Survival has improved for patients with cancers of the colon or rectum, breast, prostate, lung, and liver, and those improvements were better among younger patients, according to a study published online by JAMA Oncology (2015; doi:10.1001/jamaoncol.2014.161).
Cancer is a leading cause of death in the United States and many other countries although progress has been made during the past few decades with significant advances in surgery, radiotherapy, chemotherapy, and targeted therapies. Those improvements, along with better cancer screening and diagnosis, have led to steady improvements in survival, according to the study background.
Wei Zheng, MD, PhD, of the Vanderbilt Epidemiology Center and Vanderbilt-Ingram Cancer Center in Nashville, Tennessee, and coauthors analyzed cancer follow-up data from 1990 to 2010 from more than 1 million patients. The patients received diagnoses of cancer of the colon or rectum, breast, prostate, lung, liver, pancreas, or ovary from 1990 to 2009 and were included in registries of the National Cancer Institute Surveillance, Epidemiology and End Results (SEER) program.
Study results indicate that the improvement in survival was substantially greater in younger patients than in elderly patients. For example, patients ages 50 to 64 years with colon and rectum cancer diagnosed between 2005 and 2009 had a 43% lower risk of death, compared with the same age groups with this cancer diagnosed between 1990 and 1994. The reduction in risk of death for patients with breast, liver, and prostate cancer was 52%, 39%, and 68%, respectively, from 1990-1994 to 2005-2009, for this age group of patients.
However, the risk of death for older patients (75 to 85 years old) was not reduced as much: 12% lower risk for patients with cancer of the colon, rectum, or breast, 24% lower for patients with liver cancer, and 35% lower for patients with prostate cancer.
According to the study results, improvement in cancer survival over the past 20 years has been slower in older patients. The authors note that this age-related gap was most pronounced for cancers with the largest diagnosis and treatment advances during the study period, including colorectal, breast, and prostate cancers.
Authors saw a widening gap in survival by race only in ovarian cancer. They also found that African American patients with prostate cancer had larger improvements in survival over time than did white patients.
“Our data suggest that age- and race-related differences in survival improvements over time may be explained, at last in part, by differences in cancer care across these subpopulations,” the study concludes.