Numerous women refuse to undergo a mammogram to detect breast cancer because, in the event of a suspicious finding and the need to undergo a biopsy, doctors will have to inject a metal marker about five millimeters into the breast, which remains there for the rest of her life.
Now, Hebrew University of Jerusalem (HUJI) researchers have – for the first time in the world – found a possible solution to the problem. It is a biodegradable marker developed from natural and familiar materials. They conducted experiments on animals and found that the natural marker is not toxic and disappears from the body within a few months. Their scientific paper on the study has just been published in the journal ACS Applied Biomaterials under the title “Biodegradable Breast Tissue Marker Clip,” and the university has patented the technology.
If tissue suspected of being cancerous is detected via a mammogram and biopsy, the tissue is sometimes left for follow-up for several months to make sure that no tumors are developing. Prof. Zehava Gallimidi, head of the mammography service at Rambam Medical Center in Haifa, was troubled by this, so she contacted Prof. Avi Domb, head of HUJI’s School of Pharmacy, to develop a biodegradable marker that would disappear from the body after the tests and months of medical follow-up.
Breast cancer is the most common malignant disease in Israel and in the Western world in general. About 5,000 women are diagnosed with breast cancer in Israel each year. As the disease is diagnosed in the early stages, the chances of cure increase to about 90%, among other things by performing a mammogram on time. According to the Association for the War on Cancer, it seems that the number of women recovering from breast cancer is steadily increasing, thanks to early detection and thanks to improved treatment methods and increased widespread awareness in the country.
“A woman who undergoes a mammogram is forced to stay with a metallic marker on her body for the rest of her life, and often more than one marker is inserted if there are several foci suspected of cancer in her body,” noted Domb. “The metallic components can move around the body over the years in undesirable ways, so I also understand that it is better not to stay with the same metals in the body for a long time. I and my team wanted to consider how to alleviate the distress of those women – to create biomarkers, polymers or organic materials – that might suit the imaging systems used to perform a mammogram.”
According to the study, the biodegradable marker can be viewed on conventional imaging devices, including MRI, ultrasound, and CT. The researchers used materials already approved for use in the human body, because the development of a product from new materials requires more approvals before the experiments begin.
It was therefore decided to use tiny poles of biodegradable polymers that are commonly used in the medical world and have been implanted in animals. Polymers were added to commonly used contrast agents such as barium sulfate and iodixanol (which contains iodine). The results of the study were promising and the marker was detected using CT, MRI and ultrasound. Three months after the transplant, the marker depleted until it disappeared.
“This is one of many materials that manage to decompose in the body, such as surgical wires and nails for orthopedic purposes in which broken bones are fixed, so there is no fear of using them. In addition to its use in mammography, the biodegradable product can mark tissues that need to be dissected or tissues that need to be monitored for changes,” Domb added.
“Although we have shown the degradation profile of the clips using imaging methods, our next step is to characterize in detail the changes in the physical properties of the clips after in vivo [animal]studies. However, we see wide use of our polymer clips in the near future, benefitting doctors and patients in various medical applications. We hope to find an organization that will agree to fund this leading to product development so that public use will follow,” he concluded.