International Duration Evaluation Of Adjuvant Chemotherapy Research Articles

Impact of the IDEA collaboration study on practice patterns of adjuvant chemotherapy in patients with stage III colon cancer: A population-based study.

533 Background: The International Duration Evaluation of Adjuvant Chemotherapy (IDEA) collaboration showed no significant clinical difference in outcomes in patients with stage III colon cancer treated with 3 months versus 6 months of oxaliplatin-based adjuvant chemotherapy (O-ACT). We aimed to assess the change in practice patterns of ACT before and after publication of the IDEA study. Methods: This was a retrospective, population-based, cohort study of patients ≥ 18 years of age diagnosed with stage III colon cancer between January 1, 2012 and December 31, 2021 in Alberta, Canada. Eligible patients received >1 dose of ACT. Patients were divided into two groups; pre-IDEA (diagnosed prior to March 31, 2018) and post-IDEA (diagnosed on or after April 1, 2018). Treatment duration was categorized as short (<4.5 months) and long (≥4.5 months). The primary outcome was the median duration and type of ACT and factors associated with a shorter duration of ACT. Two-year overall survival (OS) and cancer-specific survival (CSS) were secondary outcomes. Results: We identified a total of 735 patients. Median age at diagnosis was 64 years (range 27-90 years) and 52.8% (N=388) were male. 48.8% (N=359) patients had had pT4 and/or pN2 disease. 78% (N=572) received O-ACT. In the post-IDEA era, the use of capecitabine plus oxaliplatin (CAPOX) ACT increased (23.0% to 50.9%, p<0.001) and median duration of O-ACT was significantly shorter (2.7 vs 4.8 months, p<0.001). On multivariable logistic regression, factors associated with shorter duration of ACT included treatment in the post-IDEA era (odds ratio [OR] 1.85, p=0.007), no pT4 and/or pN2 disease (OR 1.6, p=0.02), and receipt of CAPOX ACT (OR 2.7, p<0.001). Characteristics not significantly associated with ACT duration included age, sex, residence rurality, neighborhood income, and comorbidity index. The 2-year OS and CSS was similar in the pre-IDEA and post-IDEA eras (OS 95% vs 93%, p=0.29; CSS 96% vs 96%, p=0.30). Neither time era or treatment duration were independently associated with OS or CSS in multivariable models. Conclusions: Our study is one of the first that shows that the results of the IDEA trial have been largely adopted in clinical practice with shorter duration of ACT and increased use of CAPOX ACT in low-risk stage III colon cancer using population-based data.

Elevated serum carcinoembryonic antigen level after curative surgery is a prognostic biomarker of stage II-III colorectal cancer

BackgroundHigh preoperative carcinoembryonic antigen (CEA) is a well-known risk factor for stage II-III colorectal cancer (CRC); however, in most cases, cancer does not recur. Conversely, postoperative CEA (post-CEA) is occasionally measured, and high post-CEA patients often develop recurrence; however, the clinical significance of post-CEA testing is unknown. The purpose of this study was to determine whether post-CEA elevation might indicate a poor prognosis for stage II-III CRC patients who underwent curative surgery. Patients and methods482 patients with pathological stage II-III CRC were included. Univariate and multivariate analyses were performed to evaluate post-CEA levels. ResultsMultivariate analysis showed that elevated post-CEA (hazard ratio (HR): 3.14, P < 0.001), pathological lymph node metastasis (pN+), and pathological T4 (pT4) are associated with poor recurrence-free survival (RFS), and that elevated post-CEA (HR: 3.12; P = 0.002), pN+, pT4, age >70, and smoking are independently associated with poor overall survival. Subgroup analysis among stage III patients, in combination with the risk classification of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) study, showed that elevated post-CEA is a significant indicator of poor prognosis for RFS in both low-risk (73.8% vs. 21.2%, P < 0.001) and high-risk (49.9% vs. 25.0%, P = 0.04) groups. ConclusionsPost-surgical CEA elevation is independently associated with poor prognosis in stage II-III CRC. Adding post-CEA levels to the IDEA risk classification may provide a more reliable indicator of the need for individualized surveillance and adjuvant chemotherapeutic strategies.

