The goal of this real world study is to observe the efficacy and safety of Oxycodone Hydrochloride Sustained-release Tablets in the treatment of moderate to severe cancer pain participants in real clinical practice.

After entering the study, participants will take Oxycodone Hydrochloride Sustained-release Tablets. The investigators need to observe and record relevant data, and finally analyze and summarize the data to understand the efficacy and safety.

This study is a prospective, single arm, multicenter real world study, the investigators didn't set up a control group. After the participant is enrolled, the participant will enter a 14 day treatment cycle, where the medication will be proportionally converted into Oxycodone Hydrochloride Sustained-release Tablets. The daily medication dose will be adjusted based on the number of pain outbreaks and pain scores (According to the drug increment principle of NCCN), and various information (Daily oxycodone dose, average pain score, minimal pain score, most severe pain score, number of breakout pain, name of rescue drugs, number of rescue, heart rate, blood pressure, respiratory rate, SPO2, combination of drugs, pain control satisfaction, etc) about the participant's medication will be recorded. The participant will not be limited to whether to combine medication. Observe the efficacy and safety of Oxycodone Hydrochloride Sustained-release Tablets.

Inclusion Criteria:

1. Voluntarily sign an informed consent form;
2. Age ≥ 18 years old;
3. Patients with moderate to severe (NRS ≥ 4 points) cancer pain;
4. Patients with oral equivalent Oxycodone Hydrochloride Sustained-release Tablets ≥ 80mg/d.

Exclusion Criteria:

1. Patients with severe mental illness who cannot cooperate with follow-up

This study is a prospective, single arm, multicenter real-world study that only needs to meet the requirements of age, disease type, drug dosage, and no severe mental illness in the study population