Pathological complete response of locally advanced colon cancer after preoperative radiotherapy: a case report and narrative review of the literature

Downregulation of NAT1 Expression is Associated with Poor Prognosis and Immune Infiltration in COAD

Background

An increasing corpus of evidence has identified the involvement of N-acetyltransferase 1 (NAT1), a member of the NAT family, in the progression of various cancers. However, the specific function of NAT1 in colon cancer (COAD) remains elusive. This study aims to decip her the role of NAT1 in COAD and its associated mechanisms.

Methods

The Tumor Immunity Evaluation Resource (TIMER), The Cancer Genome Atlas (TCGA), and the Gene Expression Omnibus (GEO) databases were employed to assess the NAT1 expression level in COAD. The differential expression between COAD and normal colon tissue was further validated using quantitative real-time reverse-transcription PCR (RT-qPCR) and Western blot (WB) analyses. Additionally, survival analysis of NAT1 in COAD was carried out using the PrognoScan database and TCGA dataset. The functions of NAT1 were explored through gene set enrichment analysis (GSEA) and immuno-infiltration analysis.

Results

There was a significant reduction in NAT1 expression in COAD samples compared to normal tissue. Notably, low NAT1 expression in COAD correlated significantly with various clinical parameters such as tumor stage (T stage, N stage, M stage, pathologic stage), primary therapy outcome, carcinoembryonic antigen (CEA) level, and lymphatic invasion. The downregulation of NAT1 was also strongly linked with poor outcomes in overall survival (OS), progression-free interval (PFI), and disease-specific survival (DSS). Cox regression analysis highlighted NAT1 as an independent prognostic indicator for overall survival in COAD patients. GSEA results revealed NAT1's involvement in multiple pathways, including the neuroactive ligand-receptor interaction, olfactory transduction, olfactory signaling, extracellular matrix receptor interaction, calcium signaling, and focal adhesion pathways. Furthermore, NAT1 expression was found to significantly correlate with infiltration levels of various immune cells.

Conclusion

The findings reveal NAT1's potential as a valuable prognostic biomarker for COAD. Moreover, its associated mechanisms offer insights that might pave the way for therapeutic interventions for COAD patients.

Stage IV and recurrent colorectal cancer cured following multimodal therapy: A case series

The treatment strategies for colorectal cancer (CRC) with distant metastasis or metastatic recurrence after resection of the primary tumor are controversial. In the present study, four cases of patients with advanced CRC with distant metastasis who achieved disease-free survival (DFS) for >5 years and were deemed potentially cured were reported. Case 1 was that of a 53-year-old male patient with rectal cancer and liver metastases (pT3N2bM1, pStage IV), and case 2 was that of a 58-year-old female patient with descending colon cancer (pT3N1M1, pStage IV) who had lung metastases at surgery and postoperatively. Both patients achieved DFS for >5 years after simultaneous or staged partial hepatectomy or pneumonectomy followed by chemotherapy. Case 3 was that of a 75-year-old male patient with transverse colon cancer (pT3N1M0, pStage IIIB) and case 4 was that of a 73-year-old male patient with sigmoid colon cancer (pT3N0M0, pStage IIA). These cases developed liver metastases after resection of the primary tumour and were subsequently treated with chemotherapy before or after partial hepatectomy. DFS for >5 years was achieved. All four patients were considered cured. The data revealed that even patients with CRC and distant metastases can potentially be cured following multidisciplinary treatment. In the present case report, the factors that enabled these patients to be considered cured were discussed and the aim was to improve the treatment strategy to cure CRC with distant metastasis or recurrence.

Changes and Prognostic Value of lncRNA CASC9 in Patients with Advanced Colon Cancer after Chemotherapy

OBJECTIVE

Colon cancer (CC) shows a gradual increasing incidence in recent years, and chemotherapy is a frequently adopted treatment for patients with middle or advanced colon cancer (ACC), but it lacks prognostic markers after CC.

METHODS

The changes of lncRNA CASC9 in 58 patients with CC were determined using a real-time quantitative PCR (qRT-PCR) assay before and after chemotherapy, and the correlation of serum lncRNA CASC9 with efficacy of FOLFOX4 regimen (oxaliplatin + calcium folinate + fluorouracil) was analyzed. The patients were followed up to understand the association of lncRNA CASC9 with overall survival (OS) and progression-free survival (PFS).

RESULTS

Patients with CC showed notably higher lncRNA CASC9 expression than controls, and lncRNA CASC9 presented an association with the clinical stage of the patients. In addition, lncRNA CASC9 demonstrated a clinical value in predicting efficacy on patients and acted as one independent prognostic factor for PFS in patients with ACC.

CONCLUSIONS

With increased expression of serum lncRNA CASC9, patients with ACC suffered an unfavorable chemotherapy effect. In addition, serum lncRNA CASC9 is a promising sensitive indicator for prediction of ACC and is related to the clinical efficacy and prognosis of patients.

LncRNA, a novel target biomolecule, is involved in the progression of colorectal cancer

Colorectal cancer is one of the most commonly diagnosed malignancies among males and females worldwide. Although China is a country with a low incidence of colorectal cancer, with the improvement of China's economy and lifestyle changes, the incidence rate in China has generally increased in recent years, and the morbidity and mortality of colorectal cancer rank fifth among those of all malignant tumours. Furthermore, despite recent improvements in screening strategies and treatments for colorectal cancer, the prognosis of advanced colorectal cancer is still poor, mainly due to the recurrence or distant metastasis of this disease. Thus, colorectal cancer still seriously threatens the health and life of people and is a major public health problem worthy of further study. Recently, accumulating evidence has revealed that colorectal carcinogenesis might be a multistep process driven by progressive genetic abnormalities, including changes in lncRNA expression. Moreover, a large number of studies have discovered and studied the abnormal expression of lncRNAs in colorectal cancer, providing a promising target for the diagnosis and treatment of colorectal cancer, which will promote human understanding of the pathogenesis of colorectal cancer and improve diagnosis and treatment. Therefore, in the present review, we mainly summarize the present status of colorectal cancer, the characteristics, functions and clinical perspectives of lncRNAs, and the current therapeutic methods used for colorectal cancer, especially the application of lncRNAs in the treatment of colorectal cancer. It is hoped that this review will give readers a new understanding of the roles of lncRNAs in colorectal cancer.