Nav: Home

Elderly survivors of three common cancers face persistent risk of brain metastasis

May 03, 2019

Bottom Line: Elderly survivors of breast cancer, lung cancer, and melanoma face risk of brain metastasis later in life, and may require extra surveillance in the years following initial cancer treatment.

Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Authors: Jill S. Barnholtz-Sloan, PhD, Sally S. Morley Designated Professor in Brain Tumor Research, Cleveland Institute for Computational Biology and Department of Population and Quantitative Health Sciences at Case Western Reserve University School of Medicine in Cleveland, and Mustafa S. Ascha, MS, a PhD candidate in the Center for Clinical Investigation, Department of Population and Quantitative Health Sciences at Case Western.

Background: "As cancer treatments have gotten better and more people are surviving a primary cancer diagnosis, it's important to study secondary cancers, including metastasis to the brain," Barnholtz-Sloan said. "With an aging U.S. population, the number of people with brain metastasis is increasing, although sometimes that metastasis does not occur until many years after the initial cancer diagnosis."

"As people are living longer after an initial cancer diagnosis, their 'time at risk' for metastasis is going up. In addition, the majority of primary cancer diagnoses have no standard of care for brain metastasis screening," Ascha added.

How the Study Was Conducted: In this study, researchers analyzed rates of synchronous brain metastases (SBM), those diagnosed during the staging workup for the primary cancer, and lifetime brain metastases (LBM), those diagnosed later in life. Primary cancers in this study were lung cancer, breast cancer, and melanoma, which are more likely to metastasize to the brain than many other cancer types.

The researchers linked data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database to Medicare claims data on brain metastases to investigate rates of brain metastasis in elderly patients. Because Medicare is the primary insurer for most patients age 65 or older, the results of SEER-Medicare studies are generalizable to the elderly population, Barnholtz-Sloan explained. Final data included patients diagnosed in 2010 through 2012, with 70,974 lung cancer cases, 67,362 breast cancer cases, and 21,860 melanoma cases.

The researchers calculated incidence proportion, the ratio of brain metastases counts to the total number of cases, for each primary cancer.

Results: For primary lung cancer, the incidence proportion of SBM was 9.6 percent and for LBM, 13.5 percent. The highest rates of metastasis were in small-cell and non-small-cell lung carcinoma, compared with adenocarcinoma, a more common type of lung cancer.

For primary breast cancer, the incidence proportion of SBM was 0.3 percent and for LBM, 1.8 percent. The rates of brain metastasis were lowest among patients who had localized breast tumors and highest among those whose cancer had already spread to another part of the body. The rates also varied by molecular subtype, with the highest rates for triple-negative breast cancer.

For melanoma, the incidence proportion of SBM was 1.1 percent and for LBM, 3.6 percent. Rates rose dramatically for patients whose melanoma had already spread at the time of diagnosis; 30.4 percent of those who had distant disease at diagnosis would later develop brain metastasis, compared with 15.2 percent of those who had regional and lymph node involvement, 13.2 percent who had lymph node involvement only, 7.8 percent who had regional tissue involvement, and 2.5 percent among those who had localized disease.

Author's Comments: Barnholtz-Sloan and Ascha said that the results of the study could help clinicians better understand patients' risk for brain metastasis and could potentially influence screening and surveillance practices.

"Brain metastases are detected with MRI, which is very expensive," Barnholtz-Sloan said. "An improved understanding of who is likely to develop a brain metastasis could help determine who should get an MRI."

Ascha added that more targeted surveillance could potentially help physicians detect metastases at early stages. "If we can identify brain metastases earlier in their progression, that could allow for earlier treatment and improved outcomes for these patients," he said.

Study Limitations: The authors said the study's primary limitation is that Medicare data, while providing a comprehensive view of the elderly population, cannot always be generalized to younger patients. Also, the study encompassed four to five years of follow-up, whereas in some cancers, such as breast cancer, brain metastasis can occur decades after the initial cancer, Barnholtz-Sloan said.

Funding & Disclosures: This study was supported in part through support to the Central Brain Tumor Registry of the United States, which receives funding from the American Brain Tumor Association, The Sontag Foundation, Novocure, AbbVie, the Musella Foundation, and the Centers for Disease Control and Prevention. The authors declare no conflicts of interest.
-end-


American Association for Cancer Research

Related Breast Cancer Articles:

Does MRI plus mammography improve detection of new breast cancer after breast conservation therapy?
A new article published by JAMA Oncology compares outcomes for combined mammography and MRI or ultrasonography screenings for new breast cancers in women who have previously undergone breast conservation surgery and radiotherapy for breast cancer initially diagnosed at 50 or younger.
Blood test offers improved breast cancer detection tool to reduce use of breast biopsy
A Clinical Breast Cancer study demonstrates Videssa Breast can inform better next steps after abnormal mammogram results and potentially reduce biopsies up to 67 percent.
Surgery to remove unaffected breast in early breast cancer increases
The proportion of women in the United States undergoing surgery for early-stage breast cancer who have preventive mastectomy to remove the unaffected breast increased significantly in recent years, particularly among younger women, and varied substantially across states.
Breast cancer patients with dense breast tissue more likely to develop contralateral disease
Breast cancer patients with dense breast tissue have almost a two-fold increased risk of developing disease in the contralateral breast, according to new research from The University of Texas MD Anderson Cancer.
Some early breast cancer patients benefit more from breast conservation than from mastectomy
Breast conserving therapy (BCT) is better than mastectomy for patients with some types of early breast cancer, according to results from the largest study to date, presented at ECC2017.
More Breast Cancer News and Breast Cancer Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Teaching For Better Humans
More than test scores or good grades — what do kids need to prepare them for the future? This hour, guest host Manoush Zomorodi and TED speakers explore how to help children grow into better humans, in and out of the classroom. Guests include educators Olympia Della Flora and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#535 Superior
Apologies for the delay getting this week's episode out! A technical glitch slowed us down, but all is once again well. This week, we look at the often troubling intertwining of science and race: its long history, its ability to persist even during periods of disrepute, and the current forms it takes as it resurfaces, leveraging the internet and nationalism to buoy itself. We speak with Angela Saini, independent journalist and author of the new book "Superior: The Return of Race Science", about where race science went and how it's coming back.