NP prevalence in cancer pain is 33%. DN4 reports only about half the cancer NP cases diagnosed by clinicians. Pharmaceutical treatment of cancer pain, including NP, has a greater effect in patients with metastases and seems to depend on the specific treatment used.

Background: Neuropathic pain can be overlooked in cancer patients. The advent of screening tools can help in recognizing it. However, little is known about their relative diagnostic performance and factors that affect it. This study evaluated the prevalence of neuropathic pain using several diagnostic strategies in cancer patients undergoing chemotherapy. Methods: Patients attending the Oncology Unit of the investigators' site to continue their chemotherapy schedule were systematically screened for this cross-sectional study. Before starting chemotherapy drugs, pain specialists made a clinical diagnosis of neuropathic pain (either disease related, treatment related or comorbid) and medical oncologists administered three validated screening tools. Their relative diagnostic performance and the impact of some pain features on it were analysed using multivariate statistical methods. Results: From a total of 358 patients, 194 (54.2%) suffered from pain and 73 (20.4%) had a clinical diagnosis of pure neuropathic or mixed pain. Among the screening tools, the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) was more specific (93.4%), although less sensitive (68.1%) than the Douleur Neuropathique in 4 Questions (DN4) (sensitivity: 87.5%, specificity: 88.4%). Interestingly, the specificities of these two instruments did not differ in patients with mild pain, while the DN4 remained to be more sensitive than the LANSS regardless of pain severity. Conclusions: Neuropathic pain is common in cancer patients undergoing chemotherapy. The DN4 might be of great help for the early detection of patients at risk because of incipient chemotherapy-related neuropathies and the LANSS to rule out neuropathic pain in patients with complex pain conditions.

One of the most common treatments available for cancer patients is surgical removal of the malignant tumor; its long-term implications, however, are still little-known. The purpose of this review is to look at the perioperative effects and determine if there is any correlation between surgery, anesthetics and analgesics, and cancer progression, in the form of cancerous tumor growth and progression and patient survival, within the Puerto Rican population. A retrospective literature review was conducted. Current data suggest that surgery is associated with an increase in cancer proliferation and metastasis, for various reasons such as angiogenesis enhancement and bloodstream migration. Also, it was found that some anesthetics and analgesics have been associated with cancer progression, based on the peri- and postoperative immune status of the patient. Thiopental, ketamine, isoflurane, halothane and some opioids were positively correlated with cancer progression given their role in immunosuppression; while propofol, lidocaine, ropivacaine and bupivacaine were negatively correlated with tumor progression given their immune enhancement. Others, like sevoflurane, nitrous oxide, and etomidate showed inconclusive correspondence. Therefore, it was concluded that immune system boosting anesthetics and analgesics can reduce cancer progression in a patient that has undergone surgical resection. For further research and since the available data are not extensive, other variables such as age, sex, stressors and comorbidities could be considered to better understand the mechanism in which the chemicals hereby studied can cause cancer progression.