Background: Delayed post-polypectomy bleeding (DPPB) is a serious complication of polypectomy that is poorly understood. The aim of this study was to evaluate the effectiveness of endoscopic hemostasis in managing DPPB and to identify associated risk factors. Methods: We retrospectively analyzed 289 patients who experienced DPPB (≥ 24 hours after polypectomy) and underwent endoscopic hemostasis at five university hospitals between 2005 and 2018. Patient characteristics, polyp size, technical factors, rebleeding, complications, and length of hospitalization were assessed. Results: Endoscopic hemostasis was successful in all 289 cases of DPPB. The techniques and devices employed included epinephrine injection (24.9%), argon plasma coagulation (18.0%), hemostatic forceps (10.7%), and hemoclips (87.9%). Rebleeding occurred in 15 cases (5.2%) after initial endoscopic hemostasis. The incidence of rebleeding was significantly associated with polyp size (< 10 mm: 2.8%, 10 mm–19 mm: 5.6%, ≥ 20 mm: 13.5%, P = 0.030) and sedation status (yes: 1.8%, no: 7.3%, P = 0.040). However, hemostasis method, bleeding characteristics, and polyp location were not significantly linked to rebleeding. Multivariate analysis revealed that polyp size (odds ratio, 5.02; 95% confidence interval, 1.25–20.13; P = 0.023) was significantly associated with rebleeding after endoscopic hemostasis for DPPB. In all 15 cases of rebleeding, a second endoscopic hemostasis was successfully performed without the need for embolization or surgical intervention. No perforations occurred during the first or second endoscopic hemostatic procedures. Conclusion Polyp size and sedation status were associated with rebleeding after endoscopic hemostasis for DPPB. As an intervention for DPPB, endoscopic hemostasis appears safe and effective.

Background: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs.

Background: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs.

Background: Delayed post-polypectomy bleeding (DPPB) is a serious complication of polypectomy that is poorly understood. The aim of this study was to evaluate the effectiveness of endoscopic hemostasis in managing DPPB and to identify associated risk factors. Methods: We retrospectively analyzed 289 patients who experienced DPPB (≥ 24 hours after polypectomy) and underwent endoscopic hemostasis at five university hospitals between 2005 and 2018. Patient characteristics, polyp size, technical factors, rebleeding, complications, and length of hospitalization were assessed. Results: Endoscopic hemostasis was successful in all 289 cases of DPPB. The techniques and devices employed included epinephrine injection (24.9%), argon plasma coagulation (18.0%), hemostatic forceps (10.7%), and hemoclips (87.9%). Rebleeding occurred in 15 cases (5.2%) after initial endoscopic hemostasis. The incidence of rebleeding was significantly associated with polyp size (< 10 mm: 2.8%, 10 mm–19 mm: 5.6%, ≥ 20 mm: 13.5%, P = 0.030) and sedation status (yes: 1.8%, no: 7.3%, P = 0.040). However, hemostasis method, bleeding characteristics, and polyp location were not significantly linked to rebleeding. Multivariate analysis revealed that polyp size (odds ratio, 5.02; 95% confidence interval, 1.25–20.13; P = 0.023) was significantly associated with rebleeding after endoscopic hemostasis for DPPB. In all 15 cases of rebleeding, a second endoscopic hemostasis was successfully performed without the need for embolization or surgical intervention. No perforations occurred during the first or second endoscopic hemostatic procedures. Conclusion Polyp size and sedation status were associated with rebleeding after endoscopic hemostasis for DPPB. As an intervention for DPPB, endoscopic hemostasis appears safe and effective.

Background: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs.

Background: Delayed post-polypectomy bleeding (DPPB) is a serious complication of polypectomy that is poorly understood. The aim of this study was to evaluate the effectiveness of endoscopic hemostasis in managing DPPB and to identify associated risk factors. Methods: We retrospectively analyzed 289 patients who experienced DPPB (≥ 24 hours after polypectomy) and underwent endoscopic hemostasis at five university hospitals between 2005 and 2018. Patient characteristics, polyp size, technical factors, rebleeding, complications, and length of hospitalization were assessed. Results: Endoscopic hemostasis was successful in all 289 cases of DPPB. The techniques and devices employed included epinephrine injection (24.9%), argon plasma coagulation (18.0%), hemostatic forceps (10.7%), and hemoclips (87.9%). Rebleeding occurred in 15 cases (5.2%) after initial endoscopic hemostasis. The incidence of rebleeding was significantly associated with polyp size (< 10 mm: 2.8%, 10 mm–19 mm: 5.6%, ≥ 20 mm: 13.5%, P = 0.030) and sedation status (yes: 1.8%, no: 7.3%, P = 0.040). However, hemostasis method, bleeding characteristics, and polyp location were not significantly linked to rebleeding. Multivariate analysis revealed that polyp size (odds ratio, 5.02; 95% confidence interval, 1.25–20.13; P = 0.023) was significantly associated with rebleeding after endoscopic hemostasis for DPPB. In all 15 cases of rebleeding, a second endoscopic hemostasis was successfully performed without the need for embolization or surgical intervention. No perforations occurred during the first or second endoscopic hemostatic procedures. Conclusion Polyp size and sedation status were associated with rebleeding after endoscopic hemostasis for DPPB. As an intervention for DPPB, endoscopic hemostasis appears safe and effective.

