Cervical soft tissue metastases in head and neck cancer

Evolution of Head and Neck Cutaneous Squamous Cell Carcinoma Nodal Staging—An Australian Perspective

Simple Summary

Australia has the highest incidence of cutaneous squamous cell carcinoma of the head and neck (HNcSCC) in the world. Although the majority of HNcSCCs are cured by simple surgical excision, those that spread to lymph nodes require aggressive and debilitating surgery in conjunction with radiation therapy, with a significant risk of treatment failure and subsequent loss of life. Cancer staging is critical to guide prognosis, treatment (to maximise disease control and minimise morbidity), and for research. Australian institutions have been at the forefront of prognostication for HNcSCC with lymph node spread. Despite this, the search for a well performing staging system is ongoing. This review chronologically explores and summarises the Australian contribution to date and highlights the ongoing challenges.

Abstract

Cutaneous squamous cell carcinoma of the head and neck (HNcSCC) is one of the commonest malignancies. When patients present with regional metastatic disease, treatment escalation results in considerable morbidity and survival is markedly reduced. Owing to the high incidence, Australian institutions have been at the forefront of advocating for reliable, accurate, and clinically useful staging systems that recognise the distinct biological characteristics of HNcSCC. As a result, an extensive body of literature has been produced over the past two decades, which has defined critical prognostic factors, critiqued existing staging systems, and proposed alternative staging models. Notwithstanding, a suitable staging system has proved elusive. The goal of cancer staging is to group patients according to cancer characteristics for which survival differs between groups (distinctiveness), consistently decreases with increasing stage (monotonicity), and is similar within a group (homogeneity). Despite implementing major changes based on published data, the latest edition of the American Joint Committee on Cancer (AJCC) staging manual fails to satisfy these fundamental requirements. This review chronologically explores and summarises the Australian contribution to prognostication and nodal staging of HNcSCC and highlights the ongoing challenges.

Soft Tissue Metastases in Head and Neck Cutaneous Squamous Cell Carcinoma

OBJECTIVE

Soft tissue metastases (STM) in head and neck cutaneous squamous cell carcinoma (HNcSCC) are non-nodal based metastases to the parotid and cervical soft tissues of the head and neck. This is a unique subgroup of regional metastases amongst patients with cSCC and have been shown to be associated with poor prognosis. Detailed studies of this subgroup are lacking in the literature. A retrospective cohort analysis was performed to characterize the prognostic significance of STM in HNcSCC based on individual clinicopathological features.

METHODS

Patients with HNcSCC with STM were identified from the Sydney Head and Neck Cancer Institute database. Clinicopathological characteristics were extracted from the histopathological reports. Recurrence and follow-up data were analyzed to determine disease-free and overall survival using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

After excluding all patients with lymph node metastasis with no STM, there were 200 patients identified (161 parotid, 32 cervical, and seven with concurrent parotid and cervical STM) with a 5-year overall survival of 36%. In univariable analysis, age of patients, size of the deposits, location of the deposits, and patients that were not offered adjuvant radiotherapy have worse overall survival. However, on multivariable analysis, age and the number of STM deposits were independent factors that predict for worse survival.

CONCLUSION

The presence of STM in patients with HNcSCC is associated with poor prognosis. Increasing number of STM deposits, as well as involved margin of the regional excision, negatively impacted on the overall prognosis.

LEVEL OF EVIDENCE

Level III - retrospective cohort study. Laryngoscope, 131:E1209-E1213, 2021.

Regional Metastasis in Head and Neck Cutaneous Squamous Cell Carcinoma: An Update on the Significance of Extra-Nodal Extension and Soft Tissue Metastasis

BACKGROUND

Soft tissue metastases (STMs) are reported to predict worse prognosis than extra-nodal extension (ENE) in metastatic head and neck cutaneous squamous cell carcinoma. This study aimed to update the authors' previous analysis of STM in a larger series.

