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| LETTER TO EDITOR |
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| Year : 2022 | Volume
: 5
| Issue : 1 | Page : 179-180 |
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iT may improve prognostication but is not meant for staging in its current form
MP Sreeram, Narayana Subramaniam
Department of Head and Neck Oncology, Sri Shankara Cancer Hospital and Research Centre, Shankarapuram, Bengaluru, Karnataka, India
| Date of Submission | 18-Jan-2022 |
| Date of Decision | 29-Jan-2022 |
| Date of Acceptance | 01-Feb-2022 |
| Date of Web Publication | 31-Mar-2022 |
Correspondence Address:
Narayana Subramaniam
Department of Head and Neck Oncology, Sri Shankara Cancer Hospital and Research Centre, Shankarapuram, Bengaluru - 560 100, Karnataka
India
 Source of Support: None, Conflict of Interest: None
DOI: 10.4103/crst.crst_34_22
How to cite this article:
Sreeram M P, Subramaniam N. iT may improve prognostication but is not meant for staging in its current form. Cancer Res Stat Treat 2022;5:179-80 |
Cancer staging is done based on the tumor's anatomical spread, which signifies the patient's tumor burden. The tumor, node, metastasis staging system by the American Joint Committee on Cancer is based on this for each organ or subsite. A staging system must be accurate, succinct, easy to perform, and reproducible. Surgical resectability entirely depends on the involvement of anatomical boundaries by the tumor; extension beyond these boundaries makes the tumor inoperable, or results in excessive surgical morbidity, which makes the operation not worthwhile. A T4b tumor represents a very advanced unresectable tumor, which has recently been challenged for oral cancers by many authors/centers.
In the previous issue of the journal, Mahajan et al.[1] have written an excellent narrative review describing the predictive and prognostic factors of T4 tongue cancer. They have comprehensively classified perineural invasion, hyoid bone involvement, lingual septum proximity, and extrinsic muscle involvement. However, there are a few points that the authors need to clarify.
The authors have proposed including ipsilateral neurovascular bundle involvement as T4a and contralateral neurovascular bundle involvement as T4b. Technically, a total or subtotal glossectomy through a pull-through approach would suffice to extirpate these kinds of tumors. Designation of a tumor as T4b implies that it is very advanced and probably unresectable. Thus, the inclusion of contralateral nerve bundle involvement tumors in this group questions the discriminatory power of the staging system.[2] The current criteria that make a tumor T4b include factors such as internal carotid involvement, and prevertebral fascia involvement; these factors confer unresectability and therefore are appropriate criteria to determine the T4b stage of a tumor. A similar rationale exists for the genial tubercle involvement which the authors have proposed to be included in the criteria for T4b. Although we appreciate the proposal of these novel criteria, which will certainly aid in better delineation of these structures and will help with surgical planning, it is unclear whether they confer similar prognostic relevance as the well-established current T4b criteria.
As mentioned earlier, there are centers that have challenged the concept of T4b tumor resectability in oral cancer. The concept of compartment resection for advanced buccal cancers has led to a 2-year overall survival of 58%.[3] In addition, the stage migration from cT4b to pT4a was documented to be 35%.[4] Advanced tongue tumors can be resected and when treated with surgery, they have been shown to have a better prognosis. Calabrese et al. introduced the concept of compartment tongue surgery which resulted in an impressive 5-year overall survival of 70%.[5]
The rationale of updating or modifying a staging system is to better predict outcomes as compared to earlier systems. Factors such as advanced imaging technologies and novel therapeutics can contribute to this. Although a more detailed assessment of these novel factors may refine our decision to operate and the planning of treatment, without providing outcomes data, it is unclear how each of them impacts survival or treatment. Even if the patient is noted to have poor prognostic factors, modifications to the official staging system should be made only after appropriate validation; otherwise, we increase the complexity and bias in staging, without improving the accuracy or precision.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | |  |
| 1. | Mahajan A, Suthar M, Agarwal U, Shukla S, Thiagarajan S, Sable N. Imaging-based T stage (iT) as a predictive and prognostic marker for outcome in T4 stage tongue carcinomas: A narrative review. Cancer Res Stat Treat 2021;4:677-83.  [Full text] |
| 2. | Groome PA, Schulze K, Boysen M, Hall SF, Mackillop WJ. A comparison of published head and neck stage groupings in carcinomas of the oral cavity. Head Neck 2001;23:613-24. |
| 3. | Pillai V, Yadav V, Kekatpure V, Trivedi N, Chandrashekar NH, Shetty V, et al. Prognostic determinants of locally advanced buccal mucosa cancer: Do we need to relook the current staging criteria? Oral Oncol 2019;95:43-51. |
| 4. | Munnangi A, Kadapathri A, Pillai V, Shetty V, Rangappa V, Subramaniam N. Should radiological staging of advanced buccal mucosa cancer preclude curative intent treatment? A prospective evaluation. Oral Oncol 2021;119:105246. |
| 5. | Calabrese L, Bruschini R, Giugliano G, Ostuni A, Maffini F, Massaro MA, et al. Compartmental tongue surgery: Long term oncologic results in the treatment of tongue cancer. Oral Oncol 2011;47:174-9. |
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