCCUP is a common presentation for patients with human papillomavirus-mediated oropharyngeal cancer (HPV + OPSCC), as patients with HPV + OPSCC often present with smaller primary tumours and early nodal metastasis. Meticulous work-up of the SCCUP patient is central to the management of these patients as identification of the primary site improves overall survival and allows for definitive oncologic resection or more focused radiation when indicated. This review summarizes the comprehensive diagnostic approach to the SCCUP patient, including history and physical examination, methods of biopsy of the cervical lymph node, imaging modalities and intraoperative methods to localize the unknown primary. Novel techniques such as transcervical ultrasound of the oropharynx, narrow band imaging and diagnostic transoral robotic surgery are also discussed.

Disease Profile and Oncologic Outcomes After Delayed Diagnosis of Human Papillomavirus-Associated Oropharyngeal Cancer

OBJECTIVE

Diagnostic delay in human papillomavirus-associated oropharynx squamous cell carcinoma (HPV(+)OPSCC) is common due to nonspecific symptoms. We aim to describe the disease burden and oncologic outcomes of patients with HPV(+)OPSCC diagnosed >12 months after symptom onset.

STUDY DESIGN

This is a retrospective cohort study of HPV(+)OPSCC patients receiving intent-to-cure treatment (including surgery ± adjuvant therapy or primary chemoradiation).

SETTING

2006-2016, tertiary care center.

METHODS

Tumor stage was compared between patients with and without delayed diagnosis using χ² tests. Kaplan-Meier survival analysis with univariate and multivariable Cox regressions were used to determine the effect of diagnostic delay on oncologic outcomes.

RESULTS

In total, 664 patients were included. Compared to patients diagnosed <12 months from symptom onset (n = 601), those diagnosed at >12 months (n = 63) were more likely to have T4 disease and higher overall American Joint Committee on Cancer (AJCC) clinical stage at presentation (P < .01 for both). At 5 years, rates of overall survival, cancer-specific survival, progression-free survival, and distant metastases-free survival in the delayed diagnosis cohort were 80%, 90%, 80%, and 89%, respectively. A >12-month delay in diagnosis did not significantly impact overall survival (adjusted hazard ratio [aHR], 1.16; 95% CI, 0.58-2.31), cancer-specific survival (aHR, 0.83; 95% CI, 0.29-2.39), progression-free survival (aHR, 1.15; 95% CI, 0.56-2.37), or distant metastases-free survival (aHR, 1.00; 95% CI, 0.42-2.40) after adjusting for age, sex, and clinical AJCC stage (P > .05 for all).

CONCLUSIONS

Delayed diagnosis of HPV(+)OPSCC is associated with greater burden of disease at presentation, but oncologic outcomes remain favorable across treatment modalities. When appropriate, intent-to-cure therapy should be pursued despite diagnostic delay.

LEVEL OF EVIDENCE

Level III.

Treatment Outcomes of Patients with Head and Neck Squamous Cell Carcinoma of Unknown Primary

The purpose of this study was to evaluate clinical characteristics and treatment outcome of patients with head and neck squamous cell carcinoma of unknown primary (HNSCCUP), treated according to the method of our hospital. Six patients with histopathologically and radiologically confirmed HNSCCUP January 2010-December 2016 were enrolled in this study. All patients underwent radical neck dissection involving level I-V, bilateral tonsillectomy, and diagnostic esophagoscopy and postoperative radiotherapy (RT), with or without concurrent chemotherapy. There were no major complications resulting from surgical intervention. Duration of follow-up was 56.3±20.2 months (range, 28-82 months). There was no recurrence or late detection of primary site of HNSCCUP. All patients with HNSCCUP except one were alive, at the time of the last follow-up. The other patient had no recurrence of HNSCCUP, but died of colon cancer at 58 months postoperatively. We have successfully treated patients with HNSCCUP by performing radical neck dissection, bilateral tonsillectomy, and diagnostic esophagoscopy and postoperative RT with concurrent chemotherapy, and recommend using this method as the main treatment method.

Current Indications for Transoral Robotic Surgery in Oropharyngeal Cancer

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing dramatically and is conclusively linked to increasing rates of human papillomavirus (HPV) infection. HPV-related oropharyngeal cancers have been shown to occur in a unique demographic group and show favorable oncologic outcomes compared with HPV-negative OPSCC. There has been a paradigm shift in the treatment of early-stage OPSCC, with most patients now undergoing primary surgery in the United States. Transoral robotic surgery is associated with excellent oncologic and functional outcomes in the treatment of OPSCC and is increasingly being used for a broader range of oropharyngeal indications.

