this work is looking for comparison between the effect of tramadol versus morphine on PD1 and PD1-ligand in patients with chronic cancer pain

The use of opioids is the mainstay in the treatment of many types of chronic pain, including cancer and non-cancer-related pain]. Opioids are known to suppress immune function following both acute and chronic administration; however, they appear to be different according to the schedule of administration as well as the state of the organism. Programmed death-1 (PD-1, also known as CD279) belongs to the CD28 receptor superfamily. It is an inhibitory receptor, and its expression is upregulated on activated leukocytes, resulting in an inhibited immune response. PD-1 interacts with two ligands: programmed death ligand-1 (PD-L1, also referred to as B7-H1) and programmed death ligand-2 (PD-L2, also known as B7-DC). PD-L2 is expressed mainly on activated dendritic cells (DCs) and macrophages, whereas PD-L1 is distributed widely. In addition to immune cells, some subsets of tumor cells also express PD-L1 to escape from immunosurveillance. It has been reported that the PD-1/PD-L1 pathway could be activated by surgical stress.

Inclusion Criteria:

• patients with cancer pain of varying etiology,
• documented metastatic cancer, currently on step I WHO ladder and whose pain necessitates a shift to step II,
• those who have never received radiotherapy, chemotherapy, or immunosuppressive drugs, -- and in good general and nutritional condition and without infectious diseases at the time of investigation.

Exclusion Criteria:

• abnormal hepatic, renal, and pulmonary function, gastrointestinal pathology, and
• those with cerebral metastases and/or psychological disorders,
• patients with contraindication to morphine or tramadol according to their respective data sheets, and
• patients who could not complete the diary information correctly.

tramadol or morphine