MICROCHIMERISMO CELLULARE FETALE NEL CARCINOMA PAPILLARE DELLA TIROIDE: ANALISI SU TESSUTI E SU SANGUE PERIFERICO

The fetal cell microchimerism (FCM) is defined as the persistence for decades after pregnancy of fetal cells in maternal circulation and organs without any apparent form of rejection. The FCM is a common occurrence during pregnancy and, in fact, was detected at a frequency of 20-75% in the peripheral blood of women with sons and of 40-100% in the tissues of patients with malignant or benign diseases. Nevertheless, the physiological consequences of this phenomenon remain to be clarified in both healthy women and in those affected by carcinoma. There are conflicting data about the pathogenic role of FCM in autoimmune diseases and in tumors. In short, most of the studies provides that the FCM can play a pathogenic role in autoimmune diseases and conversely a protective role for neoplastic diseases. In this context, our group has recently demonstrated a possible role of FCM in the damage-induced thyroid cancer and in the recovery or protection of the affected tissue. In particular, male cells were found in a high proportion of women than had a male pregnancy before the diagnosis of cancer. These cells were found to be significantly represented in contralateral cancer tissue compared to healthy tissue. To extend in the peripheral blood our knowledge of the FCM in thyroid cancer and to explore the possible relationship between the presence of microchimerism and the development of this tumor were enrolled 106 women with a previous male pregnancy, including 57 patients with papillary carcinoma thyroid cancer (PTC) diagnosed after pregnancy and 49 healthy controls. At the level of peripheral blood FCM was found less frequently in women with PTC compared with healthy controls. These findings suggest a protective role of microchimerism on the development of cancer. However additional data are needed to know in depth the role of FCM is the development of cancer and autoimmune diseases.