Reductions in mortality were most notable for tumor types with relatively more approvals, including lung and breast cancer, melanoma, lymphoma, and leukemia.
A report from the American Cancer Society (ACS) estimated that, from 1991 to 2017, there were 2,902,200 total cancer deaths avoided from improvements in mortality from all potential sources.
The new findings, reported in the Journal of Medical Economics, suggest that drugs approved between 2000 and 2016 to treat the 15 most common cancer types helped to reduce mortality by 24% per 100,000 people.
“This study provides evidence that a significant share of that reduction from 2000 to 2016 was associated with the introduction of new therapies. The ACS report and other studies demonstrate that the improvements in lung cancer specifically are likely due to new treatments,” said lead study author Joanna P. MacEwan, MD, of PRECISIONheor in Los Angeles.
The findings contribute to a better understanding of whether increased spending on cancer drugs are worth the investment, according to the study authors.
“We provide evidence that the gains in survival measured in clinical trials are translating into health benefits for patients in the real world and confirm previous research that has also shown that new pharmaceutical treatments are associated with improved real-world survival outcomes for patients,” Dr. MacEwan said.
Full effect not yet observed
The researchers used a series of national data sets from sources including the Centers for Disease Control and Prevention; the U.S. Mortality Files by the National Center of Health Statistics; Survival, Epidemiology and End Results program; and United States Cancer Statistics.
The team calculated age-adjusted cancer mortality rates per year for the 15 most common tumor types and also looked at incident cases of cancer by tumor type, represented as per 100,000 people, for all ages, races, and genders.
The researchers then translated the change in cancer mortality in the U.S. from 2000 to 2016 associated with treatment stocks in each year into deaths averted per year.
Across the 16 years, mortality was down by 1,291,769 deaths. The following cancers had significant reductions in mortality: breast (n = 127,874), colorectal (n = 46,705), lung (n = 375,256), prostate (n = 476,210), gastric (n = 758), and renal (n = 739) cancers, as well as non-Hodgkin lymphoma (n = 48,836) and leukemia (n = 4,011).
Estimated mortality increased by 825 deaths in patients with thyroid cancer and 7,768 deaths for those with bladder cancer. These rises are likely due to the result of sparse drug approvals during this period – five for thyroid cancer and three for bladder cancer – Dr. MacEwan said. There were no approvals in liver or uterine cancer and few approvals in pancreatic and oral cancer.
The full effect of new drug introductions may not have been observed yet, Dr. MacEwan noted.
“There are fewer patients using the treatments for drugs approved in the later years of our study and less follow-up time to measure outcomes,” she said. “Over time, utilization of the newer therapies will likely increase and the full effect on mortality will be observed.”