Efeitos do maleato de sunitinibe e da quimioterapia metronômica na microangioarquitetura do carcinoma oral de células escamosas em bolsa jugal de hamster sírio

Abstract

Oral cancer is among the six most common types of cancer worldwide, considered as the seventh most frequent in the Brazil. Tumor angiogenesis has become a promising target for the treatment of malignancies. Methods that allow three-dimensional evaluation of the vascular network of tumors have a great importance to assess the effects of antiangiogenic treatments in tumors. The objective of this study was to evaluate the effect of sunitinib maleate and the metronomic chemotherapy with cyclophosphamide on the vascular network of the oral squamous cell carcinoma by scanning electron microscopy (SEM) of corrosion casts. 24 Syrian hamsters (Mesocricetus auratus) were divided into three groups of eight animals each and had their right buccal pouches submitted to tumor induction with dimethylbenzanthracene and carbamide peroxide for 55 days. Following, the animals were maintained without treatment (group I) or receiving sunitinib (group II), or cyclophosphamide (group III) for a period of 4 weeks. After the treatment, six animals of each group had their vascular networks casted by Mercox® resin and analyzed qualitatively and quantitatively by SEM. The two remaining animals of each group had their buccal pouches prepared for qualitative analysis by light microscopy. It was observed changes in the angioarchitecture of the pouches that were treated with these two drugs, suggesting an improvement in the tumors vascularization. The main changes caused by the treatments were the reduction of vessel tortuosity, the reestablishment of vascular hierarchy, besides the decrease of sprouting and intussusception images, compressed vessels, saccular dilations, and other vascular figures. Quantitative analysis of the samples exhibited a statistically significant reduction in vascular diameter and intervascular distances ofthe pouches treated with cyclophosphamide, when compared with the pouches no treated and those treated with sunitinb. The findings of the present study suggest that these two drugs may act in the vascular normalization of squamous cell carcinomas induced in hamster buccal pouch, however the metronomic chemotherapy exhibited superior results.