In previous research, we have demonstrated the value of using necropsy "surprise" lung cancer cases, in those in whom lung cancer was not suspected during life, to estimate the size and composition of the "reservoir" of undetected lung cancer in the general population. The current research was done to determine the characteristics and consequences of secular changes over time in the composition of the lung cancer "reservoir." The results suggest that further advances in diagnostic technology will enhance detection during life of the large "reservoir" of resectable lung cancer, particularly in women. With the increased detection of these reservoir cases during life, the statistical occurrence rates for lung cancer will seem to increase, but survival rates will seem to improve because more of the detected cases will be resectable.