Adjunctive tests cannot replace scalpel biopsy for oral cancer diagnosis

TNFα Signaling Is Increased in Progressing Oral Potentially Malignant Disorders and Regulates Malignant Transformation in an Oral Carcinogenesis Model

Oral carcinogenesis represents a multi-stage process which encompasses several genetic and molecular changes that promote the progression of oral potentially malignant disorders (OPMDs) to oral squamous cell carcinomas (OSCCs). A better understanding of critical pathways governing the progression of OMPDs to OSCCs is critical to improve oncologic outcomes in the future. Previous studies have identified an important role of tumor necrosis factor α (TNFα) and TNF receptor 1 (TNFR1) in the invasiveness of oral cancer cell lines. Here, we investigate the expression of TNFα and TNFR1 in human OPMDs that progress to OSCC compared to non-progressing OPMDs utilizing fluorescent immunohistochemistry (FIHC) to show increased TNFα/TNFR1 expression in progressing OPMDs. In order to interrogate the TNFα/TNFR1 signaling pathway, we utilized a 4-nitroquinoline 1-oxide (4-NQO) mouse model of oral carcinogenesis to demonstrate that TNFα/TNFR1 expression is upregulated in 4-NQO-induced OSCCs. TNFα neutralization decreased serum cytokines, inhibited the development of invasive lesions and reduced tumor-associated neutrophils in vivo. Combined, this data supports the role of TNFα in oral malignant transformation, suggesting that critical immunoregulatory events occur downstream of TNFR1 leading to malignant transformation. Our results advance the understanding of the mechanisms governing OSCC invasion and may serve as a basis for alternative diagnostic and therapeutic approaches to OPMDs and OSCC management.

Real Time Optical Vascular Imaging: A Potential Technique for the Diagnosis of Mucosal Disease Including Early Oral Cancer

Early detection of oropharyngeal carcinoma is imperative in order to minimise morbidity and increase survival rate, but most of these patients present to the specialist with already advanced stages of malignancy, when the prognosis is relatively poor. General dental practitioners and dental care professionals have a unique opportunity during routine examination to detect any suspicious lesions. However, we continue to rely mostly on conventional examination, which is known to have limitations. There are diagnostic adjuncts available to help detect oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD), such as vital staining, brush cytology and macroscopic light-based detection techniques, discussed elsewhere in this issue. However a recent meta-analysis demonstrated that these techniques are not reliable enough as standalone diagnostics and that conventional biopsy remains the diagnostic gold standard. This article shows a new imaging technique which has the potential to detect early signs of oral cancer. This technique is based on the use of green light which allows the observation of oral microvasculature. General dental practitioners and dental care practitioners have a privileged opportunity during routine examination to detect any suspicious lesions in the head and neck region and refer when necessary to specialist care. However, they rely mostly on conventional examination, which is known to be insufficient for the detection of early signs of malignancy. There are diagnostic adjuncts available to help detect oral cancer and oral premalignant disorders, such as vital staining, brush cytology and macroscopic light-based detection techniques, but a recent meta-analysis has concluded that alone, these are not reliable enough to make a full tissue diagnosis. In the main, their value is more as a guide to indicate need for and to locate sites for conventional biopsy, which remains the diagnostic gold standard. However, biopsy also has inherent limitations such as sample handling and site errors and is associated with patient morbidity at every sampling event. The authors have developed and tested a new real-time optical vascular imaging technique (RTOVI) to observe the gingival microvasculature as a direct reporter of local tissue function and behaviour. In addition to direct imaging, the reliability of a potential image analysis method, developed for microvascular images, was assessed. The images were assessed for number of capillaries, capillary area (CA), total capillary area (TCA) and aspect ratio (AR). The mean number of capillaries found in our study (45.06 per mm2) which was higher than figures identified in previous 'same-location' oral mucosal studies (15.42 per mm2). This may reflect the wide variation between individuals and potentially improved resolution and contrast optics between studies. This small study suggests that mean values in CA, TCA and AR may be reliable parameters for thresholding normal values, for comparison between individuals and for the assessment of the microvasculature over time. This assessment of normal is essential to pave the way for further studies involving inflammatory and mitotic lesions.

The prognostic value of GLUT-1 staining in the detection of malignant transformation in oral mucosa

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) ranks as the sixth most common tumor entity worldwide. Unfortunately, the multimodal treatment consisting of surgery, radiation, and chemotherapy does not show the desired efficacy. The intent of this study was to evaluate the sensitivity and specificity of an oral brush biopsy in combination with glucose transporter (GLUT)-1 staining in identifying premalignant and malignant lesions.

