tokens: The Gastrointestinal Tumor Study Group ( GITSG ) protocol GI - 7175 randomized 227 patients between 1975 and 1980 following complete surgical resection of stages B2 and C rectal adenocarcinoma to four treatment arms : ( 1 ) no adjuvant therapy , ( 2 ) chemotherapy only , ( 3 ) radiotherapy only , and ( 4 ) radiotherapy and chemotherapy ( combined modality ) .