Natural course of insomnia comorbid with cancer: an 18-month longitudinal study

This study aimed to assess the prevalence and natural course (incidence, persistence, remission, and relapse) of insomnia comorbid with cancer during an 18-month period.

All patients scheduled to receive a curative surgery for a first diagnosis of nonmetastatic cancer were approached on the day of their preoperative visit to participate in the study. A total of 962 patients with cancer (mixed sites) completed an insomnia diagnostic interview at the perioperative phase (T1), as well as at 2 (T2), 6 (T3) 10 (T4), 14 (T5), and 18 (T6) months after surgery.

Findings revealed high rates of insomnia at baseline (59%), including 28% with an insomnia syndrome. The prevalence of insomnia generally declined over time but remained pervasive even at the end of the 18-month period (36%). Rates were greater in patients with breast (42% to 69%) and gynecologic (33% to 68%) cancer and lower in men with prostate cancer (25% to 39%) throughout the study. Nearly 15% of patients had a first incidence of insomnia during the study, and 19.5% experienced relapse. The evolution of symptoms varied according to sleep status. Remissions (patients becoming good sleepers) were much less likely for patients with an insomnia syndrome (10.8% to 14.9%) than for those with insomnia symptoms (42.0% to 51.3%). Most frequently (37.6%), patients with an insomnia syndrome at baseline kept that status throughout the 18-month period.

Insomnia is a frequent and enduring problem in patients with cancer, particularly at the syndrome level. Early intervention strategies, such as cognitive-behavioral therapy, could prevent the problem from becoming more severe and chronic.