Prognostic role of acellular mucin pools in patients with rectal cancer after pathological complete response to preoperative chemoradiation: systematic review and meta-analysis

ABSTRACT

The prognostic implication of acellular mucin pools [AMP] in rectal cancer is controversial. There is no Level-I evidence regarding their prognostic impact. This systematic review was performed to determine the impact of AMP on survival in patients with rectal cancer, who demonstrate pathological complete response [PCR] to preoperative chemoradiation [CRT]. A systematic literature review was performed by searching MEDLINE and EMBASE database. For overall survival, the overall random effect model favored mucin negative tumors [HR=2, 95% CI=0.8-4.8] with heterogeneity [I-squared=0, p=0.6]. However, the pooled analysis was not significant due to small sample. For disease-free survival, four studies showed HR >1; however, the pooled random effect model indicated little difference in risk [HR=1.06, 95% CI=0.4-2.4] with heterogeneity [I-squared=49.5%, p=0.07]. No definite prognostic role of AMP in rectal cancer patients with PCR was found. These results, however, should be interpreted with caution