Maintenance immunotherapy in recurrent ovarian cancer: long term follow-up of a phase II study.

Objectives: Vascular endothelial growth factor (VEGF), a mediator of tumor-associated immunodeficiency, plays a key role in angiogenesis and is a prognostic factor in advanced ovarian cancer (AOC). Previously, we showed that low-dose interleukin-2 (IL-2) and 13-cis-retinoic acid (RA) improved the tumor-associated immunodeficiency and decreased VEGF in patients with AOC. Here, we report long term follow-up of a group of patients with platinum-sensitive AOC who were treated with IL-2 and RA.

Methods: Sixty-five patients with AOC who had a clinical benefit from second line chemotherapy and elevated serum levels of VEGF were entered into the study from 04/98 to 04/05. Therapy consisted of low-dose subcutaneous IL-2 and oral RA, administered on intermittent schedules for up to 5 years.

Results: A statistically significant improvement in lymphocyte and NK counts and a decrease in VEGF levels were observed with respect to baseline values among the 65 evaluable patients. Five-year progression-free survival and overall survival rate were 29% and 38%, respectively.

Conclusions: These data show that patients treated with low-dose IL-2 and RA have a statistically significant improvement in their lymphocyte and NK counts, a decrease in VEGF, and seem to have an improved clinical outcome.