AHNS Series: Do you know your guidelines? Guideline recommendations for head and neck cancer of unknown primary site

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.

Comparative analysis of the expression of р16, PD-L1 in squamous cell carcinoma of the oropharynx and CUP syndrome

Introduction. metastases in the absence of a primary tumor (cancer of unknown primary (Cup) syndrome) are diagnosed in 2–4 % of malignant tumor cases. This pathology is characterized by early metastatic dissemination, weak response to conventional chemotherapy, and aggressive progression. The use of checkpoint inhibitors targeting programmed cell death protein 1 (pD-1) and its ligand (pD-L1) has shown good results in treatment of various cancers including oropharyngeal squamous cell carcinoma (OpSCC). In Cup syndrome, the effectiveness of checkpoint inhibitors is rarely investigated, and pD-L1 expression is often not measured.Aim. To compare the frequency of p16 and pD-L1 hyperexpression in OpSCC and Cup syndrome, and to analyze dependency of survival rates on the level of expression of p16, the most important prognostic marker.Materials and methods. The study included 121 patients (59 with OpSCC and 62 with Cup syndrome) who received medical treatment in the multidisciplinary medical Center “medical City” (Tyumen) and Chelyabinsk Oncological Center of Oncology and Nuclear medicine between 2019 and 2023. Immunohistochemical examination was performed using the vENTANA Benchmark gX with primary antibodies against pD-L1 (clone Sp263, uSA) and р16 (uS Biological, uSA). Statistical analysis of the data was performed using SpSS 26 software. Long-term treatment outcomes were evaluated using 1-, 3-, 5-year survival rates and median survival. Overall survival was analyzed using the kaplan-meier method. Statistical significance of the differences was evaluated using the Cox model.Results. The studied groups did not differ by sex (p = 0.472), age (р = 0.640), and N stage (р = 0.262). patient age in the whole population varied between 42 and 81 years (median age 61.89 ± 11.9 years; mean age 60.81 ± 9.8 years). pD-L1 expression rate was higher in Cup syndrome at 92 % compared to 73 % in OpSCC (statistically significant difference; р = 0.01). Analysis of the association of ORSCC and Cup syndrome with human papilloma virus showed statistically significant difference in p16 hyperexpression: patients with OpSCC had p16-positive status more frequently (53 % of cases) while patients with Cup syndrome mostly had p16-negative status (73 % of cases). mean life expectancy of patients with OpSCC and p16-positive status was 62.65 months (95 % confidence interval 54.98–70.31), minimal observation period was 12 months, maximal was 70 months. mean life expectancy of patients with Cup syndrome and positive p16 status was 66.22 months (95 % confidence interval 56.35–76.10), minimal observation period was 12 months, maximal was 70 months. No statistically significant differences in survival rates of patients with OpSCC and Cup syndrome were found (р = 0.999).Conclusion. The study showed higher pD-L1 expression in patients with Cup syndrome compared to patients with OpSCC: 92 and 73 %, respectively (р = 0.01). The obtained results highlight the importance of routine pD-L1 expression evaluation in patients with Cup syndrome. The frequency of p16 hyperexpression was higher in OpSCC compared to Cup syndrome: 53 % versus 27 % (р = 0.02) which agrees with the worldwide epidemiological data: among all malignant neoplasms of the head and neck, Hpv infection is most common in OpSCC. Therefore, it serves as an important sign of hidden oropharyngeal cancer in Cup syndrome.

An Unknown Foreign laryngeal Object: an exotic complication of skull base osteoradionecrosis

BACKGROUND

Osteoradionecrosis (ORN) of the skull base is a rare complication after head and neck radiation with a broad variety of subsequent complications.

METHODS

A 68-year-old woman with a complex oncological history (right-sided sphenoid meningioma; left-sided neck metastasis of a Cancer of Unknown Primary-CUP) was admitted with a right-sided epi-/ oropharyngeal mass and severe pain exacerbations for further evaluation. CT scan revealed an advanced ORN of the skull base with subsequent abruption of the ventral part of the clivus. This dislocated part of the clivus wedged in the oropharynx for 48 h and then moved towards the larynx, resulting in dyspnea and almost complete airway obstruction.

RESULTS

Due to the dangerous airway situation, an urgent exploration and removal of the dislocated clivus was necessary. After a potential cervical spine instability was ruled out, the patient's airway was initially secured with an awake tracheotomy and the clivus was removed transorally. The tracheostomy tube was removed during the ongoing inpatient stay, and the patient was discharged with significant pain relief.

CONCLUSIONS

The present case illustrates an orphan complication of skull base ORN resulting in a major airway emergency situation.

