Intrabiliary metastasis of colorectal mucinous adenocarcinoma mimicking choledocholithiasis 18 years after the primary tumor

This case report presents a 62-year-old male who had previously undergone curative colectomy and neoadjuvant chemotherapy in 2005 for colorectal cancer. He presented with jaundice, which was initially attributed to choledocholithiasis. After cholecystectomy and repeat ERCPs, hyperbilirubinemia persisted. There was persistent dilation of the right posterior duct on imaging, concerning for biliary stricture, possibly due to cholangiocarcinoma or intraductal papillary neoplasm. During a right posterior hepatectomy, a peripheral liver lesion was found in association with the dilated bile duct. On frozen evaluation, the lesion was found to be invasive adenocarcinoma. The final pathology was compatible with a metastatic mucinous adenocarcinoma of colonic origin. A repeat colonoscopy was done with no recurrence or new lesion in the colon. This case underscores the challenges associated with diagnosing biliary issues and assessing liver lesions in patients with a remote history of cancer. It raises the question of when and whether, after primary cancer treatment, it becomes safe to explore alternative diagnoses without immediately suspecting metastasis. Another significant challenge arises in ascertaining the most suitable therapeutic approaches for these patients. This is because these extremely late recurrences might be linked to an indolent, slow-growing type of tumor, but also have been linked to cancer stem cells, and as any recurrence, demands attention.

Tumor-suppressive role of the musculoaponeurotic fibrosarcoma gene in colorectal cancer

Somatic cell reprogramming using the microRNAs miR-200c, miR-302s, and miR-369s leads to increased expression of cyclin-dependent kinase inhibitors in human colorectal cancer (CRC) cells and suppressed tumor growth. Here, we investigated whether these microRNAs inhibit colorectal tumorigenesis in CPC;Apc mice, which are prone to colon and rectal polyps. Repeated administration of microRNAs inhibited polyp formation. Microarray analysis indicated that c-MAF, which reportedly shows oncogene-like behavior in multiple myeloma and T cell lymphoma, decreased in tumor samples but increased in microRNA-treated normal mucosa. Immunohistochemistry identified downregulation of c-MAF as an early tumorigenesis event in CRC, with low c-MAF expression associated with poor prognosis. Of note, c-MAF expression and p53 protein levels were inversely correlated in CRC samples. c-MAF knockout led to enhanced tumor formation in azoxymethane/dextran sodium sulfate-treated mice, with activation of cancer-promoting genes. c-MAF may play a tumor-suppressive role in CRC development.

Significance of Wnt/β-Catenin Signal Activation for Resistance to Neoadjuvant Chemoradiotherapy in Rectal Cancer

Although a therapeutic response to neoadjuvant chemoradiotherapy (NACRT) is important to improve oncological outcomes after surgery in patients with locally advanced rectal cancer, there is no reliable predictor for this. The Wnt/β-catenin signal is known to be crucial for the tumorigenesis of colorectal cancer. This study aimed to investigate the association of Wnt/β-catenin signal activation with a pathological response to NACRT. The immunohistochemical expression of nuclear and membranous β-catenin was analyzed in biopsy samples obtained from 60 patients with locally advanced rectal cancer who received curative surgery following NACRT. The association of Wnt/β-catenin signal activation with their clinical outcomes was investigated. Notably, the body mass index of these patients was significantly higher in the low nuclear β-catenin expression group. Moreover, patients in the high nuclear β-catenin expression group tended to have more advanced disease and a higher rate of positive vascular invasion than those in the low expression group. Furthermore, the rate of good histological responses was significantly higher in the low nuclear β-catenin expression group (72% vs. 37.1%, p < 0.01). Overall, relapse-free survival tended to be better in patients with low nuclear/high membranous β-catenin expression (n = 9) than in other individuals (n = 51) (p = 0.093 and p = 0.214, respectively). Activation of the Wnt/β-catenin signal pathway represented by nuclear β-catenin accumulation was significantly associated with a poor response to NACRT in patients with rectal cancer. Analysis of nuclear β-catenin accumulation before starting treatment might help predict the therapeutic response to NACRT.

