Head and neck squamous cell carcinomas of unknown primary: Can ancillary studies help identify more primary tumor sites?

A subset of head and neck squamous cell carcinomas present solely as metastatic disease in the neck and are of unknown primary origin (SCCUP). Most primary tumors will ultimately be identified, usually in the oropharynx. In a minority of cases, the primary site remains elusive. Here, we examine the role of ancillary testing, including mutational signature analysis (MSA), to help identify likely primary sites in such cases. Twenty-two cases of SCCUP in the neck, collected over a 10-year period, were classified by morphology and viral status; including human papillomavirus (HPV) testing by p16 immunohistochemistry (IHC) and RT-qPCR, as well as Epstein-Barr virus (EBV) testing by EBER-ISH. CD5 and c-KIT (CD117) IHC was done to evaluate for possible thymic origin in all virus-negative cases. Whole exome sequencing, followed by MSA, was used to identify UV signature mutations indicative of cutaneous origin. HPV was identified in 12 of 22 tumors (54.5%), favoring an oropharyngeal origin, and closely associated with nonkeratinizing tumor morphology (Fisher's exact test; p = 0.0002). One tumor with indeterminant morphology had discordant HPV and p16 status (p16+/HPV-). All tumors were EBV-negative. Diffuse expression of CD5 and c-KIT was identified in 1 of 10 virus-negative SCCUPs (10%), suggesting a possible ectopic thymic origin rather than a metastasis. A UV mutational signature, indicating cutaneous origin, was identified in 1 of 10 (10%) virus-negative SCCUPs. A cutaneous auricular primary emerged 3 months after treatment in this patient. Primary tumors became clinically apparent in 2 others (1 hypopharynx, 1 hypopharynx/larynx). Thus, after follow-up, 6 tumors remained unclassifiable as to the possible site of origin (27%). Most SCCUPs of the neck in our series were HPV-associated and thus likely of oropharyngeal origin. UV signature mutation analysis and additional IHC for CD5 and c-KIT for possible thymic origin may aid in further classifying virus-negative unknown primaries. Close clinical inspection of hypopharyngeal mucosa may also be helpful, as a subset of primary tumors later emerged at this site.

Performance of oral HPV DNA, oral HPV mRNA and circulating tumor HPV DNA in the detection of HPV-related oropharyngeal cancer and cancer of unknown primary.

A biomarker that is useful for the detection of human papillomavirus (HPV)-related oropharyngeal cancer (OPC) and cancer of unknown primary (CUP) is indispensable. We evaluated the diagnostic performance of HPV DNA and mRNA in oral gargle samples and circulating tumor HPV16 DNA (ctHPV16DNA) in blood samples. Oral HPV DNA and mRNA were analyzed using commercially available HPV assays of the GENOSEARCH HPV31 and Aptima, respectively. ctHPV16DNA was analyzed using in-house droplet digital polymerase chain reaction. Seventy-four patients with OPC and eight patients with CUP were included. The sensitivity and specificity of oral HPV DNA, oral HPV mRNA, and ctHPV16DNA were 82% (95% confidence interval [CI] = 66-92) and 100% (95% CI = 88-100), 85% (95% CI = 69-94) and 94% (95% CI = 73-100), and 93% (95% CI = 81-99) and 97% (95% CI = 84-100), respectively, for HPV16-related OPC, while those were 20% (95% CI = 1-72) and 100% (95% CI = 3-100), 0% (95% CI = 0-52) and 100% (95% CI = 3-100), and 100% (95% CI = 54-100) and 100% (95% CI = 16-100), respectively, for HPV16-related CUP. The sensitivity of ctHPV16DNA for HPV16-related OPC was higher than that of oral biomarkers, though the difference was not statistically significant. ctHPV16DNA remarkably correlated with the anatomic extent of disease, total metabolic tumor volume and HPV16 copy number per tumor genome in patients with HPV16-related OPC/CUP, whereas oral biomarkers did not. In conclusion, ctHPV16DNA is a potentially promising biomarker for HPV16-related OPC, while further studies are required for HPV16-related CUP.

p16 immunohistochemistry for primary tumor detection in HPV-positive squamous cell carcinoma of unknown primary.

