The present invention discloses a method for rapid assessment of lung cancer therapy efficacy in a few days instead of weeks by conventional imaging methods. This method can also be used to detect relapse of the cancer and to improve the current TNM cancer staging method for more accurate prognosis. The rapid assessment of therapy efficacy is based on detecting circulating cancer cells in body fluid with high positive detection rate. The high positive detection rate is achieved by using qPCR amplification of multiple marker genes identified by in silico search of DNA sequence database. This invention also discloses a scoring method to calculate the cancer cell load based on qPCR results to correlate the amount of circulating cancer cells in lung cancer patients and predict the treatment outcomes.