Endocrinopathy in patients with cancer pain on opioids: prospective observational study

OBJECTIVE: To determine the prevalence and pattern of endocrinopathy in patients with cancer pain receiving long-term opioid therapy and evaluate the associated temporal hormonal changes. METHOD: This prospective, hospital-based observational study was conducted in a tertiary care centre in India and included 175 patients with histologically confirmed cancer (≥18 years) receiving oral daily morphine of ≥25 mg for at least 3 months. Serum levels of testosterone, thyroid-stimulating hormone (TSH), thyroxine, adrenocorticotropic hormone (ACTH), follicle-stimulating hormone (FSH), luteinising hormone (LH), growth hormone (GH), estradiol and prolactin were assessed at baseline and week 12. Data were analysed using repeated-measures analysis of variance with Bonferroni post hoc correction. RESULTS: Most participants were middle-aged males (mean age, 46.96±9.30 years) with advanced-stage cancer (64.6%). Significant hormonal alterations were observed over the 12-week period (p<0.001). Mean testosterone levels decreased from 2.49±1.76 ng/mL at baseline to 2.01±1.42 ng/mL at week 12, T4 declined from 1.30 ± 0.24 to 1.05 ± 0.19 pg/mL, ACTH from 31.41 ± 18.58 to 25.36 ± 15.01 pg/mL and prolactin rose from 11.06 ± 4.22 to 13.35 ± 5.10 ng/mL. Similar downward trends were noted for FSH, LH, GH and estradiol, whereas TSH increased from 2.12 ± 1.09 to 2.57 ± 1.32 µIU/mL. CONCLUSION: Chronic opioid therapy is associated with substantial suppression of gonadal, adrenal and thyroid axes and elevation of prolactin levels, consistent with opioid-induced endocrinopathy. Regular endocrinological assessment should be integrated into palliative care to improve quality of life in patients with cancer receiving long-term opioid therapy.