Clinical outcomes of patients with pT4a and pT4b oral cavity squamous cell carcinoma who had undergone surgery: Results from a Taiwanese registry-based, nationwide cohort study

Primary Management of Operable Locally Advanced Oral Cavity Squamous Cell Carcinoma: Current Concepts and Strategies

INTRODUCTION

Locally advanced oral cavity carcinoma (LAOCSCC) is primarily treated with surgery followed by radiotherapy with or without chemotherapy.

METHODS

A review of literature using PubMED was performed for studies reporting the management of LAOCSCC. Based on the reviewed literature and opinions of experts in the field, recommendations were made.

RESULTS

Studies have shown that outcomes following resection of T4a and infranotch (inferior to mandibular notch) T4b are comparable. We discuss the concept of compartmental resection of LAOCSCC and issues concerning the management of the neck. Further, patients who refuse or are unable to undergo surgery can be treated with chemoradiotherapy with uncertain outcomes. The role of neoadjuvant chemotherapy has shown promise for organ (mandibular) preservation in a select subset of patients.

CONCLUSION

The management strategy for LAOCSCC should be determined in a multidisciplinary setting with emphasis on tumor control, functional preservation, and quality of life of the patient.

Surgical margins in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC), a prevalent and frequently recurring malignancy, often necessitates surgical intervention. The surgical margin (SM) plays a pivotal role in determining the postoperative treatment strategy and prognostic evaluation of HNSCC. Nonetheless, the process of clinical appraisal and assessment of the SMs remains a complex and indeterminate endeavor, thereby leading to potential difficulties for surgeons in defining the extent of resection. In this regard, we undertake a comprehensive review of the suggested surgical distance in varying circumstances, diverse methods of margin evaluation, and the delicate balance that must be maintained between tissue resection and preservation in head and neck surgical procedures. This review is intended to provide surgeons with pragmatic guidance in selecting the most suitable resection techniques, and in improving patients' quality of life by achieving optimal functional and aesthetic restoration.

Compartmental surgery for T4b oral squamous cell carcinoma involving the masticatory space

PURPOSE OF REVIEW

This review aims to describe the oncological outcomes of T4b oral squamous cell carcinomas (OSCC) with masticatory space involvement as well as the surgical approaches that are able to achieve compartmental 'en bloc' resection of these lesions.

RECENT FINDINGS

The masticatory space is subdivided into infra-notch and supra-notch spaces according to the axial plane passing through the mandibular notch between the coronoid process and the condyle neck. Compartmental resection for T4b OSCC with masticatory space invasion can be successfully achieved via purely external approaches or combining external and transnasal endoscopic routes. Infra-notch T4b OSCC showed survival outcomes comparable to T4a OSCC, thus prompting treatment with curative intent.

SUMMARY

Compartmental resection of the masticatory space is technically feasible with comprehensive control of tumour margins. Use of a transnasal endoscopic anterior route within a multiportal approach may provide better control of margins at the level of the pterygo-maxillary fissure. Equivalent survival outcomes between T4a and infra-notch T4b OSCC are reported. Thus, a downstaging of the latter to T4a is advisable and compartmental surgery of such advanced lesions could be considered as a first-line treatment option in selected patients.

A Meta-analysis of Surgical Outcomes of T4a and Infranotch T4b Oral Cancers

OBJECTIVE

To determine the overall surgical outcomes of infranotch T4b oral cancers and compare them with T4a oral cancers.

METHODS

PubMed, EMBASE and Cochrane databases from 2000 to 2022 were systematically searched. Clinical studies reporting at least one outcome following curative surgery and adjuvant therapy for comparison of patients with either infranotch T4b (IN-T4b) or T4a tumour. The heterogeneity of the included studies was determined using Tau-squared, Chi-squared, and the Higgins I2 test. The random effects model was used to determine the log odds ratio (logOR).

RESULTS

The systematic review comprised 11,790 patients from 16 included studies. Seven studies were included in the meta-analysis (n = 11,381). For IN-T4b patients, the pooled 2 and 5 year overall survival (OS) were 59.3% and 53.2%, 2 and 5 year disease-free survival (DFS) 57.9% and 48.4%, 2 and 5 year disease-specific survival (DSS) 72% and 68%, and 2 and 5 year local control (LC), 47% and 56%, respectively. There was no statistically significant difference in 2 year OS [logOR = 0.28 (-0.47, 1.03), p = 0.46, confidence interval (CI) = 95%], 5 year OS [logOR = 0.7 (-0.4, 1.8), p = 0.54, CI = 95%], 2 year DFS [logOR = 0.22 (-0.35, 0.79), p = 0.45, CI = 95%], 5 year DFS [logOR = 0.17 (-0.42, 0.77), p = 0.57, CI = 95%], 2 year LC [logOR = 0.47 (-0.33, 1.26), p = 0.25, CI = 95%] and 5 year LC [logOR = 0.34 (-0.31, 0.99), p = 0.31, CI = 95%] between IN-T4b and T4a oral cancers.

CONCLUSION

Results of this meta-analysis suggest that IN-T4b oral cancers have similar outcomes to T4a oral cancers, which supports down-staging IN-T4b cancers to T4a cancers.

A domain knowledge enhanced yield based deep learning classifier identifies perineural invasion in oral cavity squamous cell carcinoma

BACKGROUND

Perineural invasion (PNI), a form of local invasion defined as the ability of cancer cells to invade in, around, and through nerves, has a negative prognostic impact in oral cavity squamous cell carcinoma (OCSCC). Unfortunately, the diagnosis of PNI suffers from a significant degree of intra- and interobserver variability. The aim of this pilot study was to develop a deep learning-based human-enhanced tool, termed domain knowledge enhanced yield (Domain-KEY) algorithm, for identifying PNI in digital slides.

METHODS

Hematoxylin and eosin (H&E)-stained whole-slide images (WSIs, n = 85) were obtained from 80 patients with OCSCC. The model structure consisted of two parts to simulate human decision-making skills in diagnostic pathology. To this aim, two semantic segmentation models were constructed (i.e., identification of nerve fibers followed by the diagnosis of PNI). The inferred results were subsequently subjected to post-processing of generated decision rules for diagnostic labeling. Ten H&E-stained WSIs not previously used in the study were read and labeled by the Domain-KEY algorithm. Thereafter, labeling correctness was visually inspected by two independent pathologists.

RESULTS

The Domain-KEY algorithm was found to outperform the ResnetV2_50 classifier for the detection of PNI (diagnostic accuracy: 89.01% and 61.94%, respectively). On analyzing WSIs, the algorithm achieved a mean diagnostic accuracy as high as 97.50% versus traditional pathology. The observed accuracy in a validation dataset of 25 WSIs obtained from seven patients with oropharyngeal (cancer of the tongue base, n = 1; tonsil cancer, n = 1; soft palate cancer, n = 1) and hypopharyngeal (cancer of posterior wall, n = 2; pyriform sinus cancer, n = 2) malignancies was 96%. Notably, the algorithm was successfully applied in the analysis of WSIs to shorten the time required to reach a diagnosis. The addition of the hybrid intelligence model decreased the mean time required to reach a diagnosis by 15.0% and 23.7% for the first and second pathologists, respectively. On analyzing digital slides, the tool was effective in supporting human diagnostic thinking.

CONCLUSIONS

The Domain-KEY algorithm successfully mimicked human decision-making skills and supported expert pathologists in the routine diagnosis of PNI.