Morphometric analysis of CD34-positive vessels in salivary gland adenoid cystic and mucoepidermoid carcinomas

The Impact of Angiogenesis in the Most Common Salivary Gland Malignant Tumors

Salivary gland carcinomas (SGCs) represent a group of rare tumors, with complete surgical resection being the main treatment option. Therapeutic armory for cases of locally aggressive, recurrent, and/or metastatic SGCs, though, remains poor since they exhibit high rates of resistance to systematic therapy. Angiogenesis is considered one of the contemporary hallmarks of cancer and anti-angiogenic factors have already been approved for the treatment of several cancer types. This review aims to summarize, in a histotype-specific manner, the most current available data on the angiogenic factors implicated in SGC angiogenesis, in order to highlight the differences between the most common SGC histotypes and the factors that may have a potential role as therapeutic targets.

Angiogenesis and Lymphangiogenesis in Salivary Gland Adenoid Cystic Carcinoma and Mucoepidermoid Carcinoma

BACKGROUND AND PURPOSE

This study aimed to investigate the immunohistochemical expression of CD31 and podoplanin in order to examine angiogenesis and lymphangiogenesis, respectively in common malignant tumors of salivary glands.

MATERIALS AND METHODS

Forty formalin-fixed, paraffinated blocks (20 adenoid cystic carcinoma and 20 mucoepidermoid carcinoma blocks) were selected from the medical archives of Amir A'lam Hospital of Tehran, Iran. Sections from the blocks were stained by CD31 and D2-40 markers via immunohistochemistry. Clinical and demographic information was extracted from the patients' records.

FINDINGS

There was a significant difference between tumors in terms of intratumoral microvessel density (MVD) (P< 0.001), total MVD (P< 0.001), and intratumoral lymphatic vessel density (LVD) (P= 0.011). In mucoepidermoid carcinoma, intratumoral MVD and LVD were greater than peritumoral MVD and LVD (P= 0.001 and P< 0.001, respectively). In mucoepidermoid carcinoma, there was no relationship between histological grade with MVD (total, intratumoral or peritumoral) or LVD (total, intratumoral or peritumoral) (P> 0.05). A similar finding was reported with respect to the histopathological grade of adenoid cystic carcinoma (P> 0.05).

CONCLUSION

The higher level of angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma, specifically at the center of tumor, compared to adenoid cystic carcinoma, may be attributed to differences in the clinical behaviors and metastasis of tumors. Moreover, considering the high LVD at the center of tumor in mucoepidermoid carcinoma and infrequency of metastasis to regional lymph nodes in adenoid cystic carcinoma, it can play a significant role in metastasis to regional lymph nodes.

Immunoexpression of GLUT-1 and angiogenic index in pleomorphic adenomas, adenoid cystic carcinomas, and mucoepidermoid carcinomas of the salivary glands

This study aimed to evaluate and compare the immunoexpression of glucose transporter-1 (GLUT-1) and angiogenic index between pleomorphic adenomas (PAs), adenoid cystic carcinomas (ACCs), and mucoepidermoid carcinomas (MECs) of the salivary glands, and establish associations with the respective subtype/histological grade. Twenty PAs, 20 ACCs, and 10 MECs were submitted to morphological and immunohistochemical analysis. GLUT-1 expression was semi-quantitatively evaluated and angiogenic index was assessed by microvessel counts using anti-CD34 antibody. Higher GLUT-1 immunoexpression was observed in the MECs compared to PAs and ACCs (p = 0.022). Mean number of microvessels was 66.5 in MECs, 40.4 in PAs, and 21.2 in ACCs (p < 0.001). GLUT-1 expression and angiogenic index showed no significant correlation in the tumors studied. Results suggest that differences in biological behavior of the studied tumors are related to GLUT-1. Benign and malignant salivary gland tumors differ in the angiogenic index; however, angiogenesis may be independent of the tumor cell's metabolic demand.

Immunohistochemical analysis of CD34 expression in salivary gland tumors

Background:

Tumor growth depends on angiogenesis which is assessed by measuring the tumor microvessel density (MVD) through CD34 immunostaining. The present study was performed to evaluate the situation of angiogenic activity in salivary gland neoplasms. The possible role of CD34 in progression and invasion of salivary gland tumors is also investigated.

Materials and Methods:

Tissue specimens of 15 pleomorphic adenoma (PA) and 15 malignant salivary gland tumors including mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC) and salivary duct carcinoma (SDC) were immunostained for CD34 protein. The most vascularized areas at low power magnification (hotspots) were selected for vessel counting at ×400 magnification. Then, the mean number of microvessels in three fields within the tumor mass was calculated.