PURPOSE: To examine the potential benefit of reevaluation of original slides and p16 immunohistochemistry (IHC) of tonsillectomy specimens for primary tumor identification in cases of human papillomavirus (HPV) positive squamous cell carcinoma (SCC) of the head and neck of unknown primary. MATERIALS AND METHODS: Through a retrospective review, we identified all patients 18 or older who presented at our institution from 2003 to 2015 with histologically confirmed HPV-positive SCC in a cervical lymph node with unidentified primary tumor after initial workup. For patients for whom specimens were available, an expert head and neck pathologist re-reviewed original hematoxylin and eosin (H&E) slides to confirm absence of tumor and performed p16 IHC and deep sectioning of tissue blocks to identify potential tumor foci. RESULTS: Among 735 patient records assessed, 80 were HPV-positive SCC with unknown primary, 28 of which did not have a primary tumor identified, and 20 with original specimens available. Upon re-review of 103 original H&E slides, invasive SCC was identified for 2 patients. Deep sectioning and p16 IHC did not identify additional primary tumors. CONCLUSION: Re-review of original slides by an expert head and neck pathologist, but not p16 staining or deeper H&E sections, was able to identify additional tumors.

Approach to the Patient with Unknown Primary Squamous Cell Carcinoma of the Head and Neck.

OPINION STATEMENT: Head and neck cancer of unknown primary (HNCUP) is increasingly encountered in both community otolaryngology practice and the academic head and neck cancer program. A stepwise diagnostic evaluation will identify many primary sites. However, true HNCUP remains common in high-volume practices after appropriate examination, imaging, and biopsies. The prognosis for the majority of the patients is good, owing to the common association with high-risk HPV, and putative oropharyngeal primary origin. With high oncologic control rates, judicious treatment selection is essential to optimize functional outcomes.

Diagnostic utility of high-risk human papillomavirus mRNA in situ hybridisation in squamous cell carcinoma of unknown primary in the head and neck and implementing American Society of Clinical Oncology guideline recommendations.

INTRODUCTION: The American Society of Clinical Oncology (ASCO)-endorsed College of American Pathologists guideline recommends high-risk human papillomavirus (HPV) testing for metastatic squamous cell carcinoma (SCC) of lymph nodes level II/III of unknown primary. Herein, the performance of HPV-RNA in situ hybridisation (ISH) in detection of HPV-related SCC is evaluated implementing the ASCO guideline recommendations. METHODS: Eighty head and neck (HN) SCC fine needle aspirations, which utilized HPV-RNA ISH/P16, were evaluated at Johns Hopkins Hospital (2015-2018) to investigate their performance and concordance with histology. The results were compared to a prior study of 59 HNSCCs, which HPV-DNA ISH. RESULTS: Of the 80 reviewed fine needle aspirations, 65 (50 male, 15 female) were included. The mean age was 63.2 ± 14.0 years. The most common site was neck lymph nodes (47, 72.3%). Fifty-five cases (84.6%) were accompanied by concurrent core biopsy, and 48 cases (59.4%) had surgical follow-ups. HPV-RNA ISH was positive in 44 (67.7%), and P16 was strongly positive in 46 (70.8%). The HPV-RNA ISH/ P16 concordance rate was 92.3% on cytology material. The cytology/surgical concordance rate for HPV-RNA ISH was 88.9% (16/18). There was a discordance between the results in five cases (7.7%; HPV-RNA ISH-/P16+). CONCLUSION: HPV-RNA ISH is a robust and reliable method for detecting HPV-related HNSCC on cytology material showing concordance rate of 92.3% between HPV-RNA ISH and P16, which is a sensitive but non-specific marker. Compared to HPV-DNA ISH, HPV-RNA ISH reproducibly identifies HPV-related HNSCC with fewer discrepancies between cytology and histology. The findings of this study are in agreement with the ASCO recommendations.

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.

Antibodies against human papillomaviruses as diagnostic and prognostic biomarker in patients with neck squamous cell carcinoma from unknown primary tumor.

