Mucosal Margin Shrinkage in Oral Cavity Cancer: A Systematic Review

OBJECTIVE: Tissue shrinkage can make planning of surgical margins challenging. While shrinkage of resected oral cavity mucosa is well-described, current data quantifying these effects are variable. The aim of this systematic review was to summarize current evidence on margin shrinkage in oral cavity cancer after resection and formalin fixation. DATA SOURCES: PubMed, Embase, Web of Science, and Cochrane Database of Systematic Reviews. REVIEW METHODS: A systematic review was performed according to PRISMA guidelines to identify all published reports describing margin shrinkage in surgically resected oral cavity cancer. Only prospective cohort and cross-sectional studies were included. Non-English language studies, studies on non-human subjects, and studies describing cancer of sites other than the oral cavity were excluded. RESULTS: Ten studies met inclusion criteria, accounting for 352 patients who underwent resection of oral cavity cancer. Mean percent margin shrinkage from preresection to postresection ranged from 14.9% to 23.9%, from postresection to postfixation ranged from 3.7% to 32.9%, and from preresection to postfixation ranged from 11.3% to 59.0%. In studies reporting preresection, postresection, and postfixation margins (4 studies), preresection to postresection shrinkage was significantly larger than postresection to postfixation shrinkage. There was conflicting evidence on shrinkage by T stage and tumor subsite. There was no association between margin shrinkage and other clinicopathologic factors such as age, sex, or other adverse pathological factors. CONCLUSION: Oral cavity tissue undergoes shrinkage both after surgical resection and after fixation with formalin, with the most significant shrinkage occurring immediately after resection. Tissue shrinkage should be an important consideration in the planning of surgical margins.