The most recent Long-Term Follow-Up Guidelines from the Children's Oncology Group identified long-term pain in survivors of childhood cancer as an area of growing interest. To systematically look at the research and better understand the need, Fiona Schulte, PhD, Assistant Professor in the Department of Oncology, Division of Psychosocial Oncology in the Cumming School of Medicine at University of Calgary in Canada, and her colleagues, published a review in Cancer (2020; doi: 10.1002/cncr.33289). Schulte was a member of the task force that help prepared the Children's Oncology Group guidelines in 2018. "To our knowledge, no one has yet looked systematically at all the evidence describing pain in survivors of childhood cancer," Schulte told Oncology Times. "We thought it was important to characterize the prevalence of pain among survivors, as well as to describe the factors that might be related to pain in this group. We also thought it was important to highlight important areas for future investigation so that research in this field moves in a direction that will advance our knowledge."
1 What were your review's key findings?
"The rates of pain in survivors of childhood cancer are reported anywhere between 4.5 and 75 percent, which is not very helpful in telling us if this is a problem for survivors or not. Thus, one of the main findings of the review was a call for future research to use consistent definitions of pain (or chronic pain) to better estimate true rates of pain in this population.
"Based on the literature that does exist, we did find fairly consistently that survivors experience more pain than their healthy peers and that pain is consistently related to increased fatigue and the female sex. The remaining evidence was relatively weak or inconsistent and requires further investigation, so another key conclusion is that more work in this area is needed.
"The inclusion criteria for our review required studies that included children who had been diagnosed with cancer from 0 to 21 years of age and described survivors of any age who were at least 5 years from diagnosis and/or 2 years from the completion of therapy. We also did not discriminate by type of diagnosis. Based on the data we reviewed, there did not appear to be strong evidence to suggest there were differences in the experience of pain for different cancer types, age at diagnosis, or type of treatment undergone. This does not mean, however, that these differences do not in fact exist. We don't yet have reliable evidence to make strong conclusions.
"In our review, we intentionally left our definition of pain broad to capture the range of studies that have assessed pain among this population, but this limited our ability to describe specific outcomes. In addition, we did not include qualitative studies. I think it is important to point out that we did not acknowledge the era of diagnosis and treatment for survivors. This may be important in future research as treatment protocols are shifting in favor of less toxic therapies, which may impact rates of pain over time."
2 What's the next step to address adverse outcomes for childhood cancer survivors?
"Findings from the review suggest that we need better research on pain in survivors of childhood cancer in order to make good clinical recommendations. One of the conclusions we made from this review is that there is evidence to suggest pain is associated with reduced quality of life for these patients. This review has really inspired a whole new focus on pain in survivors of childhood cancer in our lab and one of my current students is leading this effort. Specifically, she has been careful to consider a more comprehensive definition of pain that considers pain as a complex, multidimensional construct.
"We have also been conducting qualitative interviews with survivors of childhood cancer to better understand the pain experiences from the perspective of both survivors and one of their parents. And now that we have identified through our own work that pain is an issue for survivors of childhood cancer and negatively affects their quality of life, we plan to test a psychological intervention for this population with the goal of reducing the burden of pain in survivorship."
3 What's the bottom-line message about pain in childhood cancer survivors?
"The results of our review do suggest that this population experiences pain in survivorship, and so our message to health care providers is that they should ask about the presence of pain during follow-up appointments. We do know that pain is a common symptom associated with cancer and its treatments, but our data shows that pain may persist long into survivorship.
"We think that a critical message from our work, and consistent with the purpose of the Children's Oncology Group Long-Term Follow-Up Guidelines, is that practicing oncologists and cancer care providers should be screening for the presence of pain among survivors.
"In addition, it would be great for health care providers to introduce pain management strategies where appropriate. Preliminary results from our qualitative data suggest that survivors may not be reporting their symptoms of pain either because they feel so thankful to be alive that they feel the experience of pain is a side effect they have to live with, or they are just not aware that pain could be a potential side effect of their cancer and its treatments. While pain may be an inevitable misfortune, we know based on research done in youth with chronic non-cancer pain that chronic pain can be treated, and non-pharmacological options may be excellent alternatives or complementary options to pharmacological interventions."