Royal Society of Medicine Surgical Innovation Day Adrian Tanner Prize Winner 2019: Multidisciplinary care and surgical innovation for the benefit of the patient with head and neck cancer of unknown primary

Head and neck carcinoma of unknown primary accounts for approximately 1-5% of all head and neck cancers and presents a genuine diagnostic and therapeutic dilemma. Despite advanced investigations, the primary tumour location remains unknown in up to 40% of these cases. Transoral robotic surgery presents a viable diagnostic and therapeutic option in these patients. This surgical innovation alongside advances in the understanding of head and neck cancer biology means that a multidisciplinary approach in the management of these complex patients is of utmost importance to ensure optimal therapeutic outcomes.

Transoral robotic surgery for the benefit of patients with head and neck cancer of unknown primary: our experience at St George's University Hospital, London

INTRODUCTION

Head and neck carcinoma of unknown primary represents 1-5% of all head and neck cancers and presents a diagnostic and therapeutic dilemma. In approximately 40% of cases, a primary tumour location remains unknown despite investigation. With advancements in our understanding of the role of high-risk human papilloma virus in head and neck cancer, transoral robotic surgery presents an option for diagnosis and therapy.

MATERIALS AND METHODS

This is a retrospective case series from a single centre. Case notes were reviewed for 28 patients who had transoral robotic surgery for head and neck carcinoma of unknown primary between May 2015 and July 2019.

RESULTS

Transoral robotic surgery identified an oropharyngeal primary tumour in 19 of 28 (67.8%) patients. All oropharyngeal primaries were p16 positive. The base of tongue identification rate was 63.2%. Median length of inpatient stay postoperatively was 1.0 day. Normal oral intake resumed within 48 hours in 96% (27/28) of patients. Three patients (10.3%) suffered minor postoperative bleeds that were all managed conservatively.

DISCUSSION

The base of tongue primary identification rate (63.2%) in this series is consistent with that previously reported (43-63%; 95% confidence interval). Primary tumour identification rate if a patient is p16 positive is 86.3% (19/22), with 100% of these being oropharyngeal. We suggest future investigation into p16 status as a means of stratifying patients with head and neck carcinoma of unknown primary for transoral robotic surgery.

CONCLUSION

Transoral robotic base of tongue mucosectomy (or lingual tonsillectomy) is a promising technique that offers a high yield of positive identification for the primary tumour. It is well tolerated with minimal associated morbidity. Our findings are comparable with those in the current literature.

Diagnosis and Management of Squamous Cell Carcinoma of Unknown Primary in the Head and Neck: ASCO Guideline

PURPOSE

To provide evidence-based recommendations to practicing physicians and other health care providers on the diagnosis and management of squamous cell carcinoma of unknown primary in the head and neck (SCCUP).

METHODS

The American Society of Clinical Oncology convened an Expert Panel of medical oncology, surgery, radiation oncology, radiology, pathology, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2008 through 2019. Outcomes of interest included survival, local and regional disease control, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 100 relevant studies to inform the evidence base for this guideline. Four main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate pathology techniques, and adjuvant therapy.

RECOMMENDATIONS

Evidence-based recommendations were developed to address preoperative evaluation for patients with a neck mass, surgical diagnostic and therapeutic procedures, appropriate treatment options in unilateral versus bilateral SCCUP.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

TORS Base-of-Tongue Mucosectomy in Human Papilloma Virus-Negative Carcinoma of Unknown Primary

OBJECTIVE

To analyze the role of transoral robotic base-of-tongue mucosectomy in a cohort of patients with human papilloma virus negative unknown primary carcinoma.

STUDY DESIGN

Retrospective database analysis.

METHODS

A retrospective database review from 2012 to 2018 was performed at two large tertiary centers to study patients with human papilloma virus (HPV)-negative unknown primary carcinoma who underwent transoral robotic base-of-tongue mucosectomy. P16 testing was used as a surrogate for HPV status. Patients were included that had squamous cell carcinoma metastatic to the lateral neck based on fine needle aspiration or open biopsy. Preoperatively, all patients were classified as having an unknown primary based on normal clinical and flexible endoscopic exam, normal operative endoscopy, nonlocalizing imaging, and tonsillectomy. All patients underwent robotic base-of-tongue mucosectomy. The primary outcome measure was the incidence of pathologic identification of a mucosal primary.