Extra-Capsular Spread of Lymph Node Metastasis in Oral, Oropharyngeal and Hypopharyngeal Cancer: A Comparative Subsite Analysis

BACKGROUND

The extra-capsular spread (ECS) of lymph node metastasis (LNM) is a hallmark of aggressive primary tumor phenotype in head and neck cancer (HNC); however, the factors influencing ECS are poorly understood.

PATIENTS AND METHODS

This was a retrospective study, including 190 cases of oral tongue cancer (OTC), 148 cases of oropharyngeal cancer (OPC) (118 HPV-positive and 30 HPV-negative), and 100 cases of hypopharyngeal cancer (HPC). Tumor dimension, tumor biological variables (lymphovascular/perineural invasion and histologic grade), and LNM variables (LNM number and size) were analyzed according to the presence of ECS using multivariable logistic regression and receiver operating characteristic (ROC) curve analyses.

RESULTS

LNM variables were significant factors for ECS in all subsites of HNC (p < 0.05), except HPV-positive OPC. In OTC, tumor dimensional variables were significantly related to ECS (p < 0.01). Meanwhile, in OPC and HPC, neither the primary tumor dimension nor the T status were significant factors for ECS occurrence. The predictability of ECS by ROC curve using multiple variables was 0.819 [95% confidence interval: 0.759-0.878] in OTC, 0.687 [0.559-0.815] in HPV-positive OPC, 0.823 [0.642-1.000] in HPV-negative OPC, and 0.907 [0.841-0.973] in HPC.

CONCLUSION

LNM variables were correlated with ECS occurrence for most HNC subsites, and site-dependent primary tumor characteristics might contribute differentially to the ECS development of LNM in HNC.

Comparison of PD-L1 expression in squamous cell cancer of unknown primary and oropharyngeal squamous cell carcinoma

PURPOSE

The tumorigenesis of squamous cell cancer of unknown primary (SCCUP) in the head and neck area has not been decoded so far, while poor survival rates and limited therapeutic options pose a serious challenge. The aim of this project was to investigate immunological characteristics of SCCUPs and compare them to oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

PD-L1 expression (TC) was examined by immunohistochemistry in 50 lymph node metastases of SCCUP and 47 primaries of OPSCC. CD3 + and CD8 + lymphocytic infiltration was measured in 5 high power fields. Expression of p16 and HPV ISH were assessed.

RESULTS

SCCUP demonstrated a significantly higher expression of PD-L1 than OPSCC. In p16-negative SCCUPs PD-L1 proved to be an independent prognostic factor to prioritize high-risk patients.

CONCLUSIONS

Immunologic differences between SCCUP and OPSCC were detected. A higher PD-L1 expression in SCCUP could potentially facilitate further evaluation of checkpoint inhibitor therapy.

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.

Metastasis to the oral and maxillofacial region. A systematic review

OBJECTIVE

Metastasis to oral and maxillofacial region (MOMFR) is an unusual finding; representing between 1 and 1.5% of all malignancies in the maxillofacial region. A systematic review is presented to determine trends in presentation, diagnostic features, and patient outcome.

METHODS

Searches of databases were carried out for papers reporting MOMFR. The variables were demographics, patient symptoms, tumor location, tumor size, histopathology, origin of the tumor, immunohistochemical studies, follow-up and survival.

RESULTS

696 cases were identified; 391 males, and 305 females. The most common race was white. The most common primary tumor for females was from breast 31.1% (n = 95), for males from lung 20.5% (n = 143). The most common location was the mandible 44.9% (n = 313), followed by gingival soft tissue 16.8% (n = 117). A frequent clinical symptom was pain with 17.5% (n = 122). The most common clinical presentation was a mass or tumor 37.4% (n = 260). The mean age was 58.8 years. The average time before diagnosis was 10.3 months, the mean follow-up after diagnosis was 13.1 months, and the average survival was 9.8 months.

CONCLUSION

MOMFR shows a strong predilection for the posterior mandible, with a mass or tumor being the most common clinical presentation. They are frequently painful, and demonstrate a poor prognosis.

Robotic and Endoscopic Approaches to Head and Neck Surgery

Technological developments have disrupted the practice of medicine throughout history. Endoscopic and robotic techniques in head and neck surgery have emerged over the past half-century and have been incrementally adapted to expanding indications within otolaryngology. Robotic and endoscopic surgery have an established role in treatment of oropharyngeal and laryngeal cancers, reducing surgical morbidity and improving survival relative to traditional open approaches. Surgical treatment of human papillomavirus-mediated oropharyngeal cancer via transoral robotic surgery offers equivalent oncologic and functional outcomes relative to radiotherapy. Newer iterations of single-port robotic systems continue to expand the scope of robotics in head and neck surgery.

