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

Katsushi Takebayashi, Eiji Mekata, Hiromichi Sonoda, Tomoharu Shimizu, Yoshihiro Endo, Tohru Tani


Purpose We retrospectively evaluated the clinical effi- cacy 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.