Title:Controversial Role of Opioids: From Pain Control to Cancer Recurrence in Breast Cancer
Volume: 25
Issue: 11
Author(s): Mudasir Maqbool, Gyas Khan, Liming Zhang and Md Sadique Hussain*
Affiliation:
- Uttaranchal Institute of Pharmaceutical Sciences, Uttaranchal University, Prem Nagar, Dehradun 248007, Uttarakhand, India
Keywords:
Breast cancer, immunosuppression, morphine, opioid analgesics, pain management, tramadol, tumor microenvironment, tumor progression.
Abstract: Opioids are widely used for pain management in breast cancer patients; however, their
influence on tumor progression and recurrence remains controversial. Opioid receptors-mu (MOR),
delta (DOR), and kappa (KOR)-play diverse roles in cancer biology, modulating tumor growth, immune
responses, and angiogenesis. MOR activation is associated with increased proliferation, Epithelial-
Mesenchymal Transition (EMT), and immunosuppression, contributing to an aggressive tumor
phenotype. Conversely, KOR exhibits tumor-suppressive properties, reducing angiogenesis via
VEGF inhibition. Emerging preclinical evidence suggests that opioids, particularly morphine, may
facilitate breast cancer progression by enhancing cancer cell migration, angiogenesis, and immune
evasion. Genetic variations in opioid receptor pathways, such as the OPRM1 A118G polymorphism,
further complicate the opioid-cancer relationship, demonstrating population-dependent effects on patient
outcomes. In contrast, tramadol has shown potential immune-protective effects by preserving
Natural Killer (NK) cell function and inhibiting adrenergic signaling; fentanyl and sufentanil exhibit
variable impacts on tumor biology, necessitating further investigation. Clinical studies, however, remain
inconclusive regarding opioids' direct contribution to breast cancer recurrence, highlighting the
need for targeted research. Opioid-sparing analgesic strategies, including multimodal pain management,
regional anesthesia, and immunomodulatory agents, offer promising alternatives to mitigate
potential oncogenic risks while ensuring adequate pain relief. Future studies integrating single-cell
transcriptomics and tumor microenvironment analyses will be critical in elucidating the molecular
impact of opioids in breast cancer. Personalized pain management approaches tailored to genetic and
clinical profiles may optimize oncological outcomes while preserving analgesic efficacy.