An experimental breast cancer vaccine has so far shown positive effects against an aggressive form of breast cancer.
Though still in very early stages, a new breast cancer vaccine seems effective at preventing the occurrence of HER2-positive breast cancer, a more aggressive and fast-growing type of breast cancer. This type of breast cancer contains a protein called human epidermal growth factor receptor 2 (HER2). This protein causes an increase in the growth of cancer cells.
A decade long, phase 1 human trial has shown that the new vaccine has prolonged the lives of roughly 80% of the 66 patients involved in the trial. These patients had late-stage HER2-positive breast cancer. Ten years later, there has been no reoccurrence of the cancer in 40% of these patients.
Current treatments for HER2 breast cancer, including chemotherapy, can be both harmful and ineffective. These treatments usually need to be administered regularly and over long periods of time, whereas vaccines can be administered less often and can potentially prevent cancer from reoccurring.
This new DNA-based vaccine carries the genetic code to make the HER2 protein. Once the vaccine is administered to the patient, their cells absorb that DNA and start replicating copies of HER2. The immune system then recognises the foreign protein as dangerous and creates defense mechanisms to fight it off. This helps prepare the immune system to defend itself if it encounters the HER2 protein in the future.
According to the World Health Organisation, 2.3 million women were diagnosed with breast cancer worldwide in 2020, including 685,000 deaths.
US professor and vice-chair William Gillanders, MD, at the Department of Surgery at Washington University in St. Louis School of Medicine has said: “This is a really nice study because, in essence, they’ve shown that their vaccine can induce a nice HER2-specific immune response.” Gillanders also said, “(cancer vaccines) don’t have any of the side effects of other standard treatments for cancer… These vaccines may be just as effective as some of these other treatments that patients dread so much.”