The Optimal Duration of Adjuvant Chemotherapy in Colon Cancer

Adjuvant chemotherapy for colon cancer (UICC stage II and III) has been under investigation over the last 30 years, regarding treatment duration and regimens. In this review, choice of regimen, its duration, possible limitations and future perspectives are discussed. Monotherapy with 5-fluorouracil was followed by addition of oxaliplatin, resulting in improved 3-yr disease free survival (DFS) and overall survival (OS) rates, but also increased peripheral sensory neurotoxicity (PSN). The International Duration Evaluation of Adjuvant therapy (IDEA) collaboration demonstrated less toxicity, especially PSN, when shortening treatment duration to 3 months. However, formally, the anticipated non-inferiority of 3 months with fluoropyrimidine (FP)/oxaliplatin over 6 months (at 3-yr DFS) was not met for all patients groups, although subgroup analyses showed non-inferiority with capecitabine/oxaliplatin (CAPOX) rather than with FOLFOX, and also in relation to the prognostic information (e.g., clinical low-risk group, pT1-3 N0). In addition, first data of newer parameters like Immunoscore® and ctDNA show promising results as stratification parameters. Further investigations to better define clinical risk groups and prognostic factors are mandatory. Besides this, individual decision-making of treatment intensity (FP or FP/oxaliplatin) and duration should always consider patient characteristics and preferences, also given the absolute relatively small differences and their clinical relevance.

JOIN trial: treatment outcome and recovery status of peripheral sensory neuropathy during a 3-year follow-up in patients receiving modified FOLFOX6 as adjuvant treatment for stage II/III colon cancer

Purpose

Adjuvant FOLFOX therapy is an established standard-of-care for resected colon cancer. Peripheral sensory neuropathy (PSN) is regarded as the major toxicity issue related to FOLFOX therapy. There have been a few reports on the recovery status from PSN thereafter. JOIN trial investigated the tolerability and efficacy of adjuvant modified FOLFOX6 (mFOLFOX6) in Japanese patients with stage II/III colon cancer.

Methods

Twelve cycles of mFOLFOX6 were given to patients with stage II/III curatively resected colon cancer. Treatment outcomes, including disease-free survival (DFS), relapse-free survival (RFS), overall survival (OS), and recovery status of PSN during 3-year follow-up, were investigated.

Results

Of the 882 patients enrolled from 2010 to 2012, 864 were eligible for the efficacy analyses. Three-year DFS, RFS, and OS were favorable in 92.1, 92.8, and 97.4% of stage II patients; 76.4, 77.9, and 93.8% of stage IIIA/B; and 61.6, 62.7, and 85.9% of stage IIIC, respectively. The cumulative incidence of PSN during treatment was 47.8% in grade 1 (G1), 30.3% in G2, and 5.8% in G3. For those with G3 PSN during treatment, there was gradual recovery in 1.1% of patients at 12 months after enrollment, 0.5% at 24 months, and 0.2% at 36 months. However, G1 or G2 residual PSN after 3 years was observed in 21.0% (18.7%, G1; 2.3%, G2).

Conclusions

Adjuvant mFOLFOX6 therapy was effective and well tolerated in patients with stage II/III colon cancer. Most patients recovered from G3 PSN related to oxaliplatin, but approximately 20% of patients had G1 or G2 PSN at 3-year follow-up.

Electronic supplementary material

The online version of this article (10.1007/s00280-019-03957-5) contains supplementary material, which is available to authorized users.

Adjuvant chemotherapy in resected colon cancer: When, how and how long?

The benefit of adjuvant chemotherapy has been clearly established in the adjuvant setting for node-positive colon cancer. A number of trials in the adjuvant setting have analyzed the efficacy of multiple-agent combinations, including irinotecan, oxaliplatin, bevacizumab and cetuximab. Only oxaliplatin added to fluorouracil/capecitabine has been shown to be superior beyond a fluropyrimidine alone in the adjuvant setting. As such, standard treatment options include fluorouracil (FU) or capecitabine with or without oxaliplatin. However, oxaliplatin is associated with cumulative dose-dependent neurotoxicity, characterized by distal or perioral paresthesias or dysesthesias; for this reason, in this review we discuss the results of the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) trial. The IDEA trail is the largest prospective clinical trial ever conducted in colorectal cancer, wherein patients were treated with either 3 months or 6 months of adjuvant chemotherapy. In the era of cancer gene expression-based subtyping, the Colorectal Cancer Subtyping Consortium has proposed a four-subgroup molecular classification system for colorectal cancer, consisting of CMS1 (immune), CMS2 (canonical), CMS3 (metabolic) and CMS4 (mesenchymal). In this review, we present and analyze the available data on efficacy and toxicity of the combination regimen approved for treatment of resected colon cancer, and discuss the questions of when, how and how long we need to treat such patients.

The Optimal Duration of Adjuvant Therapy for Stage III Colon Cancer: the European Perspective

OPINION STATEMENT

The International Duration Evaluation of Adjuvant Therapy (IDEA) collaboration was created to pool data from different studies worldwide in order to assess whether a shorter duration of adjuvant treatment in colon cancer could maintain the expected benefit while reducing toxicity. The results of the IDEA trials were clinically relevant. They confirmed a two- to sixfold reduction in neurotoxicity for the shorter duration across trials. Overall, the 3-year disease-free survival was very similar: only 0.9% lower for the 3 months group. However, the results were partially unexpected, because they revealed a difference among chemotherapy regimens (CAPOX better than FOLFOX) and risk groups within stage III. The similar outcome between 3 and 6 months of CAPOX coupled with the substantial reduction in toxicity makes us use the CAPOX regimen for 3 months for most stage III patients. An exception to this general rule is the patient with very high risk, i.e., either T4N1b-T4anyN2 or anyTN2b where we use 6 months of CAPOX. Our take from the trial results is also that FOLFOX should never be given for 3 months and preferably not used at all in the adjuvant setting. The conduction of the IDEA enterprise was truly global. The European contribution was major with three fourths of patients enrolled in the four European trials. Herein, we review the results of the "3 versus 6" trials and the literature regarding the interpretation of the collected data in Europe and in the rest of the world.