Background: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs.

Purpose: Nonambulatory pediatric patients may have low bone mineral density (BMD) and increased risk of pathologic fractures. Though bisphosphonate therapy is the mainstream medical intervention in these children, clinical data regarding this treatment are limited. Therefore, this study aimed to evaluate the effectiveness and safety of bisphosphonate therapy in such children. Methods: We conducted a retrospective study of 21 nonambulatory children (Gross Motor Function Classification System level V) with BMD z-score ≤ -2.0 who were treated with intravenous pamidronate for at least 1 year. These patients received pamidronate every 4 months at a dose of 1.0 to 3.0 mg/kg for each cycle and had regular follow-ups for at least 1 year. The main outcome measures were changes in BMD, risk rate of fracture, biochemical data, and adverse events. Results: The average duration of pamidronate treatment was 2.0±0.9 years, and the mean cumulative dose of pamidronate according to body weight was 7.7±2.5 mg/kg/yr. After treatment, the mean lumbar spine bone mineral content, BMD, and height-for-age-z-score-adjusted BMD z-score (BMDhazZ) significantly improved. The relative risk of fracture after treatment was 0.21 (p=0.0032), suggesting that pamidronate treatment reduced fracture incidence significantly. The increase in the average dose per body weight in each cycle significantly increased the changes in BMDhazZ. Conclusion Pamidronate treatment improved the bone health of nonambulatory children with low bone density without any significant adverse events. Independent of cumulative dosage and duration of treatment, the effectiveness of pamidronate increased significantly with an increase in the average dose per body weight in subsequent cycles.

Delayed cerebral necrosis is a well-known complication of radiation therapy (RT). Because of its irreversible nature, it should be avoided if possible, but avoidance occurs at the expense of potentially compromised tumor control, despite the use of the modern advanced technique of conformal RT that minimizes radiation to normal brain tissue. Risk factors for radiation-induced cerebral necrosis include a higher dose per fraction, larger treatment volume, higher cumulative dose, and shorter time interval (for re-irradiation). The same principle can be applied to proton beam therapy (PBT) to avoid delayed cerebral necrosis. However, conversion of PBT radiation energy into conventional RT is still short of clinical support, compared to conventional RT. Herein, we describe two patients with excessively delayed cerebral necrosis after PBT, in whom follow-up MRI showed no RT-induced changes prior to 3 years after treatment. One patient developed radiation necrosis at 4 years after PBT to the resection cavity of an astroblastoma, and the other developed brainstem necrosis that became symptomatic 6 months after its first appearance on the 3-year follow-up brain MRI. We also discuss possible differences between radiation changes after PBT versus conventional RT.

Purpose: In men with metastatic castration-resistant prostate cancer (mCRPC), new bone lesions are sometimes not properly categorized through a confirmatory bone scan, and clinical significance of the test itself remains unclear. This study aimed to demonstrate the performance rate of confirmatory bone scans in a real-world setting and their prognostic impact in enzalutamide-treated mCRPC. Materials and Methods: Patients who received oral enzalutamide for mCRPC during 2014-2017 at 14 tertiary centers in Korea were included. Patients lacking imaging assessment data or insufficient drug exposure were excluded. The primary outcome was overall survival (OS). Secondary outcomes included performance rate of confirmatory bone scans in a real-world setting. Kaplan-Meier analysis and multivariate Cox regression analysis were performed. Results: Overall, 520 patients with mCRPC were enrolled (240 [26.2%] chemotherapy-naïve and 280 [53.2%] after chemotherapy). Among 352 responders, 92 patients (26.1%) showed new bone lesions in their early bone scan. Confirmatory bone scan was performed in 41 patients (44.6%), and it was associated with prolonged OS in the entire population (median, 30.9 vs. 19.7 months; p < 0.001), as well as in the chemotherapy-naïve (median, 47.2 vs. 20.5 months; p=0.011) and post-chemotherapy sub-groups (median, 25.5 vs. 18.0 months; p=0.006). Multivariate Cox regression showed that confirmatory bone scan performance was an independent prognostic factor for OS (hazard ratio 0.35, 95% confidence interval, 0.18 to 0.69; p=0.002). Conclusion Confirmatory bone scan performance was associated with prolonged OS. Thus, the premature discontinuation of enzalutamide without confirmatory bone scans should be discouraged.