Clinical research at the Froedtert & the Medical College of Wisconsin health network — anchored by Froedtert Hospital, eastern Wisconsin’s only academic medical center — opens the door to personalized treatment options that offer extensive expertise, resources and innovation and give you access to the highest level of care.
To help plan breast cancer treatment, Medical College of Wisconsin researchers recently completed a study that could identify more people with breast cancer who may benefit from immunotherapy. Their research, exclusive to MCW, was published in the Journal of Personalized Medicine.
“Breast cancer is complicated — it is not just one cancer,” said Julie Jorns, MD, pathologist and MCW faculty member.
There are many subtypes — some aggressive, others less so. Treatments vary depending on type and stage. Additionally, the presence of certain proteins called biomarkers in breast cancer cells can make the difference between a hopeful prognosis or a guarded one.
The research of Dr. Jorns and lead investigator Lubna Chaudhary, MD, medical oncologist and MCW faculty member, builds on the discovery of certain proteins present in lung cancer that are also found in breast cancer.
“The proteins PD-L1 and PD-L2 help cancer cells figure out how to block the natural immune system and keep growing,” Dr. Chaudhary said. “When these proteins are present, the immune system is not as effective in stopping cancer. Blocking PD-L1 and PD-L2 could help immunotherapy be more effective by helping the immune system fight cancer.
“We define different types of breast cancer based on hormone receptor status and whether or not the protein HER2 is present. Proteins on the surface of breast cancer cells can be stimulated by the hormones estrogen or progesterone. If these hormones attach to protein receptors, they help cancer grow. People can have positive or negative hormone receptor status.
“Analysis of breast cancer cells can also tell us if the HER2 protein is present. Like hormones, HER2 helps cancer grow and spread faster.”
These three biomarkers, estrogen, progesterone and HER2, give doctors vital clues about the makeup of tumors and how to treat them. For instance, they can treat HER2-positive breast cancers with drugs that target that protein.
“When I look at tumor tissue under the microscope, it provides two critical pieces of the puzzle,” Dr. Jorns said. “I can determine if we are looking at a primary cancer — cancer that started in the breast. Tissue analysis also reveals the tumor’s biomarkers. Then, we suggest therapies the cancer will best respond to.”
Previous research has focused mainly on the PD-L1 pathway. Dr. Chaudhary’s and Dr. Jorns’ study was unique because it included PD-L2. They found that some breast cancer cells express PD-L2 when they do not express PD-L1. The discovery may provide another way to test for susceptibility to drugs that target the PD-L1 pathway and thus, support the immune system.
“As we look for drugs to treat cancers that have not only PD-L1 but also PD-L2, we could help more patients,” Dr. Jorns said.
Studies like these set the stage for innovation within the Froedtert & MCW Cancer Network, which offers the largest cancer clinical trials treatment program in eastern Wisconsin.
“We have the opportunity to take part in clinical studies that may offer new therapies to patients that are unavailable elsewhere,” Dr. Chaudhary said.
