A NEW TUMOR-ASSOCIATED ANTIGEN OF NONSMALL CELL LUNG-CANCER - TUMOR LIBERATED PROTEINS (TLP) - A POSSIBLE NEW TUMOR-MARKER

TLP (Tumour Liberated Proteins) is a 214 kDA protein, isolated from lu ng cancer tissue and synthetic nonapeptide CSH-275 is a major epitope identified on a 100 kDa TLP fragment and used to create antibodies in rabbit (antiserum termed CSH-419). CSH-419 antiserum, labelled or conj ugated as necessary, was used to detect TLP on sera from NSCLC patient s by a new ELISA test set up as a 1 step sandwich format test. This EL ISA was performed on sera from 534 individuals. TLP was detected in 53 .1% of NSCLC patients, with 0% response in patients with cancers other than NSCLC, 7.6% response in unknown blood donors, and 17.4% response in patients with chronic lung diseases correlated with an elevated ri sk for lung cancer. TLP was particularly present in early stages of di sease: 75% in stage I, 56% in stage II and III and 45% in stage IV. Th e presence of TLP antigen in sera from NSCLC patients indicates that T LP could represent an useful tumour marker.