Parotid Metastases from Head-Neck Cutaneous Squamous Cell Carcinoma: A Prognostic Stratification

Cutaneous squamous cell carcinomas (cSCC) of the head and neck district are among the most common non melanocytic malignant skin carcinomas. The proposal to differentiate, within the N stage, parotid metastases from lateral cervical metastases, originates from the different prognostic value of the metastatic region involved.

We retrospectively evaluated 61 patients, surgically treated for parotid metastases from cSCC between January 2002 and June 2023, in four Departments of Surgery, to assess the geographic distribution of parotid metastases and to describe their recurrence patterns, to evaluate the prognostic value of the number of affected lateral cervical lymph nodes (LN) and the number of positive intra-glandular lymph nodes (IGLN) and to identify the main prognostic histopathological factors.

Our results did not show significant differences between participating centers in the distribution of parotid metastases, nor in their recurrence rates. However, our results highlight how adjuvant radiotherapy is deeply associated with the Overall Survival (OS), improving survival rates in patients with advanced-stage neoplasms (Odds Ratio 5.0), although causality cannot be inferred because of the retrospective study design. Moreover, a statistically significant correlation was found between the major inflammatory biomarkers and the OS. The presence of IGLN was identified as one of the main factors associated with recurrence and poor prognosis in patients with cSCC and in particular, in patients with N3b nodal stage.

our findings suggest that both LN and IGLN could be used to propose an additional staging stratification for the N parameter, thereby guiding the treatment strategy and postoperative follow-up for patients with parotid metastases from cSCC of the head and neck district.