Benefit of Oxaliplatin in Stage III Colon Cancer According to IDEA Risk Groups: Findings from the ACCENT Database of 4934 Patients

BackgroundThe International Duration Evaluation of Adjuvant Chemotherapy (IDEA) pooled analysis compared 3 to 6 months of adjuvant chemotherapy for stage III colon cancer. Patients were classified into low risk and high risk, suggesting low-risk patients may be offered only 3 months of treatment. In this study, we aimed to assess the benefit of oxaliplatin in the adjuvant setting per IDEA risk groups, using data from 3 large adjuvant phase III studies, namely Multicenter International Study of Oxaliplatin/Fluorouracil/ Leucovorin in the Adjuvant Treatment of Colon Cancer (MOSAIC), C-07, and XELOXA. MethodsUsing the MOSAIC, C-07, and XELOXA previously published studies, we identified 2810 low-risk and 2124 high-risk patients with stage III colon cancer. We used Cox regression model to evaluate the magnitude of survival differences between IDEA risk groups, according to oxaliplatin use. Based on design similarity and equivalent follow-up data, MOSAIC and C-07 were pooled, whereas XELOXA was analyzed separately. Subgroup analyses were also performed for T4 and/or N2 patients. ResultsIndividuals with IDEA low and high risk derived overall survival benefit from the addition of oxaliplatin to adjuvant chemotherapy, with adjusted hazard ratios of 0.79 (0.66-0.95) and 0.84 (0.71-0.99), respectively. Among individuals with IDEA high risk, those with T4 disease did not gain overall survival benefit from addition of oxaliplatin with hazard ratio of 0.95 (0.71-1.27). Similar results were demonstrated using data from the XELOXA study. ConclusionIDEA risk classification per se does not predict benefit from addition of oxaliplatin to adjuvant chemotherapy in stage III colon cancer. T4 disease may predict lack of benefit from oxaliplatin addition.

Duration of Adjuvant Doublet Chemotherapy (3 or 6 months) in Patients With High-Risk Stage II Colorectal Cancer.

PURPOSE:As oxaliplatin results in cumulative neurotoxicity, reducing treatment duration without loss of efficacy would benefit patients and healthcare providers.PATIENTS AND METHODS:Four of the six studies in the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) collaboration included patients with high-risk stage II colon and rectal cancers. Patients were treated (clinician and/or patient choice) with either fluorouracil, leucovorin, and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (CAPOX) and randomly assigned to receive 3- or 6-month treatment. The primary end point is disease-free survival (DFS), and noninferiority of 3-month treatment was defined as a hazard ratio (HR) of < 1.2- v 6-month arm. To detect this with 80% power at a one-sided type one error rate of 0.10, a total of 542 DFS events were required.RESULTS:3,273 eligible patients were randomly assigned to either 3- or 6-month treatment with 62% receiving CAPOX and 38% FOLFOX. There were 553 DFS events. Five-year DFS was 80.7% and 83.9% for 3-month and 6-month treatment, respectively (HR, 1.17; 80% CI, 1.05 to 1.31; P [for noninferiority] .39). This crossed the noninferiority limit of 1.2. As in the IDEA stage III analysis, the duration effect appeared dependent on the chemotherapy regimen although a test of interaction was negative. HR for CAPOX was 1.02 (80% CI, 0.88 to 1.17), and HR for FOLFOX was 1.41 (80% CI, 1.18 to 1.68).CONCLUSION:Although noninferiority has not been demonstrated in the overall population, the convenience, reduced toxicity, and cost of 3-month adjuvant CAPOX suggest it as a potential option for high-risk stage II colon cancer if oxaliplatin-based chemotherapy is suitable. The relative contribution of the factors used to define high-risk stage II disease needs better understanding.

Patients' Preferences for 3 Months vs 6 Months of Adjuvant Chemotherapy for Colon Cancer.

BackgroundSCOT was an international, randomized phase 3 trial of 3 months vs 6 months of adjuvant chemotherapy with oxaliplatin and a fluoropyrimidine in patients with colorectal cancer. We sought patients’ preferences for 3 months vs 6 months of adjuvant chemotherapy in the SCOT trial.MethodsSCOT participants from Australia and New Zealand completed a validated questionnaire (at 3 and 18 months) to elicit the minimum survival benefits judged necessary to make an extra 3 months of adjuvant chemotherapy worthwhile, based on their experience. Standardized hypothetical scenarios used the following baseline survivals (with 3 months of chemotherapy): life expectancies (LE) of 5 years and 15 years and 5-year survival rates (5YS) of 65% and 85%.ResultsOf the 160 participants, 82 were assigned 3 months adjuvant chemotherapy, and 78 were assigned 6 months. Adjuvant chemotherapy was FOLFOX in 121 (75.6%) and XELOX in 39 (24.4%). Preferences varied substantially and did not differ according to treatment group. The median survival benefits judged necessary to make the extra 3 months of chemotherapy worthwhile were an extra 3 years beyond a LE of 5 years; 3 years beyond a LE of 15 years; 15% beyond a 5YS of 65%; and 5% beyond a 5YS of 85%. Preferences were similar at 3 months and 18 months. Preferences were not predicted by participants’ baseline characteristics.ConclusionPreferences varied substantially, and the benefits many required to warrant an extra 3 months of adjuvant chemotherapy were larger than the benefits of an extra 3 months of chemotherapy calculated in the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) meta-analysis.

Medical Oncologists' Perspectives on How the Results of the IDEA Collaboration Impact the Adjuvant Treatment of Stage III Colon Cancer.

