Head and neck squamous cell carcinoma of unknown primary: Outcomes of a pre-defined institutional treatment policy in a region with a high prevalence of skin cancer

Metastatic Squamous Cell Carcinoma to the Cervical Lymph Nodes From an Unknown Primary Cancer: Management in the HPV Era

Background

Patients with metastases in the lymph nodes of the neck and no obvious primary tumor, neck cancer with unknown primary (NCUP), represent a management challenge. A majority of patients have metastatic squamous cell carcinoma (SCC), although other histologies do occur.

Methods

We comprehensively reviewed the literature, compared available guidelines, and conferred with an international team of experts.

Results

Positron emission tomography-computed tomography (PET-CT) and fine needle aspiration (FNA) under ultrasound guidance increase accuracy of diagnosis. Immunohistochemistry (IHC), determination of human papilloma virus (HPV) status, by p16 staining or by in situ hybridization (ISH), and next-generation gene sequencing can guide us regarding probable primary sites and tumor biology. Narrow Band Imaging (NBI) has been introduced for the early detection of subtle mucosal lesions. Direct laryngoscopy (DL) and tonsillectomy have long been procedures used in the search for a primary site. More recently, TransOral Robotic Surgery (TORS) or Transoral LASER Microsurgery (TLM) have been introduced for lingual tonsillectomy.

Conclusions

New technologies have been developed which can better detect, diagnose, and treat occult primary tumors. Decisions regarding therapy are based on the primary tumor site (if discovered) and N stage. Options include neck dissection with or without postoperative adjuvant therapy, primary irradiation, or combined chemotherapy with irradiation. The preferred treatment of patients whose primary remains unidentified is controversial.

Role of gene signatures combined with pathology in classification of oropharynx head and neck cancer

Treatment personalisation remains an unmet need in oropharynx cancer (OPC). We aimed to determine whether gene expression signatures improved upon clinico-pathological predictors of outcome in OPC. The clinico-pathological predictors, AJCC version 7 (AJCC 7), AJCC 8, and a clinical algorithm, were assessed in 4 public series of OPC (n = 235). Literature review identified 16 mRNA gene expression signatures of radiosensitivity, HPV status, tumour hypoxia, and microsatellite instability. We quality tested signatures using a novel sigQC methodology, and added signatures to clinico-pathological variables as predictors of survival, in univariate and multivariate analyses. AJCC 7 Stage was not predictive of recurrence-free survival (RFS) or overall survival (OS). AJCC 8 significantly predicted RFS and OS. Gene signature quality was highly variable. Among HPV-positive cases, signatures for radiosensitivity, hypoxia, and microsatellite instability revealed significant underlying inter-tumour biological heterogeneity, but did not show prognostic significance when adjusted for clinical covariates. Surprisingly, among HPV-negative cases, a gene signature for HPV status was predictive of survival, even after adjustment for clinical covariates. Across the whole series, several gene signatures representing HPV and microsatellite instability remained significant in multivariate analysis. However, quality control and independent validation remain to be performed to add prognostic information above recently improved clinico-pathological variables.

Tumor control of cervical lymph node metastases of unknown primary origin: the impact of the radiotherapy target volume

PURPOSE

Debate on the extent of treatment of neck metastasis of cancer of unknown primary tumors (CUPs) is still ongoing. In two Dutch tertiary referral centers, the post-surgical radiation target volume changed from the bilateral neck including the pharyngeal axis to the unilateral neck only, in the course of the last decade. This study aims to investigate the outcome of patients with CUP before and after de-escalation of post-surgical radiotherapy.

METHODS

Data of two Dutch tertiary referral centers were merged. Disease-free survival (DFS), overall survival (OS), and regional control rate (RCR) of 80 patients diagnosed with CUP (squamous cell and undifferentiated carcinomas) between 1990 and 2009 were retrospectively analyzed.

RESULTS

Thirty patients received bilateral neck and pharyngeal axis radiotherapy and 42 patients ipsilateral radiotherapy only. In another eight patients, the postsurgical radiation target volume was expanded to the contralateral neck or to the pharyngeal axis, due to suspicious lesions on imaging. The 5-year DFS, OS and RCR were 60%, 51.2%, and 80%, respectively, in the total patient population. RCR did not differ in patients treated with ipsilateral as compared to bilateral radiotherapy nor did 5-year OS and DFS. No tumors occurred in the pharyngeal axis.

CONCLUSION

In this study, omitting elective treatment of the contralateral neck and pharyngeal axis did not lead to a decrease in locoregional control or survival rates when treating patients with CUP.