Adjuvant therapy for colon cancer.

Adjuvant therapy for colon cancer: learning from the past to inform the future.

National Surgical Adjuvant Breast and Bowel Project trials in colon cancer

Locally advanced rectal adenocarcinoma: Treatment sequences, intensification, and rectal organ preservation.

The FOGT (Study Group for GI-Oncology) was formed among clinicians and scientists with the aim of testing innovative scientific concepts in gastrointestinal tumors, especially colorectal cancers, within controlled clinical studies. In the FOGT-1 trial (n=813stage III or II(T4N0) colon cancer patients) the effect on recurrence-free and overall survivalwas tested by an adjuvant chemotherapy protocol with double-modulation of 5-fluorouracil (5-FU) and levamisole (LEV) with either folinic acid (FA) or interferon-alpha (IFNa) in a three arm randomized trial within 60 German cancer centers. In parallel, in the FOGT-2 trial stage II or III rectal cancer patients (n = 796 pts.) were treated with additional postoperative radiochemotherapy (50,4 Gy). The most effective arm of these trials was tested as control arm versus a 5-FU/FA/irinotecan (FOLFIRI) protocol in the two-arm FOGT-4 trial (n = 281stage III or II(T4N0) colon cancer pts.) for adjuvant therapy in colon cancer. In the FOGT-1 trial, we found a 11% overall survival (OAS) benefit in patients who were treated for one year adjuvantly with 5-FU plus FA (77% OAS), compared to treatment with either 5-FU or 5-FU plus interferon-alpha (each 66% OAS). This effect was statistically significant for colon cancer patients (FOGT-1), but not for rectal cancer patients (FOGT-2). In rectal cancer, the 5-FU plus FA arm showed this effect with a 12% survival benefit only in the stage II subgroup. The FA modulation of 5-FU was safe and cost-effective. The modulation with IFNa was less effective and caused more toxicity, mainly diarrhea in rectal cancer patients. When the 5FU/FA protocol was slightly modulated (treatment for 6 months, no LEV) and compared to the FOLFIRI protocol (FOGT-4), survival and toxicity in the 5FU/FA arm was similar to the toxicity observed in the earlier studies, and the FOLFIRI arm was significantly more toxic (40% vs. 14% grade III/IV toxicity) without any benefit in recurrence rates (25% vs. 23% local/systemic recurrence) or survival. The FOGT-4 study confirms three other studies that – in contrast to palliative treatment protocols – did not find any benefit for the role of irinotecan in the adjuvant treatment of colon cancer. In conclusion, by conducting the three FOGT-studies with more than 1800 patients, we identified a safe and effective treatment protocol for adjuvant therapy in colon cancer, consisting of infusional 5-fluorouracil and folinic acid, given for at least six months, and well combinable with additional postoperative radiotherapy. This protocol was not improved by addition of irinotecan in colon cancer patients.

Standard of care for non-metastatic colon cancer is surgery followed by stage-guided adjuvant therapy and/or structured follow-up. Upfront surgery in resectable colon cancer is irrespective of local T/N stage, whereas adjuvant systemic therapy is recommended according to pathological staging. The role of neoadjuvant chemotherapy remains unclear. Whereas perioperative systemic therapy in colon cancer seems to be safe and may lead to pathologic downstaging, evidence on improved survival and quality of life remains scarce. The PROTECTOR / FIRE‑10 trial aims to generate evidence that perioperative systemic therapy improves survival without compromising quality of life in locally advanced, mismatch-repair proficient colon cancer patients. Open-label, randomized, controlled, multicenter, phase III study with two parallel arms. Patients with locally advanced colon or upper rectal cancer staged cT3-4 and/or cN+ are randomized in a 2:1 fashion (favoring preoperative therapy) to investigate the efficacy, patient reported quality of life, and safety of preoperative therapy followed by surgery (Arm A) versus direct surgery followed by non-study specific stage-guided adjuvant therapy (Arm B). Stratification during randomization will be performed according to the following parameters: Fit for mFOLFOXIRI vs. mFOLFOX/CAPOX vs. 80%-mFOLFOX/CAPOX, ECOG 0 vs. ECOG 1-2, and left-sided primary vs. right-sided primary tumor. Only patients with confirmed mismatch-repair proficient and/or microsatellite stable tumor can be included. Preoperative treatment in Arm A is performed for a maximum of 6 biweekly cycles of FOLFOX/FOLFOXIRI or for a maximum of 4 triweekly cycles CAPOX (i.e., appr. 12 weeks). Patients in both arms should undergo quality-controlled surgery of the primary tumor, performed as complete mesocolic excision. Patients will be followed up with regard to relapse, survival and if applicable subsequent anti-cancer treatments until death or for at least 5 years after randomization, whichever date is earlier. The PROTECTOR / FIRE‑10 trial compares preoperative systemic therapy to upfront surgery (with stage-guided adjuvant therapy) in patients with locally advanced colon cancer. This study is registered with clinicaltrials.gov (NCT06899477) and EudraCT (2023-508076-11-00).

