A systematic review on Transoral robotic surgery (TORS) for carcinoma of unknown primary origin: Has tongue base mucosectomy become indispensable?

Trends in Investigations for Suspected Head and Neck Carcinoma of the Unknown Primary: A HNCIG and IFHNOS International Survey of Practice

BACKGROUND

The aim of this clinical survey was to assess variations in head and neck squamous cell carcinoma from an unknown primary (HNSCCUP) diagnostic practices across international centers.

METHODS

Clinical practice survey of experts nominated by Head and Neck Cancer International Group (HNCIG) and International Federation of Head and Neck Oncologic Societies (IFHNOS).

RESULTS

Responses were received from 48/49 (97.9%) participants. Outpatient laryngoscopy, CT, and 18-FDG-PETCT were used always or most of the time by 81.3%, 77.1%, and 79.2%, but only 50% regularly used MRI. Unilateral and bilateral tonsillectomy were frequently performed in 41.6% and 27.1% of unilateral nodal disease, and in 18.8% and 52.1% for bilateral disease. Ipsilateral Tongue Base Mucosectomy (TBM) was used always or most of the time in 12.5% of unilateral and 6.3% of bilateral HNSCCUP. Bilateral TBM was used in 10.4% for unilateral and 22.9% for bilateral cancers.

CONCLUSIONS

While there is broad agreement regarding examination and cross-sectional imaging, there are considerable differences in the surgical strategies used to identify occult primaries.

The Effectiveness of Tonsillectomy in the Diagnostic Workup of Squamous Cell Carcinoma Unknown Primary in the Head and Neck Based on p16 Immunohistochemistry

Background and Objectives: Despite the distinct entity of both p16-positive and p16-negative squamous cell carcinoma unknown primary in the head and neck (HNSCCUP), the diagnostic workup did not differ. The aim of the study was to determine the effectiveness of palatine tonsillectomy in the identification of primary tumours in two groups of p16-positive and p16-negative HNSCCUP. Materials and Methods: Patients with HNSCCUP managed in two tertiary care referral centres from 1 January 2014 to 31 December 2020 were analysed retrospectively. Results: Sixty-six patients with HNSCCUP diagnosis were included consecutively. HPV status of metastatic cervical lymph nodes using immunohistochemistry with p16 protein was available for all patients. The proportion of both p16-positive and p16-negative groups was not significantly different (p = 0.242). Of the 39 patients who underwent palatine tonsillectomy, tonsillar cancers were revealed histologically in 6 (15.4%) patients, and all these patients were p16-positive. No primary tonsillar tumour was found in the p16-negative group (0 of 17). The primary tumour identification rate in p16-positive HNSCCUP patients using palatine tonsillectomy was 27% (6 of 22). Conclusions: The diagnostic workup of HNSCCUP should be guided according to HPV/p16 status. Palatine tonsillectomy is a useful procedure in identifying primary cancer in p16-positive SCCUP patients, however, its effectiveness in p16-negative patients is debatable.

Impact of tongue base mucosectomy on quality-of-life outcomes: systematic review and single-centre experience

PURPOSE

Tongue base mucosectomy (TBM) is a well-established procedure in investigating cervical squamous cell carcinoma of occult primary. However, its risks have not been balanced against its benefits with validated tools.

METHODS

A systematic literature review was conducted for reported complications and quality-of-life outcomes following TBM. The complications and quality-of-life outcomes following TBM at our institution are then reported using objective metrics and validated assessment tools, including Performance Status Scale for Head and Neck Cancer Patients (PSS-HNS), University of Washington Quality-of-life Questionnaire (UW-QOL) and M. D. Anderson Dysphagia Inventory (MDADI).