RESULTS

Twenty-three patients with p16-negative unknown primary carcinoma were identified and studied. All patients underwent transoral robotic base-of-tongue mucosectomy. Median age was 60 years at the time of diagnosis, and 18 of 23 (78.2%) were male. Pathologic analysis of the base-of-tongue specimens showed a primary tumor in only three of 23 (13.0%) of patients.

CONCLUSION

Despite prior evidence suggesting a high rate of primary site identification in HPV-related disease, robotic base-of-tongue mucosectomy may not be indicated for HPV-negative unknown primary carcinoma based on a low likelihood of finding the primary.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:78-81, 2021.

Transoral robotic surgery in the management of head and neck squamous cell cancer with unknown primary

Background: Transoral robotic surgery (TORS) assisted base of the tongue (BOT) resection has been suggested as part of the work-up for head and neck squamous cell cancer with unknown primary (HNSCC-CUP). Success rates vary with regard to identification of primary BOT lesions, and cases with likely such lesions appear to be included in previous reports.Objectives: To analyse the possible benefits of a superficial TORS-assisted BOT resection in thoroughly investigated HNSCC-CUP.Material and methods: Retrospectively, 13 patients subjected to superficial TORS-assisted BOT resections due to HNSCC-CUP, where previous thorough work-ups including PET-scans had been performed and primary lesions had still not been identified, were reviewed.Results: Nodal status, according to the TNM-8 classification, was N1, N2, N2a, N2b, N2c, and N3, respectively, for 7, 1, 1, 4, 0, and 0 patients. In 38% of the cases, T1 BOT cancers were identified using superficial TORS-assisted BOT resections and treatments adjusted.Conclusion: Addition of a superficial TORS-assisted BOT resection to the work-up of HNSCC-CUP frequently identifies primary lesions and alters the treatment for this group of patients even after thorough work-up.

The emerging role of trans-oral robotic surgery for the detection of the primary tumour site in patients with head-neck unknown primary cancers: A meta-analysis

The identification of the site in head neck unknown primary (HNUP) tumour is of utmost importance to help select best treatment while decreasing treatment-related morbidity and mortality. The primary purpose of this study is to demonstrate that TORS may be a valuable tool in detecting primary tumour. Studies were systematically searched in the PubMed, EMBASE, the Cochrane Library and CENTRAL electronic databases. A total of 12 selected studies (349 patients) were analyzed. The primary tumour detection and positive surgical margins rates were 70.8% and 19.4%, respectively. The rate of HPV-related tumour was 71.3%. The primary tumour was mainly in base of tongue (64%). In conclusion, TORS seems to be an effective surgical approach both in terms of detection of primary tumour site and in terms of therapeutic perspective for HNUP. In particular, a subset of HPV-related tumours might benefits all advantages from this surgical modality.

Human papillomavirus and p16 immunostaining, prevalence and prognosis of squamous carcinoma of unknown primary in the head and neck region

The prevalence of human papillomavirus (HPV) in squamous cell carcinoma of unknown primary in the head and neck (SCCUPHN), and prognosis by HPV status of SCCUPHN patients has been difficult to estimate because of the rarity of this subtype. In MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, EMBASE, Cochrane library and Web of Science searches, observational studies and clinical trials that reported survival rates of patients with SCCUPHN by HPV status were identified. Meta-analysis estimated the prevalence and prognosis (overall survival, OS; progression-free survival, PFS) of SCCUPHN by HPV status, and compared them to studies of oropharyngeal squamous cell carcinoma (OPSCC) from the same institutions and across continents. In 17 SCCUPHN studies (n = 1,149) and 17 institution-matched OPSCC studies (n = 6,522), the pooled HPV prevalence of SCCUPHN was 49%, which was only 10% (95%CI: 1-19%) lower than OPSCC prevalence in the underlying population. Estimated 5-year OS for HPV-negative SCCUPHN was 44% (95%CI: 36-51%) vs. HPV-positive SCCUPHN of 91% (95%CI: 86-96%); hazard ratio (HR) for OS was 3.25 (95%CI: 2.45-4.31) and PFS was 4.49 (95%CI: 2.88-7.02). HRs by HPV status for OPSCC were similar to that in SCCUPHN. While North American SCCUPHNs had higher HPV prevalence than European SCCUPHNs (OR = 2.68 (95%CI: 1.3-5.6)), HR of OS for HPV-negative vs. HPV-positive patients were similar in both continents (HRs of 3.78-4.09). Prevalence of HPV among SCCUPHN patients were lower than in OPSCC. The survival benefit conferred by being HPV-positive was similar in SCCUPHN as in OPSCCs, independent of continent.