METHODS

The study analyzed 535 cases of consecutive cSCC metastatic to the parotid and/or neck treated by primary surgical resection between 1987 and 2007. A Cox proportional hazard model was used to determine the effect of STM, with adjustment for other relevant prognostic factors. Overall survival (OS) and disease-specific survival (DSS) were the primary end points.

RESULTS

Of the 535 patients, 275 (51.4%) had STM. After adjustment for the effects of age, tumor location, number of metastatic deposits, and adjuvant radiotherapy, both STM (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.08-2.22; p = 0.018) and ENE (HR, 1.56; 95% CI 1.10-2.22; p = 0.013) were shown to be independent predictors of reduced OS, with similar size of effect.

CONCLUSION

In metastatic cSCC of the head and neck, STM is an independent predictor of reduced survival and has an impact on survival similar to that of ENE.

Cutaneous head and neck squamous cell carcinoma with regional metastases: the prognostic importance of soft tissue metastases and extranodal spread

Background

Extranodal spread (ENS) is an established adverse prognostic factor in metastatic cutaneous squamous cell carcinoma (cSCC); however, the clinical significance of soft tissue metastases (STM) is unknown. The aim of this study was to evaluate the prognosis of patients with STM from head and neck cSCC, and to compare this with that of node metastases with and without ENS.

Methods

Patients with cSCC metastatic to the parotid and/or neck treated by primary surgical resection between 1987 and 2007 were included. Metastatic nodes >3 cm in size were an exclusion criterion. A Cox proportional hazard model was used to determine the effect of STM adjusting for other relevant prognostic factors.

Results

The population included 164 patients with a median follow-up of 26 months. There were 8 distant and 37 regional recurrences. There were 22 were cancer-specific deaths, and 29 patients died. STM was a significant predictor of reduced overall (hazard ratio 3.3; 95% confidence interval 1.6–6.4; P = 0.001) and disease-free survival (hazard ratio 2.4; 95% confidence interval 1.4–4.1; P = 0.001) when compared to patients with node disease with or without ENS. After adjusting for covariates, STM and number of involved nodes were significant independent predictors of overall and disease-free survival.

Conclusions

In metastatic cSCC of the head and neck, the presence of STM is an independent predictor of reduced survival and is associated with a greater adverse effect than ENS alone.

Radioguided surgical strategy in mucosal melanoma of the nasal cavity

Sinonasal mucosal melanoma (MM), although very rare (<1% of the all MM), is second only to squamous cell carcinoma among cancers of the nasal region and still represents a challenging problem in head and neck cancer. A 60-year-old woman had nasal MM stage I, which was treated with concomitant probe-guided tumor excision and an elective neck dissection after sentinel lymph node biopsy. The radioactivity status of the tumor and lymph nodes were compared with the histopathologic specimen. Surgical margins, sentinel lymph node, and lymphadenectomy were free of tumor. The patient was seen in frequent and regular follow-up and was free of disease without any other treatment (radiotherapy, immunotherapy, or chemotherapy). Radioguided surgery is an easy and reproducible surgical technique that could increase the likelihood of adequate excision and minimize the development of nodal disease by performing a "guided" neck dissection after the sentinel lymph node biopsy. A multidisciplinary approach and further studies with a longer follow-up are needed to substantiate the accuracy and safety of this strategy in the treatment of an aggressive neoplasm like MM of the head and neck, which still has a very poor prognosis.

