Materials and methods
This is a cross-sectional retrospective study on surgical laryngectomy specimens of patients diagnosed with laryngeal SCC who underwent surgery between 2016 and 2021 in Amir Alam Hospital. We gathered patients’ ages, genders, tumor sites, and tumor stages from medical records and obtained their follow-up status through phone calls. Patients who had received neoadjuvant therapy or had incomplete medical records, as well as those with SCC variants such as basaloid SCC and verrucous SCC, were excluded.
The pathology department provided the hematoxylin & eosin-stained slides of the resected tissue samples. Two pathologists then reviewed all slides to confirm the diagnosis, assess WHO histologic grade, evaluate the presence or absence of TB and CNS, and document other histologic findings such as lymphovascular invasion, perineural invasion, and nodal involvement. Tumor budding, referring to the branching of tumor clusters, is characterized histologically by less than five tumor cells within the stroma/parenchyma. Based on the study of Boxberg et al., TB was assessed in 10 continuous HPFs in areas showing maximum budding and was categorized into low TB and high TB groups, defined as 1-14 budding nests and ≥15 budding nests, respectively. CNS was also characterized as clustered tumor cells surrounded by tumor stroma and categorized into four groups as follows: >15 tumor cells=large nests, 5 to 15 tumor cells= intermediate nests, 2 to 4 tumor cells= small nests, and discohesive tumor cells without nested architecture= single-cell invasion (12).
Statistical analysis was performed by IBM SPSS Statistics 21. Descriptive statistical methods (frequency and percentage distributions) were used to evaluate the quantitative data, and the Chi-square test was used to compare the qualitative data. Multivariate survival analysis was performed using the Cox regression method. Survival analyses were performed using the Kaplan-Meier method. The results were evaluated with a significance level of P  < 0.05 and a 95% confidence interval.