The National Surgical Adjuvant Breast and Bowel Project (NSABP) C-07 trial demonstrated that the addition of oxaliplatin to fluorouracil plus leucovorin (FULV) improved disease-free survival (DFS) in patients with stage II or III colon cancer. This analysis is the first publication of overall survival (OS) for the NSABP C-07 study. We updated DFS and examined both end points in clinically relevant patient subsets. Other studies have identified patients age 70 or older and those with stage II disease as patient subsets in which oxaliplatin may not be effective. We investigated toxicity as a driver of divergent outcomes in these subsets. In all, 2,409 eligible patients with follow-up were randomly assigned to either FULV (FU 500 mg/m(2) by intravenous [IV] bolus weekly for 6 weeks; leucovorin 500 mg/m(2) IV weekly for 6 weeks of each 8-week cycle for three cycles) or FLOX (FULV plus oxaliplatin 85 mg/m(2) IV on days 1, 15, and 29 of each cycle). With 8 years median follow-up, OS was similar between treatment groups (hazard ratio [HR], 0.88; 95% CI, 0.75 to 1.02; P = .08). FLOX remained superior for DFS (HR, 0.82; 95% CI, 0.72 to 0.93; P = .002). The effect of oxaliplatin on OS did not differ by stage of disease (interaction P = .38 for OS; interaction P = 0.37 for DFS) but did vary by age for OS (younger than age 70 v 70+ interaction P = .039). There was a similar trend for DFS (interaction P = .073). Oxaliplatin significantly improved OS in patients younger than age 70 (HR, 0.80; 95% CI, 0.68 to 0.95; P = .013), but no positive effect was evident in older patients. Overall, the addition of oxaliplatin to FULV has not been proven to extend OS in this trial, but the DFS effect remained strong. Unplanned subset analyses suggest a significant OS effect of oxaliplatin in patients younger than age 70.

Oxaliplatin or Irinotecan As Adjuvant Therapy for Colon Cancer: The Results Are In

Colorectal cancer: evolving concepts in diagnosis, treatment, and prevention

Options for the adjuvant therapy of resected stage III colon cancer have expanded beyond the previously well-accepted standard of 5-fluorouracil (5-FU) combined with leucovorin. The Xeloda in Adjuvant Colon Cancer Therapy (X-ACT) study confirmed that capecitabine (Xeloda) is at least as effective and is less toxic than a bolus 5-FU and leucovorin regimen for patients with stage III colon cancer. This study, in addition to National Surgical Adjuvant Breast and Bowel Project (NSABP) C-06, which demonstrated the equivalence of tegafur-uracil (UFT)/leucovorin with 5-FU/leucovorin, provides support for use of oral fluoropyrimidines for adjuvant therapy. Support for use of multiagent chemotherapy has been provided by the European MOSAIC study, which demonstrated a significant improvement in 3-year disease-free survival for the addition of oxaliplatin (Eloxatin) to infusional 5-FU and leucovorin (FOLFOX). Although adding irinotecan (Camptosar) to a bolus 5-FU and leucovorin regimen did not improve outcome in the adjuvant setting, the PETACC studies are evaluating the combination of infusional 5-FU, leucovorin, and irinotecan. In contrast to agreement on the appropriateness of therapy for stage III colon cancer, adjuvant therapy for patients with stage II disease remains controversial. Future advances in adjuvant therapy may include targeted therapies. Based on data demonstrating efficacy for the monoclonal antibodies bevacizumab (Avastin) and cetuximab (Erbitux) in the metastatic setting, clinical trials adding these agents to standard chemotherapy have been initiated in the adjuvant setting. Specifically, one U.S. cooperative group trial will evaluate the addition of bevacizumab to chemotherapy, a second will assess the addition of cetuximab, and a third trial will evaluate FOLFOX, infusional 5-FU/leucovorin (FOLFIRI), and FOLFOX followed by FOLFIRI. Finally, a study for patients with stage II disease and adverse prognostic factors will open. An important consideration in the new clinical trials is an assessment of molecular markers that either predict response or resistance to therapy or provide other prognostic information.

