Opioid responsiveness-primary diagnosis relationship in advanced cancer patients followed at home

The aim of this study was to evaluate the influence of the primary cancer o n pain characteristics and opioid response, in terms of analgesia and adver se effects, in advanced cancer patients followed at home. A prospective stu dy was carried out in a sample of 434 consecutive advanced cancer patients who required opioids during the last four weeks of life. One hundred eighty -one patients received opioids for longer than the four weeks and were cons idered for this analysis. Demographic data, primary diagnosis, and pain mec hanisms were recorded, and mean opioid doses, pain intensity, and symptoms were assessed at weekly intervals during the last four weeks of life. In th e group of 181 patients, somatic pain was associated with lung; head and ne ck, breast, and prostate cancer (p < 0.0005), while visceral pain was assoc iated with colorectal, gastric, liver; pancreatic and uterine cancer (p < 0 .0005). Considering all primary diagnoses, there was a significant increase in the mean opioid dose (p < 0.0005) across the four weekly periods. There was a significant decrease in pain intensity scores (p < 0.0005) in all ca ses. A significant dose increase was observed only for mesothelioma (p = 0. 027) when compared with other types of cancer. In all 181 cases, a signific ant worsening in symptom intensity was observed during the last two weeks o f fife (p < 0.01). This study shows that primary cancer may have an. influe nce on pain characteristics and opioid response. Patients with some kinds o f cancer may be at risk of developing severe pain syndromes or more adverse effects. (C) U.S. Cancer Pain Relief Committee, 2000.