The NCCTG Data Monitoring Committee reviews all phase III cancer treatment and cancer control trials coordinated by NCCTG. The primary functions of the Committee are: a) to assure safety of the treatment regimens, b) to examine efficacy results and determine whether or not the trial should be continued, modified, or discontinued, c) to review changes in study design in order to promote scientific integrity of the trial, d) to review accrual information in order to assure that the trial will yield meaningful results, and e) to review requests for release of data to investigators prior to general release as specified in the trial design.