Aug. 12 (UPI) -- Deaths from non-small cell lung cancer in the United States declined by about 3% a year on average between 2006 and 2016, according to an analysis published Wednesday by the New England Journal of Medicine.
The number of Americans who died from the most common form of lung cancer dropped by 3.2% per year from 2006 through 2013 and by 6.3% per year from 2013 through 2016, researchers from the National Cancer Institute said.
Between 2001 and 2008, rates of non-small cell lung cancer diagnoses across the country fell by an average of 1.9% annually. Between 2008 and 2016, diagnoses nationally fell by an average of 3.1% per year, the analysis found.
This marks the first time deaths caused by the disease have declined faster than its incidence, researchers said.
"These findings are an important confirmation of what many of us are experiencing in practice -- in addition to reduced exposure to tobacco smoke leading to decrease in incidence, screening efforts and therapeutic advances are changing clinical outcomes for patients with lung cancer," Dr. Charles Rudin told UPI
However, "lung cancer remains the leading cause of U.S. cancer deaths for both men and women," said Rudin, chief of the thoracic oncology service at Memorial Sloan Kettering Cancer Center in New York and who was not part of the National Cancer Institute analysis.
Reduced tobacco use in the United States has been associated with a progressive decrease in lung cancer deaths in men, since 1990, and in women, since 2000, because fewer people are being diagnosed with the disease, according to the National Cancer Institute researchers.
The new figures, however, suggest the development of new treatments -- including targeted therapies -- and improved delivery of chemotherapy and radiation in recent years has had a positive impact as well, the researchers said.
For this study, researchers looked at data for both non-small cell lung cancer, which accounts for 76% of lung cancers in the U.S., and small-cell lung cancer, which accounts for 13% of lung cancers diagnosed.
The research was conducted using records compiled by the National Cancer Institute's Surveillance, Epidemiology, and End Results cancer registry.
Two-year survival for men with non-small cell lung cancer improved to 35% for patients diagnosed in 2014 from 26% for those diagnosed in 2001, the researchers said.
The decline in deaths from non-small cell lung cancer since 2013 corresponds with the time when routine genetic testing for the disease became available.
The tests screen for specific gene mutations, which are then targeted by newly developed chemotherapy drugs, Dr. Ramaswamy Govindan told UPI.
"These decreases are significant and are likely a sign of our improved ability to identify patients with stage 3 cancer and the fact we have targeted treatments ... available," said Govindan, chair of medical oncology at Washington University in St. Louis, who was not part of the analysis.
Conversely, deaths from small-cell lung cancer roughly corresponded with the decrease in incidence, the researchers said.
Among men, for example, deaths declined 4.3% annually and incidence fell 3.6% annually from 2006 through 2016, and the findings for women were similar, they said.
Two-year survival rates for this form of lung cancer also remained unchanged. This is likely because there haven't been as many effective new treatments for small-cell lung cancer, Govindan said.
"When I started in this field 20 years ago, 30% of our patients with [non-small cell lung cancer] survived for one year after diagnosis, and now up to 60% survive that long," he said.
"Despite these improvements, we still lose far too many of our patients to this disease, and we have a long way to go before we can say we have conquered it."