Retrospective analysis of cetuximab monotherapy for patients with irinotecan-intolerant metastatic colorectal cancer

Cetuximab as salvage monotherapy in chemotherapy-refractory metastatic colorectal cancer: A single-center report

In July 2008, cetuximab, a monoclonal antibody against epidermal growth factor receptor (EGFR), was approved in Japan for clinical use against chemotherapy-refractory metastatic colorectal cancer (mCRC). At Shiga University of Medical Science, between December 2007 and April 2012, a total of 24 EGFR-positive mCRC cases were administered immunohistochemistry with cetuximab as salvage monotherapy. The safety, side-effects and clinical efficacy of the treatment, including response rate, time to treatment failure, progression-free and overall survival, K-ras mutation status and impact on outcome, were investigated. The patient tumor growth control rate (TCR) was 38%, the mean time to progression (TTP) was 9.8 weeks [95% confidence interval (CI), 7.2-12.4] and the mean overall survival (OS) was 49.4 weeks (95% CI, 30.1-68.8). The most common adverse reactions reported were skin reactions, including acne (67%), hand-foot syndrome (16.7%) and paronychia (16.7%), followed by hypocalcemia (50%), hypomagnesemia (16%), stomatitis (20%) and gastrointestinal disorders (12%). The results of the present single-center study demonstrated that cetuximab monotherapy is beneficial for the treatment of chemotherapy-refractory patients with mCRC and that it has an acceptable level of safety and manageable side-effects.

Clinical potential of the anticancer drug sensitivity test for patients with synchronous stage IV colorectal cancer

PURPOSE

We retrospectively evaluated the clinical efficacy and feasibility of a collagen gel droplet-embedded culture drug sensitivity test (CD-DST) to guide therapy for patients with stage IV colorectal cancer (CRC).

METHODS

We investigated 38 patients with stage IV CRC. All patients were younger than 85 years and had untreated evaluable metastatic lesions. The primary tumors were surgically resected, and the tissue samples were investigated by CD-DST. Patients treated with in vitro sensitive drugs were defined as Group A (n = 14), while those treated with in vitro non-sensitive drugs were defined as Group B (n = 24). We evaluated response rate (RR), progression-free survival (PFS), and overall survival (OS).

RESULTS

RR was 85.71 % in Group A and 41.67 % in Group B (p = 0.0079). The median PFS was 696.5 days in Group A and 297.5 days in Group B (p = 0.0326). The median OS was 1,023.4 days in Group A and 518.5 days in Group B (p = 0.0061).

CONCLUSIONS

The CD-DST can define chemoresistant and chemosensitive tumors. The use of CD-DST might be one of the tools to supplement informed consent prior to initiation of therapy.