Table 2.docx

This population-based cross-sectional study was conducted in two public oncology hospitals in the northeast of Brazil, from 2019 to 2021. A total of 1,020 patients with histopathologically confirmed cancer were included. Prevalence and incidence of chronic neuropathic pain were assessed using the Douleur Neuropathique 4 questionnaire (DN4), Karnofsky Performance Status (KPS), Hospital Anxiety and Depression Scale (HADS), and Mini-Sleep Questionnaire (MSQ-BR). Logistic regression identified independent predictors. The prevalence of chronic pain was 35.3%, and CRNP accounted for 62.5% of these cases. In the incidence study (n=224), 12.5% developed chronic pain during six months of follow-up, with a CRNP incidence of 21.4%. CRNP was strongly associated with female sex, age 40–59 years, breast or cervical cancer, metastases, radiotherapy, and pain localized to the chest or lower limbs. Functional impairment (KPS 50–80%), anxiety, depression, and sleep disturbances were also significant predictors. Most patients were low-income women with limited education, self-identified as Black, and living in rural areas. Pain intensity was usually moderate to severe, radiating, and accompanied by sensory abnormalities. Despite this burden, use of adjuvant analgesics remained low. This is the first large-scale Brazilian population-based study on CRNP, demonstrating the highest reported prevalence to date. The findings highlight the urgent need for earlier diagnosis, better access to multidisciplinary pain management, and health policies targeting vulnerable populations.