Preoperative chemoradiation with raltitrexed ('Tomudex') for T2/N+ and T3/N+ rectal cancers: a phase I study.

The use of raltitrexed ('Tomudex') as concomitant chemotherapy during preoperative radiotherapy in chemonaïve patients with stage II/III rectal cancer has been examined in this study and its recommended dose in conjunction with radiotherapy investigated. Forty-five Gray (Gy) of radiotherapy (1.8 Gy daily, 5 days per week) was delivered to the posterior pelvis, followed by a 5.4 Gy boost. Single doses of raltitrexed (2.0, 2.5 and 3.0 mg/m(2)) were administered on days 1, 19 and 38. Only 1 of the 15 patients entered experienced a dose limiting toxicity (DLT) (grade 3 leucopenia) at the 3.0 mg/m(2) dose level. The overall response rate was 80% (five complete responses, seven partial responses). These preliminary data suggest that raltitrexed is a well tolerated and effective treatment when combined with preoperative radiotherapy in patients with stage II/III rectal cancer. The recommended dose of raltitrexed for future phase II studies will be 3.0 mg/m(2).