Abstract 2260: Haplotypes of chromosome 17q21.31 affect liver metastasis by small intestinal neuroendocrine tumors

Abstract

Abstract Neuroendocrine tumors are the most common tumors of the small intestine. Very little is known about genetic changes that cause SI-NETs, which have a very low frequency of mutations. SI-NETs are highly metastatic to the liver, and patients with liver metastases have a five year survival rate of less than 50%. Caucasian patients are more likely to develop metastasis than patients of other races. We have studied a 900 kB inversion at chromosome 17q21.31, which is common to Caucasians but rare in other races. Within a collection of 117 Caucasian patients with ileal carcinoids, patients with the inversion haplotype were significantly less likely to have liver metastasis. A second Caucasian-specific haplotype in this region, beta2, was also tested for potential association with metastasis of ileal carcinoids. Unlike the inversion haplotype, beta2 associates with increased metastasis of ileal carcinoids. We suspect that the fact that the metastasis-promoting beta2 haplotype is more common among Caucasians than the metastasis-suppressing inversion haplotype (44% incidence vs. 33% incidence) is probably why Caucasians wind up with a higher frequency of metastasis than races that carry neither beta2 nor the inversion. Citation Format: Shinta Kobayashi, Edaise da Silva, Tanupriya Contractor, Laura Tang, Chris R. Harris. Haplotypes of chromosome 17q21.31 affect liver metastasis by small intestinal neuroendocrine tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2260. doi:10.1158/1538-7445.AM2017-2260