Mucinous Differentiation in Colorectal Cancer: A 10-Year Experience Audit at King Faisal Specialist Hospital and Research Centre, Jeddah

Given that colorectal cancer is one of the leading causes of mortality, mucinous adenocarcinoma is one of the subtypes and is characterized by the presence of mucin-producing tumor cells with mucin components and is more challenging to manage. In Saudi Arabia, it represents approximately 10-15% of all colorectal carcinoma. The main etiological cause of mucinous adenocarcinoma is yet not well understood. The main goal of our study is to discuss the histopathology and the molecular background of mucinous colorectal adenocarcinoma and also to provide an update on its prognosis and therapeutics from recent published literature. It is a retrospective cohort study that was conducted at King Faisal Specialist Hospital, Jeddah, Saudi Arabia. The study included 68 adult patients diagnosed with mucinous colon cancer, who did surgical resection alone or with or without adjuvant chemotherapy following from January 2011 to December 2020. The mucinous subtypes are found more commonly in the proximal colon. In our study, 26 patients (38.2% of the cases) were right -sided and 35 patients (51.5%) were from the left side, but these included the rectum as well and this reflects the higher incidence of diagnosis of rectal cancer in the region. Most tumors were classified as Grade II in 56 patients (82.4%), consistent with the intermediate differentiation status often associated with the mucinous subtypes. The most common symptom at presentation was abdominal pain in 38 patients (55.9%) followed by per rectal bleeding and abdominal mass. The management in our study was in line with the standard established practice and surgical resection as expected was the primary potentially curative approach. Notably of patients presenting with locally advanced rectal cancer, six patients underwent concomitant chemoradiotherapy followed by surgery and four patients had upfront surgery. The duration of the median follow-up was 32 months. At the time of analysis, 30 patients (44.1%) were alive and remained on regular follow-up, 17 patients (25%) had succumbed to the disease, and 21 patients (30.9%) were lost to follow-up. The median overall survival was not reached, and notably, 49 patients (71.6%) remained alive at the four-year mark. Whilst our study contributes to the current understanding of mucinous adenocarcinomas of the colon, further research in molecular profiling and genomic testing and larger clinical trials with tailored treatments is necessary to refine treatment strategies and improve outcomes.