1. DiGiulio, Sarah

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There are a lot of conversations happening across cancer care, medicine, and beyond when it comes to how to best manage pain-especially chronic pain, and particularly debilitating chronic pain. One important part of that conversation is how many people are in chronic, debilitating pain to start with, including how many patients who've had cancer fall into those groups. There are currently more than 15 million people in the U.S. who have had cancer and the number is expected to grow to more than a quarter billion by 2040. Cancer survivors are known to have higher rates of chronic pain than those without histories of cancer, so cancer survivors constitute a significant population to consider when talking about pain.

Changchuan Jiang, MD... - Click to enlarge in new windowChangchuan Jiang, MD, MPH. Changchuan Jiang, MD, MPH

But there's not robust data when it comes to quantifying how many people with a history of cancer living in the U.S. currently live with chronic pain, explained Changchuan Jiang, MD, MPH, an internal medicine resident at Icahn School of Medicine at Mount Sinai, who is the lead author of a JAMA Oncology research letter that investigated the question (2019; doi:10.1001/jamaoncol.2019.1439).


ASCO's 2016 guideline on chronic pain management in survivors of adult cancers reports the prevalence of chronic pain in cancer survivors to be "as high as 40 percent," citing a study that looked at chronic pain in cancer survivors in Denmark, a study that looked at chronic pain in long-term breast cancer survivors, and a 2016 meta-analysis of studies that measured chronic pain prevalence in cancer survivors in some way (J Clin Oncol 2016; doi: 10.1200/JCO.2016.68.5206).


Jiang and his colleagues identified 4,526 cancer survivors who had participated in the National Health Interview Survey and had answered questions about chronic pain and high-impact chronic pain.


The data showed the following findings:


* 34.6 percent of survivors reported having chronic pain;


* 16.1 percent of survivors reported having high-impact chronic pain;


* sex, marital status, or region did not vary pain rates; and


* rates of both chronic pain and high-impact chronic pain were higher in survivors with less education, low household incomes, public insurance, and the unemployed.



In an interview with Oncology Times, Jiang said the new data are noteworthy.


1 What were the key findings from your research and how are they different from what was previously known on the topic?

"The key findings include that 1 in 3 cancer survivors (about 5.4 million Americans [if the estimates accurately reflect the proportion of U.S. cancers survivors in chronic pain]) suffer from chronic pain. Half of them report their life/work activities were limited by chronic pain [high-impact chronic pain].


"Chronic pain is defined as pain on most days or every day in the past 6 months; high-impact chronic pain was defined as chronic pain limiting life or work activities on most days or every day in the past 6 months. The major difference was if the pain limited patients' life or work activities.


"We also noticed the chronic pain persists even years after the cancer diagnosis and treatment and the prevalence of chronic pain varied remarkably by different sociodemographic factors.


"Several previous studies provided important data about chronic pain in patients with single cancer type (such as breast cancer), at the community level, or from certain clinical trials. Other researchers report the prevalence of chronic pain in the cancer survivors outside of the U.S. Our study was the first research to report a nationwide estimate on the prevalence of chronic pain in the U.S. cancer survivors."


2 Why is it important to look at and accurately quantify chronic pain in the general population of cancer survivors now (rather than rely on existing estimates that have looked at chronic pain rates in single types of cancer)?

"Chronic pain is one of the major public health issues in the U.S. especially in the context of the recent opioid epidemic. It is also the most common side effect of cancer treatment.


"The Centers for Disease Control and Prevention, ASCO, and the National Comprehensive Cancer Network have announced their guidelines on chronic pain management in the general population or in cancer patients. But the medical community has concerns on the divide in the recommendations for cancer survivors. Meanwhile, we don't have the U.S. nationwide data to estimate the burden of chronic pain in this rapid-growing vulnerable community.


"We used the National Health Interview Survey, a cross-sectional, national representative dataset conducted by the U.S. Census Bureau. It has been widely used by the CDC and other research institutes to report the health data in the U.S. including the prevalence of chronic pain in the U.S."


3 What's the bottom-line takeaway about this data and its implications?

"This study highlighted the unmet need for cancer survivorship care, especially in the underserved population. It also added to the [robust] evidence that socioeconomic disparities [exist] in U.S. health care. Future research may focus on finding a better way to manage pain in cancer survivors, including cancer pain or non-cancer pain. It is also important to educate the primary care providers and prepare them to take care of cancer survivors as this vulnerable community rapidly grows.


"Chronic pain is very common in cancer patients, even years after their cancer diagnosis and treatments. It is important to work closely with palliative care and primary care providers to address unmet needs in this rapidly growing community."