DETECTION AND QUANTITATION OF CIRCULATING CANCER-CELLS IN THE PERIPHERAL-BLOOD OF LUNG-CANCER PATIENTS

Detection and quantitation of circulating cancer cells in peripheral b lood may improve cancer staging and monitoring, This study explored th e feasibility of using circulating cancer cell detection in peripheral blood for the rapid assessment of chemotherapeutic response. Cytokera tin 19 mRNA was amplified by nested reverse transcriptase-PCR in the p eripheral blood of 29 healthy volunteers, 33 pneumonia patients, and 8 6 lung cancer patients. Circulating cancer cells in the peripheral blo od were semiquantitatively determined by taking the ratio of cytokerat in 19 band intensity from the second round of nested PCR to the glycer aldehyde-3-phosphate dehydrogenase band intensity from the first round of PCR amplification. The detection limit of the method was 1 cancer cell in 10(7) peripheral blood mononuclear cells. The positive detecti on rate was 40% for lung adenocarcinoma patients of all stages, 41% fo r squamous carcinoma patients of all stages, and 27% for small cell lu ng cancer patients. Only one control sample from a pneumonia patient s howed a positive result (1.6%), The quantitative method reliably and s ensitively estimated cancer cell numbers in the peripheral blood of lu ng cancer patients. Serial measurement of the relative number of circu lating cancer cells correlated with the tumor burden and treatment res ponse of patients. This method may help rapidly assess the efficacy of anticancer treatment, redefine cancer staging, and facilitate the des ign of better therapeutic strategies for the treatment of cancer patie nts.