Treatment of patients with neck lymph node metastasis of squamous cell carcinoma (SCC) from unknown primary tumor (NSCCUP) is challenging due to the risk of missing occult tumors or inducing toxicity to unaffected sites. Human papillomavirus (HPV) is a promising biomarker given its causal link to oropharyngeal SCC and superior survival of patients with HPV-driven oropharyngeal SCC and NSCCUP. Identification of HPV-driven NSCCUP could focus diagnostic work-up and treatment on the oropharynx. For the first time, we assessed HPV antibodies and their prognostic value in NSCCUP patients. Antibodies against E6 and E7 (HPV16/18/31/33/35), E1 and E2 (HPV16/18) were assessed in 46 NSCCUP patients in sera collected at diagnosis, and in follow-up sera from five patients. In 28 patients, HPV tumor status was determined using molecular markers (HPV DNA, mRNA and cellular p16INK4a ). Thirteen (28%) NSCCUP patients were HPV-seropositive for HPV16, 18, 31, or 33. Of eleven patients with HPV-driven NSCCUP, ten were HPV-seropositive, while all 17 patients with non-HPV-driven NSCCUP were HPV-seronegative, resulting in 91% sensitivity (95% CI: 59-100%) and 100% specificity (95% CI: 80-100%). HPV antibody levels decreased after curative treatment. Recurrence was associated with increasing levels in an individual case. HPV-seropositive patients had a better overall and progression-free survival with hazard ratios of 0.09 (95% CI: 0.01-0.42) and 0.03 (95% CI: 0.002-0.18), respectively. For the first time, seropositivity to HPV proteins is described in NSCCUP patients, and high sensitivity and specificity for HPV-driven NSCCUP are demonstrated. HPV seropositivity appears to be a reliable diagnostic and prognostic biomarker for patients with HPV-driven NSCCUP.

Cytology and direct human papillomavirus testing on fine needle aspirates from cervical lymph node metastases of patients with oropharyngeal squamous cell carcinoma or occult primary.

OBJECTIVE: Cervical lymph node fine needle aspirates (FNAs) may represent the only specimens available for an initial characterisation of patients with lymphadenopathy. Morphology and human papillomavirus (HPV) DNA presence were evaluated in FNAs collected from patients with oropharyngeal squamous cell carcinoma (OPSCC) or cancer of unknown primary (CUP). FNA HPV results were compared with those of the respective formalin-fixed paraffin-embedded (FFPE) primary cancer. METHODS: Liquid-based cytology was performed on FNAs collected in PreservCyt. HPV-DNA was analysed by the INNO-LiPA HPV genotyping Extra II on both cytological and FFPE samples. The CINtec® Histology Kit was used to assess p16 expression in cancer tissues. RESULTS: Forty-seven FNAs were collected from OPSCC and 16 from CUP patients. Cancer cells were found in 35/47 cases (74.5%), while 11 (23.4%) showed only necrosis and one (2.1%) was negative for malignancy. HPV-DNA was detected in 30/47 FNAs (63.8%), mostly harbouring HPV16 (90.0%). An excellent agreement was observed between the FNA and corresponding FFPE HPV status (raw agreement: 97.5%; Cohen κ: 0.94). The HPV test result on the necrotic FNAs completely matched that of the respective primary cancer. FNA HPV testing correctly identified 26/27 HPV-driven OPSCCs (96.3%). HPV was detected in nine of 16 FNAs (56.2%) from CUP patients. CONCLUSIONS: HPV status of metastatic cervical lymph node FNAs reflects that of the corresponding primary OPSCCs even when cell integrity in the FNA is not preserved and only necrotic debris are present. In patients with initial CUP, HPV-positivity on the FNA may guide the diagnostic workup and therapeutic management, since it suggests an oropharyngeal origin.

Cytologic evaluation of cervical lymph node metastases from cancers of unknown primary origin.

