BACKGROUND/OBJECTIVES: This study aimed to use plasma metabolites to identify clusters of breast cancer survivors and to compare their dietary characteristics and health-related factors across the clusters using unsupervised machine learning. SUBJECTS/METHODS: A total of 419 breast cancer survivors were included in this crosssectional study. We considered 30 plasma metabolites, quantified by high-throughput nuclear magnetic resonance metabolomics. Clusters were obtained based on metabolites using 4 different unsupervised clustering methods: k-means (KM), partitioning around medoids (PAM), self-organizing maps (SOM), and hierarchical agglomerative clustering (HAC). The t-test, χ2 test, and Fisher’s exact test were used to compare sociodemographic, lifestyle, clinical, and dietary characteristics across the clusters. P-values were adjusted through a false discovery rate (FDR). RESULTS: Two clusters were identified using the 4 methods. Participants in cluster 2 had lower concentrations of apolipoprotein A1 and large high-density lipoprotein (HDL) particles and smaller HDL particle sizes, but higher concentrations of chylomicrons and extremely large very-low-density-lipoprotein (VLDL) particles and glycoprotein acetyls, a higher ratio of monounsaturated fatty acids to total fatty acids, and larger VLDL particle sizes compared with cluster 1. Body mass index was significantly higher in cluster 2 compared with cluster 1 (FDR adjusted-PKM < 0.001; PPAM = 0.001; PSOM < 0.001; and PHAC = 0.043). CONCLUSION The breast cancer survivors clustered on the basis of plasma metabolites had distinct characteristics. Further prospective studies are needed to investigate the associations between metabolites, obesity, dietary factors, and breast cancer prognosis.

BACKGROUND/OBJECTIVES: Isoflavones are estrogen-like compounds found in plants and their health effects remain equivocal. We investigated dietary isoflavone intake and its associated factors in Korean breast cancer survivors, with a comparison to cancer-free women. SUBJECTS/METHODS: The usual dietary intake of breast cancer survivors (n = 981, mean age 52 yrs) in 9 hospitals between 2012 and 2019 was assessed using 3-day food records or food frequency questionnaires (FFQs). They were age-matched to 2,943 cancer-free women who completed FFQs as part of a nationwide study conducted between 2012 and 2016. We used the flavonoid database of common Korean foods and the Phenol-Explorer database to estimate isoflavone intake. The contribution of each food or food group to the total isoflavone intake was calculated. The adjusted least-squares means of dietary isoflavone intake according to lifestyle and clinical factors were calculated using generalized linear models. RESULTS: Breast cancer survivors had a higher mean dietary isoflavone intake (23.59 mg/day) than cancer-free women (17.81 mg/day). Major food sources, including tofu, soybeans, and doenjang, contributed to over 70% of the isoflavone intake in both groups. When we estimated dietary isoflavone intake according to lifestyle characteristics, isoflavone intake increased with higher scores of adherence to the American Cancer Society dietary guidelines but decreased with increasing body mass index in both groups. Among cancer-free women, dietary isoflavone intake was higher among those who had never smoked and among dietary supplement users. Among breast cancer survivors, dietary isoflavone intakes did not vary with clinical characteristics, including time since surgery and estrogen receptor status. CONCLUSION Breast cancer survivors were more likely to consume isoflavones than agematched cancer-free women. Dietary isoflavone intake was associated with healthy lifestyle characteristics in women both with and without breast cancer. Further research is needed to understand the role of the higher isoflavone intake among breast cancer survivors compared to cancer-free women on their prognosis.

