Survival outcomes following modern multidisciplinary management of oral squamous cell carcinoma in Australia

CRISPR/Cas9-mediated knock out of ITGB6 in human OSCC cells reduced migration and proliferation ability

BACKGROUND

The treatment of oral squamous cell carcinoma (OSCC) remains challenging and survival rates have not been improved significantly over the past decades. Integrins have been recognized driving the cancer progression and high expression levels cause poor outcomes in patients afflicted with OSCC. Integrin αvβ6 and its subunit integrin beta 6 (ITGB6) were discovered to enhance the invasiveness by providing beneficial effects on downstream pathways promoting the cancer progression. The objective of this study was to establish a CRISPR/Cas9-mediated knock out of ITGB6 in the human OSCC cell line HN and investigate the effects on the migration and proliferation ability.

METHODS

ITGB6 knock out was performed using the CRISPR/Cas9-system, RNPs, and lipofection. Monoclonal cell clones were achieved by limiting dilution and knock out verification was carried out by sanger sequencing and FACS on protein level. The effects of the knock out on the proliferation and migration ability were evaluated by using MTT and scratch assays. In addition, in silico TCGA analysis was utilized regarding the effects of ITGB6 on overall survival and perineural invasion.

RESULTS

In silico analysis revealed a significant impact of ITGB6 mRNA expression levels on the overall survival of patients afflicted with OSCC. Additionally, a significantly higher rate of perineural invasion was discovered. CRISPR/Cas9-mediated knock out of ITGB6 was performed in the OSCC cell line HN, resulting in the generation of a monoclonal knock out clone. The knock out clone exhibited a significantly reduced migration and proliferation ability when compared to the wildtype.

CONCLUSIONS

ITGB6 is a relevant factor in the progression of OSCC and can be used for the development of novel treatment strategies. The present study is the first to establish a monoclonal CRISPR/Cas9-mediated ITGB6 knockout cell clone derived from an OSCC cell line. It suggests that ITGB6 has a significant impact on the proliferative and migratory capacity in vitro.

Pathogenesis and Therapy of Oral Carcinogenesis

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the head and neck with an extremely poor five-year survival rate of approximately 50 to 55%, despite significant advances in diagnostic and therapeutic procedures over the past three decades [...].

Malignant and non-malignant oral lesions classification and diagnosis with deep neural networks

OBJECTIVES

Given the increasing incidence of oral cancer, it is essential to provide high-risk communities, especially in remote regions, with an affordable, user-friendly tool for visual lesion diagnosis. This proof-of-concept study explored the utility and feasibility of a smartphone application that can photograph and diagnose oral lesions.

METHODS

The images of oral lesions with confirmed diagnoses were sourced from oral and maxillofacial textbooks. In total, 342 images were extracted, encompassing lesions from various regions of the oral cavity such as the gingiva, palate, and labial mucosa. The lesions were segregated into three categories: Class 1 represented non-neoplastic lesions, Class 2 included benign neoplasms, and Class 3 contained premalignant/malignant lesions. The images were analysed using MobileNetV3 and EfficientNetV2 models, with the process producing an accuracy curve, confusion matrix, and receiver operating characteristic (ROC) curve.

RESULTS

The EfficientNetV2 model showed a steep increase in validation accuracy early in the iterations, plateauing at a score of 0.71. According to the confusion matrix, this model's testing accuracy for diagnosing non-neoplastic and premalignant/malignant lesions was 64% and 80% respectively. Conversely, the MobileNetV3 model exhibited a more gradual increase, reaching a plateau at a validation accuracy of 0.70. The MobileNetV3 model's testing accuracy for diagnosing non-neoplastic and premalignant/malignant lesions, according to the confusion matrix, was 64% and 82% respectively.

CONCLUSIONS

Our proof-of-concept study effectively demonstrated the potential accuracy of AI software in distinguishing malignant lesions. This could play a vital role in remote screenings for populations with limited access to dental practitioners. However, the discrepancies between the classification of images and the results of "non-malignant lesions" calls for further refinement of the models and the classification system used.

CLINICAL SIGNIFICANCE

The findings of this study indicate that AI software has the potential to aid in the identification or screening of malignant oral lesions. Further improvements are required to enhance accuracy in classifying non-malignant lesions.

Outcomes of immediate dental implants in vascularised bone flaps for mandibular reconstruction

BACKGROUND

The aim of this study is to assess the outcomes of immediate implant placement for dental rehabilitation following mandibular reconstruction with vascularised bone flaps in a single Australian tertiary cancer centre.

METHODS

A retrospective analysis of patients who underwent immediate dental implant or delayed placement in vascularised bone flaps was performed. Primary outcome measures assessed included the number of implants placed, operative time, complication rates, time to radiotherapy initiation, dental rehabilitation rates and time to dental rehabilitation.

RESULTS

In total, 187 dental implants were placed in 52 patients, of which 34 patients underwent immediate implant placement and 18 had delayed implant placement. There were no significant differences in the postoperative complication rate (32% immediate vs. 33% delayed, P = 0.89) or time to postoperative radiotherapy (median 42 days immediate vs. 47 days delayed, P = 0.24). Dental rehabilitation was achieved in 62% of the immediate cohort versus 78% of the delayed cohort. The time to be fitted with a dental prosthesis was significantly shorter in the immediate cohort (median 150 days immediate vs. 843 days delayed, P = 0.002).

