[A perspective: role of targeted therapy in colon cancer]

Colorectal cancer is the third most common malignant disease in incidence according to a report in 2009 from Korea. The 5-fluorouracil (5-FU) remains to be a major chemotherapeutic agents. But, over the last 10-15 years, the treatment pattern for metastatic colorectal cancer changed significantly. Irinotecan and oxaliplatin are cytotoxic drugs, or bevacizumab and cetuximab are monoclonal antibodies against molecular targets. The introduction of novel agents targeting specific molecular features of cancer cells promises more options and marked improvements in efficacy for the treatment of metastatic colon cancer. Bevacizumab has been shown to extend survival in colorectal cancer when used in combination with irinotecan and 5-FU-based chemotherapy, and the addition of cetuximab to irinotecan and 5-FU-based chemotherapy eliminates irinotecan resistance. Better understanding of the tumor biology and the molecular pathway and mechanisms of tumorigenesis has led to the discovery of novel agents with improved outcomes.

[The development of the first line treatment of metastatic colorectal cancer (mCRC)]

Chemotherapy options of metastatic colorectal cancer (mCRC) have been progressed rapidly in the last years. Besides of the standard fluorouracil/folinic acid treatment some new active agents (oxaliplatin and irinotecan) have been introduced, and more recently the "targeted" biologicals (bevacizumab, cetuximab, panitumumab) have demonstrated their high effectiveness. This review summarizes the development of the first line treatment of mCRC.

Innovations in chemotherapy for metastatic colorectal cancer: an update of recent clinical trials

It has been estimated that cancer of the colon and rectum (CRC) would be diagnosed in 153,760 men and women in the U.S. alone in 2007. Approximately one in five patients has metastatic CRC (mCRC) at diagnosis, which, at best, is associated with a 5-year survival rate of just 10.3%. Oxaliplatin- and irinotecan-based combination regimens are standard first-line therapies for mCRC. Recent studies suggest that survival outcomes can possibly be further improved by adding biologic agents to chemotherapy. Novel treatment strategies are being investigated to optimize the opportunity for patients to receive and benefit from the increasing number of available active agents and to further improve the efficacy, safety, and tolerability of multiagent therapy. These include switching therapy before progression, maintenance therapy, and chemotherapy-free intervals. Recent innovations in chemotherapy for mCRC are reviewed, with a focus on emerging data that may significantly improve both survival and quality of life for patients with CRC in the future.

Phase I and pharmacokinetic study of mitomycin C and celecoxib as potential modulators of tumor resistance to irinotecan in patients with solid malignancies

PURPOSE

Based on the preclinical evidence of topoisomerase I (Topo-1) upregulation by mitomycin C(MMC) and decreased NF-kappaB activation by celecoxib, we evaluated combinations of irinotecan/MMC and irinotecan/MMC/celecoxib in patients with advanced solid malignancies.

PATIENTS-METHODS

Initially, patients received MMC on day 1 and irinotecan on days 2, 8, 15 and 22, every 6 weeks. MMC dose was fixed at 6 mg/m(2) and cumulative doses of >36 mg/m(2) were not permitted. Irinotecan was escalated in 25 mg/m(2) increments. Due to late-onset diarrhea, the schedule was subsequently shortened to 4 weeks, omitting irinotecan on days 15 and 22. In the second part of the study, celecoxib 400 mg orally twice daily was added to irinotecan/MMC regimen. Potential pharmacokinetic interactions and Topo-1 and DT-diaphorase (NQ01) gene expressions in peripheral-mononuclear cells were evaluated.

RESULTS

Forty-five patients were enrolled. Irinotecan 125 mg/m(2) on days 2 and 8 in combination with MMC 6 mg/m(2) on day 1 every 4 weeks is recommended for future studies; myelosuppression and diarrhea are dose-limiting. The addition of celecoxib resulted in unacceptable toxicities despite reductions on irinotecan's dose. No relevant pharmacokinetic interactions occurred between irinotecan and MMC, and mean increases in Topo-1, were observed. Sixteen of 36 patients evaluable for response-assessment had discernable anti-tumor activity, including 1 complete, 4 partial, 10 minor and 1 tumor marker response. Four patients had prolonged (>4 months) disease-stability (stable disease, not included in CR or PR). Patients experiencing complete and partial responses had higher increments in Topo-1 expression.

CONCLUSIONS

Modulation of irinotecan by MMC is feasible, devoid of pharmacological interactions and active in solid malignancies. The lack of improvement in therapeutic index does not support the addition of celecoxib.

Hot topics and landmark studies from the 43rd annual meeting of the American Society of Clinical Oncology

The results of several preclinical and clinical studies were reported by oncology professionals at the 43rd American Society of Clinical Oncology (ASCO) meeting, the largest international forum in which the latest achievements in cancer research are annually presented. The central theme this year was 'Translating Research into Practice', emphasizing the goal of forging stronger links between basic research and clinical practice. This review offers a critical, summarized selection of several of the foremost studies presented at the meeting. The focus is on the findings from randomized phase III trials that, in the authors' opinion, are most likely to have an immediate effect on clinical practice.