A 54-year-old man presented with constipation with a six-month duration and a 5 kg weight loss over 10 months. He had undergone a subtotal gastrectomy and chemotherapy for advanced gastric cancer 13 years earlier. A colonoscopy revealed a firm, circular, in-growing mass in the rectum. A computed tomography (CT) scan showed a 3.0×1.2 cm invasive mass near the prostate, abutting the rectal wall and invading the right ureterovesical junction, causing hydroureteronephrosis. A positron emission tomography-CT scan indicated low fluorodeoxyglucose uptake in the rectal or prostate area. The biopsy results showed poorly differentiated carcinoma. An immunohistochemistry study confirmed CK7 positive, CK20 negative, MUC2 negative, and CDX2 focally positive immune phenotype for cancer cells, suggesting a diagnosis of metastatic adenocarcinoma with a gastric origin rather than a prostate and rectal origin.

A 54-year-old man presented with constipation with a six-month duration and a 5 kg weight loss over 10 months. He had undergone a subtotal gastrectomy and chemotherapy for advanced gastric cancer 13 years earlier. A colonoscopy revealed a firm, circular, in-growing mass in the rectum. A computed tomography (CT) scan showed a 3.0×1.2 cm invasive mass near the prostate, abutting the rectal wall and invading the right ureterovesical junction, causing hydroureteronephrosis. A positron emission tomography-CT scan indicated low fluorodeoxyglucose uptake in the rectal or prostate area. The biopsy results showed poorly differentiated carcinoma. An immunohistochemistry study confirmed CK7 positive, CK20 negative, MUC2 negative, and CDX2 focally positive immune phenotype for cancer cells, suggesting a diagnosis of metastatic adenocarcinoma with a gastric origin rather than a prostate and rectal origin.

A 54-year-old man presented with constipation with a six-month duration and a 5 kg weight loss over 10 months. He had undergone a subtotal gastrectomy and chemotherapy for advanced gastric cancer 13 years earlier. A colonoscopy revealed a firm, circular, in-growing mass in the rectum. A computed tomography (CT) scan showed a 3.0×1.2 cm invasive mass near the prostate, abutting the rectal wall and invading the right ureterovesical junction, causing hydroureteronephrosis. A positron emission tomography-CT scan indicated low fluorodeoxyglucose uptake in the rectal or prostate area. The biopsy results showed poorly differentiated carcinoma. An immunohistochemistry study confirmed CK7 positive, CK20 negative, MUC2 negative, and CDX2 focally positive immune phenotype for cancer cells, suggesting a diagnosis of metastatic adenocarcinoma with a gastric origin rather than a prostate and rectal origin.

A 54-year-old man presented with constipation with a six-month duration and a 5 kg weight loss over 10 months. He had undergone a subtotal gastrectomy and chemotherapy for advanced gastric cancer 13 years earlier. A colonoscopy revealed a firm, circular, in-growing mass in the rectum. A computed tomography (CT) scan showed a 3.0×1.2 cm invasive mass near the prostate, abutting the rectal wall and invading the right ureterovesical junction, causing hydroureteronephrosis. A positron emission tomography-CT scan indicated low fluorodeoxyglucose uptake in the rectal or prostate area. The biopsy results showed poorly differentiated carcinoma. An immunohistochemistry study confirmed CK7 positive, CK20 negative, MUC2 negative, and CDX2 focally positive immune phenotype for cancer cells, suggesting a diagnosis of metastatic adenocarcinoma with a gastric origin rather than a prostate and rectal origin.

A 54-year-old man presented with constipation with a six-month duration and a 5 kg weight loss over 10 months. He had undergone a subtotal gastrectomy and chemotherapy for advanced gastric cancer 13 years earlier. A colonoscopy revealed a firm, circular, in-growing mass in the rectum. A computed tomography (CT) scan showed a 3.0×1.2 cm invasive mass near the prostate, abutting the rectal wall and invading the right ureterovesical junction, causing hydroureteronephrosis. A positron emission tomography-CT scan indicated low fluorodeoxyglucose uptake in the rectal or prostate area. The biopsy results showed poorly differentiated carcinoma. An immunohistochemistry study confirmed CK7 positive, CK20 negative, MUC2 negative, and CDX2 focally positive immune phenotype for cancer cells, suggesting a diagnosis of metastatic adenocarcinoma with a gastric origin rather than a prostate and rectal origin.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Background/Aims: Papillary adenocarcinoma is classified to differentiated-type gastric cancer and is indicated for endoscopic submucosal dissection. However, due to its rare nature, there are limited studies on it. The purpose of this study was to determine the outcome of endoscopic submucosal dissection in patients with papillary-type early gastric cancer and to find the risk factors of lymph node metastasis. Methods: Patients diagnosed with papillary-type early gastric cancer at eight medical centers, who underwent endoscopic submucosal dissection or surgical treatment, were retrospectively reviewed. The clinical results and long-term outcomes of post-endoscopic submucosal dissection were evaluated, and the risk factors of lymph node metastasis in the surgery group were analyzed. Results: One-hundred and seventy-six patients with papillary-type early gastric cancer were enrolled: 44.9% (n=79) in the surgery group and 55.1% (n=97) in the endoscopic submucosal dissection group. As a result of endoscopic submucosal dissection, the en bloc resection and curative resection rates were 91.8% and 86.6%, respectively. The procedure-related complication rate was 4.1%, and local recurrence occurred in 3.1% of patients. Submucosal invasion (odds ratio, 3.735; 95% confidence interval, 1.026 to 12.177; p=0.047) and lymphovascular invasion (odds ratio, 7.636; 95% confidence interval, 1.730 to 22.857; p=0.004) were the risk factors of lymph node metastasis in papillary-type early gastric cancer patients. Conclusions The clinical results of endoscopic submucosal dissection in papillary-type early gastric cancer were relatively favorable, and endoscopic submucosal dissection is considered safe if appropriate indications are confirmed by considering the risk of lymph node metastasis.

