387 - Prognosis of Three Histological Subtypes of Colorectal Adenocarcinoma: A Retrospective Analysis of 8005 Chinese Patients

Background

To evaluate the effect of the varied histological subtypes on clinical outcome and to determine the prognostic implications of mucinous adenocarcinoma (MAC) and signet ring cell carcinoma (SRCC) compared with common adenocarcinoma (AC).

Methods

A total of 9015 patients with colorectal adenocarcinoma undergoing definitive surgery between 2007 and 2015 at FUSCC were enrolled in this study. After 1010 of these patients were excluded because of neoadjuvant therapy, 8005, including 7502 AC, 428 MAC and 75 SRCC, remained for analysis, where clinical, histopathological, and survival data were analyzed.

Results

MAC and SRCC were more common in right-sided colon cancer together with male or young patients, compared to AC, with a higher probability to develop lymph node metastasis, lymphovascular invasion and perineural invasion. As for survival outcomes, we found that the 5-year OS of SRCC was significantly lower than that of MAC and AC, while the 5-year OS of MAC is much lower than that of AC. However, in multivariable analysis, the difference in survival between SRCC, MAC and AC was no longer significant, especially when stratified by N stage.

Conclusions

MAC and SRCC are rare subtypes of colorectal cancer with a higher T stage, N stage as well as higher invasion ability. However, neither MAC or SRCC was an independent predictor of decreased survival in multivariate analysis.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

Shanghai Cancer Center Fudan University.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.