Oral cancer involving masticator space (T4b): Review of literature and future directions

Abstract

The oral cancer with masticator-space involvement is classified as T4b disease. The limited data suggest that the masticator space is a complex anatomic area and tumors with varying degrees of infiltration may have different oncologic outcomes. It is not advisable to group all T4b tumors as one and consider them for palliative-intent treatment. A group of patients with limited spread (infra-notch) has potential for good outcome. These cancers can be considered for downstaging to T4a classification based on best available data and clinical considerations. The radical surgical resection remains the mainstay of curative-intent treatment and the ability to achieve negative margins at the skull base remains the most important prognostic factor. The alternative approaches to either increase radicality of surgery or to downsize the tumor with neoadjuvant therapies have shown encouraging trends but larger, well designed, and prospective studies will be needed to make meaningful conclusions. It is important to rationalize and form common ground for further research.

Surgical Resection is Justifiable for Oral T4b Squamous Cell Cancers With Masticator Space Invasion

“…Masticator space invasion is the most common subset of T4b OCSCC compared to disease invasion of the pterygoid plates, skull base, and/or encasement of the internal carotid artery 4 . The masticator space contains the ramus and body of the mandible, the muscles of mastication (medial and lateral pterygoids, masseter and temporalis), and the mandibular nerve 6 . Radical, compartmental, en bloc resection of the entire masticator space contents for improved margin control has been proposed in the Indian population by Trivedi et al This can include en bloc resection of the mandible, maxilla, pterygoid plates, and all of the muscles of mastication from origin to insertion 7 .…”

“…4 The masticator space contains the ramus and body of the mandible, the muscles of mastication (medial and lateral pterygoids, masseter and temporalis), and the mandibular nerve. 6 Radical, compartmental, en bloc resection of the entire masticator space contents for improved margin control has been proposed in the Indian population by Trivedi et al This can include en bloc resection of the mandible, maxilla, pterygoid plates, and all of the muscles of mastication from origin to insertion. 7 Unlike T4b OCSCC invading the pterygoid plates, skull base, and/or encasing the internal carotid artery, masticator space resectability may be more feasible given less morbid constraints on margin clearance (e.g., masseter muscle resection vs. internal carotid artery resection).…”

Survival and clinicopathological characteristics of cT4b oral squamous cell carcinoma based on different treatment modalities

“…Moreover, it would be difficult to assess tumor invasion if intraoperative bleeding from the pterygoid venous plexus or internal maxillary vessels occurred. [3,4] All these factors contribute to achieving negative margins in T4b OSCC, which is a very arduous process and is presumed to be the major reason why surgical treatment is still not the mainstay treatment for patients with T4b OSCC according to the NCCN guideline. [2] Furthermore, to investigate suitable patients with T4b OSCC who were candidates for primary surgical treatment, Liao et al demonstrated that those patients with T4b OSCC with infranotch tumor involvement who received primary surgical treatment exhibited significantly higher local control, neck control, disease-free survival, and OS rates compared with those with tumor supra-notch spread.…”

Survival Impact of Surgical Resection in Locally Advanced T4b Oral Squamous Cell Carcinoma

“…Spread to the MS can be merely due to close anatomical proximity to the tumors involving the posterior part of buccal mucosa. 8 To categorize all tumors involving varying degrees of MS under one prognostic stage is one of the limitations of the current staging system.…”