Identification and functional validation of HLA-C as a potential gene involved in colorectal cancer in the Korean population.

BACKGROUND: Colorectal cancer (CRC) is the third most common cancer worldwide and is influenced by environmental and genetic factors. Although numerous genetic loci for CRC have been identified, the overall understanding of the genetic factors is yet to be elucidated. We sought to discover new genes involved in CRC applying genetic association analysis and functional study. RESULTS: We conducted exome array analysis on 194 CRC and 600 control subjects for discovering new candidate CRC genes. Fisher's exact test detected one exome-wide significant functional locus for CRC on SMCO1 (P < 10-6) and two suggestive functional loci on HLA-C and NUTM1 (10-6 ≤ P < 10-4). To evaluate the biological role of three candidate CRC genes, the differential expression of these genes between CRC and non-cancer colorectal cells was analyzed using qRT-PCR and publicly available gene expression data. Of three genes, HLA-C consistently revealed the significant down-regulation in CRC cells. In addition, we detected a reduction in cell viability in the HLA-C overexpression CRC cell line, implying the functional relevance of HLA-C in CRC. To understand the underlying mechanism exerted by HLA-C in CRC development, we conducted RNA sequencing analyses of HLA-C overexpression CRC cells and non-cancer colorectal cells. Pathway analysis detected that significantly down-regulated genes in HLA-C overexpression CRC cells were highly enriched in cancer-related signaling pathways such as JAK/STAT, ErbB, and Hedgehog signaling pathways. CONCLUSIONS: Exome array CRC case-control analysis followed by functional validation demonstrated that HLA-C likely exerts its influence on CRC development via cancer-related signaling pathways.

Paraneoplastic Guillain-Barré Syndrome in Small Cell Lung Cancer.

Guillain-Barré syndrome (GBS) is defined as an acute, autoimmune polyradiculoneuropathy. It is a rare disease that occurs at a rate of 1.11 cases per 100,000 person-years. However, once infected, up to 20%percnt; of patients develop severe disability, and approximately 5%percnt; die. There have been reports of GBS in different cancers. Among them, there are 6 previous reports of GBS in small cell lung cancer. Here, we report a case of a 52-year-old man who was diagnosed with GBS in the setting of small cell lung cancer with chemotherapy.

Two cases of electrocautery incision therapy using an insulated-tip knife for treatment of symptomatic benign short-segment colonic stenosis following colonic resection.

Anastomotic stenosis of the colon is not an uncommon finding; however, its frequency varies from one study to another. Traditionally, postoperative colonic stenosis is managed surgically. However, endoscopic therapy has recently become the preferred treatment modality over traditional surgery. Good short-term success has been achieved with use of endoscopic balloon dilation; however, restenosis may occur over time in 14% to 25% of patients. The current report showed the effectiveness and usefulness of an insulated-tip knife (IT-knife) for electrocautery therapy of a patient with symptomatic anastomotic colonic stenosis.

Prognostic Implications of Primary Tumor Resection in Stage IVB Colorectal Cancer in Elderly Patients.

PURPOSE: The aim of this study was to identify prognostic factors in stage IVB colorectal cancer in elderly patients, focusing on the influence of treatment modalities, including palliative chemotherapy and primary tumor resection. METHODS: A cohort of 64 patients aged over 65 years who presented with stage IVB colorectal cancer at the Gangneung Asan Hospital between July 1, 2001, and December 31, 2009, was analyzed. Demographics, tumor location, tumor grade, performance status, levels of carcinoembryonic antigen (CEA), level of aspartate aminotransferase (AST), and distant metastatic site at diagnosis were analyzed. Using the treatment histories, we analyzed the prognostic implications of palliative chemotherapy and surgical resection of the primary tumor retrospectively. RESULTS: The cohort consisted of 30 male (46.9%) and 34 female patients (53.1%); the median age was 76.5 years. Primary tumor resection was done on 28 patients (43.8%); 36 patients (56.2%) were categorized in the nonresection group. The median survival times were 12.43 months in the resection group and 3.58 months in the nonresection group (P < 0.001). Gender, level of CEA, level of AST, Eastern Cooperative Oncology Group performance status, tumor location, and presence of liver metastasis also showed significant differences in overall survival. On multivariate analysis, male gender, higher level of CEA, higher AST level, and no primary tumor resection were independent poor prognostic factors. In particular, nonresection of the primary tumor was the most potent/poor prognostic factor in the elderly-patient study group (P = 0.001; 95% confidence interval, 2.33 to 21.99; hazard ratio, 7.16). CONCLUSION: In stage IVB colorectal cancer in elderly patients, resection of the primary tumor may enhance survival.

Male breast adenoid cystic carcinoma.

INTRODUCTION: Adenoid cystic carcinoma (ACC) of the breast is a rare condition, and cases in male patients are even less common. CASE: We describe a case of ACC of the breast with axillary lymph node metastasis, disseminated osteolytic bone metastasis and bone marrow involvement in a 41-year-old man. CONCLUSION: Male breast ACC is an extremely rare malignancy; there can be difficulty in obtaining a final diagnosis. We report this case because of its rarity.