Fighting the Good Fight Against "Chemo Brain"

I have no connection to the University of Rochester in New York other than I interviewed one of their scientists while researching and writing "Your Brain After Chemo." Perhaps if I did, I wouldn't sound like some gushing MC. But here it goes: Boys and girls, brothers and sisters, give it up for the University of Rochester!

Why am I fawning like this? Because several of their researchers have made little cracks in the case of chemotherapy-related cognitive impairment, also known as chemo brain, chemonesia, brain fog, post-chemo brain, and my hands-down personal favorite: Memory? What memory! That's a big issue to those of us who have suffered through it (and to those of us who write books about it). In fact, up to 80 percent of people who have undergone chemotherapy (at least in studies of breast cancer and lymphoma patients) report problems with attention, concentration, word retrieval, decision making and/or multitasking, among other cognitive tasks.

I'm one of the lucky ones. My fog cleared within a few months after I completed treatment for breast cancer, which is the case for most survivors. But about one-fourth of us continue to show signs of impairment even five to ten years later. Symptoms can be mild or so debilitating that they affect day-to-day functioning.

What exactly causes brain fog? That's the big question that leads me back to the research rock stars at the University of Rochester (and if you can't say that five times really, really fast, then you may - or may not - have chemo brain...). In 2006, Mark Noble, Ph.D., director of the University of Rochester Stem Cell and Regenerative Medicine Institute, and his team, were among the first scientists to directly link chemotherapy to brain cell death in humans and rodents. They found that three drugs used to treat cancer (carmustine, cisplatin, and cytarabine) were more toxic to healthy brain cells than to cancer cells.

For me, reading about this study and two others in major newspapers at the time amounted to an "aha!" moment.

Then two years later, Noble et. al. exposed mice and cell lines to the common chemo drug 5-fluorouracil or 5-FU. They found that 5-FU damaged healthy immature cells in the central nervous system and also destroyed cells called oligodendrocytes. Our brains rely on the fatty coating produced by oligodendrocytes to function normally. Without it, our nerve cells can't fire off signals to each other. You might look at an apple and think it's a baseball. Who would want that?

And now there are more findings from this small private university with its share of Nobel Prize winners among faculty and alumni. Again using animal models, Robert Gross, MD, PhD and Michelle Janelsins, PhD and their team reported that chemo drugs cyclophosphamide, 5-FU, paclitaxel and doxorubicin disrupt the birth of new brain cells. But insulin-like growth factor (IGF-1), a protein that is generally secreted by the liver, potentially may help reverse the damage. At least it seems so in mice. For us humans, we'll have to stay tuned.

The researchers speculated that chemotherapy might destroy the ability of our brain cells to regenerate in the hippocampus. That's the region of the brain responsible for forming new memories. If you're able to remember appointments without writing them down and recognize your new co-worker, then thank your hippocampus.

This study, says a UR media release, "is relevant to the legions of cancer survivors who experience a frustrating decline in cognitive function after chemotherapy treatment, known as chemo brain."

The scientists deserve kudos for their good work. But they're not alone in their efforts. Others at institutions like UCLA, Sloan-Kettering, MD Anderson, University of Chicago, the Mayo Clinic, University of Michigan, Dana-Farber, Stanford, Dartmouth, Eastern Maine Medical Center, University of Toronto, and at research centers in the U.K., Japan, The Netherlands and elsewhere are advancing the research as well. The data is coming out faster now. One day, hopefully, cancer patients will need not sacrifice their minds to regain their health. And that will be a lot more than an "aha" moment.

To learn more about "chemo brain," read "Your Brain After Chemo: A Practical Guide to Lifting the Fog and Getting Back Your Focus" by Dan Silverman, MD, PhD and Idelle Davidson.