Kathryn E. Vinson, MS, CCRC
Pretty much not a day goes by where you don’t see an advertisement for a new pharmaceutical. It may be on the TV, in a magazine, or on the radio – but they are everywhere. I have strong feelings about advertisements for pharmaceuticals for many reasons – one including ads for ED treatments during family shows. All jokes aside, some of these side effects that are spoken of in the commercials are pretty scary and can be off-putting to patients. What if your physician recommends a treatment, but you just saw a commercial with a side effect that could be dire? Do you take your doctor’s word for it or refuse based on what you heard?
Side effects, or adverse events in pharma speak, can have profound effects on our lives. As cancer patients, we utilize treatments whose side effects can be far reaching and long lasting. Sadly, some of these adverse reactions to medications can be so profound that patients will choose to forgo treatments. Today I’d like to visit with you about some fascinating research that is being done to better understand side effects and hopefully find and end run around them.
I’ve always associated chemo brain with anemia that can be brought on by chemotherapeutic drugs. I’m not far off, as many researchers believe that may play a role, but the truth of the matter is, they don’t know exactly what causes it. After all, if it was something like anemia, shouldn’t the symptoms resolve when blood counts rebound? The cognitive effects of chemo brain can make it difficult for adults to go back to work after treatments, and for children to succeed academically.
In some fascinating research, scientists at the Stanford University School of Medicine have found that methotrexate, a commonly used chemotherapy drug, has profound and lasting effects of three types of cells in the brain – certain types of glial cells. Within these glial cells, oligodendrocytes, or cells that are responsible for producing and maintaining the myelin sheath were damaged. The myelin sheath is like an insulator around the nerves. Not only does it protect the nerves, it also helps in the conduction of nerve impulses. So, you can imagine that when these cells are damaged, signals don’t flow in their normal, orderly fashion. They further found that precursors to oligodendrocytes become stuck, if you will, at an immature stage, and don’t progress even after chemotherapy has stopped. In animal studies though, they found that by injecting healthy precursor cells into the brains of mice that had received methotrexate, they didn’t get stuck at that immature stage. This provides great hope for addressing this issue!
Further research showed that chemotherapy treatment also activated the microglia – cells that act as a type of immune cell in the brain. The activation of the microglia made it difficult for the astrocytes to get nutrients to the neurons that they support. Fascinatingly, when a drug that inhibits the microglia was administered, not only did astrocyte function improve, but the maturation problems in oligodendrocytes were reversed. With these results, researchers saw many of the cognitive issues eased.
If you or a loved one have gone through hormone receptor positive breast cancer, you have probably heard of drugs that are generically called – hormone blockers. While there is a class of drugs that literally blocks the hormones – selective estrogen receptor modulators (SERMs), aromatase inhibitors work by inhibiting and enzyme that is needed for the production of estrogen. While aromatase inhibitors absolutely help women and men that have been stricken with hormone receptor positive breast cancers, the side effects of these drugs can be life altering. The side effects are similar to menopause, but can be much worse, and very sudden. These effects can be so profound, that patients have opted to discontinue these life saving treatments and “risk it,” so to speak.
Researchers at the University of Massachusetts Amherst looked at marmocets as their models, as their brain structure is much like that of a human, and they exhibit complex behaviors. When the animals were given similar doses of aromatase inhibitors as humans, they exhibited symptoms much like human patients, including problems with temperature control (a bit like hot flashes, but not exactly), in the female primates.
The really interesting/crazy finding is that estrogen levels in the hippocampus – a portion of the brain responsible for long term memory consolidation – actually increased in the animals treated with aromatase inhibitors. The researchers think that this part of the brain made its own estrogen to compensate for low levels in the rest of the body. While a lot of research remains to be done in this area to understand the exact mechanisms, there are hopes that addressing this synthesis of estrogen could provide a way to alleviate some of the side effects.
If you know someone going through cancer treatments, take a look at our page dedicated to Chemotherapy Gifts – you might find something to help them through some of the side effects and to show your love.
As always, much love, many prayers, and abundant blessings to all of the warriors out there!