Fine-needle aspiration biopsy (FNAB) is often the first diagnostic procedure performed in patients with head and neck (HN) masses. Metastatic squamous cell carcinoma (SCC) to cervical lymph nodes is by far the most common malignancy aspirated in the HN, but in approximately 3-10% of patients, a primary tumor will not be found even after complete clinico-radiological workup. Several HN cancers are associated with oncogenic viruses, including HPV-associated SCC and EBV-associated nasopharyngeal carcinoma (NPC). While the primary tumor is sometimes small or undetectable, patients often present initially with cervical lymph node metastases. HPV-associated SCC and EBV-associated NPC are typically non-keratinizing carcinomas that can mimic several other poorly differentiated HN cancers by FNAB but have a significantly better prognosis. Therefore, the precise classification of the metastatic disease in the FNAB material is very useful since it can facilitate the subsequent location of the primary tumor, and it can provide prognostic and therapeutic information as well. In this review, we discuss the major entities that can present as a metastatic cancer of unknown primary in cervical lymph node other than supraclavicular, including their cytologic features and the role of ancillary studies.

Merkel cell carcinoma of lymph node with unknown primary has a significantly lower association with Merkel cell polyomavirus than its cutaneous counterpart.

Rare cases of Merkel cell carcinoma have been encountered in lymph nodes with unknown extranodal primary, which exhibit similar morphologic and immunophenotypic features to those in primary cutaneous Merkel cell carcinomas. However, it is uncertain whether the nodal Merkel cell carcinoma is a primary tumor of the lymph node or represents a metastasis from an occult or regressed extranodal lesion. To establish an accurate diagnosis of the nodal Merkel cell carcinoma can be challenging because of significant morphologic mimics, including lymphoblastic lymphoma and metastatic small cell carcinoma. Moreover, there is no consensus for a diagnostic term, and many different terms have been used, which can be confusing and may not fully reflect the nature of nodal Merkel cell carcinoma. In this study, we investigated the detailed clinicopathologic features of 22 nodal Merkel cell carcinomas, with comparison to 763 primary cutaneous cases retrieved from the literature. Overall, the nodal and cutaneous Merkel cell carcinomas shared similar clinical presentations, morphologic spectrum, and immunophenotype; both were mostly seen in elderly male with a typical neuroendocrine morphology. Most of cases expressed CK20, synaptophysin, and chromogranin A; and PAX5 and TdT were also positive in majority of cases. However, nodal Merkel cell carcinomas had a significantly lower association with Merkel cell polyomavirus than cutaneous cases (31% vs 76%, P=0.001). Therefore, these two entities may arise from overlapping but not identical biological pathways. We also recommend the use of the diagnostic term 'Merkel cell carcinoma of lymph node' to replace many other names used.

Clinical features of human papilloma virus-related head and neck squamous cell carcinoma of an unknown primary site.

PURPOSE: Head and neck squamous cell carcinoma of an unknown primary site (HNSCCUP) is a heterogeneous group of tumors that includes the human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma. To investigate the relationship between HNSCCUP and HPV, we reviewed p16 overexpression and HPV DNA in lymph node metastases and examined their correlation with the primary site and clinical features. MATERIALS AND METHODS: Thirty-three patients with HNSCCUP were retrospectively studied. Dissected neck metastases were analyzed for p16 overexpression by immunohistochemistry, and the presence of HPV DNA was investigated by in situ hybridization. RESULTS: Of the 33 patients, 8 (24%) exhibited p16 overexpression. p16-positive lymph node metastases contained significantly more HPV DNA and were most frequently associated with occult primary lesions in the oropharynx and a favorable prognosis. Patients with a lower alcohol consumption, only level II/III metastasis, and cystic lymph node metastasis tended to have p16 overexpression. CONCLUSIONS: This is the first report on the relationship of HNSCCUP with p16 and HPV DNA status in Asian patients. In total, 24% of the HNSCCUP patients were p16 positive. p16 overexpression in neck metastasis was predictive of both an occult primary lesion in the oropharynx and an association with HPV infection. Alcohol consumption, location, and features of neck metastasis were correlated with p16 expression.

[HPV-associated oropharyngeal carcinoma. Status quo and relationship with cancer of unknown primary]. / HPV-assoziierte oropharyngeale Karzinome. Aktueller Stand und Verhältnis zum Karzinom unbekannter Herkunft.

