Microscopically Controlled Surgery

Abstract

I am a co-author of the S2k-guideline on basal cell carcinoma (BCC), which is in its final stages of development. Supported by 40 years’ experience in tumor surgery on facial skin and by long-term analyses of more than 3800 operations for facial BCC, my views differ somewhat from those expressed in the article. Hedgehog signaling pathway inhibitors allow a new therapeutic principle in BCC. Because of their short time of use, however, many questions remain open. In the guideline indications are defined for so extensive and metastatic cases of BCC, which therefore can be neither treated by radiation nor by surgery. — A tumor board decides on their use. Competent surgeons and radiologists are a mandatory on such a board. Non-surgical local therapies (laser, cryotherapy, immunomodulators imiquimod, 5-fluorouracil, photodynamic therapy) are reserved for individual cases because of barely predictable oncological and esthetic results. Local recurrences or residual tumors occur in more than 10% of cases after such treatments. For the surgery that is potentially required subsequently, these cause problems regarding R0 resection because of multilocal and poorly localizable tumor residues. According to the guideline, the surgical approach with the highest possible degree of control of the resection margin (Microscopically controlled surgery- MCS) is the method of choice. Compared with conventional surgery, MCS lowers the recurrence rate in primary BCC by only 1% and thus does not significantly improve the prognosis. When treating tumor recurrences, MCS reduces the recurrence rate from 12% to 2.4%. According to my own analyses, surgical treatment for BCC by means of MCS using plastic-surgical or rare epithetic defect repairs on the face, will—in primary BCC—yield a probability for 20 tumor-free years of 98.2%; in the treatment of recurrences in a retrospective analysis of 74%; and in a prospective analysis, consistenly using our variant of MCS, of 98%. Untreated R1 results lower this probability of success drastically, to 52% (primary BCC) and 29% (BCC recurrence). This confirms the validity of the R1 finding for tumor clearance. It does not affect survival. Diverse methods for reconstructions of the defects in the repertoire of maxillofacial surgeons in association with MCS allow a high degree of oncological certainty even in extensive BCC in combination with good esthetic results, even in the problematic facial region.