Pain mechanisms involved and outcome in advanced cancer patients with possible indications for celiac plexus block and superior hypogastric plexus block

Aims and background: There is controversy about the role of neurolytic sympathetic blocks in advanced cancer, when pain syndromes may assume other characteristics, with a possible involvement of structures other than visceral. The aim of the present study was to assess the pain characteristics and the analgesic response of a consecutive sample of home care patients with pancreatic and pelvic pain, which would have possible indications for a celiac plexus block and a superior hypogastric block, respectively. Methods: From January 1999 to December 1999, 400 consecutive advanced cancer patients were surveyed for a prospective longitudinal survey. We considered only patients who had pancreatic cancer or pelvic cancer with pain. Results: Thirty-six patients were surveyed: 22 patients had pelvic cancers and 14 had pancreatic cancer. Patients with pelvic cancers showed a longer survival than those with pancreatic cancer (P = 0.019). Patients with pelvic cancers more frequently showed a neuropathic component associated with a visceral or somatic mechanism than patients with pain due to pancreatic cancer (P = 0.019). When the pain mechanism was taken into consideration, patients with pelvic cancers with a neuropathic component showed worse pain relief than patients with pain due to pancreatic cancer (P= 0.040). Conclusions: Sympathetic procedures for pain conditions due to pancreatic and pelvic cancers should be intended as adjuvant techniques to reduce the analgesic consumption, and not as a panacea, given that multiple pain mechanisms are often involved because progression of disease is able to change the underlying pain mechanisms. Pancreatic pain seems to maintain visceral characteristics amenable to sympathetic block more than pain due to pelvic cancer.