Gjeilo KH, et al. - Researchers assessed data of patients undergoing surgery for primary lung cancer (n = 264; 95% thoracotomies) on the average and worst pain intensity, pain location, and comorbidities before, and at one month and five, nine, and 12 months after surgery in order to define the pain trajectory in these patients. Further, they assessed if different pain trajectories could assist in identifying distinct groups of patients. The occurrence of any pain rose from 40% before surgery to 69% after one month and reduced to 56%, 57%, and 55% at five, nine, and 12 months, respectively. Both for the average and worst pain, two classes were identified with latent class mixed models; one class began low with high ratings after one month, then reverting to a level slightly higher than baseline. The other class began higher with comparable scores through the trajectory. Patients reporting no pain (8%) comprised a separate class. Patients in the class with overall highest pain for average and/or worst pain exhibited higher comorbidity score, preoperative use of both pain and psychotropic medicine. These findings suggest the presence of both postoperative pain and pain from chronic conditions among these patients. In order to tailor interventions and attain information about pain, knowledge about vulnerable patients and risk factors for pain is essential.