Clinicopathological Features and Survival of Signet-Ring Cell Carcinoma and Mucinous Adenocarcinoma of Right Colon, Left Colon, and Rectum

Histological subtype plays an important role in the different clinical characteristics and survival outcomes of patients with colorectal carcinoma (CRC). However, in previous studies, the influences of tumor locations and tumor stages have not been strictly controlled. This study focused on the assessment of the prognostic value of each histological subtype in different tumor locations and tumor stages of CRC. We used the Surveillance, Epidemiology, and End Results (SEER) database (1973–2011) to analyze 818,229 CRC patients with different clinical and pathological features, and analyzed the prognostic value of each histological subtype. Under the condition of stratification by tumor stage, signet-ring cell carcinoma (SRCC) presented the worst survival in each stage of right colon cancer (stage I, log-rank, p = 0.002, stages II, III, and IV, log-rank, p < 0.001), rectal cancer (RC) (log-rank, p < 0.001), and in stages II, III, and IV of left colon cancer (log-rank, p < 0.001). Multivariate survival analysis suggested SRCC subtype, male gender, age ≥ 70 years, tumor size ≥ 5 cm, stage progression, and poor differentiation were all significant factors worsening survival in CRC (p < 0.001, respectively). Mucinous adenocarcinoma (MC) histological subtype proved to be an independent protective factor for the prognosis of right colon cancer (p = 0.003). Overall, in our study, the results suggested SRCC had the worst survival among the three histological subtypes of CRC. MC was associated with favorable prognosis in right colon cancer but not with other tumor locations.