Merkel cell carcinoma (MCC) is an infrequent, rapidly growing skin neoplasm that carries a greater probability of regional lymph node involvement, and a grim prognosis in advanced cases. While it is seen predominantly in old age in sun-exposed body parts, the prevalence varies among different races and geographical regions. Merkel cell polyomavirus and UV radiation-induced mutations contribute to its etiopathogenesis. The clinical presentation of MCC lacks pathognomonic features and is rarely considered highly at the time of presentation. Histopathological examination frequently reveals hyperchromatic nuclei with high mitotic activity, but immunohistochemistry is required to confirm the diagnosis. Sentinel lymph node biopsy (SLNB) and imaging are advised for effective staging of the disease. Multimodal management including surgery, radiation therapy, and/or immunotherapy are deployed. Traditional cytotoxic chemotherapies may result in an initial response, but do not result in a significant survival benefit. Checkpoint inhibitors have dramatically improved the prognosis of patients with metastatic MCC, and are recommended first-line in advanced cases. There is a need for well-tolerated agents with good safety profiles in patients who have failed immunotherapies.

Background: Suppressor of fused (SuFu) is a tumor-suppressor gene that regulates hedgehog signaling. Its involvement in some malignancies is broadly accepted. However, its association with colorectal cancer (CRC) pathogenesis is not clear. Likewise, no study has clearly associated blood-based inflammatory biomarkers with cancer diagnosis/prognosis as yet. Aim: Our goal was to look at SuFu expression levels in CRC patients and its relationship with other clinicopathological factors. Additionally, we looked into the function of a few blood-based biomarkers in CRC and whether or not a combined strategy at the genetic and clinical levels can be applied in CRC. Methods: The investigation included 98 histopathologically confirmed CRC samples and adjacent normal tissues (controls). A colonoscopy was followed by a targeted biopsy for each suspected colon cancer patient. A CT scan and MRI were also performed on every patient with rectal cancer. Real-time polymerase chain reaction and immunohistochemistry (IHC) were used for assessment. A Beckman Coulter DxH900 was used to examine blood parameters. A Beckman Coulter DxI800 was used to identify pretreatment carcinoma embryonic antigens (CEA) and carbohydrate antigens (CA 19–9) in CRC patients. Results: The expression of SuFu was associated with gender, education, passive smoking, tumor grade, perineural invasion (PNI), lymph node metastasis (LNM), node status, stage, vital status, and recurrence (p < 0.05). In the combined analysis, the areas under the curve produced by the platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), and red cell distribution width (RDW) were the greatest (AUC_RDW+PLR+NLR = 0.91, 95% CI: 0.86–0.93, p < 0.05). Furthermore, the most severe pathological features were linked to RDW, PLR, NLR, and HPR. SuFu expression, node status, LNM, PNI, and stage all had significant correlations with OS and DFS rates in IHC-based univariate survival analysis (p < 0.05). According to the Cox regression, CA-19.9 had a strong independent predictive link with 3-year DFS (p < 0.05). Conclusion: In CRC, SuFu was downregulated both transcriptionally and translationally, was primarily nucleo-cytoplasmic, and was expressed less in high-grade tumors. In addition, SuFu was linked to a poor overall and disease-free survival rate. It may be possible to use SuFu as a therapeutic target for CRC in the future. However, SuFu expression had no effect on RDW, PLR, NLR, or HPR serum levels.