The Diminishing Importance of Primary Site Identification in Cancer of Unknown Primary: A Canadian Single-Center Experience

BACKGROUND

Cancer of unknown primary (CUP) describes patients with metastatic disease without an identified primary tumor site. Successful diagnosis and treatment of these patients remains difficult. Published guidelines on CUP have highlighted "favorable" subtype groups. We investigated a series of CUP patients to review adherence to guidelines, and identification of primary cancers or "favorable" subtypes.

METHODS

Patients with histologically confirmed CUP at an academic institution from 2012 to 2018 were identified. Patient demographics, tumor presentation, diagnostic work-up and treatment information were retrospectively collected from electronic data records for descriptive analysis and compared to published clinical guidelines. The primary endpoint was the proportion of patients where the primary site was identified. Multivariable logistic regression models were used to identify factors associated with primary site identification. Kaplan-Meier survival curves were used to determine factors associated with poorer OS.

RESULTS

Three hundred and five patients were included with a median follow-up time of 4.3 months. Primary tumor sites were identified in 109 patients (37.5%), which was most commonly lung cancer (33%). Statistical analyses did not identify any demographic or initial presentation factors associated with identifying the primary or not. More diagnostic tests did not increase the likelihood of primary site identification (P=0.44). Patients with an identified primary did not have longer OS than other patients (median 5.2 months vs. 4.7 months, P=0.47). 57 patients (18.7%) who had a defined "favorable" subtype experienced superior OS (36.6 months vs. 3.8 months; P<0.0001). Further, patients with good prognostic status who followed published treatment guidelines had longer OS (17.6 months vs. 13.2 months; P=0.04).

CONCLUSIONS

CUP remains a difficult cancer to diagnose and treat. These results suggest identifying the primary has less impact than anticipated, but particular efforts to identify patients with "favorable" subtypes of CUP is important prognostically.

NBI utility in oncologic surgery: An organ by organ review

The main aims of the oncologic surgeon should be an early tumor diagnosis, complete surgical resection, and a careful post-treatment follow-up to ensure a prompt diagnosis of recurrence. Radiologic and endoscopic methods have been traditionally used for these purposes, but their accuracy might sometimes be suboptimal. Technological improvements could help the clinician during the diagnostic and therapeutic management of tumors. Narrow band imaging (NBI) belongs to optical image techniques, and uses light characteristics to enhance tissue vascularization. Because neoangiogenesis is a fundamental step during carcinogenesis, NBI could be useful in the diagnostic and therapeutic workup of tumors. Since its introduction in 2001, NBI use has rapidly spread in different oncologic specialties with clear advantages. There is an active interest in this topic as demonstrated by the thriving literature. It is unavoidable for clinicians to gain in-depth knowledge about the application of NBI to their specific field, losing the overall view on the topic. However, by looking at other fields of application, clinicians could find ideas to improve NBI use in their own specialty. The aim of this review is to summarize the existing literature on NBI use in oncology, with the aim of providing the state of the art: we present an overview on NBI fields of application, results, and possible future improvements in the different specialties.

Role of Tonsillectomy in the Management of Carcinomas of Unknown Primary of the Head and Neck: A Retrospective Study Based on p16 Analysis

Purpose

To evaluate the impact of tonsillectomy on the detection of the primary tumor, based on p16 immunohistochemistry analysis, in patients with cervical unknown primary of squamous cell carcinoma (SCC-CUP).

Methods

This was a retrospective study of 63 patients, included from January 2008 to December 2017 in a single institution. All patients had an initial assessment with physical examination, CT scan of the neck and chest, whole body FDG-PET CT, and endoscopy under general anesthesia, which failed to determine the primary tumor.

Results

Forty-seven out of the 63 patients had an ipsi- or bilateral tonsillectomy which revealed 12 tonsil cancers (26%). The tonsil primary was ipsilateral to positive nodes in 10 cases, contralateral in 1 case and, in 1 case, the patient had bilateral neck involvement. The analysis of the p16 status was carried out in 41/63 patients (65%). Among the 32 patients who had a p16 analysis and tonsillectomy, the rate of primary detection was 59% (10/17) for p16-postives and 0% (0/15) for p16-negatives (p < 0.001).

Conclusion

These results suggest that an extended work-up should be systematically proposed including bilateral tonsillectomy (+/- mucosectomy of the base of tongue) in SCC-CUP p16-positive patients but not in p16-negatives.

