Double minutes and premature chromosome condensation in blood lymphocytes of four breast cancer patients.

Double minutes (dmin) and premature chromosome condensation (PCC) were observed in the peripheral blood lymphocytes (PBL) of four breast cancer patients using GTG banding. Among 53 breast cancer patients studied, four cases revealed dmin of which one case had PCC along with dmin. PCC might be an indicator of the spontaneous proliferative potential of tumor cells manifested in lymphocytes as a rare phenomenon. The presence of dmin represents amplified genes (well documented in different types of tumors), but their presence in PBL has rarely been reported in the literature. These findings in PBL might indicate that defective genetic/molecular mechanisms expressed generally in tumor tissue are also manifested in a similar manner in the circulating lymphocytes of patients at a lower frequency.