KRAS as a predictor of poor prognosis and benefit from postoperative FOLFOX chemotherapy in patients with stage II and III colorectal cancer.

PURPOSE: The KRAS gene frequently mutates in colorectal cancer (CRC). Here we investigated the prognostic and predictive role of KRAS mutation in patients with stage II or III CRC. EXPERIMENTAL DESIGN: A consecutive cohort of patients with stage II or III CRC from a single center database was studied. The association between KRAS status, adjuvant FOLFOX therapy, and 3-year disease-free survival (3-y DFS) was analyzed. RESULTS: Of our 433 patients, 166 (38.3%) exhibited the KRAS mutation. Among the 190 patients who did not receive adjuvant therapy, those with KRAS mutation tumors had a worse 3-y DFS (hazard ratio [HR], 1.924; 95% confidence interval [CI], 1.078-3.435; P = 0.027). Among patients who received adjuvant chemotherapy, KRAS mutation was not correlated with worse 3-y DFS (HR, 1.083; 95% CI, 0.618-1.899; P = 0.781). Adjuvant chemotherapy improved 3-y DFS only among patients with KRAS mutant tumors (78.0% vs 69.2%) on multivariate analysis adjusted for age, stage, grade, site, vessel invasion, and carcinoembryonic antigen level (HR, 0.454; 95% CI, 0.229-0.901; P = 0.024). In contrast, there was no benefit of adjuvant chemotherapy in the KRAS wild-type group (84.3% vs 82.0%). CONCLUSIONS: KRAS mutation indicates poor prognosis. FOLFOX adjuvant chemotherapy benefits patients with stage II or III colorectal cancer with KRAS mutant tumors and is worth further investigation.

DNA mismatch repair status and colon cancer recurrence and survival in clinical trials of 5-fluorouracil-based adjuvant therapy.

BACKGROUND: Approximately 15% of colorectal cancers develop because of defective function of the DNA mismatch repair (MMR) system. We determined the association of MMR status with colon cancer recurrence and examined the impact of 5-fluorouracil (FU)-based adjuvant therapy on recurrence variables. METHODS: We included stage II and III colon carcinoma patients (n = 2141) who were treated in randomized trials of 5-FU-based adjuvant therapy. Tumors were analyzed for microsatellite instability by polymerase chain reaction and/or for MMR protein expression by immunohistochemistry to determine deficient MMR (dMMR) or proficient MMR (pMMR) status. Associations of MMR status and/or 5-FU-based treatment with clinicopathologic and recurrence covariates were determined using χ(2) or Fisher Exact or Wilcoxon rank-sum tests. Time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS) were analyzed using univariate and multivariable Cox models, with the latter adjusted for covariates. Tumors showing dMMR were categorized by presumed germline vs sporadic origin and were assessed for their prognostic and predictive impact. All statistical tests were two-sided. RESULTS: In this study population, dMMR was detected in 344 of 2141 (16.1%) tumors. Compared with pMMR tumors, dMMR was associated with reduced 5-year recurrence rates (33% vs 22%; P < .001), delayed TTR (P < .001), and fewer distant recurrences (22% vs 12%; P < .001). In multivariable models, dMMR was independently associated with delayed TTR (hazard ratio = 0.72, 95% confidence interval = 0.56 to 0.91, P = .005) and improved DFS (P = .035) and OS (P = .031). In stage III cancers, 5-FU-based treatment vs surgery alone or no 5-FU was associated with reduced distant recurrence for dMMR tumors (11% vs 29%; P = .011) and reduced recurrence to all sites for pMMR tumors (P < .001). The dMMR tumors with suspected germline mutations were associated with improved DFS after 5-FU-based treatment compared with sporadic tumors where no benefit was observed (P = .006). CONCLUSIONS: Patients with dMMR colon cancers have reduced rates of tumor recurrence, delayed TTR, and improved survival rates, compared with pMMR colon cancers. Distant recurrences were reduced by 5-FU-based adjuvant treatment in dMMR stage III tumors, and a subset analysis suggested that any treatment benefit was restricted to suspected germline vs sporadic tumors.

Phase III noninferiority trial comparing irinotecan with oxaliplatin, fluorouracil, and leucovorin in patients with advanced colorectal carcinoma previously treated with fluorouracil: N9841.

PURPOSE: The primary goal of this multicenter phase III trial was to determine whether overall survival (OS) of fluorouracil (FU) -refractory patients was noninferior when treated with second-line infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX4; arm B) versus irinotecan (arm A). Cross-over to the other treatment on disease progression was mandated. PATIENTS AND METHODS: Patients who experienced treatment failure with one prior FU-based therapy and had not received prior irinotecan or oxaliplatin, either for metastatic disease or within 6 months of adjuvant FU therapy, were randomly assigned to arm A (irinotecan 350 or 300 mg/m(2) every 3 weeks) or arm B (FOLFOX4). RESULTS: A total of 491 patients were randomly assigned (arm A, n = 245; arm B, n = 246); 288 (59%) had experienced treatment failure with FU for metastatic colorectal cancer. Two hundred twenty-seven patients (46%) received protocol-mandated third-line therapy (arm A, 43%; arm B, 57%). Median survival was 13.8 months (95% CI, 12.2 to 15.0 months) for initial treatment with FOLFOX4 and 14.3 months (95% CI, 12.0 to 15.9 months) for irinotecan (P = .38; hazard ratio = 0.92; 95% CI, 0.8 to 1.1). Response rates (RR; 28% v 15.5%; P = .0009) and time to progression (TTP; 6.2 v 4.4 months; P = .0009) were significantly superior with FOLFOX4. In the nonrandom subset of patients who crossed over, RR and TTP improvements with FOLFOX4 continued into third-line treatment. Irinotecan therapy was associated with more grade 3 nausea, vomiting, diarrhea, and febrile neutropenia; FOLFOX4 was associated with more neutropenia and paresthesias. CONCLUSION: In patients who experienced treatment failure with front-line FU therapy, OS does not significantly differ whether second-line therapy begins with irinotecan or FOLFOX4. FOLFOX4 produces higher RR and longer TTP. Both arms had notable OS in patients who experienced treatment failure with first-line FU therapy.

