The terminal cancer patient: Effects of age, gender, and primary tumor site on opioid dose

Objective. The objective of the current study is to describe correlations between age, gender, and primary cancer site and sustained-release opioid doses prescribed for hospice patients at the end of life. Patients and Setting. This study included all 7,201 hospice patients referred to a North American palliative care specialty pharmacy with the primary diagnosis of cancer and who were prescribed transdermal fentanyl, sustained-release oral morphine, or sustained-release oxycodone. Design. This is a retrospective analysis of the final sustained-release morphine, oxycodone, or transdermal fentanyl doses prescribed to cancer patients, according to pharmacy records. Comparisons between sex and age group were performed with chi-square tests. Mann-Whitney U tests were used to compare mean doses between the sexes. Analyses of covariance (ANCOVA) were used to compare opioid doses between genders and among primary cancer sites while controlling for age. Results. The inverse association between age group and dose was highly significant. For example, final opioid doses less than or equal to120 mg/day oral morphine equivalent were prescribed for only 46.4% of patients between 40 and 49 years of age compared with 86.4% of patients 90 years of age and older. An ANCOVA on the largest non-sex-related diagnoses found primary tumor site and patient age, but not gender, to be associated with sustained-release opioid dose. Conclusion. Both primary tumor site and patient age were associated with final opioid dose. Further investigation is warranted to determine which primary tumor sites are associated with unusually high opioid doses and may highlight the need to optimize adjuvant medication therapy if neuropathic and/or inflammatory pain mechanisms are involved and to refer to pain specialists when appropriate.