Combination of panendoscopy and positron emission tomography/computed tomography increases detection of unknown primary head and neck carcinoma

OBJECTIVES/HYPOTHESIS

With positron emission tomography/computed tomography (PET/CT) now commonplace as a diagnostic tool, new questions have arisen regarding the utility and cost-effectiveness of panendoscopy. In this retrospective review of a large cohort of head and neck squamous cell carcinoma of unknown primary (HNSCC-UP), we describe the enduring utility of panendoscopy in the detection of the primary site of mucosal disease even when PET/CT is negative.

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective analysis of patients presenting to the senior author (y.d.) from July 1 1997 to July 1 2017 with fine-needle aspiration-proven metastatic squamous cell carcinoma to the neck. All patients underwent formal panendoscopy (direct laryngoscopy, bronchoscopy, and rigid esophagoscopy). Presence of squamous cell carcinoma on final pathology was examined.

RESULTS

A total of 190 patients had HNSCC-UP, with 87 positive and 103 negative on PET/CT. Of the PET/CT-negative patients, 71 patients retained the HNSCC-UP designation after panendoscopy. Eighteen patients (56% of cases) were found to have primary tonsillar squamous cell carcinoma. Eight of 32 primary sites were found in the base of tongue (25%), with HPV positivity in two of these patients. The sensitivity and negative predictive value of PET/CT in detecting the primary site in unknown primary head and neck squamous cell carcinoma in the total study population were 73.1% and 68.9%, respectively.

CONCLUSIONS

Surgical panendoscopy has an important role in the workup of patients with unknown primary head and neck squamous cell carcinoma. There is a high rate of cancer diagnosis, even in PET/CT negative patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 2573-2575, 2018.

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.

[Advances in the management of cervical lymphadenopathies of unknown primary: advances in diagnostic imaging and surgical modalities and new international staging system]

INTRODUCTION

Cervical lymphadenopathies of unknown primary represent 3 % of head and neck cancers. Their diagnostic work up has largely changed in recent years. This review provides an update on diagnostic developments and their potential therapeutic impact.

MATERIALS AND METHODS

This is a systematic review of the literature.

RESULTS

In recent years, changes in epidemiology-based prognostic factors such as human papilloma virus (HPV) cancers, advances in imaging and minimally invasive surgery have been integrated in the management of cervical lymphadenopathies of unknown primary. In particular, systematic use of PET scanner and increasing practice of robotic or laser surgery have contributed to increasing detection rate of primary cancers. These allow more adapted and personalized treatments. The impact of changes in the eighth TNM staging system is discussed.

CONCLUSION

The management of cervical lymphadenopathies of unknown primary cancer has changed significantly in the last 10 years. On the other hand, practice changes will have to be assessed.

Current Role of Surgery in the Management of Oropharyngeal Cancer

The 1990s saw an increased use of chemoradiotherapy protocols, commonly referred to as organ-sparing therapy, for the treatment of oropharyngeal cancer after the Groupe d'Oncologie Radiothérapie Tête et Cou trial. Since that time, human papillomavirus-associated oropharyngeal squamous cell carcinoma has been identified as a unique disease, with improved survival regardless of treatment modality. The improved outcomes of this population has led to re-evaluation of treatment paradigms in the past decade, with a desire to spare young, human papillomavirus-positive patients the treatment-related toxicities of chemoradiotherapy and to use new minimally invasive surgical techniques to improve outcomes. Numerous retrospective and prospective studies have investigated the role of surgery in treatment of oropharyngeal carcinoma and have demonstrated equivalent oncologic outcomes and improved functional outcomes compared with chemoradiotherapy protocols. Ongoing and future clinical trials may help delineate the role of surgery in the future.