Analysis of current and recently completed trials of adjuvant therapy for colorectal cancer permit a few very broad generalizations. Survival of patients initially treated by resection has improved during the past 2 decades, unrelated to adjuvant therapy. While pilot, uncontrolled, and historically controlled studies often suggest a treatment benefit, controlled trials have, to date, failed to show any advantage for adjuvant therapy in colon cancer. For rectal cancer, only those trials including radiation therapy alone or in combination with chemotherapy have provided enhanced patient survival. Superiority of preoperative versus postoperative radiotherapy has not been demonstrated.Of interest is the current United States intergroup trial in colon cancer which is evaluating levamisole in combination with 5‐fluorouracil, based on preliminary experience in a smaller study of the North Central Cancer Treatment Group which suggests that levamisole and 5‐fluorouracil may be a potentially beneficial adjuvant combination. Recent reports of pharmacologic modulation of 5‐fluorouracil resulting in significantly enhanced response rates in advanced metastatic colorectal cancer invite a trial of this pharmacologic concept for surgical adjuvant therapy.

Targeted Agents for Adjuvant Therapy of Colon Cancer

Oxaliplatin As Part of Adjuvant Therapy for Colon Cancer: More Complicated Than Once Thought

North Central Cancer Treatment Group--Mayo Clinic trials in colon cancer.

IntroductionThe metastatic lymph node ratio (MLNR) has been proposed as a meaningful prognostic indicator in colon cancer (CC). This study aimed to assess the prognostic relevance of MLNR by investigating its association with disease-free survival (DFS), overall survival (OS), and recurrence, and to compare its predictive value with traditional parameters, including the TNM classification and total lymph node count (TNLC).Materials and methodsThis retrospective, single-center study included patients who underwent surgical resection for colon cancer. Survival outcomes were analyzed using Kaplan-Meier survival curves and multivariate logistic regression. MLNR was evaluated in relation to demographic and clinical factors, including age, tumor location, surgical type, and the administration of adjuvant chemotherapy. The optimal MLNR cut-off value for predicting recurrence was determined via receiver operating characteristic (ROC) curve analysis.ResultsA total of 122 patients were analyzed. MLNR >0.125 was significantly associated with increased recurrence risk (adjusted HR: 7.0, p<0.001) and reduced DFS. Patients with an MLNR ≤0.125 demonstrated significantly longer DFS (p<0.001). MLNR emerged as an independent prognostic factor, offering potential prognostic benefit compared to TNLC in predicting both DFS and OS. Additionally, adjuvant chemotherapy was independently associated with a lower recurrence risk (Exp(B):0.234, p=0.038). Emergency surgery was found to be significantly correlated with poorer survival outcomes (p=0.023).ConclusionMLNR contributes additional prognostic information to the TNM staging system and may support more individualized risk stratification and decision-making regarding adjuvant therapy in colon cancer. Further large-scale prospective studies are warranted to validate these findings and to establish a clinically applicable MLNR threshold.

CA: A Cancer Journal for Clinicians publishes information about the prevention, early detection, and treatment of cancer, as well as nutrition, palliative care, survivorship, and additional topics of interest related to cancer care.