The International Duration Evaluation of Adjuvant Chemotherapy (IDEA) collaboration aimed to evaluate whether 3 months of adjuvant chemotherapy are noninferior to 6 months. Our study objectives were to characterize medical oncologists' perspectives toward the results of the IDEA collaboration and to evaluate how IDEA impacted prescribing patterns of adjuvant FOLFOX and CAPOX in colon cancer. A list of questions developed by four medical oncologists regarding IDEA results were formulated and distributed online to gastrointestinal medical oncologists globally. Descriptive statistics and chi-square tests were used to summarize information. Of 174 responses, 145 were complete and analyzed. Responses were obtained globally from South America (53%); the U.S. and Canada (28%); Europe, Australia, and New Zealand (12%); and Asia (7%). Most clinicians (98%) were aware of the IDEA study. Prior to IDEA, clinicians preferred FOLFOX over CAPOX (81% vs. 19%). Subsequent to IDEA, 55% of clinicians preferred CAPOX over FOLFOX (odds ratio, 5.0; 95% confidence interval, 3.0-8.5; p < .01 compared with pre-IDEA). Two thirds (68%) of responders tailored duration of adjuvant therapy based on risk stratification. Most oncologists (76%) were more willing to discontinue oxaliplatin early if toxicities develop after the results of IDEA. Half of responders (50%) found that IDEA increased their confidence in decision making for adjuvant treatment; 36% were unchanged, and 15% indicated decreased confidence. Less than half (48%) were comfortable communicating the study results and the concept of a noninferiority trial with patients. IDEA appears to have shifted clinician preference from FOLFOX to CAPOX for adjuvant therapy, and most clinicians now use a risk-stratified approach in determining duration of adjuvant therapy. Patient education resources may facilitate better communication of IDEA results to patients. This global survey illustrates that most gastrointestinal medical oncologists now use a risk-stratified approach for determining the duration of adjuvant chemotherapy for stage III colon cancer. Clinicians are five times more likely to choose CAPOX over FOLFOX after the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) collaboration results.

Three- versus six-month adjuvant FOLFOX or CAPOX for high-risk stage II and stage III colon cancer patients: the efficacy results of Hellenic Oncology Research Group (HORG) participation to the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) project.

The International Duration Evaluation of Adjuvant Chemotherapy (IDEA) aimed to investigate whether a 3 months (3M) of oxaliplatin/fluoropyrimidine-based adjuvant chemotherapy (CT) is non-inferior to the 6-month (6M) administration in 3-year disease-free survival (3yDFS) in high-risk (HR) stage II or stage III colon cancer (CC). Hellenic Oncology Research Group (HORG)-IDEA randomized patients between 3M and 6M of CT with FOLFOX4 or CAPOX. In total 1115 patients, 413 with HR stage II and 702 with stage III CC, were randomized. The median follow-up was 67.0 (38.3-126.0) months. Overall, 394 DFS events (202 in 3M arm and 192 in 6M arm) where recorded. The 3yDFS rate was 77.2% [95% confidence interval (CI) 72.1% to 82.3%] for 3M and 77.9% (72.6% to 82.5%) for 6M of treatment [hazard ratio (HR) 1.05 (95% CI 0.61-1.55); P = 0.647]. Eighty DFS events (3M N = 41; 6M N = 39) were observed in HR stage II patients for a 3yDFS rate of 82.7% and 83.4%, respectively (HR 1.05; 95% CI 0.68-1.63, P = 0.829). For stage III patients, 314 DFS events (3M N = 161 and 6M N = 153) were observed, for a 3yDFS rate of 72.9% for 3M versus 74.1% for 6M (HR 1.06; 95% CI 0.81-1.42, P = 0.622). For HR stage II patients receiving FOLFOX4, 3yDFS rate was 76.7% for 3M and 79.3% for 6M (HR 1.21; 95% CI 0.54-2.70). For HR stage II patients receiving CAPOX the 3yDFS rate was 85.4% for 3M and 83.8% for 6M (HR 0.99; 95% CI 0.59-1.67). For stage III patients receiving FOLFOX4, the 3yDFS rate was 71.5% for 3M and 77.3% for 6M (HR 1.18; 95% CI 0.74-1.86). For stage III patients receiving CAPOX, the 3yDFS rate was 74.5% for 3M and 74.7% for 6M (HR 0.99; 95% CI 0.70-1.44). The results of the HORG-IDEA study are in line with those of the global IDEA project, indicating that the 3yDFS is dependent on the administered adjuvant regimen and the choice and duration of regimen should be personalized. NCT01308086.