Personalized medicine: Stem cells in colorectal cancer treatment

Treatment failure in primary as well as metastatic cancer patients, caused by chemo and radioresistance, has reinforced the research for the applicability of personalized medicine. The use of stem cells (SCs) and cancer stem cells (CSCs) in such a treatment approach will be reviewed in this study. Colorectal cancer (CRC) SCs prove to be a promising asset for CRC treatment optimization both by serving as biomarkers for the current therapy modalities, by means of treatment personalization and patient/tumor stratification, as well as in the development of targeted therapies, selective for the stem cell population. Similar conclusions are drawn, regarding mesenchymal stromal cells (MSCs) and their effect in CRC therapy; while resident stromal cells (RSCs) of tumor microenvironment (TME) seem to promote the tumorigenic and metastatic processes in addition to conferring to the chemo- and radioresistance, under certain conditions they are able to improve the treatment outcome of CRC chemotherapy, e.g. by targeted enzyme/prodrug treatment of CRC cells. This review, points out the dynamic potential of CSCs and other SCs types in CRC treatment personalization as well as, in the improvement of current treatment approaches, opting to a higher therapeutic rate, improved prognosis, survival and quality of life for CRC patients.

Late recurrence of cancer stem cell-positive colorectal cancer liver metastases after 15 years

No cases of late recurrence of colorectal cancer liver metastasis (CRLM) over 10 years have been reported in the literature. A 72-year-old woman had a surgical history of sigmoid colectomy and partial hepatic resections for sigmoid colon cancer and multiple liver metastases 15 years previously. The patient had been postoperatively treated with chemotherapy for 6 months and was observed regularly with no recurrence. Computed tomography (CT) performed due to high carcinoembryonic antigen (CEA) revealed a tumor of 70 mm in diameter at the anterior segment of the liver and a 6-mm nodule at the left lateral segment. There was no other malignant finding. We performed central bisegmentectomy and partial resection of the liver. Pathological findings showed the tumors to be well to moderately differentiated adenocarcinoma, and positive cytokeratin 20 (CK20) and caudal-type homeobox transcription factor 2 (CDX2) expression with negative expression of cytokeratin 7 (CK7). In addition, the tumors showed cluster of differentiation 44 (CD44) and 133 (CD133) positive signified cancer stem cell immunohistochemically. The postoperative diagnosis was recurrence of hepatic metastasis of sigmoid colon cancer. We report a rare case of late recurrence of CRLM more than 15 years after the primary diagnosis.

Sox2 is associated with cancer stem-like properties in colorectal cancer

Sox2 is known as the undifferentiated cell marker. Recent studies have shown that Sox2 may also be involved in the maintenance of cancer stem cells (CSCs) in skin and bladder cancers. In this study, we aimed to clarify the role of Sox2 in colorectal CSCs. Sox2 expression was measured in colon cancer cells and colorectal clinical samples by qRT-PCR and western blot analysis. To visualize the active Sox2 mRNA production, we generated a Sox2 promoter-dependent DsRed fluorescence emission system. Colon cancer cell lines and colorectal tumor tissues generally expressed the Sox2 protein. Knockdown of Sox2 by siRNA led to increased proliferative activity in Caco2 cells. Kaplan-Meier survival curves showed that the group with high Sox2 mRNA expression had a worse prognosis for relapse-free survival (RFS) than the low expression group (P = 0.045, median follow-up 60.0 months). Time-lapse image analysis revealed that most DsRed⁺ cells exhibited typical asymmetric cell division and had higher CSC marker expressions. The DsRed⁺ cells exhibited chemoresistance and they grew slower in vitro, yet they established rather larger tumors in vivo. Our data suggest that Sox2 may be a potential biomarker for colorectal CSCs.