Phase IB study on prevention of surgery-induced immunodeficiency with preoperative administration of low-dose subcutaneous interleukin-2 in gastric cancer patients.

Background And Objectives: Low count of total and T helper lymphocytes predicts a poor prognosis in cancer patients and surgical trauma can worsen cancer-related immunodeficiency. Aim of this phase IB study is to verify toxicity and biological effects of interleukin-2 (IL-2) at 9 million IU/day subcutaneously (sc.) administered one, two or three preoperative days in patients with gastric cancer undergoing radical surgery.

Methods: Absolute value of total and T-helper (CD4) lymphocytes were measured at baseline and at 7th, 14th, and 50th postoperative days in 12 gastric cancer patients, who preoperatively received IL-2 at 9 million IU/day sc. as follows: group A (4 pts) 1-day; group B (4 pts) 2-days; group C (4 pts) 3-days administration. T and total lymphocytes count were recorded and retrospectively analyzed in a historical control-group of 22 consecutive patients, age and stage-matched.

Results: Toxicity consisted of fever grade I. In group A (1 day) T helper lymphocytes count decreased at 7th and at 14th postoperative day; in group B (2 days) and group C (3 days) no decrease of neither total nor T helper lymphocyte count occurred postoperatively, whereas in the historical group these parameters decreased significantly postoperatively and recovered only at 50th day.

Conclusions: Two- and three-day schedules of sc. IL-2 preoperative administration at 9 million IU/daily prevented postoperative lymphocytopenia, whereas one-day administration did not. Since the IL-2 dose was so tolerable, that it could be given safely as outpatient, based on the previous results on survival observed in colorectal cancer patients with 3-days schedule we suggest that a 3-day schedule of Interleukin-2 as outpatient preoperative treatment seems advisable for further studies in gastric cancer patients.