58 Background: Signet ring cell carcinoma accounts for less than 1% of all colon cancers. We examined the clinical pathological features and prognosis of signet ring cell carcinoma of colon and compare it with mucinous and non-mucinous adenocarcinoma of colon. Methods: A total of 206 patients diagnosed with signet ring cell carcinoma from 1995 to 2009 were identified from the VA Central Cancer Registry (VACCR) database. Age, race, histology, grade, lymph node status, stage and type of treatment received data were collected. Results: Out of 206 patients, 173 (83.9%) were white, 31 (15%) were black, and 2 patients were listed as unknown. Median age of diagnosis was 67 years as compared to 70 years for both mucinous and non-mucinous adenocarcinoma of colon. Pathological T-stages were as follows: T1 = 2.9%, T2=5.3%, T3=33.9%, T4= 25.7%, and unknown 32%. Of the total, 22.3% were located in caecum, 21.8% in ascending colon, 15.5% in sigmoid colon, 7.7% in appendix and hepatic flexure of colon, 11.1% in transverse colon, 2.9% in splenic flexure and 4.4% in descending colon. 33.5% were lymph node positive, 34.6% were lymph node negative, and 31.8% were unknown. Histologically grade 3 (55.4%) was most commonly reported followed by grade 2 (7.3%), grade 1 (2.5%), grade 4 (1.9%)and in 33% grade was unknown. 41.3% patients received only surgery while 34% received surgery with adjuvant chemotherapy, 7.3% received chemotherapy alone and 7.8% patients received either chemotherapy, radiation or hormonal therapy alone, 9% did not receive any therapy. 1 year, 3 year and 5 year survivals for signet ring cell cancer compared to adeno carcinoma was 60% vs 80%, 33% vs 60%, and 24% vs 47% respectively. Median survival of signet ring cell carcinoma compared to mucinous and non mucinous adenocarcinoma was 19 months, 48 months and 62 months respectively. Conclusions: Signet ring cell carcinoma of colon has poor survival rates than the other histological subtypes. Signet ring cell carcinoma presents at an earlier age, higher tumor grade and advanced stage at diagnosis when compared to mucinous and non-mucinous adenocarcinoma of colon. Due to rarity of this disease further multi-institute studies are required for in-depth understanding and analysis of this disease. No significant financial relationships to disclose.
Pathobiological behavior and molecular mechanism of signet ring cell carcinoma and mucinous adenocarcinoma of the stomach: A comparative study
