Molecular characterisation in tongue squamous cell carcinoma reveals key variants potentially linked to clinical outcomes

A Truncated Mutation of TP53 Promotes Chemoresistance in Tongue Squamous Cell Carcinoma

Tongue squamous cell carcinoma (TSCC), a subtype of head and neck squamous cell carcinoma, is characterized by frequent chemoresistance. Genetic mutations commonly observed in TSCC play a critical role in malignant progression; thus, elucidating their functional significance is essential for developing effective treatment strategies. To more accurately investigate the relationship between mutations and chemoresistance, we established low-passage TSCC cells, CTSC-1, obtained from a chemoresistant patient, and CTSC-2, from a treatment-naïve patient. Sanger sequencing revealed a specific TP53 mutation (Q331*) in CTSC-1, leading to the loss of the tetramerization and C-terminal regulatory domains. Notably, CTSC-1 cells harboring TP53-Q331* and CTSC-2 cells with TP53 knockout that have been engineered to ectopically express TP53-Q331* exhibit enhanced chemoresistance and increased cancer stem cell-like properties. Mechanistically, TP53-Q331* upregulates the expression of inhibitor of DNA binding 2 (ID2), which is crucial for maintaining the stemness of TSCC cells. Subsequently, ID2 activates the expression of nucleotide excision repair (NER) pathway-related genes ERCC4 and ERCC8, thereby enhancing the chemoresistance in TSCC. In conclusion, our study demonstrates that the TP53-Q331* mutation enhances TSCC chemoresistance through an ID2-mediated NER pathway, providing a potential prognostic marker and therapeutic target for TSCC chemotherapy resistance.

Multiple Mutations-A Genetic Marker for Extracapsular Spread in Human Papillomavirus/p16-Positive Oropharyngeal Carcinoma

Background

In the 8th edition of the TNM classification, extracapsular spread (ECS) became a factor in classifying the UICC stage of oropharyngeal carcinomas (OPSCC). We aimed to find genetic markers for ECS and to identify differences between HPV/p16-positive and HPV/p16-negative cases.

Methods

We performed targeted next-generation sequencing on 99 samples of operable OPSCC and a retrospective analysis of clinical data.

Results

We included 55 HPV/p16-positive and 44 HPV/p16-negative patients. We found a significant difference between both groups, particularly in TP53 mutation (p < 0.001). Among other things, a small primary tumor (p < 0.001), no ECS (p = 0.026) were identified as predictors for survival. Multiple mutations were associated with an increased incidence of ECS, especially in HPV+/p16+ cases (p = 0.017). A mutation in PIK3CA occurred more frequently in nonsmokers, especially in HPV-/p16- patients (p = 0.027). A PTEN mutation-which only occurred in HPV+/p16+ tissues-reduced disease-free survival (DFS, p = 0.026).

Conclusion

The presence of multiple mutations in HPV+/p16+ OPSCC was associated with a higher risk of ECS.

Level of Evidence

3.

Long-term outcomes of early stage oral tongue cancer: Main cause of treatment failure and second primary malignancy

Objective

We attempted to investigate the long-term outcomes, prognostic factors, treatment failures, second primary malignancies, and salvage therapies in early (pT1-2N0) oral tongue squamous cell carcinoma (OTSCC).

Methods

We retrospectively analyzed the medical records of 295 early stage OTSCC patients.

Results

Two hundred ninety-five patients were enrolled. The average follow-up period was 64.5 months (range, 1-190 months). Five-year recurrence-free survival rate was 84.8% and disease-specific survival rate was 91.2%. On multivariate analysis, only the depth of invasion (DOI) exhibited significant correlations with the disease recurrence. Patient's age and DOI demonstrated a significant association with survival. A total of 53 recurrence and 35 death events occurred, with the main cause of treatment failure being regional or local recurrence. In recurrent cases, the success rate of salvage treatment was 42% at 5 years. During the follow-up period, second primary malignancy occurred in 13 patients, and 8 (61.5%) of those patients were successfully treated.

Conclusions

In pT1-2N0 OTSCC, regional or local recurrence is the main recurrence pattern, whereas age and DOI >5 mm are significant prognostic factors related to recurrence and survival. Since several patients experienced second primary malignancies in the head and neck, careful and thorough surveillance may be required to detect second primary lesions.

Level of Evidence

4.

Clinical Outcomes of Patients With pT1-T2N0 Oral Tongue Squamous Cell Carcinoma

OBJECTIVE

The objective of this study was to evaluate the clinical outcomes in a cohort of patients with early-stage oral tongue squamous cell carcinoma (OTSCC).

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with pT1-T2N0 (American Joint Committee on Cancer [AJCC] seventh edition) OTSCC treated from 2000 to 2018. Two-year actuarial rates of local regional control, cancer-specific survival, and overall survival were calculated for the entire cohort and patients with/without adjuvant radiation.

RESULTS

Ninety-six patients met the criteria with a median follow-up of 4 years; 14 had adjuvant radiation, while 82 had surgery alone. Two-year local regional control was 82.7% (75.4% to 90.8%) for the entire cohort, 84.9% (77.8% to 93.2%) for surgery only, and 70.7% (50.2% to 99.6%) for patients with adjuvant radiation. Two-year progression-free survival was 82.7% (75.3% to 90.8%). Of the 20 patients with recurrence, 11 (55%) were successfully salvaged.

CONCLUSION

Local regional recurrence remains modest in early-stage OTSCC, but salvage is possible with high survival rates.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Construction of Prognostic Risk Prediction Model of Oral Squamous Cell Carcinoma Based on Nine Survival-Associated Metabolic Genes

The aim was to investigate the independent prognostic factors and construct a prognostic risk prediction model to facilitate the formulation of oral squamous cell carcinoma (OSCC) clinical treatment plan. We constructed a prognostic model using univariate COX, Lasso, and multivariate COX regression analysis and conducted statistical analysis. In this study, 195 randomly obtained sample sets were defined as training set, while 390 samples constituted validation set for testing. A prognostic model was constructed using regression analysis based on nine survival-associated metabolic genes, among which PIP5K1B, NAGK, and HADHB significantly down-regulated, while MINPP1, PYGL, AGPAT4, ENTPD1, CA12, and CA9 significantly up-regulated. Statistical analysis used to evaluate the prognostic model showed a significant different between the high and low risk groups and a poor prognosis in the high risk group (P < 0.05) based on the training set. To further clarify, validation sets showed a significant difference between the high-risk group with a worse prognosis and the low-risk group (P < 0.05). Independent prognostic analysis based on the training set and validation set indicated that the risk score was superior as an independent prognostic factor compared to other clinical characteristics. We conducted Gene Set Enrichment Analysis (GSEA) among high-risk and low-risk patients to identify metabolism-related biological pathways. Finally, nomogram incorporating some clinical characteristics and risk score was constructed to predict 1-, 2-, and 3-year survival rates (C-index = 0.7). The proposed nine metabolic gene prognostic model may contribute to a more accurate and individualized prediction for the prognosis of newly diagnosed OSCC patients, and provide advice for clinical treatment and follow-up observations.