MONITORING OF P53 AUTOANTIBODIES IN LUNG-CANCER DURING THERAPY - RELATIONSHIP TO RESPONSE TO TREATMENT

Alteration of the p53 gene is the most frequent genetic alteration in human cancer, and it leads to the accumulation of mutant p53 in the nu cleus of tumor cells, In addition, it has been shown that patients wit h various types of neoplasias have p53 antibodies in their sera. ELISA was used to detect anti-p53 antibodies in the sera of 167 patients wi th lung cancer. Among these, 32 individuals (16 positive for p53 antib odies and 16 negative) were monitored over a period of 30 months for p 53 antibodies. Twelve of 16 antibody positive patients had reduced tit ers during chemotherapy that led to partial or complete remissions of disease. The specificity of these antibodies was confirmed by two diff erent ELISA procedures and by immunoprecipitation, The very rapid, spe cific decrease in these antibodies during therapy suggests that a cons tant level of tumoral cells with nuclear accumulating p53 protein is n ecessary for a detectable humoral anti-p53 response. The good correlat ion found between the specific evolution of the p53 antibody titer and the response to therapy suggests that p53 antibodies could represent a useful tool for checking the response to therapy and for monitoring some relapses before they are clinically detectable.