Radiation to the Brain Improves Survival Rates for Small Cell Lung Cancer Patients

Tuesday, July 05, 2011

SCOTTSDALE, Ariz. — A wider spectrum of patients with small cell lung cancer (SCLC) may now benefit from receiving prophylactic cranial irradiation (PCI).

According to a recent study led by Mayo Clinic and members of the North Central Cancer Treatment Group (NCCTG), PCI treatment improved survival rates in participants afflicted with this rapidly growing malignancy.

These findings were presented at the World Conference on Lung Cancer in Amsterdam on Thursday, July 7.

Small cell lung cancer makes up about 15 percent of all lung cancer cases. In 2010, it was estimated that there were 222,520 cases diagnosed with lung cancer in the U.S., according to National Cancer Institute (NCI) estimates.

"SCLC has a very high propensity to spread to the brain," explained Steven Schild, M.D., Chair of Radiation Oncology at Mayo Clinic in Arizona and lead investigator of the study. "The brain is a sanctuary site for this disease because the blood brain barrier prevents full doses of chemotherapy from getting into the brain to kill microscopic cancer deposits. PCI is radiation given to the brain of patients after initial therapy (chemotherapy+/-thoracic radiotherapy), to prevent the subsequent development of brain metastases (tumor growth within the brain)," he added.

Prior studies typically included only SCLC patients with complete or partial responses to initial therapy (chemo +/- thoracic radiotherapy), when evaluating the role of PCI. This Mayo Clinic-led study expanded the spectrum of patients to include those with stable disease or better following chemotherapy, explained Dr. Schild.

The pooled analysis from the four NCCTG phase II trials examined the results of PCI in SCLC patients: 318 patients exhibited extensive SCLC (ESCLC) and 421 patients with limited SCLC (LSCLC). Of the study participants, 459 patients received PCI (30Gy/15 or 25Gy/10) and 280 did not.

According to the study, PCI patients had significantly improved survival as compared to patients who didn't receive PCI. The 1 and 3-year survival rates were 73 percent and 20 percent respectively for PCI patients vs. 52 percent and 6 percent for non-PCI patients. The survival advantage from PCI was still significant after adjusting for age, performance status, gender, stage, response to initial therapy and number of metastatic sites. PCI-related side effects included an increase in patient lethargy and hair loss.

The study also identified that one particular radiation prescription was superior to another. "This study affirms the benefit of PCI in terms of improved survival for a wider spectrum of patients with small cell lung cancer. The hope is that physicians will recommend this treatment to a wider population of SCLC patients. Additionally, it points out a better method of treatment delivery in terms of proper dosage," said Dr. Schild.

Dr. Schild added, "This study is important because it highlights ways we can improve patient survival with the tools we already have just by using them more effectively."

About Mayo Clinic Cancer Center

Mayo Clinic Cancer Center (MCCC) is a National Cancer Institute (NCI)-designated comprehensive cancer center with a multi-site national presence. Its three campuses — in Phoenix/Scottsdale, Ariz.; Jacksonville, Fla.; and Rochester, Minn. — offer MCCC a broad geographic reach to serve diverse patient populations. MCCC's internationally-recognized physicians and scientists collaborate across the spectrum of cancer research — including basic, translational, clinical and population sciences — seeking to find ways to lessen the burden of cancer on society.

About the North Central Cancer Treatment Group

The North Central Cancer Treatment Group (NCCTG) is a national clinical research group sponsored by the National Cancer Institute. NCCTG consists of a network of cancer specialists at community clinics, hospitals and medical centers in the United States and Canada. The research base for NCCTG is located at Mayo Clinic in Rochester, Minn.

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About Mayo Clinic

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