There is weak proof increased acute grade three or four 4 adverse events in the chemoradiotherapy group . Grade 3 or 4 4 toxic effects occurred in 64 of 178 sufferers in the chemoradiotherapy group, as compared with 50 of 182 sufferers in the radiotherapy group . These events were primarily gastrointestinal toxic effects, with 17 events in the chemoradiotherapy group versus 5 events in the radiotherapy group . Grade three or four 4 RTOG adverse events occurred in some true point during follow-up in 10 of 120 patients in the chemoradiotherapy group and 17 of 108 in the radiotherapy group at some time during follow-up .Subgroup Analyses The inverse association of colonoscopy with colorectal cancer appeared to be similar across subgroups defined according to age, body-mass index, smoking status, and status regarding regular usage of aspirin . Among individuals with a grouped genealogy of colorectal cancer, a substantial association was no longer noticed beyond 5 years after colonoscopy . By contrast, there was a sustained association beyond 5 years among people without a family history of colorectal cancer .