Toronto, Aug 7: At a time of rising rates of opioid overdose and addiction, new research by an Indian-origin scientist reveals that its use is more common among cancer survivors than in individuals without a history of cancer. "Our research findings raise concerns about the diagnosis and management of chronic pain problems among survivors stemming from cancer diagnosis or treatment," said Rinku Sutradhar, Associate Professor at University of Toronto in Canada. The finding was true even among survivors who were 10 or more years past their cancer diagnosis, according to the study published online in the journal CANCER. Sutradhar and her colleagues analysed information dating back to 2010 on 8,601 adults at least five years past a cancer diagnosis who were matched with equal number of individuals without a prior cancer diagnosis. Follow-up was stopped at any indication of cancer recurrence, second malignancy, or new cancer diagnosis. The researchers looked for opioid prescriptions filled at a pharmacy during the observation period for each individual. The rate of opioid prescribing was 1.22 times higher among survivors than corresponding matched controls. Over a 36-month period, the average number of opioid prescriptions filled by survivors was 7.7, compared with 6.3 for controls. This increased rate of opioid prescribing was also seen among survivors who were 10 or more years past their cancer diagnosis. Individuals with lower income, and those who were younger, from rural neighbourhoods, and with more comorbidities had significantly higher prescribing rates. Sex was not associated with prescribing rates. "Physicians providing primary care to cancer survivors should consider close examination of reasons for continued opioid use to differentiate chronic pain from dependency," said Sutradhar, who is also a senior scientist at the Institute for Clinical Evaluative Sciences in Toronto.