Early-onset colorectal cancer (EOCRC) incidence is increasing worldwide. Efforts are directed to understand the biological and clinical signatures of EOCRC compared to late-onset colorectal cancer (LOCRC). EOCRC is thought to present differently across different ethnic groups and geographical regions. This study was an attempt to contribute with data from the Arab world toward the understanding of the clinicopathological parameters of EOCRC compared to LOCRC. Data from 254 CRC patients diagnosed at Sultan Qaboos University Hospital from the period 2015–2020 were studied. About 32.6% of all diagnosed CRC patients are below 50 years old, with no differences in gender distribution between EOCRC and LOCRC (p-value 0.417). Rectal involvement and tumor laterality were comparable among the two groups. Adenocarcinoma accounts for 83.3% and 94.2% of EOCRC and LOCRC, respectively. More mucinous and signet ring adenocarcinoma (8.3% each) were reported in EOCRC than LOCRC (2.9% and 2.2%, respectively). MLH1 and PMS2 loss are more common among LOCRC, but MSH6 loss is more frequent in EOCRC. The overall survival of EOCRC and LOCRC was comparable (median survival 64.88 and 67.24 months, respectively). This study showed comparable clinicopathological parameters between EOCRC and LOCRC from Arabs, which adds to the bigger picture of understand the disease.

Clinical trials have shown that many patients with breast cancer with limited sentinel lymph node (SLN) metastatic disease can safely avoid axillary lymph node dissection. Ultra-staging of initially negative SLNs may not confer additional clinical benefit. Despite this, protocols of ‘enhanced pathological examination’ (EPE) are still widely used. We evaluated the impact of our EPE protocol. If initial SLN H&Es are negative, we cut three additional H&E levels at 500 µm intervals with two spare sections at each level, to allow for immunohistochemistry if necessary. Occult micrometastases or isolated tumour cells were identified, using this protocol, in 3.4%, resulting in change of N stage in 3%. 1% of patients had further axillary surgery based on these findings. Our SLN-EPE protocol provided additional information in a small number of cases and changed axillary management in a minority. It represented a significant workload for scientists and pathologists, and had time and cost implications. We concluded that emphasising careful gross examination along with judicious use of additional levels and immunohistochemistry may be more beneficial than our current protocol.