Chemotherapy can treat your cancer but can also permanently harm your heart.
Learn how your cells can predict your hearts' response to chemo.
Important note: Silene Biotech does not supply medical advice or diagnoses; if you have a medical concern or question, please contact your doctor
Cancer is a serious medical burden in the United States and with nearly 600,000 cancer-related deaths per year, cancer remains the number 2 cause of death in the US . The treatment options for cancer patients vary by cancer type, stage, and patient age, but many cancer patients will undergo chemotherapy, or cancer treatments that use drugs to kill cancer cells. Most side effects of chemotherapy are well-known, such as nausea, hair loss, and fatigue , but chemotherapy can have serious side effects on other organs, such as your heart.
In fact, certain chemotherapeutics can cause permanent, irreversible damage to the heat of the patients they are treating. Anthracyclines (doxorubicin, daunorubicin, amrubicin) are drugs that are well known to be cardiotoxic, or harmful to the heart . The precise mechanism is unknown, but these compounds damage and cause the death of heart cells. This results in a decrease in ejection fraction, or the ability of the heart to pump blood - and if this progresses, this damage can also cause congestive heart failure (CHF). In fact, up to 5% of patients treated with anthracyclines may experience heart failure . As heart failure can require a heart transplant and may even lead to death, cardiotoxicity of chemotherapy remains a serious concern for cancer patients and their doctors.
However, cancer therapy is a balancing act between aggressively treating the cancer and ensuring the rest of the patient's body is able to function normally, so often doctors will prescribe anthracyclines despite their side effects. The cardiotoxicity of these drugs is closely tied to the cumulative dose, or the total amount, of the drug taken - the highest cumulative doses of doxorubicin caused cardiotoxicity in over 65% of the patients . In many cases, the doctor must monitor the total dose of anthracyclines and their patients' heart function over time to determine if they are having a cardiotoxic response, but the consensus is out on the timing . In some cases, doctors may choose to monitor heart function 3-6 months post-treatment, but heart function can be permanently affected even within 1 month of chemotherapy .
Fortunately, researcher are starting to identify biomarkers in our blood that may be predictive if a patient is sensitive to anthracycline cardiotoxicity . There have also been studies that show certain compounds can be taken or given in conjunction to chemotherapy or immediately after cardiotoxicity is found to protect heart cells [6, 7]. However, these results are from a small sample size and are a reactive treatment. Since patients have different responses to anthracyclines, both in response to how effective the drugs are to treat the cancer as well as how sensitive their heart is to the cancer drugs, it would be valuable to predict ahead of time if a patient's heart was sensitive to anthracycline, so the doctor could dose and monitor the patient accordingly. Also, by knowing this, doctors could prescribe protective drugs in conjunction with chemo to reduce the risk of effects on patients' hearts if they are sensitive to anthracycline cardiotoxicity .
Enter stem cell technology. Scientists now have the ability to reprogram our cells into stem cells, and then turn those stem cells into heart cells - this technology is called induced Pluripotent Stem cell technology and it won the Nobel Prize in Physiology and Medicine in 2012 (you can read a stem cell primer here). So could patients' stem cells be used to model their heart cells and predict their response to chemotherapy? Absolutely - in fact, scientists at Stanford have used patients' heart cells to investigate why anthracyclines are toxic to the heart to possibly reduce or eliminate their harmful side effects . Interestingly, they also found that genetics may play a strong part in determining if our hearts are sensitive to anthracycline .
So how predictive are our heart cells of our actual response to chemotherapy? A new study out of Stanford showed that patients' heart cells could accurately predict the patient response to chemotherapy . Specifically, the heart cells of patients who did not experience cardiotoxicity in response to chemo also demonstrated resistance to chemo in vitro, or in a culture dish outside of the body, and the heart cells of patients that did experience cardiotoxicity also showed signs of damage in vitro .
Promisingly, we believe that patient heart cells could be generated ahead of time and then used immediately after a cancer diagnosis to inform doctors of possible patient sensitivity to anthracycline - and this would be especially useful for patients who might be at high-risk for developing cancers in the future. Silene Biotech's vision of the future is truly personalized, predictive medicine - starting with your cells. If you're interested in learning more about your cells and the future of personalized medicine, book a phone consultation with us today.