Transoral robotic surgery for management of cervical unknown primary squamous cell carcinoma: Updates on efficacy, surgical technique and margin status

IMPORTANCE

Management of cervical unknown primary squamous cell carcinoma (CUP) has evolved with the introduction of transoral robotic surgery (TORS).

OBJECTIVES

1. To describe the efficacy of TORS lingual and palatine tonsillectomy in identifying the primary site of malignancy. 2. To explore how the extent of surgery affects diagnostic yield. 3. To report margin status of TORS resections.

DESIGN, SETTING AND PARTICIPANTS

A retrospective, single-center cohort study utilizing a prospectively collected database of CUP patients in a high-volume tertiary referral center. Patient underwent operative laryngoscopy plus TORS as clinically indicated.

MAIN OUTCOMES AND MEASURES

Primary end point was successful identification of the primary. The extent of surgery and margin status were also examined.

RESULTS

From 2010-2016, 64 patients with CUP were treated. The primary tumor was found in 51 patients (80%). Fourteen patients (22%) were identified with operative laryngoscopy alone. Fifty patients underwent TORS lingual tonsillectomy ± palatine tonsillectomy with 37 primary tumors identified (74%). The primary was located in the lingual tonsil in 32 patients (86%) and palatine tonsil in 5 patients (10%, p<0.001). Negative margins were achieved in 19 patients (51%). The deep margin was the most commonly positive margin (47%, p=0.049).

CONCLUSION AND RELEVANCE

Operative laryngoscopy with TORS is efficacious, localizing the primary in 80% of patients. If a margin was positive, it was most commonly the deep margin. This study provides valuable information that can help standardize surgical technique, further increasing the diagnostic yield and decreasing the negative margin rate of TORS for CUP.

Human papillomavirus is a favourable prognostic factor in cancer of unknown primary in the head and neck region and in hypopharyngeal cancer

Human papillomavirus (HPV), in addition to smoking and alcohol, is a cause of oropharyngeal squamous cell carcinoma (OPSCC), particularly of the tonsils and base of the tongue (TSCC and BOTSCC, respectively). Moreover, HPV-positive TSCC and BOTSCC are associated with a better outcome compared with their HPV-negative counterparts (80 vs. 40% 3-year disease-free survival rate, respectively) and their incidence has increased in several countries. Recently, accumulating evidence of HPV in a considerable proportion of cancers of unknown primary (CUP) in the head and neck region and in a small proportion of hypopharyngeal SCCs has been reported. Furthermore, HPV-positive tumours, particularly cases with HPV DNA positivity in combination with overexpression of p16, also tend to have a better clinical outcome compared with that of the corresponding HPV-negative tumours. This finding is particularly prominent in HPV-positive CUPs of the head and neck region, where the primary tumour likely originates from the oropharynx. Thus, the determination of HPV status and p16 expression may be of value for the diagnosis and treatment of CUP of the head and neck region and may also be of value for hypopharyngeal cancers in the future. However, for hypopharyngeal cancer as well as other non-OPSCCs, additional studies per subsite on the effect of HPV status on survival are required.

Applications of Evolving Robotic Technology for Head and Neck Surgery

OBJECTIVE

Assess the use and potential benefits of a new robotic system for transoral radical tonsillectomy, transoral supraglottic laryngectomy, and retroauricular thyroidectomy in a cadaver dissection.

METHODS

Three previously described robotic procedures (transoral radical tonsillectomy, transoral supraglottic laryngectomy, and retroauricular thyroidectomy) were performed in a cadaver using the da Vinci Xi Surgical System. Surgical exposure and access, operative time, and number of collisions were examined objectively.

RESULTS

The new robotic system was used to perform transoral radical tonsillectomy with dissection and preservation of glossopharyngeal nerve branches, transoral supraglottic laryngectomy, and retroauricular thyroidectomy. There was excellent exposure without any difficulties in access. Robotic operative times (excluding set-up and docking times) for the 3 procedures in the cadaver were 12.7, 14.3, and 21.2 minutes (excluding retroauricular incision and subplatysmal elevation), respectively. No robotic arm collisions were noted during these 3 procedures. The retroauricular thyroidectomy was performed using 4 robotic ports, each with 8 mm instruments.

