A clinical trial that combined stereotactic body radiation therapy (SBRT) with a specific chemotherapy regimen more than doubled survival rates for certain patients with stage 4 lung cancer, according to a new report in the Journal of Clinical Oncology (2015; doi:10.1200/JCO.2014.56.7412).
The combination of erlotinib with SBRT improved overall survival time to 20 months compared with historic 6- to 9-month survival times among patients treated with erlotinib only. The combination improved progression free survival from the historical 2 to 4 months to 14.7 months for similarly selected patients with lung cancer.
“Our approach dramatically changed the pattern of relapse. We saw a shift in failure from existing, local sites to new, distant sites,” said senior author Robert Timmerman, MD, director of the Annette Simmons Stereotactic Treatment Center, and vice chairman of Radiation Oncology at University of Texas Southwestern Medical Center in Dallas. “This shift resulted in a surprisingly long remission from the reappearance of cancer in treated patients.”
According to the National Cancer Institute, lung cancer was diagnosed in an estimated 224,210 men and women during 2014. Five-year relative survival rates remain low at just 16.8% from 2004 to 2010. Of these cancer cases, approximately 85% fall into the category of non-small cell lung cancer (NSCLC).
This phase II clinical trial involved 24 patients with stage 4 NSCLC whose cancer has continued to spread during their initial therapy. Such patients typically have poor survival rates, and SBRT is not typically used to treat these patients, said first author Puneeth Iyengar, MD, PhD, assistant professor and director of Clinical Research of Radiation Oncology, and co-leader of the Simmons Cancer Center Thoracic Oncology Group.
The revolutionary SBRT technique is a type of radiation therapy in which a few very high doses of radiation are delivered from multiple angles to small, well-defined tumors. The goal is to deliver a radiation dose high enough to kill the cancer, while minimizing exposure to surrounding healthy tissue and organs, explained Timmerman.
SBRT has been shown to offer better cure rates in certain instances, particularly for cancers that have metastasized, said Timmerman. He was one of the first researchers in the world to use the SBRT techniques initially developed for brain tumors to treat cancer in the body.
“Technologies have developed in the last few years that have yielded game-changing, paradigm-shifting approaches, allowing us to reconsider how radiation is delivered in combination with surgery, chemotherapy, and other systemic therapies,” said Timmerman, who served as the lead investigator in several national trials designed to evaluate the efficacy and safety of SBRT to treat cancer in the lung, liver, spine, and prostate. “I am motivated by the need I see every day in the clinic to provide better treatments for our patients.”