Signet ring cell cancer: Harbinger of doom?
10 Background: Signet ring cell cancer (SRC) is associated with worse prognosis. However, studies in Asia have questioned this idea. Our aim is to determine differences in presentation and outcomes between SRC and gastric adenocarcinoma (AC) to establish if SRC conveys worse prognosis in the U.S. Methods: NCI SEER was used to analyze differences in presentation and outcomes of SRC and AC from 2004−2007. Results: 10,886 gastric cancers included 2,872 SRC and 8,014 AC. SRC presented younger (62.0 vs 68.9 years, p<0.001) and less in males (53.7 vs 68.0%, p<0.001). SRC were more likely Asian (16.5 vs 13.5%) or Hispanic (23.3 vs 14.9%) and less Black (10.7 vs 11.5%) or White (71.8 vs 74.1%); p<0.001. SRC was more likely to be T-3 or T-4 (46.0 vs 33.8%), have nodal spread (72.5 vs 62.0%), and metastases (29.0 vs 24.1%); p<0.001. SRC was more likely lower stomach (30.6 vs 24.6%) or body (30.8 vs 21.6%) and less upper stomach (24.7 vs 46.9%); p<0.001. SRC more often overlapped regions (13.9 vs 6.9%, p<0.001). SRC was associated with mortality (HR 1.07, CI 1.01−1.14, p=0.017) and decreased median survival (12.0 vs. 13.0 months, p=0.034). Multivariate analysis stratified by AJCC stage and radiation found SRC was not independently associated with mortality (HR 1.04, CI 0.98−1.11, p=0.195). Mortality was associated with age (HR 1.01, CI 1.01−1.01, p=0.001), Black race (HR 1.11, CI 1.02−1.21, p=0.013), and tumor grade ( table ). Survival was associated with Asian race (HR 0.88, CI 0.81−0.95, p=0.001) and surgery (HR 0.21, CI 0.19−0.22, p=0.001). Conclusions: In the U.S., SRC differs from AC in presentation with younger age, less male predominance, greater tumor extent, metastases, and Asian or Hispanic ethnicity. Survival for SRC is associated with Asian race and surgical resection. Overall, SRC survival is less than AC. However, adjusted for stage at presentation, SRC does not portend a worse prognosis. [Table: see text]