Pemetrexed and oxaliplatin for metastatic colorectal cancer: results of a phase I Mayo Cancer Center Research Consortium trial, MC0248.

PURPOSE: Pemetrexed, an antifolate involved in purine and pyrimidine formation, is a potential alternative to fluoropyrimidines in the treatment of colorectal cancer. A phase I trial was performed to establish the maximum tolerated dose (MTD) of pemetrexed and oxaliplatin when B(12) and folate supplementation is used. PATIENTS AND METHODS: Patients with metastatic colorectal cancer received folate (> 350 microg) daily and vitamin B(12) (1000 microg) every 9 weeks starting 7 days before chemotherapy. Pemetrexed over 10 minutes and oxaliplatin over 2 hours were given every 3 weeks in escalating dose cohorts. RESULTS: Twenty-two patients were entered on 6 dose levels. The MTD was established at the highest dose level, pemetrexed 900 mg/m(2) and oxaliplatin 130 mg/m(2). Toxicities related to treatment at the MTD included grade 3 neutropenia and thrombocytopenia. For all dose levels combined, grade 3/4 toxicities included hematologic, neurologic, and gastrointestinal. Nine of 21 evaluable patients responded overall (response rate, 43%). The time to tumor progression was 11.9 months. CONCLUSION: The MTD was determined to be pemetrexed 900 mg/m(2) and oxaliplatin 130 mg/m(2) every 21 days when folate and B (12) supplementation are used. Because of the observed tolerability and activity of this regimen, further evaluation is warranted.

Oxaliplatin in the treatment of colorectal cancer.

Significant advances in the treatment of colorectal cancer have been observed over the past several years. With the introduction of oxaliplatin combined with infusional 5-fluorouracil and leucovorin, survival for patients with metastatic colorectal cancer has nearly doubled. The incorporation of biologic agents that target angiogenesis (bevacizumab) and tumor growth pathways (cetuximab, panitumimab) extends survival even further, in addition to increasing response rates in patients with metastatic disease. The benefit of these newer drugs is also being realized in the adjuvant setting, where the addition of oxaliplatin to infusional 5-fluorouracil and leucovorin has led to improvements in 3-year disease-free survival. Future challenges with the use of oxaliplatin include defining strategies to optimize its use while avoiding treatment-limiting neurotoxicity and identification of markers predictive of response.

Enhancing oxaliplatin-based regimens in colorectal cancer by inhibiting the epidermal growth factor receptor pathway.

In the past several years, significant advances in the treatment of colorectal cancer (CRC) have been made. With the introduction of irinotecan and oxaliplatin combined with infusional 5-fluororuracil, survival times for patients with metastatic CRC have nearly doubled. With the incorporation of biologic agents that target the vascular endothelial growth factor and epidermal growth factor (EGF) pathways, additional improvements in response, progression-free survival, and overall survival have been seen in patients with advanced, metastatic disease. This article reviews the impact of EGF receptor inhibitors on improving survival in CRC when combined with oxaliplatin-containing regimens.

Evaluation of shark cartilage in patients with advanced cancer: a North Central Cancer Treatment Group trial.

BACKGROUND: Shark cartilage has been a popular complementary or alternative medicine intervention. The basis for this popularity is the claim that sharks rarely get cancer because of the high proportion of cartilage in the shark's body. However, early studies were equivocal. Therefore, a clinical trial was conducted to look at the impact of shark cartilage in patients with advanced cancer. The primary goal of this trial was to determine whether a shark cartilage product improved overall survival for patients with advanced cancer who were getting standard care. Secondary research goals were to evaluate toxicities, tolerability, and quality of life associated with this shark cartilage product. METHODS: The study was a two-arm, randomized, placebo-controlled, double-blind, clinical trial. Patients with incurable breast or colorectal carcinoma had to have good performance status and organ function. Patients could be receiving chemotherapy. Patients were all to receive standard care and then to be randomly selected to receive either a shark cartilage product or an identical-appearing and smelling placebo 3 to 4 times each day. RESULTS: Data on a total of 83 evaluable patients were analyzed. There was no difference in overall survival between patients receiving standard care plus a shark cartilage product versus standard care plus placebo. Likewise, there was no suggestion of improvement in quality of life for patients receiving the shark cartilage, compared with those receiving placebo. CONCLUSION: This trial was unable to demonstrate any suggestion of efficacy for this shark cartilage product in patients with advanced cancer.