Background: Despite the abundant literature on this topic, accurate prevalence estimates of pain in cancer patients are not available. We investigated the prevalence of pain in cancer patients according to the different disease stages and types of cancer.Patients and methods: A systematic review of the literature was conducted. An instrument especially designed for judging prevalence studies on their methodological quality was used. Methodologically acceptable articles were used in the meta-analyses.Results: Fifty-two studies were used in the meta-analysis. Pooled prevalence rates of pain were calculated for four subgroups: (i) studies including patients after curative treatment, 33% [95% confidence interval (CI) 21% to 46%]; (ii) studies including patients under anticancer treatment: 59% (CI 44% to 73%); (iii) studies including patients characterised as advanced/metastatic/terminal disease, 64% (CI 58% to 69%) and (iii) studies including patients at all disease stages, 53% (CI 43% to 63%). Of the patients with pain more than one-third graded their pain as moderate or severe. Pooled prevalence of pain was >50% in all cancer types with the highest prevalence in head/neck cancer patients (70%; 95% CI 51% to 88%). Conclusion:Despite the clear World Health Organisation recommendations, cancer pain still is a major problem.

This study was the first to identify the joint contribution of somatic and psychologic factors to chronic pain, functional limitations, and quality of life 6 months after surgical interventions. It replicates previous findings that intense acute postoperative pain is a risk factor for long-term adverse outcome and also identified additional risk factors, namely, long duration of the operation, ASA status, and preoperative fear of surgery.

Patients from a multi-disciplinary university pain clinic experience strikingly low quality of life, whereby low back pain patients and patients with multiple pain localisations have the lowest quality of life. Pain catastrophising showed the strongest association with quality of life, and stronger than pain intensity.

Cervical radicular pain affects approximately 1 on 1000 adults per year. Although many treatment modalities are described in the literature, the available evidence for efficacy is not sufficient to allow definitive conclusions on the optimal therapy to be made. The effect of pulsed radiofrequency treatment for this type of patients was evaluated in a prospective audit that showed satisfactory pain relief for a mean period of 9.2 months, justifying a randomized sham controlled trial. Twenty-three patients, out of 256 screened, met the inclusion criteria and were randomly assigned in a double blind fashion to receive either pulsed radiofrequency or sham intervention. The evaluation was done by an independent observer. At 3 months the pulsed radiofrequency group showed a significantly better outcome with regard to the global perceived effect (>50% improvement) and visual analogue scale (20 point pain reduction). The quality of life scales also showed a positive trend in favor of the pulsed radiofrequency group, but significance was only reached in the SF-36 domain vitality at 3 months. The need for pain medication was significantly reduced in the pulsed radiofrequency group after six months. No complications were observed during the study period. These study results are in agreement with the findings of our previous clinical audit that pulsed radiofrequency treatment of the cervical dorsal root ganglion may provide pain relief for a limited number of carefully selected patients with chronic cervical radicular pain as assessed by clinical and neurological examination.

Discussion: Several predictive factors of postoperative pain were identified in this study. These factors could be taken into account in postoperative pain management.

The CARS-DLV proved to be a valuable instrument to measure women's' concerns about breast cancer recurrence. More than half of former breast cancer patients indicated moderate to severe concerns about disease recurrence. Health and death worries were the most prominent. The levels of worry were independent of the time since diagnosis.

A substantial proportion of cancer patients does suffer from moderate to severe pain and does not receive adequate pain treatment.

Pain has been studied more intensely as a symptom of Parkinson's disease (PD) in recent years. However, studies on the characteristics and prevalence of pain in PD have yielded conflicting results, prompting us to do a systematic review of the literature. A systematic review of the literature was conducted, using different databases. The last inclusion date was March 15, 2011. The modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used, which is especially designed for judging prevalence studies on their methodological quality. Only articles that met the predefined criteria were used in this review. We found 18 articles, of which only 8 met the methodological criteria. Prevalence frequency ranges from 40% to 85% with a mean of 67.6%. Pain is most frequently located in the lower limbs, with almost one-half of all PD patients complaining about musculoskeletal pain (46.4%). The pain fluctuates with on-off periods. Surprisingly, only 52.4% of PD patients with pain used analgesics, most often nonopioids. PD patients seem to be predisposed to develop pain and physicians should be aware of pain as a common feature of PD. As many as one-half of PD patients with pain may be missing out on a potentially useful treatment, and proper treatment could increase quality of life in PD patients.