Cancer survivors, even those 10 years or longer past diagnosis, had 1.22-times higher prescription opioid use than matched individuals without a history of cancer, according to results of a population-based study.
“Our study indicates that the prevalence of chronic pain for cancer survivors may continue to be higher, and remain higher over time, compared [with] people with no history of cancer,” Rinku Sutradhar, PhD, senior scientist at Institute for Clinical Evaluative Sciences in Toronto, Canada, and associate professor at the University of Toronto, told HemOnc Today. “This may be because of the cancer itself, or due to the effects of treatment.”
Opioids can relieve moderate to severe pain arising from cancer and its treatment. However, a risk for dependency is high, which is why it’s important to have a plan for how to manage any ongoing pain once individuals are cancer free, Sutradhar said.
“For some survivors, being cancer free doesn’t necessarily mean being pain free, for a variety of reasons,” Sutradhar said. “Pain lingering during survivorship could be associated with factors such as type and invasiveness of tumors, the type of treatments other illnesses that may coincide with the cancer, as well as other aspects of the patient’s life, such as their age, work situation, socioeconomic status and so forth.”
No data are available detailing the prevalence of persistent pain among adult cancer survivors.
“We also know that socio-economically disadvantaged populations are more at risk for opioid dependency, but previous studies have not examined cancer survivors who are a part of this disadvantaged group, so this is an important knowledge gap to fill,” Sutradhar said.
Thus, Sutradhar and colleagues evaluated health records of 8,600 cancer survivors 5 or more years past their diagnosis (median, 10 years past diagnosis; interquartile range, 7-16) in Ontario, Canada, who were recipients of the Ontario Drug Benefits Program (ODB).
“The ODB is the Ontario pharmacare program that is available to people younger than 65 years who receive social assistance or whose drug costs are determined to be high relative to their household income,” Sutradhar said.
Researchers matched patients 1:1 to 8,600 controls without cancer who also were residents of Ontario and in the ODB program.
The study — conducted from 2010 to 2012 — excluded patients who experienced a cancer recurrence or a second malignancy.
The researchers linked administrative health databases held at the Institute for Clinical Evaluative Sciences to assess any differences in the patterns of opioid use among cancer survivors compared with controls, taking into account the specific type of cancer diagnosis, other comorbidities, demographic factors and other factors.
Survivors demonstrated a significantly higher crude rate of opioid prescriptions than controls (relative rate = 1.22; 95% CI, 1.21-1.23).
After multivariate adjustment, the relative rate for opioid prescription remained 1.22 times greater among survivors (relative rate = 1.22; 95% CI, 1.11-1.33).
The higher prescription rate among survivors persisted whether they were 5 to 10 years past diagnosis (relative rate = 1.19; 95% CI, 1.04-1.36) or 10 years or longer past diagnosis (relative rate = 1.24; 95% CI, 1.09-1.42).
By the end of the study, survivors showed a higher mean cumulative number of opioid prescriptions filled (7.7 vs. 6.3; P < .0001).
Lower income, younger age, living in a rural neighborhood and having more comorbidities appeared linked to higher prescribing rates, whereas sex did not appear associated with prescription rates.
Researchers found no significant increase in opioid use for breast cancer survivors. Survivors of lung, gastrointestinal, genitourinary or gynecological cancers demonstrated more prominent opioid use than controls.
Survivors are often discharged from an oncology clinic after no recurrence after 5 years, Sutradhar said, suggesting that family physicians treating survivors should look closely at the reasons for ongoing opioid use among their cancer survivors.
“It may be important for cancer survivors to consider being cared for by specialized pain management teams that can offer a more integrative and holistic approach that includes a combination of drug therapy with opioids, along with physical therapy, regular exercise, and psychosocial interventions,” Sutradhar said. – by Melinda Stevens
For more information:
can be reached at Institute for Clinical Evaluative Sciences, G1-06 2075 Bayview Ave., Toronto, ON M4N 3MS, Canada; email: firstname.lastname@example.org.
Disclosures: The researchers report no relevant financial disclosures.