RESULTS

Eighteen studies met the criteria for inclusion in the systematic review. Of these, 9 addressed swallowing outcomes described in text, without using validated assessment tools. No studies reported taste, speech and pain outcomes after TBM. Post-operative bleeding was not consistently reported. 20 patients underwent robotic TBM at our institution between 2017 and 2023. The primary tumour was identified in 50% (10/20) of cases. The median time to commencing soft diet and median time of NG feeding was 0 days. The median return to normalcy of diet score was 95. Median post-treatment UW-QOL pain and swallowing scores were 100 and 70 respectively. The median speech score was 100, saliva 70, and taste 70. The median normalised MDADI scores were: global 80; emotional 67; functional 80 and physical 65.

CONCLUSIONS

Validated assessment tools better inform patients about treatment options and can help compare post-TBM results across institutions. Our data demonstrates that TBM patients have a functional post-operative swallow, are pain and gastrostomy free, even after adjuvant treatment. Routine post-operative insertion of NG tube is not necessary.

Indications for oropharyngeal biopsy in head and neck squamous cell carcinoma of unknown primary: A systematic review (HNSCCUP)

INTRODUCTION

Patients presenting with head and neck squamous cell carcinoma of unknown primary (HNSCCUP) remain challenging clinical scenarios as large variation exists in practices used to locate the primary.

OBJECTIVE

The objective of this systematic review is to review of the literature and offer recommendations for oropharyngeal biopsies in HNSCCUP.

METHOD

Pubmed, Medline and Embase were searched to identify studies from inception to October 2021. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed.

RESULTS

A total of 483 articles were included and screened, 41 studies met the inclusion criteria, including over 3400 patients from the original articles (122 of these patients were reported on in two sequential articles by a single author - table 1) and 4 large metaanalyses including 1852 patients. The primary site identification rate following random biopsies or deep tissue biopsies is less than 5% in most studies. The mean detection rate following ipsilateral tonsillectomy is 34%; two pooled analyses indicate that the mean detection rate following tongue base mucosectomy is 64%, with this figure rising when the tonsils are negative.

CONCLUSIONS

High level evidence is lacking, with heterogeneity in the reported studies. Published meta-analyses are based on retrospective data. There is little evidence supporting the practice of random/non-directed oropharyngeal biopsies. Available evidence supports palatine tonsillectomy and tongue base mucosectomy compared to deep tissue biopsies.

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.

The Role of Trans Oral Robotic Surgery in the Carcinoma of Unknown Primary: A New Evidence in the Horizon?

The detection of the primary site in Carcinoma of Unknown Primary (CUP) is a challenging task which can significantly alter the course of management and also prognosis. Various modalities have been assessed with varying sensitivity and specificity. Imaging and cytological diagnosis have formed a key part of the diagnostic algorithm of CUP. Trans Oral Robotic Surgery offers the advantage of being both diagnostic as well as therapeutic with promising sensitivity and specificity and can form an integral part in the management of CUP. A prospective study was carried out at a tertiary care centre over a period of one year. Patients with unilateral neck swelling which was histopathologically proven squamous cell carcinoma neck metastasis were included in the study. They were evaluated with endoscopy and radiology according to the standard algorithm. When these failed to detect the primary, the patients underwent ipsilateral radical tonsillectomy and tongue base mucosal wedge biopsy via TORS. Post-operative histopathological examination was done on the resected specimens to detect the primary site. Transoral Robotic Surgery was able to localise primary in 50% of the patients enrolled in the study. Out of the primary site identified by TORS; 55.56% were located in the tonsil and 44.4% in the tongue base. TORS can offer promising detection rates of the occult primary in CUP and should form an integral part of the diagnostic algorithm.

Transoral robotic surgery in HPV+ oropharyngeal cancer of unknown primary

PURPOSE

This study was designed to assess trends in and outcomes associated with TORS-treated HNCUP using a large national database.

MATERIALS AND METHODS

HPV+ oropharyngeal HNCUPs were isolated from the 2004-2017 National Cancer Database. Overall survival (OS) was assessed, with patients stratified by 1) use of TORS and 2) whether the occult tumor was ultimately located. Demographic and oncologic predictors of survival were evaluated on regression.

