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Impact of immune response in the prognosis of patients with differentiated thyroid carcinomas : from bench to bedside

Lucas Leite Cunha
Total Authors: 1
Document type: Doctoral Thesis
Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
Defense date:
Examining board members:
Maria Izabel Chiamolera; Janete Maria Cerutti; Ligia Vera Montali da Assumpção; Luis Alberto Magna
Advisor: Laura Sterian Ward

Thyroid cancer is the most common endocrine malignancy. Although most of these patients experience clinical improvement with current therapeutic tools, 10-30% will develop recurrent disease and contribute to the 1,890 deaths that are estimated for 2014 in the United States. The cyclooxygenase (COX) are a group of enzymes that catalyze the formation of prostaglandins from arachidonic acid and COX2 activity has been implicated in carcinogenesis. Our group previously demonstrated that mixture of immune cells infiltrates tissue of thyroid cancers. The present study investigated the presence of immune cells markers and tumor markers of inflammatory profile, looking for prognostic markers in patients with differentiated thyroid carcinoma. We retrospectively investigated 437 patients with differentiated thyroid carcinoma, whose tissue samples previously fixed in formalin and included in paraffin blocks were kept in the Tissue Bank of the AC Camargo Cancer Center. Well-differentiated thyroid cancer was diagnosed in 305 patients: 252 with papillary carcinoma and 53 with follicular carcinoma. Clinical information was obtained from medical records. We obtained tissue of lymph node metastases at diagnosis of 25 patients. For these cases, we performed a paired analysis of metastatic tissue and primary tumor. Immunological cell markers were investigated in intratumoral areas, including tumor-associated macrophages (CD68) and subpopulations of tumor infiltrating lymphocytes, such as CD3, CD4, CD8, CD16, CD20, CD45RO, GRANZYME B, CD69 and CD25. We also investigated the expression of COX2, IL-17A, IL-1'beta', IL-10, IL-6, IL-23 and CD134 in the tumor cells. Among all the immunological parameters evaluated, only the enrichment of CD8+ lymphocytes and expression of COX2 were associated with recurrence. Multivariate analysis using the Cox model of proportional hazards adjusted for the presence of concurrent chronic lymphocytic thyroiditis, identified CD8+/COX2 as an independent marker for recurrence. Other immunohistochemical markers failed to predict the prognosis of patients. We notice an increase in the density of GRANZYME B + lymphocytes in lymph node metastases when compared with their primary tumors. Lymph node metastases have lower expression of COX2 and IL-10. This suggests that tumor evasion mechanisms are impaired in metastatic tissues, explaining, at least in part, why the presence of lymph node metastases would not be an excellent prognostic marker in patients with differentiated thyroid cancer. Our study showed that the differentiated thyroid cancer is infiltrated by multiple immune cells and that the pattern of cellular infiltration appears to be associated with distinct clinical and pathological characteristics. This infiltrative mixed cell along with the production of inflammatory cytokines, creates a microenvironment profile that is important in determining the tumor aggressiveness. In fact, the presence of cytotoxic T lymphocytes and COX2 expression could predict the worst prognosis of the patients. Still, we found that lymph node metastasis is the place where there would be a more productive immune response and less evasive, favoring and effective immune response. It is fairly coherent with the little strength of lymph node metastasis as a prognostic predictor. (AU)

FAPESP's process: 11/19681-2 - Critical analysis of the prognostic role of tumor infiltrating lymphocytes in differentiated thyroid carcinomas
Grantee:Lucas Leite Cunha
Support type: Scholarships in Brazil - Doctorate