Duration of Adjuvant Chemotherapy in Colon Cancer: Current Standards and New Updates

Adjuvant therapy for 6 months is the standard of care for stage III colon cancer. The use of oxaliplatin-based therapy over fluoropyrimidine alone increases toxicity, including dose-dependent peripheral neuropathy. Evaluation of a shorter duration of adjuvant therapy was therefore warranted, aiming to reduce toxicity while maintaining clinical efficacy. The International Duration Evaluation of Adjuvant chemotherapy (IDEA) collaboration was a pivotal prospective pooled analysis of 6 randomized phase III trials across 12 countries. IDEA evaluated the non-inferiority of 3 versus 6 months of adjuvant oxaliplatin-based chemotherapy. The 3-year disease-free survival was very similar between the 3-month and 6-month study arms. Despite this, non-inferiority was not confirmed. However, important differences were observed between FOLFOX and CAPOX regimens, and risk groups within stage III disease, which allow for greater individualization of adjuvant therapy. The IDEA results suggest 3 months of therapy is reasonable in most patients with stage III disease, especially those with low-risk disease. Importantly, 3 months of therapy is associated with a dramatic reduction in peripheral neuropathy. A thorough discussion of the risks and benefits with patients regarding the duration of therapy is required. In this review, we discuss the IDEA findings and the optimal duration of adjuvant chemotherapy in stage III colon cancer.

Prognostic value of tumor deposits for disease free survival in patients with stage III colon cancer: A post hoc analysis of IDEA France phase III trial (PRODIGE-GERCOR).

3519 Background: Tumor deposits (TDs) are isolated tumor foci in the pericolic, perirectal or mesocolic fat without residual lymph node (LN) tissue. TDs seem to impact the prognosis of stage III colon cancer (CC) patients (pts) but are only considered in TNM staging in the absence of LN metastases (LNM). We aimed at evaluating the prognosis value for disease free survival (DFS)of TDs in International Duration Evaluation of Adjuvant Chemotherapy (IDEA) France phase III study (NCT00958737) that compared 3 versus 6 months of adjuvant FOLFOX or CAPOX for stage III CC pts. Methods: All pathological reports of pts included in IDEA France trial were retrospectively analyzed. DFS according to the presence or absence of TDs was evaluated using Kaplan-Meier estimator. Multivariable Cox model analysis was performed to evaluate the association between TDs and DFS. This analysis did not included immunohistochemical biomarkers. Results: Among the 2022 pts included in IDEA France study, 1942 (96%) were analyzed. 80 pts were excluded: no pathological report (n = 68), pts without treatment (n = 12). TDs were found in 184 pts (9.47%), of whom 74 with N1a/b (40%), 55 with N1c (30%) and 55 with N2 LN stage (30%). All characteristics were similar according to the presence of TDs, except for tumor/node (TN) stage (T4 and/or N2 are more frequent in pts with TDs; p = .0046). The 3-year DFS rates were 65.59% [95% confidence interval (95%CI) 58.04-72.12] and 74.71% [95%CI 72.57-76.71] for pts with and without TDs, respectively (p = 0.0079). In multivariable analysis, TDs were associated with higher risk of recurrence or death (hazard ratio (HR) = 1.36, 95%CI 1.05-1.75, p = .0201), as well as T4 and/or N2 (HR = 2.21, 95%CI 1.03-1.59, p &lt; .001), 3 months of adjuvant treatment (HR = 1.29, 95%CI 1.09-1.52, p = .0029), obstruction (HR = 1.28, 95%CI 1.03-1.59, p = .0233) and male (HR = 1.24, 95%CI 1.04-1.46, p = .0151). Adding TDs count to the LNM count, 35 out of 1454 N1a/b/c CC pts (2.4%) were reclassified as N2 and experienced worse 3 years DFS than confirmed N1 CC pts (p = .0151). Conclusions: TD is an independent and valuable prognostic factor for DFSin stage III CC pts and should be considered whatever the LNM status.

Three versus six months adjuvant FOLFOX or CAPOX for high risk stage II and stage III colon cancer patients: The efficacy results of Hellenic Oncology Research Group (HORG) participation to the International Duration Evaluation of Adjuvant chemotherapy (IDEA) project.

