Adequate resection margins are critical to the treatment decisions and prognosis of patients with head and neck squamous cell carcinoma (HNSCC). However, there are numerous controversies regarding reporting and interpretation of the status of resection margins. Fundamental issues relating to the basic definition of margin adequacy, uniform reporting standards for margins, optimal method of specimen dissection, and the role of intraoperative frozen section evaluation, all require further clarification and standardization. Future horizons for margin surveillance offer the possible use of novel methods such as "molecular margins" and contact microscopic endoscopy, However, the limitations of these approaches need to be understood. The goal of this review was to evaluate these issues to define a more rational, standardized approach for achieving resection margin adequacy for patients with HNSCC undergoing curative resection.
The incidence of distant metastases in head and neck squamous cell carcinoma (SCC) is relatively small in comparison to other malignancies. Distant metastases adversely impact survival and may significantly affect treatment planning. The incidence of distant metastases is influenced by location of the primary tumor, initial T and N stage of the neoplasm, and the presence or absence of regional control above the clavicle. Patients with advanced nodal disease have a high incidence of distant metastases, particularly in the presence of jugular vein invasion or extensive soft tissue disease in the neck. Primary tumors of advanced T stages in the hypopharynx, oropharynx and oral cavity are associated with the highest incidence of distant metastases. Pulmonary metastases are the most frequent in SCC, accounting for 66% of distant metastases. It may be difficult to distinguish pulmonary metastasis from a new primary tumor, particularly if solitary. Other metastatic sites include bone (22%), liver (10%), skin, mediastinum and bone marrow. An important question remains as to how intensely pre- and postoperative screening for distant metastases should be performed. Preoperative chest X-ray is warranted in all cases. If the primary tumor and nodal status place the patient at high risk for pulmonary metastasis, then preoperative computed tomography scan of the chest should be done. Screening for distant metastases at other sites is usually not indicated in SCC of the upper aerodigestive tract. Postoperatively, annual X-rays of the chest are usually sufficient, but in high-risk situations a chest X-ray performed every 3–6 months may be beneficial. Certain histologic types of primary tumor have greater or lesser propensity to metastasize distantly, and have a different natural history. Adenoid cystic carcinoma metastasizes frequently, even in the absence of extensive local or regional disease. Basaloid squamous cell carcinoma and neuroendocrine carcinomas also metastasize widely. Extensive evaluation for distant metastases is justified for these tumors. Knowledge of the natural history of various neoplasms and the factors that contribute to distant metastases as well as good judgement are essential for cost-effective treatment planning and decision-making with regard to pre- and postoperative evaluation for distant metastases in cancer of the head and neck.
There is evidence that EBRT and SRS offer a similar chance of tumor control with lower risks of morbidity compared with surgery in patients with JPGs. Although the evidence is based on retrospective studies, these results suggest that surgery should be considered only for selected cases, but the decision should be individual for every patient.
Neuroendocrine neoplasms of the larynx are rare but are the most common nonsquamous tumors of this organ. In the past, there has been considerable confusion about the nature and classification of these neoplasms, but the current consensus is that there are 4 different types of laryngeal neuroendocrine tumors composed of paraganglioma, typical carcinoid, atypical carcinoid tumor, and small cell neuroendocrine carcinoma. Carcinoids and small cell neuroendocrine carcinomas are epithelial neoplasms, whereas paragangliomas are of neural origin. Diagnosis is based primarily on light microscopy and confirmed by immunohistochemistry and electron microscopy. Precise diagnosis is essential because the natural history, treatment, and prognosis vary widely for the different neoplastic categories. Typical carcinoids are very rare and are treated by wide local excision, usually partial laryngectomy, without elective neck dissection. Atypical carcinoid tumors are more common and more aggressive. They are treated by partial or total laryngectomy with elective or therapeutic neck dissection. Adjuvant chemo/radiotherapy may be of benefit in some cases. Small cell neuroendocrine carcinomas are highly aggressive and should be considered disseminated at initial diagnosis. The treatment is by irradiation and chemotherapy as surgery has proven to be of a little benefit. Paragangliomas are treated by local excision or partial laryngectomy. It is difficult to determine the valid survival statistics for typical carcinoids because of their rarity and confusion in the literature with their atypical counterparts. They have a greater tendency to metastasize, and thus a worse prognosis than was previously believed. Atypical carcinoid tumors have a 5-year survival rate of approximately 50%, which decreases with time. The prognosis of small cell neuroendocrine carcinoma of the larynx is dismal, with 5-year survival rates of 5%. The biological behavior of laryngeal paraganglioma is generally benign and the prognosis is excellent.
Squamous cell carcinoma of the hypopharynx represents a distinct clinical entity. Most patients present with significant comorbidities and advanced-stage disease. The overall survival is relatively poor because of high rates of regional and distant metastasis at presentation or early in the course of the disease. A multidisciplinary approach is crucial in the overall management of these patients to achieve the best results and maintain or improve functional results. Traditionally, operable hypopharyngeal cancer has been treated by total (occasionally partial) laryngectomy and partial or circumferential pharyngectomy, followed by reconstruction and postoperative radiotherapy in most cases. Efforts to preserve speech and swallowing function in the surgical treatment of hypopharyngeal (and laryngeal) cancer have resulted in a declining use of total laryngopharyngectomy and improved reconstructive efforts, including microvascular free tissue transfer. There are many surgical, as well as nonsurgical, options available for organ and function preservation, which report equally effective tumor control and survival. The selection of appropriate treatment is of crucial importance in the achievement of optimal results for these patients. In this article, several aspects of surgical and nonsurgical approaches in the treatment of hypopharyngeal cancer are discussed. Future studies must be carefully designed within clearly defined populations and use uniform terminology and standardized functional assessment and declare appropriate patient or disease endpoints. These studies should focus on improvement of results, without increasing patient morbidity. In this respect, technical improvements in radiotherapy such as intensity-modulated radiotherapy, advances in supportive care, and incorporation of newer systemic agents such as targeted therapy, are relevant developments.
In an era of advanced diagnostics, metastasis to cervical lymph nodes from an occult primary tumor is a rare clinical entity and accounts for approximately 3% of head and neck malignancies. Histologically, two thirds of cases are squamous cell carcinomas (SCCs), with other tissue types less common in the neck. With modern imaging and tissue examinations, a primary tumor initially undetected on physical examination is revealed in >50% of patients and the site of the index primary can be predicted with a high level of probability. In the present review, the range and limitations of diagnostic procedures are summarized and the optimal diagnostic workup is proposed. Initial preferred diagnostic procedures are a fine-needle aspiration biopsy (FNAB) and imaging. This allows directed surgical biopsy (such as tonsillectomy), based on the preliminary findings, and prevents misinterpretation of postsurgical images. When no primary lesion is suggested after imaging and panendoscopy, and for patients without a history of smoking and alcohol abuse, molecular profiling of an FNAB sample for human papillomavirus (HPV) and/or Epstein-Barr virus (EBV) is important.
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