RESULTS

The cohort contained 284,734 cases, of which 8336 were HNCUPs. HNCUPs represented 2.49 % of all HNSCC in 2010 versus 3.13 % in 2017. 3897 (46.7 %) of these unknown primaries were ultimately identified. The proportion of cases treated with TORS increased from 6.9 % in 2010 to 18.1 % in 2017 (p < 0.001). Kaplan-Meier analysis of 2991 HPV+ oropharyngeal HNCUPs demonstrated higher 5-year overall survival (OS) for patients treated with robotic surgery versus no robotic surgery (95.4 % ± 1.7 % standard error [SE] versus 84.0 % ± 0.9 % SE; p < 0.001). Patients with primary tumors identified during treatment had improved OS compared to those whose tumors were not located (5-year OS was 90.5 % ± 0.9 % SE and 77.3 % ± 1.5 % SE, respectively; p < 0.001). For patients in which the primary tumor was found, those who received robotic surgery survived longer than those who did not (96.5 % ± 1.4 % SE versus 89.1 % ± 1.0 % SE 5-year OS; p < 0.001). The relationship between TORS and OS remained significant on Cox regression controlling for confounders.

CONCLUSIONS

Use of TORS in the workup for HPV+ HNCUP is associated with higher rates of tumor identification and improved OS.

Transoral robotic surgery without adjuvant therapy: A systematic review and meta-analysis of the association between surgical margins and local recurrence

BACKGROUND

Transoral robotic surgery (TORS) is increasingly employed in the management of oropharyngeal cancer without adjuvant treatment. Attaining safe surgical margins is paramount to preventing local recurrence (LR), but the necessary surgical margin dimension remains contentious.

METHODS

Systematic review and meta-analysis of studies reporting margin status and LR following TORS without adjuvant therapy for primary OPSCC.

RESULTS

The search identified 269 articles and 11 were selected for inclusion, with 406 patients included in the meta-analysis. Heterogeneity was noted in the definition of "close" margins. Random-effects pooled rate of positive margins was 7 % (95 % CI 0.04-0.12, I2 = 54 %, p = 0.02) and close margins was 7 % (95 % CI 0.02-0.27, I2 = 86 %, p=<0.01). The random-effects overall rate of LR was 6 % (95 % CI 0.04-0.10, I2 = 11 %, p = 0.35), 13 % (95 % CI 0.02-0.620, I2 = 0 %, p = 1.0) after a positive margin, and 3 % (95 % CI 0.03-0.24, I2 = 23 %, p = 0.26) after a close margin. Odds ratio (OR) for LR indicated higher risk of LR for positive compared to close margins (7.5; 95 % CI 1.31-42.91, I2 = 0 %, p = 0.51), and a slightly lower risk of LR between close and negative margins (2.22; 95 % CI 0.67-7.38, I2 = 0 %, p = 0.8). A lack of frozen-section analysis (OR 2.91, p = 0.36) and HPV-negative disease (OR 1.68, p = 0.03) were associated with an elevated risk of LR.

CONCLUSIONS

TORS as a standalone treatment is associated with low rates of LR; however, the literature is hampered by considerable heterogeneity in margin definitions. Larger multicentre studies are required to determine the precise margin cut-off required for oropharyngeal tumours managed with TORS alone.

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.

Transoral Robotic Surgery for Head and Neck Cancer: Advances and Residual Knowledge Gaps

Minimally invasive surgery is a growing field in surgical oncology. After acquiring its first Food and Drug Administration approval in 2009 for T1–T2 malignancies of the oral cavity, oropharynx, and larynx, transoral robotic surgery (TORS) has gained popularity thanks to its wristed instruments and magnified three-dimensional view, enhancing surgical comfort in remote-access areas. Its indications are expanding in the treatment of head and neck cancer, i.e., resection of tumors of the larynx, hypopharynx, or parapharyngeal space. However, this expansion must remain cautious and based on high-level evidence, in order to guarantee safety and oncological outcomes which are comparable to conventional approaches. This narrative review assesses the current role of TORS in head and neck cancer from an evidence-based perspective, and then identifies what knowledge gaps remain to be addressed.

