[Two Cases of Long-Term Use of TAS-102 for Unresectable Colorectal Cancer].

TAS-102 has been administered to patients with unresectable colorectal cancer. We initiated TAS-102 administration in 2014 and gradually increased the number of indications. In a global, multicenter, randomized, double-blind, phase III study (RECOURSE study), TAS-102 administration improved overall survival by 1.8 months and progression-free survival by 0.3 months compared with those in the placebo group. However, there are limited clinical reports of long-term administration of TAS-102. We encountered 2 cases of continuous long-term use of the TAS-102 for over 2 years. In our cases, although the cancer had been recognized early as exhibiting slow growth during follow-up, the physical symptoms did not appear for an extended period. Although grade 3 neutropenia was pointed out several times during the follow-up term, severe digestive symptoms had not occurred. Therefore, the patients could remain motivated to receive the drug. In our cases, the adequate treatment for neutropenia enabled long-term administration of TAS-102; therefore, TAS-102 would be tolerable for patients of colorectal cancer after receiving chemotherapy for an extended period.