Carcinomas of the oropharynx with association to high-risk types of human papillomavirus (HPV) have been identified as a new tumour entity with favourable prognosis, distinct from classical nicotine- and alcohol-associated carcinoma. They develop through oncogenic transformation of the basal cells of reticulated cryptal epithelium of the palatinal tonsils and the base of the tongue. Positivity for HPV strongly correlates with an atypical, non-keratinizing histological differentiation and cystic transformation of lymph node metastases. Strong immunohistological positivity for p16 reliably detects transcriptionally active infection with high-risk HPV. Hence, p16 staining has been regarded as an effectual diagnostic tool in the appropriate setting. Frequent nodal metastasation as well as considerable size of (cystic) metastases, and frequent small size as well as submucosal location of primary tumours all contribute to frequent initial manifestation of cervical cancer of unknown primary (CUP). In a situation of CUP diagnostic testing for HPV (in negative cases in addition to EBV) is recommended in lymph node metastases, due to the high predictive value for the localization of occult primary carcinomas. Intense clinicopathological cooperation is mandatory for improved detection of small, occult primary carcinomas. The relevance of this new carcinoma entity will increase, as the incidence continues to increase worldwide.

Detection of HPV16/18 E6 Oncoproteins in Head and Neck Squamous Cell Carcinoma Using a Protein Immunochromatographic Assay.

OBJECTIVES/HYPOTHESIS: The accurate diagnostic assessment of clinically relevant human papillomavirus (HPV) infections in patients with head and neck squamous cell carcinoma represents an urgent unmet medical need. The aim of this study was to determine feasibility, accuracy, and clinical significance of HPV16/18 E6 oncoprotein detection on cytological specimens from oropharyngeal squamous cell carcinoma (OPSCC) and neck lymph node metastasis of SCC from unknown primary tumor (CUP) via a protein immunochromatographic assay. STUDY DESIGN: Cross-sectional study. METHODS: Cytological specimens from primary tumor and neck metastases were collected from 34 patients with OPSCC or CUP and applied to a lateral flow format test that detects HPV16 and HPV18 E6 oncoproteins. E6 oncoprotein positivity or negativity in these specimens was compared to the specimens' "HPV-driven" reference status, defined by presence of HPV-DNA in combination with p16INK4a overexpression and/or HPV E6 seropositivity. RESULTS: Eighteen of 29 OPSCC (62%) and three of five CUP (60%) were HPV-driven according to our reference method. The E6 oncoprotein lateral flow test had a sensitivity of 94% (95% CI: 70%-100%) and a specificity of 100% (95% CI: 66%-100%) on primary tumor, and a sensitivity of 88% (95% CI: 64%-99%) and a specificity of 100% (95% CI: 74%-100%) on neck metastases. Test agreement between the E6 lateral flow test and the clinical reference method, HPV-DNA plus p16INK4a was excellent, both for primary lesion and neck metastases. CONCLUSIONS: We found the detection of HPV16/18 E6 oncoproteins to be a feasible, highly reliable, and low-invasive method to assess "HPV-driven" status in OPSCC and CUP. LEVEL OF EVIDENCE: II Laryngoscope, 131:1042-1048, 2021.

Human papillomavirus detection and genotyping on pelvic nodes in patients with synchronous gynecological malignancies: a tool for identifying the primary site of lymphatic spread?

INTRODUCTION: Synchronous gynecological tumors are uncommon. Identifying the primary site of lymphatic spread may be difficult. METHODS: Two women with synchronous squamous cervical and adenosquamous endometrial cancers (patient A) and squamous cervical and serous borderline ovarian tumors (patient B) entered retrospectively this study. Both patients had pelvic nodal metastases of unknown origin. Uterine cervix, endometrium, and lymph nodes were tested for human papillomavirus DNA using high-sensitive polymerase chain reaction, followed by oligonucleotide microarray for genotyping. RESULTS: Human papillomavirus 16 DNA was extracted from portio vaginalis and pelvic nodes of both women. Viral homology between cervical and lymph nodal lesions helped to identify the primary metastasizing tumors in both patients. CONCLUSIONS: Human papillomavirus testing on pelvic lymphatic tissue represents a feasible tool to detect the primary site of lymphatic spread in synchronous gynecological malignancies, when uterine cervix is involved.

Predictors of survival and recurrence after primary surgery for cervical metastasis of unknown primary.

