Clinical outcomes of colorectal neoplasm with positive resection margin after endoscopic submucosal dissection.

A positive resection margin after colorectal endoscopic submucosal dissection (ESD) is associated with an increased risk of recurrence. We aimed to identify the clinical significance of positive resection margins in colorectal neoplasms after ESD. We reviewed 632 patients who had en bloc colorectal ESD at two hospitals between 2015 and 2020. The recurrence rates and presence of residual tumor after surgery were evaluated. The rate of additional surgery after ESD and recurrence rate were significantly higher in patients with incomplete resection (n = 75) compared to patients with complete resection (n = 557). When focusing solely on non-invasive lesions, no significant differences in recurrence rates were observed between the groups with complete and incomplete resection (0.2% vs. 1.9%, p = 0.057). Among 84 patients with submucosal invasive carcinoma, 39 patients underwent additional surgery due to non-curative resection. Positive vertical margin and lymphovascular invasion were associated with residual tumor. Lymphovascular invasion was associated with lymph node metastasis. However, no residual tumor nor lymph node metastases were found in patients with only one unfavorable histological factor. In conclusion, a positive resection margin in non-invasive colorectal lesions, did not significantly impact the recurrence rate. Also, in T1 colorectal cancer with a positive vertical resection margin, salvage surgery can be considered in selected patients with additional risk factors.

Cytochrome P450 Family 46 Subfamily A Member 1 Promotes the Progression of Colorectal Cancer by Inducing Tumor Cell Proliferation and Angiogenesis.

BACKGROUND/AIM: Cytochrome P450 family 46 subfamily A member 1 (CYP46A1) has been implicated in the development and progression of various cancers. This study aimed to analyze the expression of CYP46A1, examining its relationship with oncogenic behaviors, and determining its prognostic implications in colorectal cancer (CRC). MATERIALS AND METHODS: A total of 225 patients with CRC who underwent curative surgical resection were examined using paraffin-embedded tissue blocks and subjected to tumor-specific survival analysis. The expression of CYP46A1 was assessed in CRC tissues through reverse transcription-polymerase chain reaction, western blotting, and immunohistochemistry. The CRC cells' apoptosis, proliferation, angiogenesis, and lymphangiogenesis were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays, alongside immunohistochemical staining for Ki-67, CD34, and D2-40 antibodies. RESULTS: CYP46A1 expression was found to be up-regulated in CRC tissues compared to normal colorectal mucosa. Such expression was significantly associated with advanced stage, deeper tumor invasion, lymph node metastasis, distant metastasis, and decreased survival. Furthermore, the mean Ki-67 labeling index and microvessel density values in CYP46A1-positive tumors were significantly elevated compared to CYP46A1-negative tumors. However, there was no discernible correlation between CYP46A1 expression and either the apoptotic index or lymphatic vessel density value. CONCLUSION: CYP46A1 promotes CRC progression, specifically through the induction of tumor cell proliferation and angiogenesis. The insights provided may hold potential implications for future therapeutic interventions targeting CYP46A1.

Clinical Outcome and Risk Factors of Chronic Radiation Proctitis Following Pelvic Radiation Therapy.

BACKGROUND/AIM: Pelvic radiation therapy (RT) is a common treatment for malignancies, including gynecological, genitourinary, and lower gastrointestinal tract cancers. However, chronic radiation proctitis (RP) is an unavoidable side effect, and its clinical presentation varies from asymptomatic to potentially life-threatening. This study evaluated the clinical characteristics and risk factors of chronic RP. PATIENTS AND METHODS: Patients with chronic RP (212) following RT for various pelvic cancers between January 2015 and December 2021 were enrolled. Clinical characteristics of RP were analyzed retrospectively. Severity was graded according to the Radiation Therapy Oncology Group (RTOG) modified rectal toxicity score and Vienna rectoscopy score (VRS), and risk factors were statistically analyzed. RESULTS: The most common pelvic cancer observed was cervical cancer. The patients received three-dimensional conformal RT (3D-CRT), intensity-modulated RT, or a combination of 3D-CRT and intracavitary RT (ICR). Rectal bleeding occurred in 70 (33.0%) patients. Previous abdominopelvic surgery and total radiation dose significantly correlated with the RTOG score and VRS. Previous abdominopelvic surgery, ICR, and total radiation dose were associated with chronic hemorrhagic RP. All patients with chronic hemorrhagic RP were treated with argon plasma coagulation (APC). 91.4% of cases required 1-3 APC sessions to resolve the bleeding, with a mean of 1.7 sessions. CONCLUSION: Our results showed that previous abdominopelvic surgery and total radiation dose were significant risk factors related to chronic RP, while total radiation dose was related to chronic hemorrhagic RP. We also showed that APC was effective and safe for chronic hemorrhagic RP.

