Background. Gastrointestinal (GI) neuroendocrine tumor (NET) incidence has been increasing; however, GI NET within the national Veterans Affairs (VA) health system has not been described. Methods. We used the VA Central Cancer Registry to identify the cohort of patients diagnosed with GI NET in 1995–2009. Cox regression models were constructed to explore factors associated with survival. Results. We included 1793 patients with NET of the stomach (9%), duodenum (10%), small intestine (24%), colon (19%) or rectum (38%). Twenty percent were diagnosed in 1995–1999, 35% in 2000–2004, and 45% in 2005–2009. Unadjusted 5-year survival rates were: stomach 56%, duodenum 66%, small intestine 52%, colon 67%, and rectum 84%. Factors associated with shorter survival were increasing age, hazard ratio (HR) 1.05 (95% CI 1.04–1.06), NET location [compared to rectum: stomach HR 2.26 (95% CI 1.68–3.05), duodenum HR 1.70 (95% CI 1.26–2.28), small intestine HR 1.85 (95% CI 1.42–2.42), and colon 1.83 (95% CI 1.41–2.39)], stage [compared to in situ/local: regional HR 1.15 (95% CI 0.90–1.47), distant HR 2.38 (95% CI 1.87–3.05)], and earlier period of diagnosis [compared to 1995–1999: 2000–2004 HR 0.70 (95% CI 0.59–0.85), 2005–2009 HR 0.43 (95% CI 0.34–0.54)]. Conclusions. The incidence of GI NET has also increased over time in the VA system with similar survival rates to those observed in non-VA settings. Worsened survival was associated with older age, tumor site, advanced stage, and earlier year of diagnosis. 1. Introduction Neuroendocrine tumors (NETs) arise from the embryologic neuroendocrine system and thus can occur in any location in the body. The gastrointestinal (GI) tract and lungs are the most common primary tumor sites. Based on Surveillance Epidemiology and End Results (SEER) data, NET incidence has increased 300%, up to 5.3 per 100,000, in the last three decades [1]. International data also suggest similar increases, as more recent studies have observed higher incidences than previous studies [2–4]. NET prevalence has also increased to 103,312 in the US population making it more prevalent than adenocarcinoma of the stomach and pancreas combined [1, 5]. Much of the apparent rise in new diagnoses may reflect incidental detection of NET through the increased use of imaging modalities such as computed tomography (CT) scans and endoscopic procedures for other indications rather than a true increase in tumor incidence. NETs are relatively slow growing tumors usually diagnosed late in the clinical course. Retrospective analysis suggests an average delay of nine years
References
[1]
J. C. Yao, M. Hassan, A. Phan et al., “One hundred years after “carcinoid”: epidemiology of and prognostic factors for neuroendocrine tumors in 35,825 cases in the United States,” Journal of Clinical Oncology, vol. 26, no. 18, pp. 3063–3072, 2008.
[2]
J. N. Newton, A. J. Swerdlow, I. M. dos Santos Silva et al., “The epidemiology of carcinoid tumours in England and Scotland,” British Journal of Cancer, vol. 70, no. 5, pp. 939–942, 1994.
[3]
K. Hemminki and X. Li, “Incidence trends and risk factors of carcinoid tumors: a nationwide epidemiologic study from Sweden,” Cancer, vol. 92, no. 8, pp. 2204–2210, 2001.
[4]
E. Crocetti, E. Buiatti, and A. Amorosi, “Epidemiology of carcinoid tumours in central Italy,” European Journal of Epidemiology, vol. 13, no. 3, pp. 357–359, 1997.
[5]
“Prevalence of NET: more common than one might think,” 2011, http://www.neuroendocrinetumor.com/health-care-professional/prevalence-of-nets.jsp.
[6]
G. Aggarwal, K. Obideen, and M. Wehbi, “Carcinoid tumors: what should increase our suspicion?” Cleveland Clinic Journal of Medicine, vol. 75, no. 12, pp. 849–855, 2008.
[7]
J. K. Ramage, A. H. G. Davies, J. Ardill et al., “Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours,” Gut, vol. 54, supplement 4, pp. iv1–iv16, 2005.
[8]
M. A. Maggard, J. B. O'Connell, and C. Y. Ko, “Updated population-based review of carcinoid tumors,” Annals of Surgery, vol. 240, no. 1, pp. 117–122, 2004.
[9]
I. M. Modlin, K. D. Lye, and M. Kidd, “A 5-decade analysis of 13,715 carcinoid tumors,” Cancer, vol. 97, no. 4, pp. 934–959, 2003.
[10]
I. M. Modlin and A. Sandor, “An analysis of 8305 cases of carcinoid tumors,” Cancer, vol. 79, no. 4, pp. 813–819, 1997.
[11]
VA Information Resource Center (VIReC). In., vol. 2011; 2011http://www.virec.research.va.gov/.
[12]
N. Arnold, M.-W. Sohn, C. Maynard, and D. Hynes, “VA-NDI mortality data merge project,” VIReC Technical Report 2, VA Information Resource Center, 2006.
[13]
B. Lawrence, B. I. Gustafsson, A. Chan, B. Svejda, M. Kidd, and I. M. Modlin, “The epidemiology of gastroenteropancreatic neuroendocrine tumors,” Endocrinology and Metabolism Clinics of North America, vol. 40, no. 1, pp. 1–18, 2011.
[14]
H. B. El-Serag, L. Petersen, H. Hampel, P. Richardson, and G. Cooper, “The use of screening colonoscopy for patients cared for by the Department Of Veterans Affairs,” Archives of Internal Medicine, vol. 166, no. 20, pp. 2202–2208, 2006.
[15]
I. M. Modlin, K. Oberg, D. C. Chung et al., “Gastroenteropancreatic neuroendocrine tumours,” The Lancet Oncology, vol. 9, no. 1, pp. 61–72, 2008.
