4. Characteristics of ongoing studies.

Study PI	Start date (clinical trials.gov)	Population	Sample size	Intervention	Control group
Sessler 2007	2007	Female patients 18‐85 years of age, diagnosed with primary breast cancer without known extension beyond the breast and axillary nodes, scheduled for unilateral or bilateral mastectomy with or without implant or isolated "lumpectomy" with axillary node dissection (anticipated removal of at least 5 nodes)	1100	Regional anaesthesia and analgesia (epidural or paravertebral), combined with deep sedation or general anaesthesia (sevoflurane)	General anaesthesia (sevoflurane) followed by opioid administration
Kurz 2008	2008	Patients scheduled for open, laparoscopic or laparoscopic‐assisted surgery for colon cancer without known extension beyond colon	2500	Intraoperative and postoperative regional anaesthesia and analgesia (epidural or paravertebral anaesthesia) plus intraoperative general anaesthesia	General anaesthesia followed by postoperative opioid analgesia
Chang 2009	2009	Female patients 21‐75 years of age, ASA I‐II, diagnosed with biopsy‐proven breast cancer, scheduled for mastectomy and axillary node dissection in a single procedure	40	Local anaesthesia + sedation	General anaesthesia
Kurz 2010	2010	Male and female patients 18‐85 years of age, diagnosed with primary non‐small cell lung cancer and scheduled for potentially curative tumour resection	1532	Intraoperative and postoperative general anaesthesia + epidural anaesthesia and analgesia	General anaesthesia and postoperative intravenous analgesia
Ilfeld 2010	2010	Female patients 18 years of age and older, undergoing unilateral or bilateral mastectomy	60	Postoperative paravertebral catheter analgesia with ropivacaine	Placebo (normal saline)
Gupta 2011a	2011	Male and female patients 40‐80 years of age, ASA I‐III, undergoing elective surgery for colorectal cancer	300	Epidural analgesia with ropivacaine and opioid	PCA with morphine
Lee 2011	2011	Male and female patients 25‐80 years of age, diagnosed with non‐small cell lung cancer with clinical staging of I or II for whom thoracoscopic lobectomy (VATS) is feasible	100	Intraoperative thoracic epidural anaesthesia	Intraoperative general anaesthesia
Van Aken 2012	2012	Patients scheduled for inguinal lymph node dissection because of malignant melanoma of the lower limb	230	Spinal anaesthesia	General anaesthesia
Chan 2013	2013	Male and female patients 20‐85 years of age with pancreatic cancer, expected to receive curative Whipple operation	150	Epidural analgesia with ropivacaine and opioid	PCA with opioid

VATS = video‐assisted thoracic surgery.

ASA = American Society of Anesthesiologists physical status classification.

PCA = patient‐controlled analgesia.