Implications for clinical staging of metastatic cutaneous squamous carcinoma of the head and neck based on a multicenter study of treatment outcomes

Abstract

BACKGROUNDCutaneous squamous cell carcinoma (SCC) of the head and neck is a common cancer that has the potential to metastasize to lymph nodes in the parotid gland and neck. Previous studies have highlighted limitations with the current TNM staging system for metastatic skin carcinoma. The aim of this study was to test a new staging system that may provide better discrimination between patient groups.METHODSA retrospective multicenter study was conducted on 322 patients from three Australian and three North American institutions. All had metastatic cutaneous SCC involving the parotid gland and/or neck and all were treated for cure with a minimum followup time of 2 years. These patients were restaged using a newly proposed system that separated parotid disease (P stage) from neck disease (N stage) and included subgroups of P and N stage. Metastases involved the parotid in 260 patients (149 P1; 78 P2; 33 P3) and 43 of these had clinical neck disease also (22 N1; 21 N2). Neck metastases alone occurred in 62 patients (26 N1; 36 N2). Ninety percent of patients were treated surgically and 267 of 322 received radiotherapy.RESULTSNeck nodes were pathologically involved in 32% of patients with parotid metastases. Disease recurred in 105 (33%) of the 322 patients, involving the parotid in 42, neck in 33, and distant sites in 30. Parotid recurrence did not vary significantly with P stage. Disease‐specific survival was 74% at 5 years. Survival was significantly worse for patients with advanced P stage: 69% survival at 5 years compared with 82% for those with early P stage (P = 0.02) and for those with both parotid and neck node involvement pathologically: 61% survival compared with 79% for those with parotid disease alone (P = 0.027). Both univariate and multivariate analysis confirmed these findings. Clinical neck involvement among patients with parotid metastases did not significantly worsen survival (P = 0.1).CONCLUSIONSThis study, which included a mixed cohort of patients from six different institutions, provides further information about the clinical behavior of metastatic cutaneous SCC of the head and neck. The hypothesis that separation of parotid and neck disease in a new staging system is supported by the results. The benefit of having subgroups of P and N stage is uncertain, but it is likely to identify patients with unfavorable characteristics that may benefit from further research. Cancer 2006. © 2006 American Cancer Society.

N1S3: A revised staging system for head and neck cutaneous squamous cell carcinoma with lymph node metastases

“…Recognition of the prior work by O'Brien 11 is fundamental to understand the evolution of this staging system. His research culminated in a multicenter study published in 2006 6 confirming the hypothesis that extent of disease is prognostic in metastatic HN cutaneous SCC, in a similar fashion to mucosal SCC, and highlighted the limitations of the current American Joint Committee on Cancer system. However, on critical analysis, the P and N staging system did not adequately stratify all subgroups of patients, particularly when applied to pathological data.…”

“…Andruchow et al published in 2006 a clinical staging system where parotid and neck metastases were classified separately. 6 This study was designed to validate O'Brien's hypothesis that parotid (P stage) and neck (N stage) involvement may have independent prognostic significance, and to address the deficiencies in the current TNM system. Although O'Brien's system represented a substantial improvement on the existing TNM system, several problems remained.…”

Significance of clinical stage, extent of surgery and outcome in cutaneous squamous cell carcinoma of the head and neck

“…1,8,13 Bearing that in mind, local and regional disease control is essential in improving survival. O'Brien et al have shown the importance of the parotid gland in the management and prognosis of CSCC, using a modification to current staging systems that includes parotid involvement.…”

“…This data correspond to that previously reported in literature. 1,12,13 When comparing the standard AJC N1 staging and the extended PN classification N group, a lack of prognostic capability of the AJC staging system is evident.…”

“…8,9,10,11,12 The parotid gland is the first site for metastatic spread of head and neck CSCC, and parotid involvement poses a significant diagnostic and therapeutic challenge. 1,13,14 Therefore it is important to examine the relationship between patterns of metastatic spread in the parotid and the neck when planning surgical treatment.…”