Blood proteins test may speed up diagnosis by 2 years

According to Dr. Wilma Mesker, an asssistant professor in the Department of Surgery at Leiden University Medical Center in The Netherlands, in 2003, she and her research team decided to investigate new methods of mass spectrometry for the early detection of breast cancer and colorectal cancer for population screening.

“Over the years, we have been improving our strategy, methods, sampling handling, techniques, (and) statistics,” she told Medical News Today.

“When we were confident with our breast cancer data, we applied the method to the group of women with the most urgent clinical need for early detection, namely the group of genetic and (familial) high-risk women,” she said.

That led to the start of the Trial Early Serum Test Breast cancer (TESTBREAST) study. The TESTBREAST study was launched in 2011 by Dr. Mesker and Dr. Rob Tollenaar, professor of surgery and head of the Department of Surgery of the Leiden University Medical Center.

The TESTBREAST study includes 1,174 women at high risk for developing breast cancer, either due to family history or genetic variants.

Since the study began, participating women provide blood samples at least once a year when they go for screening at one of nine hospitals across The Netherlands. And any woman diagnosed with breast cancer also provides blood samples.

For this study, Dr. Mesker and her team analyzed 30 blood samples from three women in the TESTBREAST study diagnosed with breast cancer and three who did not develop breast cancer.

Upon analysis, scientists identified six proteins in the blood that were at higher or lower levels up to two years before they were diagnosed with breast cancer.

“In earlier research, we looked at protein profiles — names of the proteins not known. Already then we noticed changes in the profiles two years before the detection of breast cancer in a small set of patients,” Dr. Mesker explained.

“So we were excited that with the newly applied method of targeted proteomics — proteins known — our earlier findings were confirmed and moreover, the proteins involved are known. These small variances within the patient itself can only be detected in a longitudinal setup — not the conventional case-control commonly used,” she continued.

Researchers believe their findings could eventually be used to make a simple blood test for the early detection of breast cancer in high risk women.

“By collecting the blood of the patient every half year — more often is also possible — a baseline of the patient is created, thus the patient is their own control,” Dr. Mesker explained when asked how this type of blood test might work.

“Small changes in the proteins can be accurately detected. Based on these findings, the doctor/patient can decide to monitor more frequently (or use for) clinical decision-making, e.g. prophylactic mastectomy or surgery of the tumor. A simple blood test can be more frequently applied, is more convenient, has low costs, and no risk of complications.”
— Dr. Mesker

When asked when a blood test like this might be available to the public, Dr. Mesker said their hope is to have it available in several years.

“We currently are measuring the patients in the total TESTBREAST study. There are almost 70 patients … who developed breast cancer over the last years, and of which we have longitudinal samples available. These will be analyzed for the set of six proteins and a set of additional high-potential markers and evaluated,” she said.

“When data are confirmed, the test can be used for patient analysis as an add-on next to mammography and/or MRI,” Dr. Mesker continued.

“Next to this, we will evaluate the test in women with other genetic carriers, and women with (familial) high risk, also (with stored samples). Furthermore, we have a large database available of women with high breast density,” she added.

Medical News Today also spoke with Dr. Parvin Peddi, a board certified medical oncologist and director of Breast Medical Oncology for the Margie Petersen Breast Center at Providence Saint John’s Health Center and associate professor of medical oncology at Saint John’s Cancer Institute in Santa Monica, California, about this study.

Dr. Peddi said it was a “very intriguing idea” and fascinating that researchers are seeing a potential change in protein levels that can predict the development of breast cancer.

“I don’t see the actual proteins listed in the presentation, so I can’t speculate on why the levels go up at time/prior to breast cancer development. Furthermore, this needs to be evaluated in the rest of the study cohort to confirm validity,” she added.

“I would not use this test yet as it is an association, and other patients without these protein patterns may also develop breast cancer.”
— Dr. Parvin Peddi

“And number two, we need to know whether intervention with medications that can reduce breast cancer risk — such as tamoxifen — would then change the trajectory of these patients and prevent them from developing breast cancer. Those steps are needed as a future direction of this intriguing result before adoption in clinical practice,” she concluded.