Tumour budding as a risk factor for lymph node metastases in cutaneous squamous cell carcinoma: a systematic review and meta-analysis.

Background: Current staging systems have limitations in stratifying high-risk cutaneous squamous cell carcinoma (cSCC). Tumour budding (TB) has emerged as a potential prognostic factor in various cancers.

Objectives: To evaluate the prognostic significance of TB in predicting lymph node metastases (NM) in cSCC.

Methods: A comprehensive search of the PubMed, Web of Science, Embase and Cochrane databases was conducted. Studies investigating the association of TB using a 5-bud cutoff and NM in cSCC were included. A meta-analysis was performed using odds ratios (OR) to evaluate the association between TB and NM.

Results: Six retrospective studies comprising 793 patients with cSCC were included. The random-effects analysis showed a significant association between high TB (≥ 5 buds) and NM (OR = 13.29, 95% confidence interval 5.55-31.86).

Discussion: TB is a promising histopathological feature for predicting NM in cSCC. The results show a strong association between high TB and NM, supporting its utility as a risk factor for NM in cSCC. Its inclusion in clinical practice and cSCC staging might be helpful in the stratification of patients with high-risk cases and to guide optimal management strategies for each patient. However, further investigation is needed to determine standardized reporting guidelines for TB in cSCC.