3500 Background: The IDEA aimed to investigate whether a 3-month (3M) of oxaliplatin/fluoropyrimidines-based adjuvant chemotherapy (CT) is non-inferior to the 6-month (6M) in 3-year disease free survival (DFS) in stage high risk stage II and in stage III colon cancer (CC). Methods: HORG-IDEA randomized patients between 3M and 6M of CT with FOLFOX4 or CAPOX with primary end point the 3 years DFS (3yDFS). Results: In total 1121 patients, 413 with high risk stage and 708 with stage IIICC, were randomized between May 2009 and October 2015. The median follow-up was 67 (38-126) months. There were 79 DFS events (43 in 3M and 38 in 6M arm) in high risk stage II patients leading to 3yDFS rate of 82.7 and 83.4% for 3M and 6M, respectively (HR: 1.05; 95%CI: 0.68-1.63, p = 0.829). Similarly, 214 DFS events (161 in 3M and 153 in 6M arm) has been recorded in stage III patients, leading to a 3yDFS rate of 72.9% in the 3M vs. 74.1% in the 6M (HR = 1.06; 95%CI: 0.81–1.42, p = 0.622). For high risk stage II patients receiving FOLFOX4, 3yDFS rate was 76.7% in the 3M vs.79.3% in the 6M (HR = 1.21; 95%CI: 0.54–2.70 p = 0.641). For high risk stage II patients receiving CAPOX 3-year DFS rate was 85.4% in the 3M vs. 83.8% in the 6M (HR = 0.99; 95%CI: 0.59–1.67 p = 0.968). For stage III CC patients receiving mFOLFOX6, 3-year DFS rate was 71.5% in the 3M vs.77.3% in the 6M (HR = 1.18; 95%CI: 0.74–1.86 p = 0.479). For stage III CC patients receiving CAPOX 3-year DFS rate was 74.5% in the 3M vs. 74.7% in the 6M (HR = 0.99; 95%CI: 0.70–1.44 p = 0.991). Conclusions: The results of the HORG-IDEA study are in line with those of the global IDEA project, indicating that 3yDFS is depended on the administered adjuvant regimen, and the choice of regimen and duration should be personalized. Clinical trial information: NCT01308086.

Duration of Oxaliplatin-Containing Adjuvant Therapy for Stage III Colon Cancer: ASCO Clinical Practice Guideline.

To develop recommendations for duration of adjuvant chemotherapy with a fluoropyrimidine and oxaliplatin for patients with completely resected stage III colon cancer based on the results of trials of 3 months compared with 6 months of treatment. ASCO convened an Expert Panel and conducted a systematic review of relevant studies. The guideline recommendations were based on the review of evidence by the Expert Panel. Pooled data from the six International Duration Evaluation of Adjuvant Chemotherapy (IDEA) Collaboration randomized controlled trials comprise the evidence base for these guideline recommendations. The recommendations for therapy duration apply to patients with completely resected stage III colon cancer who are being offered adjuvant chemotherapy with oxaliplatin and a fluoropyrimidine. Recommendations are informed by the findings of a recent pooled analysis of clinical trials that compared 6 months versus 3 months of oxaliplatin-based chemotherapy. For patients at a high risk of recurrence (T4 and/or N2), adjuvant chemotherapy should be offered for a duration of 6 months. For patients at a low risk of recurrence (T1, T2, or T3 and N1), either 6 months of adjuvant chemotherapy or a shorter duration of 3 months may be offered on the basis of a potential reduction in adverse events and no significant difference in disease-free survival with the 3-month regimen. In determining duration of therapy, the Expert Panel recommends a shared decision-making approach, taking into account patient characteristics, values and preferences, and other factors and including a discussion of the potential for benefit and risks of harm associated with treatment duration. Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines .

Recent advances in understanding colorectal cancer.

The achievements in the treatment of metastatic colorectal cancer during recent years are based on a better understanding of the disease and individualized regimen planning. In adjuvant treatment, the highly important IDEA (International Duration Evaluation of Adjuvant Chemotherapy) study has shown that treatment duration can safely be reduced in selected patient populations. In patients with pN1 and pT1-pT3 tumors, 3 months of treatment with 5-fluorouracil and oxaliplatin is comparable with respect to 3-year survival rate to 6 months of treatment. For patients with N2 tumors, 6 months of treatment should stay the standard of care. The limitation of the duration of the adjuvant treatment is significantly reducing the chemotherapy-induced morbidity. New studies will explore the use of immune-checkpoint inhibitors in the adjuvant setting in microsatellite-instable (MSI) tumors. In metastatic disease, next to the required molecular testing for RAS and BRAF mutations, MSI testing is recommended. In the rare group of patients with a MSI tumor, immune-checkpoint inhibition is changing the course of the disease dramatically. Therefore, it is important to identify those patients early. For the RAS-mutant cases, no new and targeted treatment options have been identified yet. An optimal treatment strategy for those patients is urgently needed. RAS wild-type patients with tumors derived from the left side of the colon (splenic flexure to rectum) should be treated in first line with epithelial growth factor receptor (EGFR) antibodies. This selection by a molecular and a clinical marker increased the benefit derived by EGFR antibodies dramatically and defined the most effective treatment option for those patients. New selection criteria based on gene expression, methylation, and other molecular changes are explored and will further influence our therapeutic strategies in the future.

Noninferiority of three months versus six months of oxaliplatin-based adjuvant chemotherapy for resected colon cancer. How should IDEA findings affect clinical practice?

