Methods
This retrospective study with a cohort case-series design was conducted at a single center, public Teaching Hospital with the same assistant surgeons and included referred consecutive patients with laCSCC and reCSCC in the head and neck region with or without parotid or neck metastasis from 2009 to 2019. Institutional ethical review board approval was obtained before beginning this project and the patients provided informed consent. The [removed for blind peer review] Ethics Committee approval number to this study was 0905/2015, CAAE: 48857315.6.0000.5505, in March 2016.
This study was conducted in accordance with the Preferred reporting of case series in surgery (PROCESS) criteria following the PROCESS guidelines 23; the Guidelines for Cohort studies in Surgery by Agha et al. 24 and with the Standards for quality improvement reporting excellence guidelines (SQUIRE 2.0)25. The study was in accordance with the declaration of Helsinki and has been registered under the WHO Universal Trial Number (UTN) U1111-1249-0072 and the Brazilian Clinical Trials Registry (ReBeC) number RBR-36vxx7.
Anatomopathological evaluation of tissue samples was according to university standards, all samples of the primary skin tumors and surgical specimens were re-examined by two experienced pathologists and reclassified according to the TNM 8ed. and WHO definition criteria11,20,26,27.
After confirmation of CSCC diagnosis, descriptions of patients and tissue samples were recorded, including sex, age, comorbidities, date of diagnosis, mean duration of symptoms, surgical procedure, surgical complications, parotid status, neck lymph node status, clinical (cTNM) and pathological (pTNM) stages as defined by the TNM 8ed.20, margin status (positive, negative, exiguous: ≤ 5 mm 28), PNI, ALI, radiotherapy, chemotherapy data, recurrence data, date and patient condition at last consultation. The parotid staging adopted by our service, was done according to the P stages by O’Brien et al. 29: P1, metastatic SCC < 3 cm; P2, tumor 3-6 cm or multiple metastatic parotid nodes; P3: tumor > 6 cm, VII nerve palsy or skull base invasion.
The inclusion criteria were as follows: non-melanoma skin cancer in the head and neck region, recurrence status or advanced primary stage, referred to our multidisciplinary team in the head and neck cancer department, CSCC histologic variants, with or without parotid or neck metastasis, subjected to surgical treatment with curative intent for the skin primary tumor and/or the tumors in the parotid and/or in the neck, with a minimum follow-up of six months.
The exclusion criteria were as follows: Merkell cell carcinoma, melanoma, patients lost to follow-up, incomplete clinical data, surgery performed at other institutions on their primary tumor or neck, distant metastasis at first presentation, refusal to participate in the study, refusal to undergo surgical treatment, and surgery not performed due to advanced clinical status.
Statistical analyses were conducted with the odds ratios to calculate the risk of exposed cases; a two-proportion test to compare the proportions of two variables; the chi-squared test and T-student test with a significance of p < 0.05 for comparing frequencies; logistic regression analyses with a significance of p < 0.05; and univariate and multivariate analysis and Kaplan-Meier survival curve analyses.