Neck dissection: then and now

The significance of metastatic disease in the lymph nodes of the neck as a critical independent prognostic factor in head and neck cancer has long been appreciated. Although 19th century surgeons attempted to remove involved cervical lymph nodes at the time of resection of the primary cancer, a systematic approach to en bloc removal of cervical lymph node disease, described in detail by Jawdyński in 1888 and popularized and illustrated by Crile in the early 20th century, provided consistent and more effective treatment, and forms the basis of our current techniques. During the first half of the 20th century, developments included preservation of the accessory nerve in selected cases, elective neck dissection performed in association with resection of various primary tumors, bilateral neck dissection and limited neck dissection. The greatest impetus to the status of radical neck dissection came from Martin, whose technique consisted of resection of all lymph nodes from level I-V together with the accessory nerve, internal jugular vein, sternocleidomastoid muscle and various other structures in a single block of resected tissue. Martin's technical precepts were followed until the latter part of the 20th century when modifications in technique began to find general acceptance. The first description of an effective technique of modified radical neck dissection was published in Spanish by Suárez, in 1963. This technique, which preserves important structures, such as the internal jugular vein, sternocleidomastoid muscle and accessory nerve, was refined and popularized by various authors who published their results in the English language literature during the period from 1964 through 1990 and beyond. Modified or "functional" neck dissection avoids much of the morbidity of radical neck dissection while achieving equivalent degrees of control of regional disease in properly selected cases. By the late 20th century, the concept of selective neck dissection, consisting of resection of only the nodal groups at greatest risk for metastasis from a given primary site, was studied and developed. These limited dissections are now widely employed for elective, and in properly selected cases, therapeutic treatment and staging of the neck, and have been proposed for limited cervical recurrences after various chemoradiation protocols. Prospective studies have demonstrated similar rates of neck recurrence and survival after elective selective neck dissection compared to elective modified radical neck dissection. Other modifications and factors applied to treatment of cervical lymph node disease include the use of adjuvant and neo-adjuvant radiation and chemotherapy, a revised system for classification of neck dissections, the identification of various adverse prognostic factors such as extracapsular spread and extranodal soft tissue deposits, application of sentinel lymph node biopsy to staging of the neck, the use of immunohistochemical and molecular techniques for identification of lymph node metastases not detectable by light microscopy, and the possibility of endoscopic neck dissection. The authors conclude that neck dissection, as evolved over the past century, is a fundamental tool in management of patients with head and neck cancer, but is still a work in progress.

Elective and therapeutic selective neck dissection

Selective neck dissection is a modification of the more comprehensive modified radical or radical neck dissection that is designed to remove only those nodal levels considered to be at risk for harboring nodal metastases. The role of selective neck dissection continues to evolve: while initially designed as a staging and diagnostic procedure for patients without clinical evidence of nodal disease, a growing body of literature suggests that selective neck dissection has a therapeutic role in patients with clinical and histologic evidence of nodal metastases. The rationale behind selective neck dissection, its application in the clinically negative but histologically node-positive neck and the extended application of selective neck dissection in patients with clinical evidence of nodal disease are discussed.

Immunohistochemical Studies in the Identification of Lymph Node Micrometastases in Patients with Squamous Cell Carcinoma of the Head and Neck

In the prediction of likely disease-free and overall survival intervals in patients with squamous carcinomas of the head and neck, cervical lymph node status assumes a prime role, and patients with cervical node metastases have diminished survivals, as a group, compared with patients whose cervical nodes are reported as negative for metastatic carcinoma. Conventional means of pathologic examination of cervical node biopsy specimens include examination of a single section through each individual node identified on gross examination, a process which, of necessity, leaves a significant portion of the node unexamined by microscopy. Recently, it has become apparent that more exhaustive pathologic sampling techniques, such as examining multiple sections of each lymph node, or staining each lymph node with antibodies to keratin via immunohistochemistry, will reliably yield a greater incidence of positive cervical lymph nodes ("micrometastases") than do conventional pathologic techniques. This suggests that the next line of inquiry should answer this question: just because micrometastases can be detected, should they be? Does the identification of (otherwise likely to be overlooked) tiny microscopic foci of spread of tumor in regional nodes by more sophisticated techniques yield additional data of real import to the patients, or is such information of lesser value? Should a role be defined in the care of head and neck cancer patients for the use of such advanced inquiries in the structuring of therapies, then the best approach to finding such elusive micrometastases (intraoperative immunohistochemistry? immunohistochemistry using routinely fixed tissues? polymerase chain reaction?) may subsequently be established.