The eagerly awaited results of the multi-continental International Duration Evaluation of Adjuvant Chemotherapy (IDEA) project have recently been presented at major oncological meetings. The 3-year disease-free survival (DFS) was presented for 12,834 Stage III colon cancer patients in a pooled analysis of 6 individual noninferiority phase III randomized trials, all investigating three versus six months of oxaliplatin-based adjuvant therapy. Noninferiority (NI) could not be demonstrated for the whole population as the DFS hazard ratio (HR) of 1.07 with its 95% CI of 1.00-1.15 crossed the postulated NI boundary of 1.12. However, there was an expected reduction in the incidence of specific side effects with the three months treatment. NI could be demonstrated for the T3N1 subgroup (∼60% of patients, HR for DFS 1.01, 95% CI 0.90-1.12). Moreover, NI was also declared for the subgroup treated with the CAPOX regimen (capecitabine plus oxaliplatin, ∼40% of patients), but the CAPOX choice was physician-based and not subject to randomization. Overall, the IDEA results indicate that three months of therapy might be adequate for most of Stage III tumors; however, a small subset of these patients still have high risk of recurrence and death with short treatment duration. Precise predictors of benefit need to be identified, nonetheless tumor-intrinsic factors, such as tumor stage, might currently be considered as useful tools to inform the decision-making process.

LBA21_PR - Prospective pooled analysis of six phase III trials investigating duration of adjuvant (adjuv) oxaliplatin-based therapy (3 vs 6 months) for patients (pts) with stage III colon cancer (CC): Updated results of IDEA (International Duration Evaluation of Adjuvant chemotherapy)

LBA21_PR - Prospective pooled analysis of six phase III trials investigating duration of adjuvant (adjuv) oxaliplatin-based therapy (3 vs 6 months) for patients (pts) with stage III colon cancer (CC): Updated results of IDEA (International Duration Evaluation of Adjuvant chemotherapy)

Prospective pooled analysis of six phase III trials investigating duration of adjuvant (adjuv) oxaliplatin-based therapy (3 vs 6 months) for patients (pts) with stage III colon cancer (CC): The IDEA (International Duration Evaluation of Adjuvant chemotherapy) collaboration.

LBA1 Background: Since 2004, 6 months (m) of oxaliplatin (oxali)-based treatment has been the standard of care as adjuvant therapy for stage III CC. Since oxali is associated with cumulative neurotoxicity, shorter duration of adjuv therapy could spare pts toxicity and lead to substantial saving in health expenditures. Methods: A prospective, pre-planned pooled analysis of 6 concurrently conducted randomized phase III trials (SCOT, TOSCA, Alliance/SWOG 80702, IDEA France (GERCOR/PRODIGE), ACHIEVE, HORG) was performed to evaluate the non-inferiority (NI) of 3m compared with 6m (ref) of adjuv FOLFOX/XELOX. The primary endpoint was disease-free survival (DFS), defined as time from enrolment to relapse, 2nd CRC, and death (all causes). NI was to be declared if the 2-sided 95% confidence interval (CI) for DFS hazard ratio (HR 3m v 6m) estimated by a stratified Cox model was below 1.12. NI was examined within regimen and stage subgroups as pre-planned. Results: The analysis included 12,834 pts from 12 countries, accrued from 6/07 to 12/15. Stage distribution: 13% T1-2, 66% T3, 21% T4; 28% N2; 40% received XELOX. G3+ neurotoxicity was higher in the 6m v 3m arm (16 v 3% FOLFOX, 9 v 3% XELOX, p&lt;0.0001). With a median follow-up of 39 mos, 3263 DFS events were observed. Overall, the 3 year DFS rate was 74.6% (3m) and 75.5% (6m), with estimated DFS HR of 1.07 (95%CI, 1.00-1.15). The 3m v 6m DFS HRs were 1.16 (95%CI, 1.06-1.26) and 0.95 (95% CI, 0.85-1.06) for FOLFOX and XELOX treated pts, respectively. The 3m v 6m DFS HRs were 1.01 (95%CI, 0.90-1.12) in T1-3 N1, and 1.12 (95%CI, 1.03-1.23) for T4 or N2 pts. Conclusions: While NI was not established for the overall cohort, NI of 3m v 6m oxali-based adjuv therapy was supported for XELOX. As each IDEA trial treated varying proportions of pts with XELOX (0 to 75%), the regimen interaction likely produced the differential outcomes observed between individual studies. Certain substages (T1-3 N1) also showed NI for 3m v 6m. These data provide a framework for discussions on risks and benefits of individualized adjuv therapy approaches. Support: U10CA180821, U10CA180882, U10CA180888, U10CA180835, INCA, PHRC2009, EME 09/800/34, HTA 14/140/84, CRUK C1348/A15960, JFMC. Clinical trial information: NCT01150045.

Three versus six months adjuvant oxaliplatin-based chemotherapy for patients with stage III colon cancer: The French participation to the International Duration Evaluation of Adjuvant chemotherapy (IDEA) project.

