Effect of mucin production on survival in colorectal cancer: a case-control study

To investigate the impact of mucin production on prognosis in colorectal cancer, in terms of overall survival (OS) and time to disease progression (TTP) in patients with mucinous compared to those with non-mucinous colorectal cancer (NMCRC), matched for age, gender, and tumor stage.

Thirty five patients with mucinous colorectal cancer (MCRC) were matched for age, gender, and tumor stage with 35 controls having NMCRC. OS and TTP were compared among 4 groups divided according to mucin content: group A (50%-75% mucin), group B (75%-100% mucin), group C or controls (<50% mucin). Group D consisted of all patients with tumors having <75% mucin (controls and groups A together).

Median survival in MCRC and NMCRC groups was 46.2 and 112.9 mo, respectively (P=0.26). OS in groups A and B was 70.1 and 32.8 mo (P=0.46), and in groups B and D was 32.8 and 70.1 mo, respectively (P=0.143). TTP in MCRC and NMCRC was 50.17 and 44.77 mo, respectively (P=0.795). TTP in groups A, B, and D was 70.1, 24.8, and 65.5 mo, respectively. Twenty-eight percent of patients with MCRC had poorly differentiated adenocarcinoma versus 8.6% in NMCRC patients (P=0.028).

MCRC is associated with a non-significant decrease in median survival and TTP, particularly when mucin content is >75% of tumor volume. However, it tends to be more poorly differentiated. A larger study matching for stage and grade is needed.