Diagnostic Value of Lingual Tonsillectomy in Unknown Primary Head and Neck Carcinoma Identification After a Negative Clinical Workup and Positron Emission Tomography-Computed Tomography

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.

Reducing the unknowns: A systematic review & meta-analysis of the effectiveness of trans-oral surgical techniques in identifying head and neck primary cancer in carcinoma unknown primary

OBJECTIVES

The use of transoral robotic surgery (TORS), transoral laser microsurgery (TLM) and more recently reported transoral endoscopic electrocautery (TOEC) in identifying the primary cancer in head and neck Carcinoma Unknown Primary (CUP) patients have gained popularity. This review aims to assess the effectiveness of TORS, TLM and TOEC.

MATERIALS & METHODS

A systematic review and meta-analysis was carried out. EMBASE, MEDLINE and CINAHL databases were searched from inception to September 2020. All primary studies were considered for inclusion. Primary outcome measure was detection rates of primary cancer of the different techniques. Secondary outcome measures were complications and length of hospital stay.

RESULTS

289 studies were identified of which 30 met the inclusion criteria. The primary cancer was identified in 567 /777 patients (pooled results was 64% (95% CI 54-73). The primary identification rates were 45% and 32% in lingual (n = 273) and palatine tonsillectomy (n = 118) respectively. The primary cancer identification rates by surgical techniques are: TORS was 60% (95% CI 49-70), TLM was 80% (95% CI 0.58, 1.01), TOEC was 41% (95% CI 0.05, 0.76). 529/777 (68%) tumours were Human Papilloma Virus (HPV) related. The pooled data of studies that reported on detection rates relating to HPV status were 178/216 (82%) for HPV +ve and 7/59 (12%) for HPV -ve tumours. Coefficient of variation results suggest heterogenous data for TORS and TLM. The commonest complication was haemorrhage (5.3%). The length of reported hospital stay ranged from 1.4 to 7 days.

CONCLUSIONS

This is the largest systematic review in the subject. The quality of studies and heterogeneity of data limit conclusive findings. Lingual tonsillectomy is an effective procedure in CUP work up. Further larger, multicentre, prospective studies of PET CT negative CUP patients is needed to draw conclusive results.

Potential therapeutic implications of the new tumor, node, metastasis staging system for human papillomavirus-mediated oropharyngeal cancer

PURPOSE OF REVIEW

The 8th edition tumor, node, metastasis (TNM) classification (TNM-8) introduced a new classification for human papillomavirus (HPV)-mediated oropharyngeal carcinoma (HPV+ OPC). This review summarizes its potential therapeutic implications focusing on literature published since 2018.

RECENT FINDINGS

The following are active research areas involved in clinical care and therapy relevant to TNM-8: tumor HPV testing and its clinical implications; stage I disease: treatment selection and lessons learned from recent deintensification trials; emerging strategies addressing stage II and III disease.

SUMMARY

The TNM-8 classification depicts prognosis of HPV+ OPC much more reliably compared with TNM-7. Among the advantages in outcome comparison and stratification for clinical trial entry and conduct, it also enables more satisfactory individual patient consultation to adequately estimate prognosis, and facilitates clinical and translational research. However, clinicians must remain mindful that the TNM classification is not a guideline for treatment but, instead, provides a framework for clinical research and treatment decision-making. The TNM-8 has potential to improve risk-tailored treatment algorithms for HPV+ OPC including selection of treatment modality (primary trans-oral surgery vs. radiotherapy, addition of chemotherapy) and adjusting the intensity of approaches. To realize these goals fully, it is apparent that the TNM-8 needs to evolve further.

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.

Long-term results of elective mucosal irradiation for head and neck cancer of unknown primary in Chinese population: The EMICUP study

Objective

Controversy still exists regarding the volume of radiation for head and neck cancer of unknown primary (HNCUP). Theoretically, elective mucosal irradiation (EMI) should achieve a balance between survival and toxicity. This prospective study was conducted to evaluate the long‐term benefit of EMI in Chinese HNCUP patients.

Methods

A phase II, single‐arm trial was performed at two centers in China. HNCUP patients with pathologically confirmed metastatic squamous cell carcinoma or poorly differentiated carcinoma were enrolled. Patients with metastatic lymph nodes limited to level IV and/or the supraclavicular fossa were excluded. The EMI approach was specifically customized to Chinese patients by differentiating HNCUP as putative nasopharyngeal carcinoma (NPC) or non‐putative NPC. The primary endpoint was 3‐year mucosal recurrence‐free survival (MRFS).

Results

A total of 48 patients were enrolled between 02/02/2010 and 08/01/2018; 46 patients were analyzed, including 24 putative NPC and 22 non‐putative NPC patients. No primary recurrence was observed during a median follow‐up period of 70 months, and only 1 patient experienced out of field recurrence in the contralateral neck. The 3‐year MRFS was 90.6% (95%CI: 76.4%‐96.4%). The 5‐year MRFS, regional‐recurrence free survival (RRFS) and overall survival (OS) were 90.6% (95%CI: 76.4%‐96.4%), 86.0% (95%CI: 71.1%‐93.7%), and 90.6% (95%CI: 76.4%‐96.4%), respectively. No grade 4 acute or late toxicities occurred, and the most frequent grade 3 acute toxicity was oral mucositis (45.7%).

Conclusion

To the best of our knowledge, this is the first prospective study to evaluate the long‐term outcomes of EMI in Chinese HNCUP patients. Excellent MRFS and OS rates were observed. Further randomized studies are warranted.

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.

PET/CT Evaluation of Head and Neck Cancer of Unknown Primary

The diagnosis of carcinoma of unknown primary in the head and neck is made when there is a metastasis but no primary lesion is identified after physical exam and diagnostic CT or MR imaging. PET/CT is the first step in searching for a primary lesion, followed by more invasive techniques such as endoscopy and surgery. Knowledge of the different tumor histologic types, preferential locations of nodal spread, imaging pitfalls, and other special considerations such as cystic metastases can be helpful in the ultimate identification of primary tumors, which leads to improved overall patient survival.