Chemotherapy-induced peripheral neuropathy (CIPN) is a common and troublesome adverse event of cancer treatment that can affect survivors’ daily activities. While some people may be at an increased risk for the condition, there is still much to be learned about the development and treatment.
Oncology Nursing News sat down with Grace Campbell, PhD, MSW, RN, CNL, CRRN, an assistant professor at the University of Pittsburgh School of Nursing, to discuss what we currently know about neuropathy – and what more needs to be figured out.
Can you give an overview of CIPN?
Campbell: We all know that CIPN is common; it is obnoxiously painful. It causes terrible symptoms for people, like numbness and tingling, but we really don't have a good understanding of the effects that neuropathy has on people's daily lives.
I did a data analysis from a pilot study that I'm currently doing where we assessed women with gynecologic cancer who were about to get first-line neurotoxic chemotherapy (platinums and taxanes). We assessed them prior to starting chemotherapy on a variety of self-report measures, including things like the severity of their numbness and tingling and also the degree of symptom interference in their daily life activities. We assessed them prior to starting chemo and we assessed them on day 1 of each chemotherapy cycle for 6 cycles. We also had them complete daily symptom diaries where they tracked their symptoms every single day for 126 days.
When we looked at those data, we were able to see that women who experience an early onset of continuous, clinically significant neuropathy, which we defined as a severity of 3 or greater on a 0 to 10 scale, were highly likely at the end of chemotherapy to complain of not being able to have enjoyment in their daily life activities, to experience interference, particularly in walking and in working. Besides being unpleasant and distressing, the neuropathy does actually have functional effects that carry on even when people are finished with chemotherapy.
Right now, do we have a standard of care for CIPN? How should the oncology nurse react when a patient comes in and they have these symptoms?
We don't really have good standards of care. Right now, the evidence is still evolving and growing. But because there's this massive interest now in cancer rehabilitation, now is the perfect time. We are building the evidence for a standard of care.
There's not a lot that we can do right now to really treat the neuropathy, but what we can do is keep people functional. The biggest way that we can do that is to get them into early rehabilitation. Typically in survivorship care, when people are finished with cancer treatment and they continue to complain of disability in their daily lives, this might be the time when the advanced practice provider or the physician or somebody says "Hey, maybe we should try a rehab referral." What some of the data that we have shown, particularly with this early-onset of numbness and tingling, is that this seems to predict long-term disability. As soon as people start to complain of continuous numbness and tingling, that's the time to initiate a rehabilitation referral. Occupational therapists have a lot of things that they can do to help people improve their fine motor skills and their coordination. Physical therapists can work on balance and gait training to help prevent falls and injuries. Those kinds of interventions can really help keep people able to work, sing in the church choir, and do all the things that the neuropathy prevents them from doing.
Can you discuss the importance of the therapy staff and the oncology staff working together to treat these patients, as well as the importance of patients speaking up about their symptoms?
Maintaining good communication among the team is crucial to optimal care for this group of patients. A lot of times when providers will ask patients about their numbness and tingling, they don't like to admit to having it because they feel like this is the quickest path to dose reduction, and they need their chemo. Our patients tell us this. What we're trying to do is educate nurses and providers in the clinic and say, "OK so we do have to be careful. We don't want to create so much neuropathy so people lose protective sensation. That's a safety hazard. But before we dose reduce or discontinue chemotherapy, let's try keeping people functional by doing these early referrals to rehab services." That's one of the things we're doing in our clinic, and it's really working out well, and the providers feel like they have something to offer patients, which is really a positive thing in an otherwise not-too-positive picture with this neuropathy.
As far as the role of the nurse, a lot of rehab service clinics don't exist in oncology settings. Some of them do and it's becoming more common, but it often necessitates a referral out. People don't have time, they don't want to pay copays, so the nurse in the oncology clinic, his or her role is crucial in being able to screen for these kinds of things and be aware of the existence of rehabilitation services and what can be done. So, the nurse really has that crucial screening and assessment role and then referring out. It's almost like a navigator or a care manager type of a function to know that these folks are likely going to need early intervention and here's what I can do about that.
Are there patients who are more susceptible to developing CIPN?
It's sort of unknown. We have some good hunches. Some evidence shows that people who are older tend to develop neuropathy more quickly. More recent evidence that has come out has shown that they may not develop it more quickly. What older adults may have is actually more persistent neuropathy. So, age may be a factor, but maybe not.
Pre-existing neuropathy from other conditions is a pretty high-risk factor for the development of neuropathy. For example, if people are diabetic or have some other sort of neuropathy, fibromyalgia and those kinds of nerve pain types of conditions, have a pretty high risk that the CIPN is going to come on sooner and accelerate more quickly for those folks. That gives us a little bit of a clue.
What is the key next step in better understanding and treating CIPN?
There are still many things that we don't know about who is going to develop CIPN. That's where I think we need our bench scientists to really start trying to figure out who is actually going to develop clinically significant, progressive, persistent neuropathy. There could be some inflammatory processes or genomic processes that may help us to know that more. Right now, it's kind of a shot in the dark. We wait for people to develop symptoms, and then we're reacting. That's what I think is the next frontier of management: How do we prevent this by identifying those at risk?