Opioid Use Disorder Tied to Increased Risk of Cancer Incidence, Mortality

People with opioid use-related disorders are at an increased risk of developing cancer and have a higher cancer mortality rate, according to new research published in Addiction.

All residents in Norway have universal health care coverage and access to opioid maintenance treatment (OMT) with methadone, buprenorphine, or morphine. To better understand the health needs of adults utilizing OMT and potentially living into older age (instead of dying prematurely due to overdose), the current study sought to determine cancer-specific incidence, mortality, and survival among adults with opioid use-related disorders.

Researchers conducted a cohort study using national register data from the POINT project, which included linked information from 6 different Norwegian registries. Participants included all adults (18 years of age and older) with an International Classification of Diseases, Tenth Revision (ICD-10) code for mental and behavioral disorders due to opioid use between 2010 and 2018. Individuals were excluded if they had ever been diagnosed with cancer prior to the index date, which was defined as the date of the first opioid use-related diagnosis. Prescription dispensing records were used to identify OMT users and the researchers performed sex-specific, age-standardized incidence ratio (SIR) and mortality ratio (SMR) analyses to investigate cancer incidence and mortality.

A total of 19,651 adults with opioid use-related disorders were included in the analysis. The mean (SD) age at index was 40 (13) years, 55% of individuals had OMT dispensing records, and 65% were men.

Over a median (interquartile range [IQR]) follow-up of 6.1 (2.9-8.3) years, 2% (n=455) of the study population developed cancer. The most frequent cancer types according to the primary site were lung (19%), liver (10%), and colon cancers (6%). Relative to the general population, adults with opioid use-related disorders had a significantly higher incidence of cancer with a SIR of 1.2 (95% CI, 1.1-1.3).

The median (IQR) follow-up time for the mortality analyses was 6.2 (3.0-8.3) years. Among those diagnosed with cancer, 33% died within the first year after cancer diagnosis. Relative to the general population, people with opioid use-related disorders had a twofold higher cancer mortality, with an SMR of 2.3 (95% CI, 2.0-2.7). Further, the 1-year all-site cancer survival rate was 10% to 15% lower among individuals with opioid use-related disorders, compared with the general population.

“The higher incidence and more than doubled cancer mortality ratios observed in our study emphasize the need for improved health services for ageing people with opioid use-related disorders,” the researchers concluded. “Increased awareness among health services, enhanced cancer screening and treatment, coupled with targeted preventive efforts among individuals who use opioids, such as improving their health literacy, is important to improve cancer outcomes and thereby improve longevity in this population. .”

The primary limitations of the study include the use of ICD-10 codes which do not differentiate between illicit and prescription opioid use; the relatively short follow-up duration, which may have excluded mortality due to certain cancers; and the lack of information regarding lifestyle risk factors, such as smoking status or other carcinogenic exposures.

This article originally appeared on Psychiatry Advisor