CD47 mediates the progression of colorectal cancer by inducing tumor cell apoptosis and angiogenesis.

CD47 is an immunoregulatory protein that is found on the cell surface and plays significant roles in cellular functions such as proliferation, apoptosis, migration, and immune homeostasis. CD47 is overexpressed in various human cancers and is associated with tumor development, progression, and poor prognosis. In this study, we analyzed the expression of CD47 to determine whether it affected the oncogenic behavior of colorectal cancer (CRC) and investigated the prognostic value of CD47 expression in patients with CRC. We investigated 468 patients with CRC who underwent curative surgery and examined the expression of CD47 in tumor and lymph node tissues by performing RT-PCR and immunohistochemistry. Apoptosis, proliferation, angiogenesis, and lymphangiogenesis were determined via a TUNEL assay and immunohistochemical staining for Ki-67, CD34, and D2-40. CD47 expression was increased in human CRC tumors and metastatic lymph nodes compared with normal colorectal mucosa and non-metastatic lymph node tissues. CD47 expression was significantly associated with perineural invasion, lymphovascular invasion, cell differentiation, cancer stage, depth of invasion, lymph node metastasis, distant metastasis, and poor survival. The mean apoptotic index and microvessel density value of CD47-positive tumors were significantly higher than those of CD47-negative tumors. However, no significant difference was observed between CD47 expression and Ki-67 labeling index or lymphatic vessel density. These results indicate that CD47 mediated the progression of CRC by inducing tumor cell apoptosis and angiogenesis.

Engulfment and Cell Motility 1 (ELMO1) Regulates Tumor Cell Behavior and Predicts Prognosis in Colorectal Cancer.

BACKGROUND/AIM: Engulfment and cell motility 1 (ELMO1) plays a crucial role in the process of migration, chemotaxis, and metastasis of tumor cells. ELMO1 has been implicated in the pathogenesis of various cancers. However, the distinct function of ELMO1 in colorectal cancer (CRC) is unclear. We determined whether ELMO1 affects the oncogenic behavior of CRC cells and investigated its prognostic value in CRC patients. MATERIALS AND METHODS: We investigated the impact of ELMO1 on tumor cell behavior using small interference RNA (siRNA) in CRC cell lines, including SW480 and DLD1. The expression of ELMO1 was investigated by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) in cancer tissues and sera obtained from CRC patients. RESULTS: ELMO1 knockdown suppressed tumor cell proliferation in SW480 and DLD1 cells. ELMO1 knockdown-induced apoptosis through up-regulation of caspase-3, -7, and PARP activities and down-regulation of the anti-apoptotic Mcl-1 protein. ELMO1 knockdown-induced cell-cycle arrest by decreasing cyclin D1, cyclin-dependent kinase 2, 4 and 6, and the 25C cell division cycle (CDC25C). ELMO1 knockdown suppressed tumor cell invasion and migration. The expression of E-cadherin was increased, while that of Vimentin and Claudin 1 decreased following ELMO1 knockdown. The phosphorylation levels of PDK1, Akt, and GSK-3ß and were down-regulated after ELMO1 knockdown. The expression of ELMO1 was found up-regulated in cancer tissues and sera taken from CRC patients. ELMO1 expression was significantly associated with tumor stage, lymph node metastasis, distant metastases, and poor survival. CONCLUSION: ELMO1 mediates tumor progression by increasing tumor cell motility and inhibiting apoptosis in human CRC.

Primary Esophageal Malignant Melanoma in Korea: Clinical features, Management and Prognosis.

Primary esophageal melanoma is a rare disease with a poor prognosis. To date, 18 cases have been reported in Korea. Four patients visited the Chonnam National University Hwasun Hospital with dysphagia, followed by epigastric pain and discomfort, odynophagia, and weight loss. Esophagogastroduodenoscopy revealed a black pigmented polypoid mass, protruding mass, or black-pigmented flat lesions. Two patients had distant metastases and lymphadenopathies in imaging studies. Two patients underwent esophagectomy and intrathoracic esophagogastrostomy. One patient was treated with chemotherapy and interferon-alpha. The other patient declined further treatment. The routine histology using H&E revealed brown-colored atypical melanocytes. Immunohistochemical staining exhibited strong reactivity for Melan-A, S-100, and HMB-45 proteins. The biopsy specimens were interpreted to be malignant melanoma. One patient had multiple distant metastases 13 months after surgery. The other patient had no recurrence for 33 months after surgery. The patient treated with chemotherapy and interferon-alpha showed disease progression in the follow-up examination. Primary esophageal melanoma in Korea is a rare disease characterized by aggressive behavior, early metastasis, and poor prognosis.