Novel Approaches in Surgical Management: How to Assess Surgical Margins

Abstract

The concept of surgical margins was born a long time ago but still lacks a univocal and sound understanding. The current biological rationale behind the recommendations on margins management relies on two pillars: (1) the observation that groups of cancer cells can leave the macroscopic tumor and disseminate throughout adjacent tissues with different degrees of aggressiveness; (2) the belief that removal of all (or most of) cancer cells can cure the patient. However, this background is undermined by some pieces of evidence. For instance, it has been proven that tissues surrounding cancer often bear precancerous traits, which means that cutting through non-cancerous tissues does not equate to cut through healthy tissues. The head and neck exquisitely poses a number of challenges in the achievement of negative margins, with special reference to anatomical complexity, high density in relevant structures, and unique histological heterogeneity of cancers. Currently, intraoperative margins evaluation relies on surgeons’ sight, palpation, ability to map tumor extension on imaging, and knowledge of anatomy, with some optical imaging technologies aiding the delineation of the mucosal margins of excision. Frozen sections are currently used to intraoperatively evaluate margins, yet with debate on whether and how this practice should be performed. Future perspectives on improvement of margins control are threefold: research is oriented towards refinements of understanding of cancers local progression, implementation of technologies to intraoperatively render tumor extension, and employment of optical imaging modalities capable of detecting foci of residual tumor in the surgical bed.

Prognostic Value of Anteroposterior Extension in Oral Tongue and Floor Squamous Cell Carcinoma

“…22 It has been postulated that a more complex geometry of growth pattern could increase the difficulty of achieving adequate resection margins in posterior tumors. 23 Indeed, the results shown herein do not support this conclusion, as we found no relevant differences in terms of margin status between anterior and posterior tumors (eFigure 3 in Supplement 1). However, it is worth noting that positive and close margins were merged in a single category (ie, R1) to avoid generation of too-small subcohorts at survival analysis.…”

“…Another hypothesis that could explain the worse prognosis for posterior tumors is the easier access to a wide spectrum of local pathways of spread (ie, styloglossus, genioglossus and hyoglossus, main branches of lingual and hypoglossal nerves) . It has been postulated that a more complex geometry of growth pattern could increase the difficulty of achieving adequate resection margins in posterior tumors . Indeed, the results shown herein do not support this conclusion, as we found no relevant differences in terms of margin status between anterior and posterior tumors (eFigure 3 in Supplement 1).…”

Navigation-Guided Transnasal Endoscopic Delineation of the Posterior Margin for Maxillary Sinus Cancers: A Preclinical Study

“…The surgeon needs to base the ablation planning on a mental representation of the tumor and surrounding structures, relying upon specific anatomical landmarks identified throughout the dissection, and this task becomes particularly challenging at the PM owing to poor visualization and maneuverability. Furthermore, cancers frequently have an irregular shape and have complex patterns of invasion into neighboring structures ( 47 ). The use of 3D navigation provides the surgeon with a real-time direct visualization of the tumor and the adjacent critical structures and facilitates positioning and orienting the margin with respect to the tumor and critical structures.…”