Research On Spontaneous Apoptosis And Its Mecroenvironment In Aggressive And Non-aggressive Basal Cell Carcinoma

OBJECTIVES: By exploring basic biological behavior of aggressive basal cell carcinoma (A- BCC) and non-aggressive basal cell carcinoma (NA-BCC), the study aims to provide valuable foundation for diagnosis, treatment, prognosis and follow-up of BCC with different clinical biological behaviors. METHODS In this retro-perspective study, seventy-eight cases were selected from paraffin- embedded files diagnosed as BCC. Cases were divided into two groups by Sexton criteria: NA-BCC (36 cases), and A-BCC (42 cases). All specimens were cut, and the sections were then stained with H & E. Apoptotic rate, necrotic degree, differential direction and focal lymphocyte infiltrative degree (FLID) were measured by light microscopy. Sections were also stained with immunohistochemical SP. M30 Cytodeath, Ki67, p53, von-Willebrand Factor (vWF) and VEGF were measured to gain apoptotic index (Al), proliferation index (P1) and state of tumor suppressor gene p53. TMVLD, new method based on stereological principals, compared with traditional TMVD were used to evaluate growth of tumor microvessel (TMV) in tumor stroma. SPSS 10.0 was used to analyze the above indicators. RESULTS 1. Degree of necrosis in central focus was higher in NA-BCC group than in A-BCC group. There was no statistical difference in proportion of tumor cell differentiation and FLID between the two groups. 2. Means of Al (HE), Al (M30) and P1 were significantly higher in A-BCC group than in NA-BCC group. Significant correlation in statistics was found among AL (M3 0), Al (HE) and P1 in A-BCC group. 3. Expression level of p53 is higher in A-BCC group than in NA-BCC group. 4. Both results by method TMVLD and TMVD showed that TMV in A-BCC group was higher than that in NA-BCC. Though VEGF expression might have positive -3- correlation with TMVLD in BCC, no statistical difference of VEGF expression was found in two groups. 5. No statistical significant correlation among Al, P1, TMV and FLID in BCC had been found in this study. CONCLUSION 1. Tumor cells in NA-BCC have low proliferation rate, prolonged life span, and decreased apoptotic rate, showing a enign?growth course of accumulation and expansion. Rates of apoptotic and proliferation in A-BCC tumor cells are significantly higher, suggesting more malignancy. 2. It is speculated that lack of TMV may lead to inhibition of proliferation of tumor cells in BCC, and to promotion of their apoptosis or necrosis, and it may be one of the environment factors that result in malignant cloning of NA-BCC and A- BCC. 3. Al, P1 and TMVLD are among the better indicators for evaluating invasiveness of BCC. 4. Method TMVLD is more sensitive than TMVD. In addition, examining tumor cells in different apoptotic stages by Immunohistochemical (M30 Cytodeath) and H.E. staining leads to satisfactory results, which provides experience for clinical pathologist. 5. By Sexton criteria, NA-BCC could be relatively accurately distinguished from A- BCC. When combined with Al, P1, and TMVLD, better judgement of biological behavior of BCC could be made.