PURPOSE: Cervical metastasis from unknown primary (CUP) is commonly classified as an advanced overall stage. P16 or human papillomavirus (HPV) positivity in metastatic lymph nodes (LN) might be associated with a favorable survival outcome of CUP. Therefore, we evaluated the prognostic values of p16 immuno-positivity in LN and other clinicopathological factors in patients with squamous cell carcinoma CUP (SCCUP). METHODS: This study involved 83 patients who underwent therapeutic neck dissection and panendoscopic examination and biopsy for suspected CUP. P16 immunostaining and HPV typing in LN were performed in 56 patients. Cox proportional hazard regression analyses were used to identify factors associated with overall survival (OS) and disease-free survival (DFS). RESULTS: Postoperatively, primary tumors (PT) were found in 32 (38.6%) patients, mainly (90.6%) in the oropharynx, and not found in 51 (61.4%) patients. The clinicopathological data (except for histological grade) and 5-year OS and DFS rates did not significantly differ between patients with and without PT identification (all P > 0.05). P16 positivity was associated with favorable OS and DFS outcomes in the patients with PT (P < 0.05) but not in those without PT (P > 0.1). Multivariate analyses showed that age (> 60 years) and LN ratio (≥ 0.1) were the independent predictors of OS and DFS outcomes (all P < 0.05). P16 positivity or other factors were not independent factors. CONCLUSION: Age and LN ratio are significant risk factors of survival and recurrence after primary surgery for SCCUP. Prognostic significance of LN p16 positivity should be further studied.

Human papillomavirus in metastatic squamous carcinoma from unknown primaries in the head and neck: a retrospective 7 year study.

GOAL: Human Papillomavirus (HPV) is found to be increasingly implicated in head and neck cancers. The objective of this study was to determine the primary site of origin of HPV positive squamous carcinomas metastatic to lymph nodes of the neck. METHODS: Surgical pathology records from January 1, 2000 to July 31, 2007 were used to identify surgically removed neck lymph nodes with the diagnosis of metastatic squamous carcinoma. Specimens in formalin-fixed, paraffin-embedded blocks were examined for HPV (+) by analyzing sequencing data generated by PCR and immunostaining for the expression of the p16INK biomarker, which is overexpressed if Rb is not present. H & E stained slides were also reviewed for histological classification. The available retrospective demographics were extracted from the charts to determine trends of confounding factors. RESULTS: Of the 43 patient samples, 41 contained adequate DNA to test for HPV. The mean age of the 41 patients was 62 years. All of the patients smoked and 39/41 patients consumed alcohol. The overall HPV (+) incident rate was 27% (11/41) by PCR with strongly diffuse or strong focal p16 staining. 9 of the 34 males and 2 of the 7 females had HPV (+) carcinomas. The average age of the 2 HPV (+) females was 44, compared to the HPV (-) females who averaged 70. The average age of the HPV (+) males was 56 compared with the average age 55 of the HPV (-) males. HPV (+) carcinomas appeared to arise from multiple sites in the oropharynx, particularly the tonsils and tongues, including unknown primaries. By histological exam, most metastatic HPV(+) squamous carcinomas were poorly differentiated (basaloid) microscopically and grossly cystic. CONCLUSION: The 27% HPV (+) squamous cancers metastatic to neck lymph node originated from multiple sites in the oropharynx. The HPV (+) female population, although a total of only 2, tended to be much younger than the HPV (-) ones, whereas the HPV (+) male population was similar in age to the HPV (-) male population.

Patterns of EBV-positive cervical lymph node involvement in head and neck cancer and implications for the management of nasopharyngeal carcinoma T0 classification.

