Chemotherapy can help lung cancer patients live longer, according to a group of international researchers, if it's given after surgery has completely removed the tumor. Writing in the New England Journal of Medicine (Vol. 350, No. 4: 351-360), the International Adjuvant Lung Cancer Trial Collaborative Group (IALT) reported that chemotherapy with the drug cisplatin improved the 5-year survival of these patients by 4%.

Although this is the first large trial to find a significant benefit from chemotherapy after lung cancer surgery, it could change the way doctors treat a disease that is expected to claim more than 160,000 lives in the United States this year alone.

"This study… represents a new standard of care," said Ronald Blum, MD, in an accompanying editorial. Blum is associated with cancer centers at Beth Israel Medical Center and St-Luke's-Roosevelt Hospital Center, both in New York.

Lung cancer is the deadliest cancer in the United States and most of the world. The most common form, non-small cell lung cancer, is treated with surgery whenever possible. The operation can cure some patients, but in many cases the disease has already spread by the time it is found. The cancer eventually returns, either in the lung or some distant site such as bone or liver. (Small cell lung cancer is much less common and is generally not treated with surgery.)

Chemotherapy after surgery has not been very helpful in preventing this relapse; most studies have found no benefit from the drugs. A few studies that used the drug cisplatin showed promise, but they were too small to serve as anything but a stepping-stone for a larger study.

To better judge the value of cisplatin-containing chemotherapy, the IALT researchers studied more than 1,800 lung cancer patients whose tumors had been completely removed by surgery. Half the patients received chemotherapy with cisplatin and a second drug, while the other half had no chemotherapy after surgery.

By the end of the study, 469 people in the chemotherapy group had died, and 504 people in the control group had died. This translated into a 4% improvement in 5-year survival for patients on chemotherapy – a figure similar to the survival benefit seen from chemotherapy given for other cancers.

Although the benefit is small, it could affect a large number of people. The researchers estimate that about 180,000 people worldwide would be eligible for treatment each year, and that 7,000 of them would live longer because of the therapy.

While this new treatment regimen holds promise, both the IALT researchers and Blum caution that it shouldn't be considered the only option.

Chemotherapy with cisplatin can be toxic, causing nausea, vomiting, kidney failure, infections, and occasionally, death. Doctors need to discuss the pros and cons with their patients before beginning this treatment. No chemotherapy might be more appropriate for some patients.

Additional studies, some of which are already underway, may help doctors determine which patients would make the best candidates for chemotherapy after lung cancer surgery. Advances in imaging and staging techniques could also help narrow the field, Blum says. The results should yield "rich rewards" for future lung cancer patients, he concludes.