3500 Background: The IDEA international collaboration was established to combine data from 6 randomized trials to assess whether a 3-month (3M) of oxaliplatin/fluoropyrimidines-based adjuvant chemotherapy (CT) is non-inferior to the 6-month (6M) for 3-year disease free survival (DFS) in stage III colon cancer (CC). Methods: French IDEA randomized patients (pts) between 3M and 6M of CT with mFOLFOX6 or XELOX (physician/pts choice). DFS was estimated using the Kaplan–Meier method and described using 3 years DFS rate. Results: Among 2022 randomized pts between May 2009 and May 2014, 2010 (99.4%) received CT and were enrolled in the mITT population: 49.9 and 50.1% in 3M and 6M, respectively. 99.5% of the mITT pts had stage III (N1: 74.9%; N2: 25.2%); median age 63.9 years; mFOLFOX6: 90% and XELOX 10% of pts. DFS median follow-up is 50.2 months. There were 578 DFS events (314 in 3M and 264 in 6M arm) leading to a 3-year DFS rate of 72.1% in the 3M vs. 75.7% in the 6M (HR=1.24; 95%CI 1.05–1.46, p=0.0112). For pts receiving mFOLFOX6, 3-year DFS rate was 72.0% in the 3M vs. 76.3% in the 6M (HR=1.27; 95%CI 1.07–1.51 p=0.0069). 94.2% and 78.0% of pts completed 3 and 6 months of CT, respectively. Median oxaliplatin doses intensity were 96.9% in 3M and 72.1% in 6M (495.0 and 735.1 mg/m2). By considering the neuropathy grade with 15375 neuropathy longitudinal measurements the overall maximal neuropathy grade 0-1/2/3-4 was 63.6/28.5/7.9% in 3M and 33.4/41.3/25.3% in 6M; p&lt;0.0001. At last follow-up assessment, with a median of 43.1 months, final residual grade 2/3-4 neuropathy was 2.1/0.4% in 3M and 5.4/1.3% in 6M; p&lt;0.0001. Conclusions: The IDEA France study, with 90% of patients treated with mFOLFOX6 regimen has shown that 6 months adjuvant treatment is superior to 3 months treatment. IDEA France study results should be considered in line with the international IDEA project that will also be presented at ASCO 2017. Clinical trial information: 2009-010384-16.

Prospective pooled analysis of six phase III trials investigating duration of adjuvant (adjuv) oxaliplatin-based therapy (3 vs 6 months) for patients (pts) with stage III colon cancer (CC): The IDEA (International Duration Evaluation of Adjuvant chemotherapy) collaboration.

LBA1 The full, final text of this abstract will be available at abstracts.asco.org at 7:30 AM (EDT) on Sunday, June 4, 2017, and in the Annual Meeting Proceedings online supplement to the June 20, 2017, issue of the Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Sunday edition of ASCO Daily News.

The Greek participitation to IDEA (International Duration Evaluation of Adjuvant Chemotherapy) study of 3 versus 6 months of adjuvant chemotherapy in stage III colon cancer: Patients’ characteristics and safety analysis.

740 Background: The International Duration Evaluation of Adjuvant (IDEA) collaboration was established to prospectively analyze data from six randomized trials to assess whether a 3-month course of oxaliplatin/fluoropyrimidines (FU)-based adjuvant chemotherapy (CT) is non-inferior to the 6-month current standard treatment in stage III colon cancer (CC). The primary endpoint of IDEA was 3-year disease-free survival. The accrual goal for the Greek IDEA study was 1.000 patients. Methods: Greek IDEA randomized patients with stage III colon cancer between 3 months (arm A) and 6 months (arm B) of adjuvant CT with modified (m) FOLFOX6 or XELOX (depending on physician/patient choice). Toxicity was graded during treatment and follow-up using NCI-CTCAE v3.0. Results: From May 2009 to October 2015, 708 patients were randomized in Greek centers either to arm A (n = 354, 50%) or to arm B (n = 354, 50.%). 297 (41.9%) patients received mFOLFOX6 and 411 (58.%) XELOX. The median age was 67 years (20-75) and 579 (81.8%) of them had PS 0. The patients’ population was balanced for the major risk factor between the two arms: N1/N2 disease (68.1/31.9% vs. 68.9/31.1 for ARM A and B, respectively), obstruction (4.5% vs. 2.5 for ARM A and B, respectively) and perforation (5.1% vs. 6.2 for ARM A and B, respectively). Overall, 96.9% and 89.5% of patients completed 3 months (arm A) and 6 months (arm B) of CT, respectively. Median oxaliplatin dose was 505 mg/m2 in arm A and 738 mg/m2 in arm B. Toxicity profiles were comparable between the two arm and the two fluoropyrimidines backbones with a total incidence of Grade 3/4 adverse events 18.9/4.4% and 19.7/5.1% for mFOLFOX6 and XELOX, respectively. Grade 2/3-4 peripheral neuropathy during the study was similar between arm A (33.9/4%) and B (38.7/3.7%). Conclusions: Both mFOLFOX6 and XELOX were safe. More patients completed the scheduled treatment in the 3-arm schedule.