The Additional Value of Ultrafast DCE-MRI to DWI-MRI and 18F-FDG-PET to Detect Occult Primary Head and Neck Squamous Cell Carcinoma

Simple Summary

Patients with cervical lymph node metastasis from squamous cell carcinoma undergo extensive irradiation or surgery of the head and neck with higher treatment morbidity, recurrence rate and lower overall survival than patients with overt primary tumor. In order to enhance treatment efficiency and morbidity reduction, the primary tumor detection accuracy was evaluated by using Ultrafast-Dynamic Contrast-Enhancement (DCE-)MRI in addition to Diffusion-Weighted (DW-)MRI and ¹⁸F-FDG-PET/CT imaging. Ultrafast-DCE, with a temporal resolution of 4 s, enabled capturing lesions with increased neoangiogenesis or perfusion compared to normal tissue. The use of Ultra-fast DCE resulted in higher confidence for suspicious locations and high observer agreement. Ultrafast-DCE showed potential to improve detection of unknown primary tumors in addition to DWI and ¹⁸F-FDG-PET/CT in patients with cervical squamous cell carcinoma lymph node metastasis. The combined use of ultrafast-DCE, DWI and ¹⁸F-FDG-PET/CT yielded highest sensitivity.

Abstract

To evaluate diagnostic accuracy of qualitative analysis and interobserver agreement of single ultrafast-DCE, DWI or ¹⁸F-FDG-PET and the combination of modalities for the detection of unknown primary tumor (UPT) in patients presenting with cervical lymph node metastasis from squamous cell carcinoma (SCC). Between 2014–2019, patients with histologically proven cervical lymph node metastasis of UPT SCC were prospectively included and underwent DWI, ultrafast-DCE, and ¹⁸F-FDG-PET/CT. Qualitative assessment was performed by two observers per modality. Interobserver agreement was calculated using the proportion specific agreement. Diagnostic accuracy of combined use of DWI, ultrafast-DCE and ¹⁸F-FDG-PET/CT was assessed. Twenty-nine patients were included (20 males. [68%], median age 60 years). Nine (31%) primary tumors remained occult. Ultrafast-DCE added reader confidence for suspicious locations (one additional true positive (5%), 2 decisive true malignant (10%). The per-location analysis showed highest specific positive agreement for ultrafast-DCE (77.6%). The per-location rating showed highest sensitivity (95%, 95%CI = 75.1–99.9, YI = 0.814) when either one of all modalities was scored positive, and 97.4% (95%CI = 93.5–99.3, YI = 0.774) specificity when co-detected on all. The per-patient analysis showed highest sensitivity (100%) for ¹⁸F-FDG-PET/CT (YI = 0.222) and either DWI or PET (YI = 0.111). Despite highest trends, no significant differences were found. The per-patient analysis showed highest specific positive agreement when co-detected on all modalities (55.6%, 95%CI = 21.2–86.3, YI = 0.456). Ultrafast-DCE showed potential to improve detection of unknown primary tumors in addition to DWI and ¹⁸F-FDG-PET/CT in patients with cervical squamous cell carcinoma lymph node metastasis. The combined use of ultrafast-DCE, DWI and ¹⁸F-FDG-PET/CT yielded highest sensitivity.

Swedish National Multicenter Study on Head and Neck Cancer of Unknown Primary: Prognostic Factors and Impact of Treatment on Survival

Introduction  Head and neck cancer of unknown primary (HNCUP) is a rare condition whose prognostic factors that are significant for survival vary between studies. No randomized treatment study has been performed thus far, and the optimal treatment is not established.

Objective  The present study aimed to explore various prognostic factors and compare the two main treatments for HNCUP: neck dissection and (chemo) radiation vs primary (chemo) radiation.

Methods  A national multicenter study was performed with data from the Swedish Head and Neck Cancer Register (SweHNCR) and from the patients' medical records from 2008 to 2012.

Results  Two-hundred and sixty HNCUP patients were included. The tumors were HPV-positive in 80%. The overall 5-year survival rate of patients treated with curative intent was 71%. Age ( p  < 0.001), performance status ( p = 0.036), and N stage ( p = 0.046) were significant factors for overall survival according to the multivariable analysis. Treatment with neck dissection and (chemo) radiation (122 patients) gave an overall 5-year survival of 73%, and treatment with primary (chemo) radiation (87 patients) gave an overall 5-year survival of 71%, with no significant difference in overall or disease-free survival between the 2 groups.

Conclusions  Age, performance status, and N stage were significant prognostic factors. Treatment with neck dissection and (chemo) radiation and primary (chemo) radiation gave similar survival outcomes. A randomized treatment study that includes quality of life is needed to establish the optimal treatment.

