Background: A 2009 analysis of 20,898 CC patients from 18 randomized studies of adjuvant therapy (AT) in the ACCENT database showed that treatment with AT (versus surgery alone) lowers the risk of recurrence and death at all time points, especially in stage III (versus stage II) disease. However, this analysis evaluated only FU/LV therapies and excluded modern oxaliplatin-based (OX) therapies. Methods: With mature follow-up now available (median 6 years), 12,233 patients from ACCENT enrolled to C-07, C-08, N0147, MOSAIC, and XELOXA (18% stage II, 82% stage III) were pooled to examine the impact of OX and tumor specific factors (tumor stage, nodal stage, tumor location, and tumor grade) on the time course of recurrence and death from all causes. For each endpoint, continuous-time risk was modeled over 8 years post-treatment in (1) OX-treated patients from all trials and (2) patients concurrently randomized to OX versus 5FU/LV, where the latter set of analyses supported time-dependent treatment comparisons. Results: Addition of OX reduced the risk of recurrence and death at all time points and in all disease subgroups, with no differences in the timing of outcomes between treatment groups (i.e., OX did not simply postpone recurrence or death compared to 5FU/LV alone; see Table). OX significantly reduced recurrence risk during the first 4 years, and significantly reduced risk of death from 2 to 6 years post-treatment. Recurrence risk peaked near 14 months for both treatment groups, with 83% of patients treated with OX (80% of patients treated with 5FU/LV) who recurred within 8 years doing so by 3 years post-treatment. Risk of recurrence and death increased with increased tumor and nodal burden. Conclusions: These analyses support the addition of oxaliplatin to fluoropyrimidines as a curative therapy in the adjuvant setting and strongly underscore the need for adequate surveillance of CC patients, especially during the first 3 years after adjuvant therapy.