Clinical significance of interstitial collagen deposition at the invading edge in oral cancer: Immunohistochemistry for type I collagen

Assessment of the association of myofibroblasts and structural components of the extracellular matrix with histopathological parameters of actinic cheilitis and lower lip squamous cell carcinoma

BACKGROUND

To evaluate the presence of myofibroblasts (MFs) in the development of lip carcinogenesis, through the correlation of clinical, histomorphometric and immunohistochemical parameters, in actinic cheilitis (ACs) and lower lip squamous cell carcinomas (LLSCCs).

METHODS

Samples of ACs, LLSCCs, and control group (CG) were prepared by tissue microarray (TMA) for immunohistochemical TGF-β, α-SMA, and Ki-67 and histochemical hematoxylin and eosin, picrosirius red, and verhoeff van gieson reactions. Clinical and microscopic data were associated using the Mann-Whitney, Kruskal-Wallis/Dunn, and Spearman correlation tests (SPSS, p < 0.05).

RESULTS

ACs showed higher number of α-SMA+ MFs when compared to CG (p = 0.034), and these cells were associated with the vertical expansion of solar elastosis (SE) itself (p = 0.027). Areas of SE had lower deposits of collagen (p < 0.001), immunostaining for TGF-β (p < 0.001), and higher density of elastic fibers (p < 0.05) when compared to areas without SE. A positive correlation was observed between high-risk epithelial dysplasia (ED) and the proximity of SE to the dysplastic epithelium (p = 0.027). LLSCCs showed a higher number of α-SMA+ MFs about CG (p = 0.034), as well as a reduction in the deposition of total collagen (p = 0.009) in relation to ACs and CG. There was also a negative correlation between the amount of α-SMA+ cells and the accumulation of total collagen (p = 0.041). Collagen and elastic density loss was higher in larger tumors (p = 0.045) with nodal invasion (p = 0.047).

CONCLUSIONS

Our findings show the possible role of MFs, collagen fibers, and elastosis areas in the lip carcinogenesis process.

Expression of type III collagen correlates with poor prognosis in oral squamous cell carcinoma

AIM

The aim of the present study was to evaluate, compare, and correlate the types of collagen fibers seen in different grades of oral cancer.

METHODS

Thirty cases of histologically-diagnosed, well-, moderately-, and poorly-differentiated oral squamous cell carcinoma (OSCC) were retrieved from the archives of the Institute. Collagen was evaluated using picrosirius red stain and immunohistochemical analysis of the antibody to type III collagen. A correlation between these findings and the grade of OSCC was evaluated.

RESULTS

Collagen fibers showed a change in birefringence ranging from reddish-orange to greenish-yellow in well- to poorly-differentiated oral squamous cell carcinoma. The findings were statistically significant for polarizing colors observed in grades of OSCC (P<.001). Immunohistochemical staining intensity of type III collagen changed from weak to strong as grade increased for OSCC, and was also statistically significant (P<.001).

CONCLUSION

In the present study, tumor progression reflected a change in collagen present, from type I to type III. Determination of the type of collagen in different grades of OSCC can facilitate therapeutic targeting of molecules responsible for invasion and progression of oral cancer.

Human ex-vivo oral tissue imaging using spectral domain polarization sensitive optical coherence tomography

We report the use of spectral domain polarization sensitive optical coherence tomography for ex-vivo imaging of human oral mandibular tissue samples. Our results show that compared to the changes observed in the epithelium thickness and the decay constant of A-scan intensity profile, a much larger degree of change was observed in the phase retardation for tissue sites progressing from normal to the malignant state. These results suggest that monitoring of tissue retardance can help in better differentiation of normal and cancerous oral tissue sites.