I’m a lucky person. I am a fifteen-year survivor of Stage IIIB inflammatory breast cancer, the most deadly form of breast cancer. I’m grateful that I’ve lived long enough to see my children graduate, get married and have children. Sure I’ve had some side effects from treatment: dental problems, "chemo-brain," and lymphedema. But these have all gone away completely or improved dramatically.
The one side effect that continues to cause me daily problems is chemotherapy-induced peripheral neuropathy. This condition happens when the nerves in the extremities–hands, feet, or legs–are damaged by chemotherapy drugs. My fingers and toes always feel like they are asleep. Somehow they manage to be both numb and painful. I’ve fallen several times because my feet aren’t giving me accurate feedback about where they are in space and the surface under them. Once I apparently didn’t feel a rock under my shoe and took a tumble that broke a bone in my foot. I drop things, especially thin objects like keys and paper. During the day, I have learned to tune out the pain, but at night when there is nothing to distract me, the pain sometimes makes it hard to fall asleep.
I’m one of the estimated 20-40% of chemotherapy patients who develop peripheral neuropathy. Radiation and the tumor itself pressing on a nerve are other reasons why some cancer patients suffer from this painful condition. Until recently no one knew why most patients don’t have trouble with neuropathy while others do. But according to a recent article in Cure, "researchers at the Mayo Clinic in Rochester, Minn., have pinpointed variations in three genes that could someday help doctors identify which patients are more susceptible to the condition findings that could help doctors one day individualize treatment, either by choosing a chemo drug less likely to cause peripheral neuropathy or by lowering the dose of the drug."
Sometimes peripheral neuropathy is hereditary. The reseachers at Mayo looked at specific genes thought to be responsible for hereditary neuropathy and found they are also connected to a tendency to get neuropathy from chemotherapy. It is way too early to apply this research at the doctor’s office, but it might be helpful for oncologists to know if a patient has a family history of hereditary neuropathy.
My father had such painful neuropathy in his last few years that he could barely walk. This happened after I had neuropathy from chemo, so we could compare notes and commiserate together. Now it appears that perhaps I was susceptible to my neuropathy because of a gene my father and I shared.
Maybe sometime soon your oncologist will be able to know if you are likely to develop neuropathy. However, patients are already reluctant to report neuropathy to their doctors because they want to receive the full dose of life-saving chemotherapy. Like me, they would rather live long enough to have side effects to complain about.
But what we don’t realize when we are in the midst of cancer treatment is how long the problem might last and how severe it might become. We also don’t know how ineffective treatments have been. Vitamins, acupuncture, anti-seizure medicines, and anti-depressants help some people, but until recently there has been no proven effective treatment for chemo-induced neuropathy pain. I certainly have tried everything over the years with little success.
In a randomized study at the University of Michigan, researchers found that duloxetine (trade name Cymbalta) helped 59% of the patients. Patients started with 30 milligrams, half a regular dose, the first week and then received a full dose after that. This gradual dosage helped avoid severe side effects. The main side effect reported was fatigue.
Cymbalta worked best on those patients whose chemotherapy was one of the platin drugs like oxaliplatin. Although it would be nice if it worked 100% of the time regardless of the drug used, this is still good news because patients whose neuropathy was caused by drugs in the taxane family are more likely to get over it without any treatment but time. So having a new drug for patients who have the more persistent neuropathy from platin drugs is helpful.
In an article on the University of Michigan Health System website, lead researcher Ellen M. Lavoie Smith explains why this is such an important breakthrough, "Treating painful chemotherapy-induced peripheral neuropathy is critical. In some cases, physicians must reduce the patient’s chemotherapy dose when the pain becomes too severe. This is not just about improving quality of life by decreasing pain, but potentially it’s helping patients live longer because they can get their full chemotherapy treatment."
What does this mean for you?
- If you are about to start chemotherapy, be sure to let the doctor know about any hereditary peripheral neuropathy in your family.
- If you are in treatment and begin to develop signs of neuropathy–numbness, tingling, or pain in your hands and feet–don’t hesitate to tell your doctor. There may be ways to adjust your dosages to reduce the chances that you will have long-term problems. Ask for a referral to a neurologist who will be the most knowledgeable doctor about treating your neuropathy and who can work with your oncologist to make sure that you are getting the best drugs to fight your cancer while preventing and/or treating nerve damage.
- If you have been suffering from neuropathy for a while now and think you have tried everything, call your doctor and ask if this new study about Cymbalta might apply to you. Depending on your overall health and other drugs you are taking, it might not be appropriate for you, but it is worth investigating.
Sometimes neuropathy goes away on its own within weeks of finishing treatment. Sometimes it is mild, more of a nuisance than a disability. Unfortunately, sometimes it is so severe that people have to stop work. Whatever form your neuropathy takes, it is important to be honest with your doctor about your pain level and how it affects your life. Though no treatment works for everyone, explore your options and see what might work for you.
Antidepressant helps relieve pain from chemotherapy, study finds. 02 April 2013. University of Michigan Health System. Retrieved from http://www.uofmhealth.org/news/archive/201304/antidepressant-helps-relieve-pain-chemotherapy-study-finds 30 June 2013.
Swartz, Amy. Numbing down neuropathy. Cure. 12 May 2013. Retrieved from http://www.curetoday.com/index.cfm/fuseaction/journey.showArticle/id/9/enableStageSubMenu/3/article_id/2116 30 June 2013.