Surgical Outcomes in Compartmental Glossectomy and Standard Wide Margin Excision in T2-T3 Oral Tongue Squamous Cell Carcinoma- A Randomised Control Trial

Oral squamous cell carcinoma (OSCC) represents the 16th most common neoplasm worldwide, with almost 389846 new cases/year and over 188 438 deaths, as estimated in GLOBOCAN-2022. The most frequent OSCC subsite involved is the mobile oral tongue (OT) and an increasing incidence has been observed among people aged <45 years in the last decades.

According to GLOBOCAN, in 2022, the estimated incidence rate for men was 14.7 per 100000, while for women in India, it was 5.0. For men, India, oral cancer is the major cancer, while for women, oral cancer is the fourth major cancer after breast, cervix and ovary. Oral tongue being the second most common subsite in OSCC.

Surgery represents the first-choice treatment for OTSCC, even though a reliable and standardized procedure has not been universally recognized so far.

The gold standard for stages I-II OTSCC is transoral surgical excision with elective neck dissection if the pathological depth of invasion (DOI) is more than 4 and up to 9 mm.  Stages III-IV OTSCC, with a DOI ≥10 mm, should be managed by “en-bloc” tumor removal and concomitant neck dissection carrying out a so called standard wide margins surgery (SWMS) or, alternatively, a compartmental surgery (CTS) approach. SWMS is performed removing the tumor with clinically disease-free margins (variably defined as in between 1 and 2 cm), not considering the anatomical structures or preferential tumor cell spreading pathways. On the other side, the principles of CTS as proposed by Calabrese et al. in 2011 described a compartmental tongue resection technique (CTS) where the muscular (mylohyoid), neurovascular (lingual nerve and vein), and glandular (sublingual and submandibular) tissues within the compartment, that form a bridge between the primary tumor and the cervical lymphatic chain will be removed as a single compartment.

A transoral glossectomy with discontinuous neck dissection seems to be the current surgical practice for patients who have oral tongue cancer. There have been arguments about whether to remove the intervening tissues between the primary site and the neck. It is apparent that the lymphatic drainage from the oral tongue travels through the floor of the mouth before entering the upper neck, and some recurrences develop in this area.

In CTS, the extrinsic muscles of the tongue, even though partially infiltrated by the neoplasm, are completely dissected from their bony insertions and the concept of “en-bloc” removal is extended to all anatomical structures and stromal tissues connecting the primary to the cervical lymph nodes identified as the “T-N tract.” A comprehensive clearance of the T-N tract represents the main difference with the SWMS, in which the continuity with cervical lymph nodes is obtained only by dissecting the sublingual area. The first study by Calabrese et al. reported that CTS ensured a better local, loco-regional disease control, overall, and disease-free survivals compared with SWMS.

This study aims to  evaluate the margin status in T2-T3 OTSCC patients treated either by CTS or SWMS.