CONCLUSIONS

The placement of immediate dental implants at the time of primary reconstruction of the mandible is a safe procedure and facilitates timely dental rehabilitation.

Prediction nomogram development and validation for postoperative radiotherapy in the management of oral squamous cell carcinoma

BACKGROUND

Predictive nomograms are useful tools to guide clinicians in estimating disease course. Oral squamous cell carcinoma (OSCC) patients would benefit from an interactive prediction calculator that defines their levels of survival-risk specific to their tumors to guide the use of postoperative radiotherapy (PORT).

METHODS

Patients with OSCC surgically treated with curative intent at four Head and Neck Cancer Centres were recruited retrospectively for development and validation of nomograms. Predictor variables include PORT, age, T and N classification, surgical margins, perineural invasion, and lymphovascular invasion. Outcomes were disease-free, disease-specific, and overall survivals over 5 years.

RESULTS

1296 patients with OSCC were in training cohort for nomogram analysis. Algorithms were developed to show relative benefit of PORT in survivals for higher-risk patients. External validation on 1212 patients found the nomogram to be robust with favorable discrimination and calibration.

CONCLUSION

The proposed calculator can assist clinicians and patients in the decision-making process for PORT.

Oral squamous cell carcinoma – clinical characteristics, treatment, and outcomes in a single institution retrospective cohort study

<b>Introduction:</b> Squamous cell carcinoma (SCC) is a common malignancy with high morbidity and mortality. </br></br> <b>Aim:</b> The aim of this study was to analyze the data of patients treated for malignant tumours of the oral cavity at the Department of Otolaryngology, Head and Neck Surgery, and Laryngological Oncology Ludwik Rydygier Collegium Medicum in Bydgoszcz between 2003–2011 to asses the influence of risk factors on survival in patients with squamous cell carcinoma of the oral cavity. </br></br> <b> Material and methods:</b> Material was collected from 62 patients treated for oral SCC between 2003–2011. Forty-three were men (69.35%) with a mean age of 56.33 years. The medical records were analysed, especially history, operative reports, histopathology reports, survival, adjuvant treatment and recurrence. </br></br> <b>Results:</b> All patients underwent surgical treatment (33.87% also had partial removal of the lower jaw, 67.74% adjuvant radio-therapy, 11.29% radiochemotherapy). More than half reported to the doctor within 6 to 15 weeks from the onset of symptoms. The majority smoked and drank alcohol (96.32%). Five-year disease specific survival (DSS) was 68.69%. </br></br> <b>Conclusions:</b> The age over 65 did not significantly influence DSS. The location on the anterior two thirds of the tongue gave the best outcome, while the worst outcome was observed in the retromandibular triangle area which was statistically almost significant (p = 0.06843). In the case of higher degrees of local and regional advancement and a higher stadium, a worse out-come was recorded. Positive surgical margins were identified in 11.29% of the cases, but they had no impact on the results of treatment. No worsening of the outcome was proven for the patients who reported to the doctor later than 15 weeks following the occurrence of symptoms.

Oral cancer awareness in patients attending university dental clinics: A scoping review of Australian studies

This scoping review was carried out to evaluate the important role Australian university-based dental teaching clinics and dental students might have in promoting oral cancer awareness in their patients. Four Online database (PubMed, OVID, Scopus and Emcare) were searched for studies that assessed oral cancer awareness amongst patients attending Australian university-associated (teaching) clinics. A total of five articles were retrieved for full-text analysis. All studies showed significant variation in patient awareness and understanding regarding the principal risk factors associated with oral cancer development. Smoking was predominantly identified as a significant risk factor, but alcohol consumption was less frequently recognized as relevant. Non-healing ulceration was most commonly identified as a symptom of concern, whilst red and/or white mucosal patches were infrequently recognized as potentially malignant conditions. Our review confirms that a significant lack of patient awareness regarding oral cancer risk and the signs /symptoms of early malignancy or potentially malignant disease exist in patients attending dental teaching clinics. Important opportunities exist to involve dental students proactively in raising oral cancer awareness, delivering smoking cessation interventions and safe alcohol consumption advice to their patients. Incorporation of established health educational models might deliver effective support for such student-delivered patient education.

The impact of intraoperative frozen section analysis on final resection margin status, recurrence, and patient outcome with oral squamous cell carcinoma

Background

The objective of this study was to evaluate the diagnostic value of intraoperative frozen section analysis (IFSA) of tumor bed margins in patients with oral squamous cell carcinoma (OSCC).

Methods

This retrospective study includes 194 primary OSCC cases. The impact of intraoperative information by IFSA on final margin status, local recurrence, and disease-specific survival were analyzed.

Results

IFSA revealed a 50% sensitivity and a 100% specificity, with a positive and negative predictive value of 100% and 89.1%, respectively. In 19 cases, margins were rated positive by IFSA and remained positive in eight cases (42.1%), despite immediate re-resection. This constellation led to higher recurrence and lower survival rates than in cases with consecutive R0 status (each p = 0.046). Positive margins in IFSA were associated with closer final margins (p = 0.022) and early recurrences (p = 0.050).

Conclusions

Achieving instant R0 status has a crucial impact on disease recurrence and patient survival. IFSA falls short to ensure secure definite surgical margins. Thus, improved intraoperative diagnostic information on the location and extent of OSCC could support patient treatment.

Clinical relevance

Considering that patient survival has not improved despite progress in surgical and adjuvant therapy, the process and outcome of IFSA was scrutinized as one part of the treatment concept.