This paper reports on the experience gained using World Health Organization Guidelines for cancer pain relief over a 10-year period in an anaesthesiology-based pain service associated with a palliative care programme. The course of treatment of 2118 patients was assessed prospectively over a period of 140,478 treatment days. Non-opioid analgesics (WHO step I) were used on 11%, weak opioids (WHO step II) on 31% and strong opioids (WHO step III) on 49% of treatment days. Administration was via the enteral route on 82% and parenterally on 9% of treatment days. On the remaining days, either spinally applied opioids (2%) or other treatments (6%) were utilised. Fifty-six percent of the patients were treated with morphine. Morphine dose escalation was observed in about one-half of the patients being cared for until death, whereas the other half had stable or decreasing doses over the course of treatment. Co-analgesics were administered on 37% of days, most often antidepressants (15%), anticonvulsants (13%) and corticosteroids (13%). Adjuvants to treat symptoms other than pain were prescribed on 79% of days, most commonly laxatives (42%), histamine-2-receptor antagonists (39%) and antiemetics (35%). In addition, palliative antineoplastic treatment was performed in 42%, nerve blocks in 8%, physiotherapy in 5%, psychotherapy in 3% and TENS in 3% of patients. A highly significant pain reduction was achieved within the 1st week of treatment (P < 0.001). Over the whole treatment period, good pain relief was reported in 76%, satisfactory efficacy in 12% and inadequate efficacy in 12% of patients. In the final days of life, 84% rated their pain as moderate or less, while 10% were unable to give a rating. Analgesics remained constantly effective in all 3 steps of the WHO ladder. Other clinical symptoms were likewise significantly reduced at 1 week after initial assessment, with the exception of neuropsychiatric symptoms. During the course of treatment, the latter were the major symptoms on 23% of days, followed by nausea (23%), constipation (23%) and anorexia (20%). Our results emphasise once again the marked efficacy and low rate of complications associated with oral and parenteral analgesic therapy as the mainstay of pain treatment in the palliative care of patients with advanced cancer. Wide dissemination of WHO guidelines among doctors and healthcare workers is thus necessary to effect a clear improvement in the treatment of the many patients suffering from cancer pain in the clinical and home setting.

Although pain assessment is a vital preliminary step towards the satisfactory control of cancer pain, data on the prevalence of different pain syndromes are rare. In a prospective study of 2266 cancer patients, we assessed localisations, aetiologies and pathophysiological mechanisms of the pain syndromes. Thirty percent of the patients presented with 1, 39% with 2 and 31% with 3 or more distinct pain syndromes. The majority of patients had pain caused by cancer (85%) or antineoplastic treatment (17%); 9% had pain related to cancer disease and 9% due to aetiologies unrelated to cancer. Pain could be classified as originating from nociceptors in bone (35%), soft tissue (45%) or visceral structures (33%) or otherwise as of an neuropathic origin (34%). In most patients, pain syndromes were located in the lower back (36%), abdominal region (27%), thoracic region (23%), lower limbs (21%), head (17%) and pelvic region (15%). The main pain syndrome was also coded according to the IASP Classification of Chronic Pain. Regions and systems affected by the main pain syndrome showed large variation depending on the site of cancer origin, whereas temporal characteristics, intensity and aetiology were not markedly influenced by the cancer site. The variety of pain syndromes evaluated in our patients confirms the importance of comprehensive pain assessment prior to treatment.

In a prospective study, the prevalence of 15 physical symptoms and symptom groups was evaluated in 1635 cancer patients referred to a pain clinic. In addition to pain, patients suffered an average of 3.3 symptoms: insomnia (59%), anorexia (48%), constipation (33%), sweating (28%), nausea (27%), dyspnea (24%), dysphagia (20%), neuropsychiatric symptoms (20%), vomiting (20%), urinary symptoms (14%), dyspepsia (11%), paresis (10%), diarrhea (6%), pruritus (6%), and dermatological symptoms (3%). While symptom prevalence was influenced by tumor site, pain intensity, and opioid treatment, only a minor relationship was seen between symptoms and gender, age, or tumor stage. The data emphasize that it is not sufficient to simply address pain during the treatment of patients with cancer pain; a more global approach to symptom management is necessary.

On admission to a pain management unit, 92.5% of 174 cancer patients suffered from more than moderate pain despite prior treatment. This inefficacy was mainly due to underdosage of drugs, inadequate intake schedule, and hesitation to use strong opioids. Following introduction of an oral drug therapy based on World Health Organization (WHO) guidelines, more than 80% of all patients described their pain as ranging between "none" and "moderate" on a six-step verbal rating scale at all times. To obtain these results, it was necessary to adapt the therapy to increasing pain in the course of terminal disease. Step III (strong opioids) gained more and more importance with time, and step I (nonopioids) was finally useful only in a minority of patients. Side effects played a minor role as a reason to change therapy. Oral drug therapy following these guidelines led to sufficient pain control in most patients over the whole study period (7,400 days); only 11% of the patients required other methods of pain management.

We surveyed 550 cancer patients who experienced pain and were treated with morphine for a total of 22,525 treatment days. Sufficient pain relief was achieved during more than 80% of this time using an average oral morphine dose of 82.4 mg--significantly lower than other studies. The use of this low dose, which was possible due to the concomitant administration of nonopioids and specific coanalgesics in most patients, resulted in a low incidence of side effects. Constipation and nausea/vomiting were the most common of these side effects. Physical dependence posed no practical problem in discontinuation of morphine treatment. Long-term opioid intake and development of tolerance did not appear to be linked; an increase in morphine dosage was most often explained by progression of the terminal disease. Addiction was a negligible problem, with only one observed case.