According to study results presented at the 2005 annual Chemotherapy Foundation Symposium in New York, patients with recurrent ovarian cancer who are treated with the combination of thalidomide and the chemotherapy drug topotecan have improved response rates and delayed cancer progression, but not better overall survival, compared to patients treated with topotecan alone.
Ovarian cancer is one of the most deadly gynecologic cancers because it tends to be diagnosed at a late stage (once the cancer has spread); it is thus difficult to cure. Patients may not notice symptoms of early-stage ovarian cancer, which can include vague sensations such as bloating, constipation, diarrhea, and/or abdominal pain.
Although advanced ovarian cancer may respond to initial therapy, it often recurs; this stage is referred to as recurrent ovarian cancer. Patients with recurrent ovarian cancer have poor long-term outcomes with standard treatment approaches. Researchers continue to evaluate new chemotherapy combinations and therapeutic approaches in order to improve the duration of survival and quality of life for patients with this disease.
One drug being explored as a treatment of recurrent ovarian cancer is thalidomide. Thalidomide belongs to a group of agents called immunomodulators, which work through several potential mechanisms. One possible mechanism is the interference of blood supply to cancer cells, ultimately inhibiting their ability to grow or spread. Another possibility involves interference with parts of the immune system that may be involved in cancer growth.
In order to evaluate whether the addition of thalidomide to treatment with topotecan improves patient outcomes, researchers from the University of Minnesota School of Medicine conducted a randomized clinical trial among 69 patients with recurrent ovarian cancer. Twenty-eight patients were randomly assigned to receive thalidomide plus topotecan, and 37 were randomly assigned to receive topotecan alone. Approximately 30% of patients in each arm were resistant to platinum-based therapy, and the average time since the last course of treatment was 7 months.
The researchers reported the following results:
- There was a reduction in detectable cancer in 50% of patients treated with thalidomide plus topotecan, compared to 22% of patients treated with topotecan alone.
- Cancer progressed at 6 months in patients treated with thalidomide plus topotecan, compared to 4 months in patients treated with topotecan alone.
- Overall survival duration was 19 months in patients treated with thalidomide plus topotecan, compared to 15 months in those treated with topotecan alone. (This difference in survival was not “statistically significant,” leading to the conclusion that survival was similar in the two groups.)
- Toxicities were similar between the two arms.
The researchers concluded that the addition of thalidomide to topotecan improves response rates and delays cancer progression in patients with advanced, recurrent ovarian cancer. Although there was a trend toward improved survival with the use of thalidomide, the improvement did not reach statistical significance. The researchers stated that further studies using agents such as thalidomide are warranted in patients with recurrent ovarian cancer.
Reference: Downs L, Argenta P, Ghebre R, et al. A prospective randomized trial of thalidomide with topotecan compared to topotecan alone in women with recurrent epithelial ovarian or primary peritoneal carcinoma. Proceedings from the 23rd annual Chemotherapy Foundation Symposium. Presented November 3, 2005. Abstract #10.