Background/Aims: This study compared the effectiveness and safety of glecaprevir/pibrentasvir (GLE/PIB) and sofosbuvir/ledipasvir (SOF/LDV) in real-life clinical practice. Methods: The data from genotype 1 or 2 chronic hepatitis C patients treated with GLE/PIB or sofosbuvir + ribavirin or SOF/LDV in South Korea were collected retrospectively. The analysis included the treatment completion rate, sustained virologic response at 12 weeks (SVR12) test rate, treatment effectiveness, and adverse events. Results: Seven hundred and eighty-two patients with genotype 1 or 2 chronic hepatitis C who were treated with GLE/PIB (n=575) or SOF/LDV (n=207) were included in this retrospective study. The baseline demographic and clinical characteristics revealed significant statistical differences in age, genotype, ascites, liver cirrhosis, and hepatocellular carcinoma between the GLE/PIB and SOF/LDV groups. Twenty-two patients did not complete the treatment protocol. The treatment completion rate was high for both regimens without statistical significance (97.7% vs. 95.7%, p=0.08). The overall SVR12 of intention-to-treat analysis was 81.2% vs. 80.7% without statistical significance (p=0.87). The overall SVR12 of per protocol analysis was 98.7% vs. 100% without statistical significance (p=0.14). Six patients treated with GLE/PIB experienced treatment failure. They were all male, genotype 2, and showed a negative hepatitis C virus RNA level at the end of treatment. Two patients treated with GLE/PIB stopped medication because of fever and abdominal discomfort. Conclusions Both regimens had similar treatment completion rates, effectiveness, and safety profiles. Therefore, the SOF/LDV regimen can also be considered a viable DAA for the treatment of patients with genotype 1 or 2 chronic hepatitis C.

Background/Aims: The prognostic significance of 18F-fluorodeoxyglucose (FDG)-positron emission tomography-computed tomography (PET/CT) in peripheral T-cell lymphomas (PTCLs) are controversial. We explored the prognostic impact of sequential 18F-FDG PET/CT during frontline chemotherapy of patients with PTCLs. Methods: In total, 143 patients with newly diagnosed PTCLs were included. Sequential 18F-FDG PET/CTs were performed at the time of diagnosis, during chemotherapy, and at the end of chemotherapy. The baseline total metabolic tumor volume (TMTV) was calculated using the the standard uptake value with a threshold method of 2.5. Results: A baseline TMTV of 457.0 cm3 was used to categorize patients into high and low TMTV groups. Patients with a requirehigh TMTV had shorter progression-free survival (PFS) and overall survival (OS) than those with a low TMTV (PFS, 9.8 vs. 26.5 mo, p = 0.043; OS, 18.9 vs. 71.2 mo, p = 0.004). The interim 18F-FDG PET/CT response score was recorded as 1, 2–3, and 4–5 according to the Deauville criteria. The PFS and OS showed significant differences according to the interim 18F-FDG PET/CT response score (PFS, 120.7 vs. 34.1 vs. 5.1 mo, p < 0.001; OS, not reached vs. 61.1 mo vs. 12.1 mo, p < 0.001). Conclusions The interim PET/CT response based on visual assessment predicts disease progression and survival outcome in PTCLs. A high baseline TMTV is associated with a poor response to anthracycline-based chemotherapy in PTCLs. However, TMTV was not an independent predictor for PFS in the multivariate analysis.

Purpose: Diffuse large B-cell lymphoma (DLBCL) is the most common hematologic malignancy worldwide. Although substantial improvement has been achieved by the frontline rituximab-based chemoimmunotherapy, up to 40%-50% of patients will eventually have relapsed or refractory disease, whose prognosis is extremely dismal. Materials and Methods: We have carried out two prospective cohort studies that include over 1,500 DLBCL patients treated with rituximab plus CHOP (#NCT01202448 and #NCT02474550). In the current report, we describe the outcomes of refractory DLBCL patients. Patients were defined to have refractory DLBCL if they met one of the followings, not achieving at least partial response after 4 or more cycles of R-CHOP; not achieving at least partial response after 2 or more cycles of salvage therapy; progressive disease within 12 months after autologous stem cell transplantation. Results: Among 1,581 patients, a total of 260 patients met the criteria for the refractory disease after a median time to progression of 9.1 months. The objective response rate of salvage treatment was 26.4%, and the complete response rate was 9.6%. The median overall survival (OS) was 7.5 months (95% confidence interval, 6.4 to 8.6), and the 2-year survival rate was 22.1%±2.8%. The median OS for each refractory category was not significantly different (p=0.529). Conclusion In line with the previous studies, the outcomes of refractory DLBCL patients were extremely poor, which necessitates novel approaches for this population.