CONCLUSIONS

The use of updated and evolving robotic technology improves the ease of previously described robotic head and neck procedures and may allow surgeons to perform increasingly complex surgeries.

The prevalence of human papillomavirus in squamous cell carcinoma of unknown primary site metastatic to neck lymph nodes: a systematic review

A subset of head and neck squamous cell carcinoma, which mainly arise from the crypt epithelium of the palatine and lingual tonsils, may be caused by high-risk human papillomavirus (HPV) infections. This topographical restriction together with other overlapping clinical features have led investigators to suspect that HPV plays a role in squamous cell carcinoma of unknown primary (SCCUP) site metastatic to neck lymph nodes. We performed a systematic review of articles listed in PubMed to identify studies testing HPV and/or p16(INK4a) status (p16) in tissue samples from initial and definitive SCCUP. The prevalence of HPV-related (HPV DNA-positive and/or p16 positive) SCCUP was calculated for all the SCCUP, initial SCCUP, suspected definitive SCCUP, and true definitive SCCUP whenever a minimum of 10 cases of each category was identified. In addition, data concerning patients' diagnostic work-up, the HPV detection methods, and the correlations between HPV-status, the localization of the occult primary tumor, and the clinical outcome were also extracted. Eighteen retrospective cohort studies, assessing a total of 659 patients, met the inclusion criteria. The overall median prevalences of HPV-DNA(pos), of p16(pos), and of positivity for both HPV markers were, respectively, 37.0, 48.5, and 36.0 %. Patients with diagnosis of initial SCCUP had overall median prevalences of HPV-DNA(pos), of p16(pos), and of positivity for both HPV markers, respectively, of 81.8, 86.2, and 80.8 %. The data uncovered by this systematic review confirm that SCCUP is frequently causally associated to HPV-driven oropharyngeal squamous cell carcinomas. This finding supports the view that HPV-status could be routinely assessed in SCCUP patients as it may lead to identifying the primary tumor and the decision to de-escalate treatment.

Challenging the need for random directed biopsies of the nasopharynx, pyriform sinus, and contralateral tonsil in the workup of unknown primary squamous cell carcinoma of the head and neck

BACKGROUND

Many guidelines recommend random directed biopsies of the nasopharynx, contralateral tonsil, and hypopharynx to evaluate an unknown primary squamous cell carcinoma of the head and neck. There are no published data documenting the need for these recommendations. The purpose of our study was to report the rate of positive blind biopsies in this setting.

METHODS

We recorded the rate of positive random directed biopsies performed as part of the workup for 156 patients treated with radiotherapy between 1985 and 2014 for an unknown primary squamous cell carcinoma presenting with the main location of adenopathy in nodal stations 2, 3, 4, or 5.

RESULTS

Rate of positive result by subsite: nasopharynx and pyriform sinus = 0%; tonsillectomy: ipsilateral = 39%, bilateral = 6%; and base of tongue = 18%.

CONCLUSION

With modern imaging, random directed biopsies of the nasopharynx and hypopharynx are unnecessary in the workup of unknown primary squamous cell carcinoma of the head and neck.

Approach to metastatic carcinoma of unknown primary in the head and neck: squamous cell carcinoma and beyond

Metastatic carcinoma to cervical lymph nodes presenting as an unknown primary is quite common. In most cases, the primary site is ultimately identified. Carcinomas that remain of unknown primary after a thorough search are uncommon. This review will focus on those cases that initially present as unknown primaries, since this is the setting in which pathologists first encounter these cases and in which they play an important role in guiding patient management. Most are squamous cell carcinomas, the majority of which are human papillomavirus (HPV)-related and originate in the palatine tonsils and base of tongue. HPV-related oropharyngeal squamous cell carcinomas are increasing in incidence and have unique clinical and pathologic features that make them particularly likely to present as an unknown primary. Understanding these features has led to improved detection of the primary tumors. Further, even when the primary tumor is not found, prognosis is very dependent on characterization of the tumor HPV status. Papillary thyroid carcinomas may also initially present without a known or clinically detectable primary, either as a neck mass or incidentally in a neck dissection performed for another indication. The latter is a very indolent disease. Finally, primary salivary gland carcinomas may mimic an unknown primary and need to be distinguished from cutaneous metastases to the parotid gland, which may present without a recognized skin tumor. Here, we review the clinical and pathologic features of these entities and provide a systematic approach to their diagnosis.