Factors influencing the opioid response in advanced cancer patients with pain followed at home: the effects of age and gender.

The aim of this study was to evaluate the influence of age and gender on pain characteristics and opioid response in advanced cancer patients followed at home. A perspective study was carried out in a sample of 181 consecutive advanced cancer patients who required opioids in the last 4 weeks before death. Pain intensity and symptoms associated with opioid therapy at weekly intervals for 4 weeks were recorded, as were the previous oncological treatments. Opioid doses increased over time, but remained stable in the last 2 weeks of life, while pain intensity decreased over time despite unchanged use of NSAIDs. A considerable increase in symptom intensity was observed in the last weeks of life, except for nausea and vomiting. Visceral pain was more often reported in women. Male patients more often presented somatic pain mechanisms. Neuropathic pain was associated with higher mean VAS intensity and was equally reported in male and female patients and in the different age groups. Very old patients, who received less chemotherapy, required less opioid doses and reported a lower intensity of some symptoms, while reporting similar pain relief. Dry mouth was more frequent in adults than in very old patients. The identification of specific factors and pain characteristics may be useful in suggesting the likelihood of response in terms of analgesia and opioid-related adverse effects. Age and gender analysis should be included in all cancer pain and symptom control studies, as they may have an influence on cancer pain prognosis.