S3025 Signet Ring Cell Carcinoma in the Hispanic Population: A Case Series

INTRODUCTION: Since the advent of treatment for Helicobacter pylori, the rates of gastric adenocarcinoma have decreased, but the rate of Signet Ring Cell Carcinoma (SRCC) have increased from 8% to 30% of gastric cancers. The risk factors for SRCC vary greatly from the risk factors for non-SRCC. It is more prevalent in women, and also seen in younger population than non-SRCC . The average age of morbidity is 50 years of age in SRCC. The distribution among ethnicities is still unclear. SRCC is seen in all ethnicities, in a study it showed distribution among African Americans, Hispanic, American Indian and Asian populations. In this case series we will have patients from a Hispanic background, who all were diagnosed with SRCC. CASE DESCRIPTION/METHODS: Case 1: 71 year old Hispanic male presented with abdominal pain and 28 lb weight loss. CT show large infiltrating mass with mass on the dome of the bladder. EGD showed friable ulcer and biopsy showed SRCC. Her-2/Neu was negative, but PD-L1 was present. Started on oxaliplatin, leucovorin and 5-fluororuacil. CA 19-9 went from 163334 U/ml to 20171 U/ml 1 month later. Case 2: 42 year old Hispanic female presented with weakness with distended abdomen. CT showed omental caking with large volume ascites. EGD showed a large ulcer, biopsy was adenocarcinoma with SRCC features. The patient started on Taxol 80 and Ramucirumab every two weeks, requiring monthly paracentesis. Case 3: 56 year old Hispanic female with constipation, urinary retention. MRI showed spinal cord compression and underwent tumor debulking. Biopsy of the dura showed metastatic adenocarcinoma. EGD showed large friable ulcer positive for SRCC with no PDL-1 expression. Patient started on folinic acid and fluorouracil. Ultimately, the patient did not tolerate treatment and passed. DISCUSSION: WHO classified SRCC in 1990, with two main processes of oncogenesis. The accretion of mucin via the E-cadherin molecule within the CDH1 gene, along with mutations in the B-catenin and APC gene. These disrupt the Wnt/B-catenin, Pi3K, MEK1 pathway. Dysregulation of MUC4 disrupts cell adhesion and is expressed in gastric mucosa and in de novo gastric cancer. High PDL-1 expression is related to better target for treatment. These genes may be more prevalent in the Hispanic population, and should be furthered studied to see if SRCC can be prevented.