Prognostic significance of opioid use in the active treatment of advanced colorectal cancer.

This study aimed to evaluate the oncologic significance of opioid use during active treatment for advanced colorectal cancer (CRC). The patients included in this study underwent therapeutic chemotherapy for metastatic and/or recurrent CRC. The primary outcomes measured were the characteristics of CRC patients who were administered opioid to maintain compliance with cancer treatments as well as the impact of opioid use on cancer-specific survival. Of the 245 patients, 117 (48%) were administered opioid during chemotherapy. No significant associations were detected between opioid use and clinicopathological factors, with the exception of age (<65 or ≥65 years; P= 0.0281), pathology (differentiated or undifferentiated; P= 0.0007) and response rate to chemotherapy (P= 0.0056). Patients administered opioid had significantly poorer cancer-specific survival compared to patients who did not receive opioid. The mean cancer-specific survival periods were 606±57 days (chemotherapy with opioid), <636±46 days (chemotherapy without opioid), <1140±95 days (multimodal therapy with opioid) and <1556±160 days (multimodal therapy without opioid). Additionally, oncologic emergencies due to cancer progression were significantly correlated with opioid use (P=0.0002), although no statistically significant differences were detected between the cancer-specific survival period and oncologic emergencies. The use of opioid to maintain compliance with active cancer therapy is advised in modern CRC management. However, CRC patients that were administered opioid may have potential progressive disease, thus clinicians need to be aware of the oncologic emergencies possibly arising during an active CRC therapy.