This trial aims to address refractory cancer pain (RCP). It will explore the synergistic efficacy and safety of hydromorphone hydrochloride sustained-release tablets (HHST) combined with electroacupuncture (EA) and ear acupoint pressing beans (EAPB) for RCP. Key outcomes will include dynamic changes in Numerical Rating Scale (NRS) scores, proportions of patients with effective analgesia (≥30% NRS reduction from baseline) and marked remission (≥50% NRS reduction from baseline), daily HHST dosage, breakthrough pain (BP) frequency, and drug-related adverse events (AEs) graded by CTCAE 5.0.

This study is a prospective, single-arm clinical trial designed to address the therapeutic challenge of refractory cancer pain (RCP). It will systematically explore the synergistic therapeutic effect of hydromorphone hydrochloride sustained-release tablets (HHST) combined with electroacupuncture (EA) and ear acupoint pressing beans (EAPB). Through a clinical research design, the study will comprehensively evaluate the efficacy and safety of this combined regimen in relieving RCP.

The primary observational focus of the study will be the dynamic changes in the Numerical Rating Scale (NRS) scores of patients before and after treatment. Researchers will quantitatively analyze the proportion of patients achieving effective analgesia (defined as a ≥30% reduction in NRS score from baseline) and marked remission (defined as a ≥50% reduction in NRS score from baseline). Meanwhile, the study will monitor key indicators to verify the analgesic efficacy and safety of the combined regimen from multiple dimensions: the daily dosage of HHST, the frequency of breakthrough pain (BP) episodes, and drug-related adverse events (AEs). All AEs will be graded in accordance with the Common Terminology Criteria for Adverse Events, Version 5.0 (CTCAE 5.0).

Inclusion Criteria:

1. Patients who meet the diagnostic criteria for cancer ;
2. Diagnosis of refractory cancer pain;
3. Aged 19 or 80 years;
4. Expected survival period ≥3 months;
5. Karnofsky Performance Status (KPS) score ≥30 and Quality of Life (QOL) score ≥20;
6. No history of allergy to opioid analgesics;
7. No intellectual or psychiatric disorders; normal comprehension ability,capable of cooperating with pain assessments and questionnaire completion;
8. Provision of signed written informed consent.

Exclusion Criteria:

1. Patients with pain clearly unrelated to the tumor itself;
2. Patients with pain relief after standardized pharmacological treatment;
3. Patients aged under 19 years or over 80 years;
4. Patients with an expected survival of less than 3 months;
5. Patients with a Karnofsky Performance Status (KPS) score < 30 or Quality of Life (QOL) score < 20;
6. Pregnant or lactating women;
7. Patients with intellectual disability, mental or consciousness disturbance, who are unable to assess pain accurately or complete questionnaire surveys;
8. Patients with needle phobia or extreme resistance to acupuncture treatment;
9. Patients with hypersensitivity to Semen Vaccariae (Wang Bu Liu Xing).