Persistent post-surgical pain following anterior thoracotomy for lung cancer: a cross-sectional study of prevalence, characteristics and interference with functioning.

OBJECTIVES Most studies of persistent post-surgical pain following thoracic surgery have focused on classic posterolateral thoracotomy in mixed surgical populations without systematic assessment of disease recurrence and other potential sources of pain. The purpose of this study was to examine patterns in the prevalence of persistent post-surgical pain following lung cancer surgery and to quantitatively assess the characteristics of persistent post-surgical pain and associated sensory changes. METHODS In May 2010, a sample of 702 patients undergoing lung cancer surgery from 1 January 2000 to 31 December 2009 was asked to complete a mail distributed questionnaire. The questionnaire included the Brief Pain Inventory and questions on pain-associated characteristics, symptoms and sensory changes. Patients were enrolled according to the following criteria: (1) no additional surgical procedures performed in the thoracic region 10 years prior to and up until the cross section; (2) no explorative surgery; (3) no resection of the thoracic wall and (4) no clinical or radiological signs of disease recurrence. Patients undergoing video-assisted thoracoscopic surgery were excluded. RESULTS The response rate was 89%. The final study population consisted of 414 patients with a median age of 69 years and a median follow-up time of 45 months. The overall prevalence of persistent post-surgical pain following anterior thoracotomy was estimated to 19% (95% CI: 15-23%). Clinically relevant pain defined as ≥4 on a 0-10 numerical rating scale was prevalent in 9% of the study participants (95% CI: 6-12%); pain with neuropathic characteristics was present in 36% (95% CI: 25-48%). A total of 62% of the participants with persistent post-surgical pain reported an increased or decreased sense of touch in the painful area. CONCLUSIONS Persistent post-surgical pain following anterior thoracotomy was prevalent in 19% (95% CI: 15-23%) of lung cancer patients for up to 10 years postoperatively. Future preventive strategies should focus on the role of intraoperative nerve damage, including the potentially protective role of anterior thoracotomy.