Results:

MVD in PA and malignant salivary gland tumors were 10.93 ± 5.95 and 26.46 ± 7.32, respectively. Tumor angiogenesis in PA was much lower than other lesions (P < 0.05). No significant difference was observed between malignant tumors (P > 0.05).

Conclusion:

Salivary gland carcinomas demonstrated higher vascular density than benign PA despite of cell types and architecture. The reason for this higher angiogenic activity could be related to metabolic characteristics of malignant cells.

TMA vessel segmentation based on color and morphological features: application to angiogenesis research

Given that angiogenesis and lymphangiogenesis are strongly related to prognosis in neoplastic and other pathologies and that many methods exist that provide different results, we aim to construct a morphometric tool allowing us to measure different aspects of the shape and size of vascular vessels in a complete and accurate way. The developed tool presented is based on vessel closing which is an essential property to properly characterize the size and the shape of vascular and lymphatic vessels. The method is fast and accurate improving existing tools for angiogenesis analysis. The tool also improves the accuracy of vascular density measurements, since the set of endothelial cells forming a vessel is considered as a single object.

The clinical impact of mean vessel size and solidity in breast carcinoma patients

Angiogenesis quantification, through vessel counting or area estimation in the most vascular part of the tumour, has been found to be of prognostic value across a range of carcinomas, breast cancer included. We have applied computer image analysis to quantify vascular properties pertaining to size, shape and spatial distributions in photographed fields of CD34 stained sections. Aided by a pilot (98 cases), seven parameters were selected and validated on a separate set from 293 breast cancer patients. Two new prognostic markers were identified through continuous cox regression with endpoints breast cancer specific survival and distant disease free survival: The average size of the vessels as measured by their perimeter (p = 0.003 and 0.004, respectively), and the average complexity of the vessel shapes measured by their solidity (p = 0.004 and 0.004). The Hazard ratios for the corresponding median-dichotomized markers were 2.28 (p = 0.005) and 1.89 (p = 0.016) for the mean perimeter and 1.80 (p = 0.041) and 1.55 (p = 0.095) for the shape complexity. The markers were associated with poor histologic type, high grade, necrosis, HR negativity, inflammation, and p53 expression (vessel size only). Both markers were found to strongly influence the prognostic properties of vascular invasion (VI) and disseminated tumour cells in the bone marrow. The latter being prognostic only in cases with large vessels (p = 0.004 and 0.043) or low complexity (p = 0.018 and 0.024), but not in the small or complex vessel groups (p>0.47). VI was significant in all groups, but showed greater hazard ratios for small and low complexity vessels (6.54-11.2) versus large and high complexity vessels (2.64-3.06). We find that not only the overall amount of produced vasculature in angiogenic hot-spots is of prognostic significance, but also the morphological appearance of the generated vessels, i.e. the size and shape of vessels in the studied hot spots.

An analysis of microvessel density in salivary gland tumours: a single centre study

BACKGROUNDS

Microvessel density (MVD) can be used for determining neoplastic neovascularisation. Tumour angiogenesis correlates with prognosis of cancers in many organs. The aims of this study were to evaluate MVD as demonstrated by CD31 and CD105 in salivary gland tumours (SGTs), and to correlate the MVD results with clinicopathological characteristics of the tumours.

MATERIALS AND METHODS

Using a retrospective cohort study design, we enrolled SGTs patients at the Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand, over the 22-year period. The predictor variables included demographic, anatomic and histopathological parameters. The outcome measure was average CD31-MVD and CD105-MVD counted by the "hot spot" method. Descriptive, uni- and bivariate statistics were computed, and P <0.05 was considered statistically significant.

RESULTS

The study sample consisted of 43 subjects with a mean age of 39.6 ± 17.8 years (range, 9-82), including 26 females (60.5%), diagnosed with SGTs. In this cohort, 58.1% of the cases were benign, and 83.7% were minor SGTs. There was a significant correlation between CD31-MVD and CD105-MVD (r = 0.8, P < 0.001), but mean CD31-MVD and CD105-MVD were 17.7 ± 9.3 and 12.8 ± 7.4, respectively (P = 0.009). Age, gender and tumour site were not individually associated with significant differences between CD31-MVD and CD105-MVD. Tumours with myoepithelial cells had lower MVD than those without myoepithelial cells (P = 0.04 for CD31; P = 0.03 for CD105). Only CD105-MVD showed statistical difference between benign and malignant SGTs (P = 0.01).

CONCLUSIONS

These results suggest that MVD in SGTs can be demonstrated by CD31 and CD105. Despite a strong correlation, CD31-MVD is always higher than CD105-MVD and cannot differentiate between benign and malignant SGTs. The presence of myoepithelial cells within SGTs affects the MVD analysis using either CD31 or CD105, while age, gender and tumour location do not.