Adding the drug thalidomide to chemotherapy did not help patients with small cell lung cancer (SCLC) live longer, but it did increase the risk of developing blood clots in veins deep within the body, British researchers reported in the Journal of the National Cancer Institute. Thalidomide was evaluated in this disease because of its ability to inhibit angiogenesis, or the growth of blood vessels, in tumors. Angiogenesis is thought to play an important role in SCLC, which accounts for about 20 percent of lung cancers.

The drug has improved survival for people with other cancers, but it provided no benefit in the first phase III, randomised trial of an antiangiogenic agent in SCLC. In the 724-person study, Dr. Siow Ming Lee of University College Hospital in London and his colleagues found that survival was essentially the same (about 10 months) in both the thalidomide group and the chemotherapy-alone group. Patients in the thalidomide group, however, faced a higher risk of clotting events such as deep vein thrombosis and pulmonary embolus.

In addition, patients with extensive disease in the thalidomide group fared worse than those in the chemotherapy-alone group. Targeting angiogenesis may not work as well in SCLC as in multiple myeloma and colorectal cancer, perhaps because of differences in the angiogenic pathways involved, the researchers concluded.

The notion that thalidomide has antiangiogenic effects in patients should be revisited, noted an accompanying editorial. But the biology of SCLC is still poorly understood, and the authors suggested that it may make sense to focus now on laboratory research that could lead to new insights and identify promising therapeutic targets.