Purpose: To compare the perioperative and postoperative outcomes between traditional trans-vesical robot-assisted simple prostatectomy (TV-RASP) and the newly introduced urethral-sparing (US) RASP. Materials and Methods: We retrospectively reviewed 42 patients who underwent TV-RASP (n=22) or US-RASP (n=20) performed by two experienced surgeons at two tertiary centers. Perioperative outcomes including operation time, estimated blood loss, length of hospital stay, and catheterization time were assessed. Postoperative outcomes were evaluated using the International Prostate Symptom Score (IPSS), quality of life (QoL), uroflowmetry parameters, Male Sexual Health Questionnaire-Ejaculation Dysfunction-Short Form (MSHQ-EjD-SF) scores, and maintenance of anterograde ejaculation. Results: This study analyzed 22 and 20 patients who underwent TV-RASP and US-RASP, respectively. Except for the TV-RASP group being older (70.0 years) than the US-RASP group (64.5 years) (p=0.028), no differences among other baseline characteristics existed. Perioperative outcomes indicated that hospital stay and catheterization time were significantly shorter in the US-RASP group than in the TV-RASP group (p<0.001). At postoperative month 1, the median IPSS and QoL scores were significantly better in the US-RASP group than in the TV-RASP group (p=0.001 and p=0.002, respectively). However, at months 6 and 12, no significant differences were noted in IPSS, QoL, maximum flow rate, and postvoid residual urine between the two groups. Sexually active patients in the US-RASP group maintained postoperative MSHQ-EjD functional and bother scores, whereas the TV-RASP group experienced a decline. Notably, 75.0% of patients in the US-RASP group preserved antegrade ejaculation, compared to only 20.0% in the TV-RASP group (p<0.001). Conclusions US-RASP is not inferior to TV-RASP in terms of functional outcomes. In addition, US-RASP yielded more rapid symptom improvements and preserved antegrade ejaculation than TV-RASP. However, larger prospective studies are required to confirm these findings and to further investigate the long-term efficacy and safety of US-RASP.

Background/Aims: Early colorectal cancer (ECC) is commonly resected endoscopically. Perforation is a devastating complication of endoscopic resection. We aimed to identify the characteristics and predictive risk factors for perforation related to endoscopic resection of ECC. Methods: This nationwide retrospective multicenter study included patients with ECC who underwent endoscopic resection. We investigated the demographics, endoscopic findings at the time of treatment, and histopathological characteristics of the resected specimens. Logistic regression analysis was used to investigate the clinical factors associated with procedure-related perforations. Survival analysis was conducted to assess the impact of perforation on the overall survival of patients with ECC. Results: This study included 965 participants with a mean age of 63.4 years. The most common endoscopic treatment was conventional endoscopic mucosal resection (n=573, 59.4%), followed by conventional endoscopic submucosal dissection (n=259, 26.8%). Thirty-three patients (3.4%) experienced perforations, most of which were managed endoscopically (n=23/33, 69.7%). Patients who undergo endoscopic submucosal dissection-hybrid and precut endoscopic mucosal resection have a higher risk of perforation than those who undergo conventional endoscopic mucosal resection (odds ratio, 78.65 and 39.72, p<0.05). Procedure-related perforations were not associated with patient survival. Conclusions Perforation after endoscopic resection had no significant impact on the prognosis of ECC. The type of endoscopic resection was a crucial predictor of perforation. Large-scale prospective studies are needed to further investigate endoscopic resection of ECC.

BACKGROUND/OBJECTIVES: This study aimed to use plasma metabolites to identify clusters of breast cancer survivors and to compare their dietary characteristics and health-related factors across the clusters using unsupervised machine learning. SUBJECTS/METHODS: A total of 419 breast cancer survivors were included in this crosssectional study. We considered 30 plasma metabolites, quantified by high-throughput nuclear magnetic resonance metabolomics. Clusters were obtained based on metabolites using 4 different unsupervised clustering methods: k-means (KM), partitioning around medoids (PAM), self-organizing maps (SOM), and hierarchical agglomerative clustering (HAC). The t-test, χ2 test, and Fisher’s exact test were used to compare sociodemographic, lifestyle, clinical, and dietary characteristics across the clusters. P-values were adjusted through a false discovery rate (FDR). RESULTS: Two clusters were identified using the 4 methods. Participants in cluster 2 had lower concentrations of apolipoprotein A1 and large high-density lipoprotein (HDL) particles and smaller HDL particle sizes, but higher concentrations of chylomicrons and extremely large very-low-density-lipoprotein (VLDL) particles and glycoprotein acetyls, a higher ratio of monounsaturated fatty acids to total fatty acids, and larger VLDL particle sizes compared with cluster 1. Body mass index was significantly higher in cluster 2 compared with cluster 1 (FDR adjusted-PKM < 0.001; PPAM = 0.001; PSOM < 0.001; and PHAC = 0.043). CONCLUSION The breast cancer survivors clustered on the basis of plasma metabolites had distinct characteristics. Further prospective studies are needed to investigate the associations between metabolites, obesity, dietary factors, and breast cancer prognosis.