Updates in the management of unknown primary of the head and neck

Squamous cell carcinoma (SCC) from an unknown primary tumor (SCCUP) accounts for 2.0%–5.0% of all head and neck cancers. SCCUP presents as enlarged cervical lymph nodes without evidence of a primary tumor upon physical examination. Primary site detection is important to target treatment and avoid treatment-related morbidity. In this review, we discuss updates in SCCUP management. Diagnostic workup should focus on localization of the primary tumor in SCCUP. Initial workup centers on neck biopsy to confirm the presence of SCC. Given the increasing incidence of HPV-related SCC in the oropharynx, HPV testing is crucial. An HPV-positive status can localize the tumor to the oropharynx, a common site for occult tumors. Imaging includes neck CT and/or MRI, and PET/CT. After imaging, panendoscopy, palatine tonsillectomy or diagnostic transoral robotic surgery can facilitate high rates of primary tumor localization. Primary tumor localization influences treatments administered. SCCUP has traditionally been treated aggressively with large treatment fields to all potential disease sites, which can induce weight loss and swallowing dysfunction. As a result, primary localization can reduce radiation fields and provide possible de-escalation to primary surgical management. Advances in intensity-modulated radiation therapy and dose management also have the potential to improve functional outcomes in SCCUP patients. Given the improved prognosis associated with HPV-positive SCCs, HPV tumor status may also inform future treatment de-intensification to reduce treatment-related toxicity.

Intraoperative delineation of p16+ oropharyngeal carcinoma of unknown primary origin with fluorescence lifetime imaging: Preliminary report

BACKGROUND

This study evaluated whether fluorescence lifetime imaging (FLIm), coupled with standard diagnostic workups, could enhance primary lesion detection in patients with p16+ head and neck squamous cell carcinoma of the unknown primary (HNSCCUP).

METHODS

FLIm was integrated into transoral robotic surgery to acquire optical data on six HNSCCUP patients' oropharyngeal tissues. An additional 55-patient FLIm dataset, comprising conventional primary tumors, trained a machine learning classifier; the output predicted the presence and location of HNSCCUP for the six patients. Validation was performed using histopathology.

RESULTS

Among the six HNSCCUP patients, p16+ occult primary was surgically identified in three patients, whereas three patients ultimately had no identifiable primary site in the oropharynx. FLIm correctly detected HNSCCUP in all three patients (ROC-AUC: 0.90 ± 0.06), and correctly predicted benign oropharyngeal tissue for the remaining three patients. The mean sensitivity was 95% ± 3.5%, and specificity 89% ± 12.7%.

CONCLUSIONS

FLIm may be a useful diagnostic adjunct for detecting HNSCCUP.

Transoral robotic surgery (TORS) using the da Vinci Xi: prospective analysis of feasibility, safety, and outcomes

BACKGROUND

The da Vinci Xi system is not Food and Drug Administration approved for transoral robotic surgery (TORS), resulting in limited data.

METHODS

This prospective study evaluates the feasibility, safety, and outcomes of Xi-TORS in an oncological setting.

RESULTS

Sixty-one patients with head and neck cancer were consecutively included for Xi-TORS. Adequate exposure and macroscopically complete resection were achieved in 59 patients (success rate = 96.7%). Intraoperative difficulties and complications were encountered in 47.5% and 20.3% of patients, respectively. Postoperative hemorrhage occurred in 11.9%; no treatment-related deaths were encountered. Two-year overall survival and disease-specific survival were 90.5% and 95.6%, respectively. No long-term (>1 month) tracheotomies were necessary, and only two patients remained tube-feeding dependent. The functional baseline level was regained at 12 months for the MD Anderson Dysphagia Inventory and at 24 months for the Swallowing quality-of-life questionnaire. QLQ-H&N35-assessed QOL returned to baseline 6 months postoperatively.