OBJECTIVES: Epstein-Barr virus (EBV)-positive cervical lymph node (CLN) metastasis of unknown primary origin is classified as nasopharyngeal carcinoma (NPC) T0 by the American Joint Committee on Cancer staging manual (8th edition). We aimed to investigate the possible primary sites and patterns of EBV-positive CLN metastases and to provide implications for the management of NPC T0 classification. MATERIALS AND METHODS: We retrospectively reviewed 269 patients with newly diagnosed EBV-positive CLN metastatic disease who underwent EBV detection via EBV-encoded RNA in situ hybridization. Fifteen patients with unknown primary tumors underwent follow-up after initial treatment. RESULTS: In patients with EBV-positive CLNs, the most common primary sites after the nasopharynx (51.7%) were the salivary gland (24.5%), lung (7.8%), oropharynx (3.3%), nasal cavity/maxillary (3.3%), oral cavity (2.2%), orbit (1.1%), and liver (0.4%). No primary site was found in 15 patients (5.6%). For salivary gland malignancies, level II and I were the most frequently involved regions. Tumors arising from the lung or liver metastasized to the lower neck (level IV, V, and VI) rather than the upper neck. After initial treatment, 2/15 patients with EBV-positive CLNs of unknown primary exhibited primary NPC and oropharyngeal tumor, respectively. Further, even without prophylactic irradiation to the nasopharynx, only one of 13 unknown primary patients developed NPC. CONCLUSIONS: The origins of EBV-positive CLNs may not be restricted to the nasopharynx alone, and are likely to involve the head and neck or non-head and neck regions. NPC T0 classification should be cautiously assigned to such tumors.

HPV status in unknown primary head and neck cancer: Prognosis and treatment outcomes.

OBJECTIVES: Approximately 3% to 9% of head and neck cancer presents with a metastatic node and no identifiable primary tumor. These cases of head and neck carcinoma of unknown primary (HNCUP) present a therapeutic challenge. Therapy of this disease varies based on factors such as institutional, surgeon, and patient preference. Evidence demonstrating the outcomes associated with these therapies for HNCUP is limited, and among the available series, the tumor human papillomavirus (HPV) status is often ignored. Treatment deintensification has been proposed for a subset of these patients. We aim to evaluate the treatment-related outcomes for HPV-associated and HPV-negative HNCUP. METHODS: A retrospective study of 978 adult HNCUP diagnosed from 2010 to 2013 in the NCDB was conducted. Multivariate Cox survival regressions as well as univariate Kaplan-Meier analyses were conducted. RESULTS: Patients with HPV-associated disease had superior survival, with a 3-year survival of 94.8% (standard error [SE]: 1.0), compared with 80.3% (SE: 2.9) among those with HPV-negative disease. Among HPV-negative patients with clinical nodal classification (cN)2/cN3 disease, treatment with definitive radiotherapy alone compared to definitive chemoradiotherapy was associated with diminished survival (hazard ratio 5.507, P = 0.005). Among patients with HPV-associated cancer and cN2/cN3 disease, all treatments (surgery alone, surgery with adjuvant radiotherapy, surgery with adjuvant chemoradiotherapy, definitive chemoradiotherapy, definitive radiotherapy) resulted in statistically equivalent survival. CONCLUSION: Tumor HPV status has a significant prognostic value for HNCUP and should be considered in future studies of treatment deintensification in this group. Treatment deintensification to radiotherapy alone in cN2/cN3 cases may result in poorer patient survival for HPV-negative patients, whereas it may be a promising option for further investigation in HPV-positive patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:684-691, 2019.

Absence of disruptive TP53 mutations in high-risk human papillomavirus-driven neck squamous cell carcinoma of unknown primary.

BACKGROUND: To enforce the evidence for causality between high-risk human papillomavirus (hrHPV) infections and neck squamous cell carcinoma from unknown primary (NSCCUP) and provide biological basis for treatment de-intensification, we searched for TP53 mutations in association with HPV status. METHODS: TP53 mutations were searched for by amplification of exons 4 to 10. RESULTS: Of the 70 NSCCUP, 27 (39%) harbored HPV infection. TP53 sequencing resulted in the identification of 19 patients harboring single mutations including 16 disruptive alterations (84%). The association of TP53 mutations and HPV could be evaluated in 48 NSCCUP including those with disruptive mutation in any exon (n = 16) and those without mutations but with complete sequence of exons 4 to 9 (n = 32): no disruptive mutations were found in the 17 HPV-driven NSCCUP but in 16 of the 31 non-HPV-driven NSCCUP (P = .0002). CONCLUSION: In a fraction of cases, NSCCUP is an HPV-driven entity harboring wild-type TP53 gene or nondisruptive TP53 mutations. HPV-driven NSCCUP might benefit from treatment de-intensification.