METHODS

A total of 72 patients were included in the study, divided into four diagnostic subgroups (24 healthy, 15 carcinoma, 18 leukoplakia, 15 oral lichen planus). Oral brush biopsies were taken and analyzed for GLUT-1 expression by immunocytologic staining. Incisional biopsy served as the gold standard.

RESULTS

Twelve (80 %) of the 15 carcinomas, nine (50 %) of the 18 leukoplakia, nine (60 %) of the 15 oral lichen planus, and none of the healthy specimens stained positive for GLUT-1. This resulted in a sensitivity rate of 80 % and a specificity rate of 68.42 %. Diagnostic accuracy was 70.83 % based on the correct diagnoses in 51 of 72 patients.

CONCLUSION

An oral brush biopsy can easily be performed throughout the entire oral cavity, is noninvasive, and shows high sensitivity and specificity rates with conventional cytology or computer-assisted analysis.

CLINICAL RELEVANCE

The significance of GLUT-1-specific staining with an oral brush biopsy is more limited than expected but could be used as an additional tool in detecting malignant transformation in the oral cavity.

Oral brush biopsy and melanoma-associated antigens A (MAGE-A) staining in clinically suspicious lesions

PURPOSE

In oral cancer and in other tumor entities, melanoma-associated antigens are present. These antigens contribute to tumor progression and poor prognosis, and reduce the cytotoxicity of antineoplastic drugs. The aim of this study was to investigate the diagnostic potential of these antigens in combination with oral brush biopsies.

MATERIAL AND METHODS

We analyzed 72 oral brush biopsy specimens for melanoma-associated antigens A (MAGE-A) expression by immunocytologic staining with the MAGE-A 57B antibody. A total of 24 healthy specimens, 15 lichen ruber cases, 18 leukoplakia cases, and 15 invasive carcinomas were studied. Incisional biopsy served as the gold standard.

RESULTS

In total, 66 of 72 specimens (91.6%) could be assessed. Twelve of 15 (80%) carcinomas stained positive for MAGE-A. MAGE-A staining was detected in four of 51 nonmalignant specimens, resulting in a false-positive rate of 7.8%. However, MAGE-A positive staining was significantly correlated with oral squamous cell carcinoma (p < 0.0005). Sensitivity and specificity for MAGE-A staining and carcinoma were 80% and 92.2%, respectively. The diagnostic accuracy was 89.4%.

CONCLUSION

Our results indicate that oral brush biopsy with MAGE-A staining serves as an additional tool for use in oral cancer diagnosis. These findings might help to facilitate an easier and more representative surveillance of the mucosa, particularly for large areas of altered mucosa.

Meta-analysis of two computer-assisted screening methods for diagnosing oral precancer and cancer

The early diagnosis of oral precancer and cancer is crucial and could have the highest impact on improving survival rates. A meta-analysis was conducted to compare the accuracy between the OralCDx brush biopsy and DNA-image cytometry in diagnosing both conditions. Bibliographic databases were systematically searched for original relevant studies on the early diagnosis of oral precancer and oral cancer. Study characteristics were evaluated to determine the accuracy of the two screening strategies. Thirteen studies (eight of OralCDx brush biopsy and five of DNA-image cytometry) were identified as having reported on 1981 oral mucosa lesions. The meta-analysis found that the area under the summary receiver operating characteristic curves of the OralCDx brush biopsy and DNA-image cytometry were 0.8879 and 0.9885, respectively. The pooled sensitivity, specificity, and diagnostic odds ratio of the OralCDx brush biopsy were 86% (95% CI 81-90), 81% (95% CI 78-85), and 20.36 (95% CI 2.72-152.67), respectively, while these modalities of DNA-image cytometry were 89% (95% CI 83-94), 99% (95% CI 97-100), and 446.08 (95% CI 73.36-2712.43), respectively. Results of a pairwise comparison between each modality demonstrated that specificity, area under the curve (AUC), and Q(∗) index of DNA-image cytometry was significantly higher than that of the OralCDx brush biopsy (Z=2.821, p<0.05; Z=1.711, p<0.05; Z=1.727, p<0.05), but no significant difference in sensitivity was found (Z=1.520, p>0.05). In conclusion, the meta-analysis of the published studies indicated that DNA-image cytometry is more accurate than the OralCDx brush biopsy in diagnosing oral precancer and oral cancer.