BACKGROUND/OBJECTIVES: Isoflavones are estrogen-like compounds found in plants and their health effects remain equivocal. We investigated dietary isoflavone intake and its associated factors in Korean breast cancer survivors, with a comparison to cancer-free women. SUBJECTS/METHODS: The usual dietary intake of breast cancer survivors (n = 981, mean age 52 yrs) in 9 hospitals between 2012 and 2019 was assessed using 3-day food records or food frequency questionnaires (FFQs). They were age-matched to 2,943 cancer-free women who completed FFQs as part of a nationwide study conducted between 2012 and 2016. We used the flavonoid database of common Korean foods and the Phenol-Explorer database to estimate isoflavone intake. The contribution of each food or food group to the total isoflavone intake was calculated. The adjusted least-squares means of dietary isoflavone intake according to lifestyle and clinical factors were calculated using generalized linear models. RESULTS: Breast cancer survivors had a higher mean dietary isoflavone intake (23.59 mg/day) than cancer-free women (17.81 mg/day). Major food sources, including tofu, soybeans, and doenjang, contributed to over 70% of the isoflavone intake in both groups. When we estimated dietary isoflavone intake according to lifestyle characteristics, isoflavone intake increased with higher scores of adherence to the American Cancer Society dietary guidelines but decreased with increasing body mass index in both groups. Among cancer-free women, dietary isoflavone intake was higher among those who had never smoked and among dietary supplement users. Among breast cancer survivors, dietary isoflavone intakes did not vary with clinical characteristics, including time since surgery and estrogen receptor status. CONCLUSION Breast cancer survivors were more likely to consume isoflavones than agematched cancer-free women. Dietary isoflavone intake was associated with healthy lifestyle characteristics in women both with and without breast cancer. Further research is needed to understand the role of the higher isoflavone intake among breast cancer survivors compared to cancer-free women on their prognosis.

Purpose: To compare the perioperative and postoperative outcomes between traditional trans-vesical robot-assisted simple prostatectomy (TV-RASP) and the newly introduced urethral-sparing (US) RASP. Materials and Methods: We retrospectively reviewed 42 patients who underwent TV-RASP (n=22) or US-RASP (n=20) performed by two experienced surgeons at two tertiary centers. Perioperative outcomes including operation time, estimated blood loss, length of hospital stay, and catheterization time were assessed. Postoperative outcomes were evaluated using the International Prostate Symptom Score (IPSS), quality of life (QoL), uroflowmetry parameters, Male Sexual Health Questionnaire-Ejaculation Dysfunction-Short Form (MSHQ-EjD-SF) scores, and maintenance of anterograde ejaculation. Results: This study analyzed 22 and 20 patients who underwent TV-RASP and US-RASP, respectively. Except for the TV-RASP group being older (70.0 years) than the US-RASP group (64.5 years) (p=0.028), no differences among other baseline characteristics existed. Perioperative outcomes indicated that hospital stay and catheterization time were significantly shorter in the US-RASP group than in the TV-RASP group (p<0.001). At postoperative month 1, the median IPSS and QoL scores were significantly better in the US-RASP group than in the TV-RASP group (p=0.001 and p=0.002, respectively). However, at months 6 and 12, no significant differences were noted in IPSS, QoL, maximum flow rate, and postvoid residual urine between the two groups. Sexually active patients in the US-RASP group maintained postoperative MSHQ-EjD functional and bother scores, whereas the TV-RASP group experienced a decline. Notably, 75.0% of patients in the US-RASP group preserved antegrade ejaculation, compared to only 20.0% in the TV-RASP group (p<0.001). Conclusions US-RASP is not inferior to TV-RASP in terms of functional outcomes. In addition, US-RASP yielded more rapid symptom improvements and preserved antegrade ejaculation than TV-RASP. However, larger prospective studies are required to confirm these findings and to further investigate the long-term efficacy and safety of US-RASP.