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.

HPV driven squamous cell head and neck cancer of unknown primary is likely to be HPV driven squamous cell oropharyngeal cancer

OBJECTIVES

To compare risk factors and survival in people with oropharyngeal cancer (OPC) and cancer unknown primary (CUP).

MATERIALS AND METHODS

We recruited 5511 people with head and neck cancer between 2011 and 2014. We collected data on age, gender, smoking, sexual behaviour, treatment intent, stage, co-morbidity, p16 protein overexpression and biological samples. We assessed human papillomavirus (HPV) status using serological response and p16 immunohistochemistry. We followed up participants to identify those who had died. We used Cox proportional hazards regression models to estimate survival and adjust for confounders.

RESULTS

Of the 4843 people with squamous cell cancer 196 had CUP - a prevalence of 4.0% (95% CI 3.5% to 4.6%). Of those people with OPC and CUP 69% (1150/1668) and 60% (106/178) respectively had HPV driven tumours. People with HPV driven tumours were likely to be younger, male, non-smokers, with higher stage disease, a history of oral sex and less co-morbidity. People with HPV negative CUP and HPV driven CUP had the survival of people with a stage II/III HPV negative OPC and a stage I/II HPV driven OPC respectively. The adjusted hazard ratio for HPV driven OPC and CUP compared with HPV negative OPC and CUP was 0.46 (95% CI 0.35 to 0.59) and 0.34 (95% CI 0.14 to 0.82) respectively.

CONCLUSION

HPV driven CUP is likely to be HPV driven OPC. Identifying effective methods of detecting occult OPC could improve CUP management and allow the detection of early lesions in high risk groups.

Real-World Outcomes and Prognostic Factors in Patients Receiving Nivolumab Therapy for Recurrent or Metastatic Head and Neck Carcinoma

Recently, a global phase III study demonstrated that nivolumab markedly improved patient outcomes in recurrent or metastatic head and neck carcinoma (RMHNC). However, the efficacy of nivolumab in patients who are ineligible for clinical trials is unknown. We investigated nivolumab efficacy in real-world patients and prognostic factors associated with the response to nivolumab. This study was conducted at 11 institutes associated with Kyoto University and its Affiliated Hospitals-Head and Neck Oncology Group. In total, 93 patients with RMHNC who received nivolumab between May 2017 and May 2018 were retrospectively reviewed. Objective response rate (ORR), overall survival, and progression-free survival (PFS) were evaluated. Univariate and multivariate analyses were performed to identify prognostic factors. The ORRs in patients with squamous cell carcinoma (SCC) and non-SCC were 21.8% and 0%, respectively. In patients with SCC and non-SCC, the 1-year PFS rates were 28.7% and 8.9%, respectively. The hazard ratio (HR) for risk of PFS events (SCC versus non-SCC) was 2.28 (95% confidence interval: 1.21–4.1; log-rank p = 0.007). Univariate and multivariate analyses revealed radiotherapy history, platinum-refractory carcinoma, and treatment-related adverse events (TRAEs) as important prognostic factors associated with PFS in patients with SCC. In a real-world setting, non-SCC and platinum-refractory carcinoma were associated with a poorer prognosis, and a history of radiotherapy to the primary tumor, and the occurrence of TRAEs were associated with a better prognosis. These findings could be useful for clinicians and patients when selecting a treatment strategy.

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.

An evaluation of the diagnostic methods in head and neck cancer of unknown primary site

BACKGROUND

Various detection methods to identify the primary in head and neck cancer of unknown primary (HN-CUP) require evaluation to improve and standardize management.

OBJECTIVES

To evaluate the use of different diagnostic methods, which aim at decreasing the incidence of HN-CUP.

MATERIAL AND METHODS

We conducted a retrospective analysis of patients with HN-CUP at the Helsinki University Hospital during 1995-2011. We evaluated clinical assessment, definitive treatment, histopathology, and follow up. We analyzed the success in identifying the primary site to show any changes in diagnostic methods over time.

RESULTS

Frequency of HN-CUP and success in identifying the primary site have remained constant despite the addition of PET-CT and determination of human papilloma virus (HPV) status in diagnostics. Among 133 patients, the diagnostic work up identified the primary site in 53% and the oropharynx predominated (69%). This left 85 patients with HN-CUP and 5-year overall and disease-free survival rates were 71 and 69%, respectively.

CONCLUSIONS

Panendoscopy including tonsillectomy should not be omitted in the work up.

SIGNIFICANCE

We demonstrate a steady frequency of HN-CUP and constant success in identifying the primary site. Detection of a primary later in the follow up did not impact the survival.