CONCLUSIONS

Xi-TORS is safe, feasible, and with high oncological and functional effectiveness.

Human papillomavirus testing in metastatic squamous cell carcinoma of the neck with unknown primary using PCR on fine-needle aspiration smears: a prospective clinical study

PURPOSE

Squamous cell carcinoma metastasis of the head and neck with unknown primary tumor (CUP) comprises a diagnostic challenge. Human papillomavirus (HPV) testing on cytologic specimens is gaining increasing focus as this may facilitate an early diagnosis of HPV-induced oropharyngeal carcinoma. This study aimed to prospectively assess PCR-based HPV-DNA testing on FNA smears in a clinical setting.

METHODS

Patients referred to a tertiary Head and Neck Cancer Center with suspected CUP were included from November 2016 to November 2018. Scraped cell material from FNA smears was analyzed for HPV-DNA with PCR using general primers (GP5 + /GP6 +) and correlated with the origin and histology of the primary tumor (oropharynx vs. outside oropharynx or benign tumor). The turn-around time reflecting the workflow for HPV-DNA testing by PCR was also calculated.

RESULTS

A total of 93 patients were enrolled in the study. The sensitivity and specificity were 86.7% [95% CI 75.4-94.1%] and 92.0% [95% CI 74.0-99.0%], and the positive and negative predictive values were 96.3% [95% CI 87.3-99.0%] and 74.2% [95% CI 59.9-84.7%], respectively. The turn-around time for HPV testing was a mean four calendar days.

CONCLUSION

HPV-DNA testing on FNA smears can be performed within a reasonable timeframe and can guide for the detection of an HPV-positive oropharyngeal primary tumor in the clinical setting for patients presenting with CUP of the head and neck.

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.

Salvage surgery in head and neck cancer

Salvage surgery after failed organ preservation treatment offers challenges for both the patient and the surgeon. The outcome is often uncertain and even today, 5‐year overall survival does not exceed 50 per cent. The chemoradiotherapy induced toxicity asks for meticulous discussion and planning in a multidisciplinary manner in a changing environment of increasing incidence of human papillomavirus induced oropharyngeal tumours, evolving surgical techniques and patient participation. Herein, we discuss the latest literature on salvage surgery and the need for identifying the proper prognosticators to ensure for an optimal treatment plan in potentially salvageable patients.

A systematic review on Transoral robotic surgery (TORS) for carcinoma of unknown primary origin: Has tongue base mucosectomy become indispensable?

Background

Transoral robotic surgery (TORS) is increasingly used in head and neck surgery and in carcinoma of unknown primary (CUP) origin specifically. Due to the rising incidence of human papillomavirus (HPV)‐related oropharyngeal squamous cell carcinoma (OPSCC), there is a rationale for finding ways to de‐escalate treatment strategies. This review aims to test the hypothesis that TORS is a meaningful adjunct in the diagnostic (and therapeutic) pathway in CUP in head and neck.

Methods

A structured search of the literature was performed with the search terms ‘TORS’ and ‘Carcinoma of Unknown Primary’.

Results

Two hundred and seventy four cases of CUP in which TORS was used were identified for further analysis. Workup for CUP was comparable in all series with regard to physical examination, fine and/or gross needle examination of cervical nodes, fibre optic endoscopy, imaging and robot assisted mucosectomy of the base of tongue (BOT). Identification rate of the primary tumour was 72% on average (range 17%‐ 90%), and 55%‐ 96% were HPV positive. Clear margins were achieved in 60% (range 0%‐85%) of resected occult tumours. Complication rate of TORS BOT mucosectomy was low with mainly grade I‐III sequelae according to Clavien–Dindo.

Conclusions

Transoral robotic surgery seems to be a useful and safe adjunct in the diagnostic and therapeutic pathway in case of CUP in an era of increasing incidence of HPV‐positive OPSCC.