Study on Women Living With Metastatic Breast Cancer
A study by Mariotto et al investigating the prevalence of women living with metastatic breast cancer in the United States estimates that there are 154,794 women living with the disease. In addition, the median and 5-year relative survival for women initially diagnosed with metastatic breast cancer is improving, especially among younger women, with more than 11% of women diagnosed between 2000-2004 under the age of 64 surviving 10 years or more. An aging population and more effective treatments are likely the reason for the increase in survivors. The study findings highlight the need for more research into how to address the health care needs of women living longer with metastatic breast cancer. The study is published in Cancer Epidemiology, Biomarkers & Prevention.
The study researchers, which included scientists from the National Cancer Institute (NCI), the Metastatic Breast Cancer Alliance, and the Fred Hutchinson Cancer Research Center, used national data on breast cancer mortality and metastatic breast cancer survival from the NCI’s Surveillance, Epidemiology and End Results (SEER) registries to estimate the prevalence of women living with metastatic breast cancer in the United States, including both women initially diagnosed with metastatic breast cancer and those who have progressed to distant metastatic breast cancer. The researchers also calculated the prevalence of women diagnosed with de novo metastatic breast cancer in SEER and the United States. The SEER de novo metastatic breast cancer prevalence was compared with an estimate based on the back-calculation method to validate the method and calibrate survival.
Key Study Findings
The researchers estimated that by January 21, 2017, there will be 154,794 women living with metastatic breast cancer in the United States, 3 in 4 initially diagnosed with stage I-III breast cancer who later progressed to metastatic breast cancer.
Median survival and 5-year relative survival for de novo metastatic breast cancer increased over the years, especially in younger women. The researchers estimated a 2-fold increase in 5-year relative survival rate from 18% to 36%, for women diagnosed with de novo metastatic breast cancer at age 15 to 49 between 1992–1994 and 2005–2012, respectively.
“The increasing burden of metastatic breast cancer highlights the importance of documenting recurrence to foster more research into the specific needs of this understudied population,” concluded the study authors.
Study Significance
“These findings make clear that the majority of metastatic breast cancer patients, those who are diagnosed with nonmetastatic cancer but progress to distant disease, have never been properly documented,” said Angela B. Mariotto, PhD, Chief of the Data Analytics Branch of the Division of Cancer Control and Population Sciences at the NCI and lead author of this study, in a statement. “This study emphasizes the importance of collecting data on recurrence at the individual level in order to foster more research into the prevention of recurrence and the specific needs of this growing population.”
Marc Hurlbert, PhD, Chair of the Metastatic Breast Cancer Alliance and Chief Mission Officer of the Breast Cancer Research Foundation, adds that this study’s findings are an important first step toward a comprehensive assessment of the burden of disease on patients with metastatic breast cancer.
“One of the critical issues that the Metastatic Breast Cancer Alliance heard from breast cancer experts and metastatic breast cancer patients when the Metastatic Breast Cancer Alliance conducted its Landscape Analysis Research Report was the inadequate statistics and epidemiological data on the number of patients living with metastatic breast cancer. This is the first study report of many in the works filling in that information,” said Dr. Hurlbert.
Funding for this study was provided by the NCI.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
