Cancer aggravation due to persistent pain signals with the increased expression of pain-related mediators in sensory neurons of tumor-bearing mice

Risk factors for chronic postsurgical pain following thoracoscopic surgery for lung cancer

OBJECTIVE

Chronic post-surgical pain (CPSP) following thoracoscopic lung cancer surgery is a common and challenging complication. Identifying risk factors and predictive markers is essential for improving patient outcome.

METHODS

In this retrospective case-control study, the clinical data from 106 patients with non-small cell lung cancer (NSCLC) who underwent thoracoscopic radical resection between January 2021 and December 2023 were comprehensively analyzed. Patients were divided into a CPSP group (n = 41) and a non-CPSP group (n = 65) based on CPSP status. An external validation cohort of 20 patients was also assessed. Demographic data, perioperative characteristics, psychological states, and pain scores were compared between the two groups. Logistic regression analysis was used to identify predictors of CPSP, and their predictive performance was validated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Age and TNM stage were significantly higher in the CPSP group (P < 0.001). Significant differences were observed in pain scores on postoperative days 1-3 and Fear of Pain Questionnaire-III (FPQ-III) scores (P = 0.003 and P < 0.001, respectively) between the two groups. Multivariate logistic regression identified age (OR, 1.230; P < 0.001), TNM staging (OR, 5.106; P < 0.001), early postoperative pain score (OR, 1.868; P = 0.012), and FPQ-III score (OR, 1.135; P < 0.001) as independent predictors of CPSP. A nomogram based on these predictors demonstrated excellent discrimination ability, with an area under the curve (AUC) of 0.891. External validation yielded an AUC of 0.956, confirming high sensitivity (1.00) and specificity (0.923).

CONCLUSION

Age, advanced TNM stage, early postoperative pain intensity, and higher fear of pain are significant predictors of chronic postoperative pain following thoracoscopic lung cancer surgery. Incorporating these factors into predictive models may improve postoperative management and reduce CPSP incidence.

Chronic Pain and Bone-Related Pathologies: A Narrative Review

Purpose

Pain related to bone may occur as a result of trauma, bone fracture, genetic disease, arthritis, benign or malignant primary bone tumors and bone cancer metastases. We discuss the pathophysiology of chronic bone-related pain, treatment options and therapeutic perspectives.

Methods

Using predefined terms, we searched PubMed, MEDLINE, and Google Scholar for meta-analyses, evidence-based reviews, and clinical practice guidelines. This narrative article reviews pathologies linked to chronic bone pain and discusses the preventive and therapeutic strategies for better bone pain management.

Results

Pathophysiology of bone-related pain is complex, especially in cancer conditions and missing gaps are underlined. Treatment of pain, after adequate evaluation, includes classical analgesics, adjuvants for neuropathic and refractory pain, specific bone drugs, surgery and non-pharmacological approaches. Prevention of chronic bone pain encompasses prevention of central sensitization and of causal diseases.

Conclusion

Translational research, drug repurposing, an interdisciplinary approach and a person-centered assessment to evaluate, beyond pain, physical, social and functional abilities, are proposed future directions to improve chronic bone pain management and optimize independence and quality of life.

Summary

Chronic bone-related pain is frequent and is associated with an impairment of quality of life. In this review, we summarize the pathophysiology of chronic bone pain, describe treatment approaches and envisage new avenues for pain alleviation. Our article will help doctors manage chronic bone pain and address unmet needs for future research to alleviate bone-related pain.

Evaluation of pain related behaviors and disease related outcomes in an immunocompetent mouse model of prostate cancer induced bone pain

Cancer-induced bone pain (CIBP) is the most common and devastating symptom of bone metastatic cancer that substantially disrupts patients' quality of life. Currently, there are few effective analgesic treatments for CIBP other than opioids which come with severe side effects. In order to better understand the factors and mechanisms responsible for CIBP it is essential to have clinically relevant animal models that mirror pain-related symptoms and disease progression observed in patients with bone metastatic cancer. In the current study, we characterize a syngeneic mouse model of prostate cancer induced bone pain. We transfected a prostate cancer cell line (RM1) with green fluorescent protein (GFP) and luciferase reporters in order to visualize tumor growth longitudinally in vivo and to assess the relationship between sensory neurons and tumor cells within the bone microenvironment. Following intra-femoral injection of the RM1 prostate cancer cell line into male C57BL/6 mice, we observed a progressive increase in spontaneous guarding of the inoculated limb between 12 and 21 days post inoculation in tumor bearing compared to sham operated mice. Daily running wheel performance was evaluated as a measure of functional impairment and potentially movement evoked pain. We observed a progressive reduction in the distance traveled and percentage of time at optimal velocity between 12 and 21 days post inoculation in tumor bearing compared to sham operated mice. We utilized histological, radiographic and μCT analysis to examine tumor induced bone remodeling and observed osteolytic lesions as well as extra-periosteal aberrant bone formation in the tumor bearing femur, similar to clinical findings in patients with bone metastatic prostate cancer. Within the tumor bearing femur, we observed reorganization of blood vessels, macrophage and nerve fibers within the intramedullary space and periosteum adjacent to tumor cells. Tumor bearing mice displayed significant increases in the injury marker ATF3 and upregulation of the neuropeptides SP and CGRP in the ipsilateral DRG as well as increased measures of central sensitization and glial activation in the ipsilateral spinal cord. This immunocompetent mouse model will be useful when combined with cell type selective transgenic mice to examine tumor, immune cell and sensory neuron interactions in the bone microenvironment and their role in pain and disease progression associated with bone metastatic prostate cancer.