The basic goals of this project are to develop and use a cancer patient data system which will (1) provide frequent, in-depth evaluation of the Mayo Clinic Cancer Center activities; (2) enable cooperation to be accomplished between Mayo and the other 17 comprehensive cancer centers, and (3) by helping in the detection of disease, treatment of patients and general protocol evaluation contribute to the improvement of the lot of the cancer patient. Methods involve a linkage of present data systems by computer terminal use and data storage. Research patients and surgically treated patients already are served by effective records which will be adapted for use in the new system. Non-research (but treated) patients will be added by a new data collection program. Records of the totality of cancer patients will be checked for completeness and correctness in a final system based on all histories as they go to file. Compliance with SEER codes (as modified by the EPISTAT committee of the cancer centers) will be maintained.