Baseline creatinine clearance as an indicator of severe adverse events associated with oxaliplatin-based adjuvant chemotherapy in patients with stage III colon cancer: Safety analysis of the phase III Japanese ACHIEVE trial.

667 Background: The phase III ACHIEVE trial (JFMC47), a project of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA), was established to prospectively analyze data from several randomized trials to test whether 3-month (arm 3) oxaliplatin-based adjuvant (FOLFOX4, mFOLFOX6, or XELOX) treatment is non-inferior to 6-month (arm 6) treatment in terms of disease-free survival in patients (pts) with stage III colon cancer. It aims to reveal the association between baseline characteristics and ≥ grade 3 adverse events (AEs) related to XELOX and mFOLFOX6, particularly focusing on the role of baseline creatinine clearance (CCr) on ≥ grade 3 AEs. Methods: This association was assessed using the Cox proportional hazards model. Results: During 2012–2014, 1,313 pts were randomized from 244 centers; 1,301 were included in the intention-to-treat population. Among the safety population (N = 1,277; 642, arm 3; 635, arm 6), the overall incidence of ≥ grade 3 AEs was 29% in arm 3 and 43% in arm 6 (p &lt; 0.0001). Neuropathy of ≥ grade 2 was more frequent in arm 6 than in arm 3 (37% vs. 14%; p &lt; 0.0001). Regarding the fluoropyrimidine backbone, grade 3–4 neutropenia was more with mFOLFOX6 than XELOX (30% vs. 12%), whereas grade 3–4 anorexia (2% vs. 5%) and grade 3–4 diarrhea (1% vs. 6%) were more with XELOX. Multivariate analysis, including treatment duration, regimen, CCr ( &lt; 50 vs. &gt; 50 mL/min), age, and sex, showed that CCr had a statistically significant impact on the occurrence of ≥ grade 3 AEs (hazard ratio = 0.44, p &lt; 0.0001). Pts with CCr &lt; 50 may have had more frequent ≥ grade 3 AEs independent of other factors, such as age. Conclusions: Grade 3 or higher AEs related to XELOX or mFOLFOX6 may be associated with the degree of CCr. Clinical trial information: UMIN 000008543.

The prospective French participitation to IDEA (International Duration Evaluation of Adjuvant Chemotherapy) study in stage III colon cancer: Patients’ characteristics and safety analysis of 3 versus 6 months of adjuvant chemotherapy.

633 Background: The IDEA international collaboration was established to prospectively combine/analyze data from six randomized trials to assess whether a 3-month course of oxaliplatin/fluoropyrimidines-based adjuvant chemotherapy (CT) is non-inferior to the 6-month current standard treatment in stage III colon cancer (CC). The primary endpoint of IDEA was 3-year disease-free survival. The accrual goal for the French IDEA study was 2,000 patients. Methods: French IDEA randomized patients with stage III CC between 3 months (arm A) and 6 months (arm B) of adjuvant CT with modified (m) FOLFOX6 or XELOX (depending on physician/patient choice). Oxaliplatin was stopped in case of persistent neuropathy grade ≥2 with fluoropyrimidines continuation for the planned duration. Toxicity was graded during treatment and follow-up using NCI-CTCAE v3.0. Results: From May 2009 to May 2014, 2,023 patients were randomized in 129 French centers either to arm A (n=1009, 49.9%) or to arm B (n=1014, 50.1%). 2012 (99.5%) patients had stage III disease (N1: 75%; N2: 25%) and 11 patients had stage II (n=2) or stage IV disease (n=9). Median age was 64 years (18-85). 89.4% of patients received mFOLFOX6, 10.1% of patients received XELOX, and 0.5% of patients did not receive any study treatment. Overall, 94.1% and 77.5% of patients completed 3 months (arm A) and 6 months (arm B) of CT, respectively. Median oxaliplatin dose was 500 mg/m2 in arm A and 747 mg/m2in arm B. Toxicity profiles depended on the FU backbone with more grade 3/4 neutropenia on mFOLFOX6 (15.0% vs 6.5%) and more grade 3/4 diarrhea (4.7% vs 8.1%) on XELOX. Grade 2/3-4 peripheral neuropathy was less common in arm A than in arm B (23.2/6% vs 37.9/20.4%). Grade 2/3-4 residual neuropathy for patients with a follow-up of at least 3 years (n=811, median follow-up of 3.91 years) was 2.3/0.5% in arm A vs 3.9/ 2.4% in arm B. At 6 months after randomization, mortality rate was 0.7% (n=7) on arm A and 0.5% (n=5) on arm B. Median follow-up is 2.74 years for the whole population. Conclusions: Both mFOLFOX6 and XELOX were safe. Peripheral neuropathy was lower in arm A than in arm B. Clinical trial information: 2009-010384-16.