Dr. Susan Love Foundation for Breast Cancer Research is actively preparing for our Metastatic Breast Cancer Collateral Damage Project Two-Day Think Tank, which is taking place November 10-11. At the Think Tank, we will present the data we have collected on the collateral damage associated with metastatic breast cancer and its treatments. We will also discuss and develop recommendations that can be implemented within our current healthcare system to improve the lives of those living with metastatic disease.
At the Think Tank, we will be talking about both how to manage the collateral damage and how to avoid or prevent it. Precision or personalized medicine is often thought of as an effort to use the information gleaned from the molecular and genetic analyses of a patient’s tumor to determine her best treatment option. Yet it seems to me that we would be remiss if we did not also talk about how to apply this approach to identifying the people who are more or less likely to experience collateral damage from particular drugs. Two recent studies caught my attention because they did just that.
The first study, published online in June in the Journal of Clinical Oncology, investigated what made it more or less likely that a patient age 65 and older would develop the chemotherapy-induced nerve pain known as peripheral neuropathy, For this study, the researchers reviewed the records of 1,401 patients from 23 Southwest Oncology Group clinical trials. They found that the drug paclitaxel (Taxol) was the most likely to cause neuropathy. This wasn’t really a surprise. Nerve damage is a well-known side effect of this drug. What interested me, was this: a person’s age and whether or not they had a history of diabetes could also predict their likelihood of developing nerve pain. And this is even more interesting: the trial participants who had an autoimmune disease were less likely to develop nerve pain! This is the kind of information we can use right now to help women make decisions about their treatment!
The second study, published October 1 in Clinical Cancer Research also looked at risk of developing nerve pain. But in this one, the researchers tried to find a genetic cause. They did this by studying single nucleotide polymorphisms or SNPs (pronounced snips). Nucleotides are the letters of the genetic code inside our DNA— Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). They are able to generate genetic variations (polymorphisms) by changing the recipe the gene uses to produce a protein. These variations are SNPs.
The researchers examined a total of nearly 500,000 SNPs from 623 Caucasian men with prostate cancer. They found that one SNP (known as VAC14) was significantly associated with nerve damage caused by docetaxel (Taxotere). This confirmed what many of us have suspected: There are detectable genetic variants that make some people more susceptible to developing neuropathy from this drug!
Many of us have experienced collateral damage from chemotherapy and other cancer drugs. This is the type of research we need to help others avoid following in our path. Precision or personalized medicine can’t only be about selecting drugs based on a tumor’s mutations. As these studies show, it must also be about selecting drugs based on a person’s genetic risk of developing side effects. When that happens, it will indeed be a real advance!