Purpose: Radiotherapy is used to reduce the risk of breast cancer recurrence after surgery, but it is a potential cause of secondary cancer. We validated the risk of secondary cancer in primary breast cancer who received radiotherapy compared with those who did not from a matched cohort using a large-scale observational study of the Observational Health Data Sciences and Informatics (OHDSI) data network. Materials and Methods: A retrospective comparative cohort study using propensity score-matched cohorts was performed using two Observational Medical Outcome Partnership common data model databases, from tertiary general hospitals in South Korea. Among female patients who underwent surgery after the diagnosis of breast cancer, the risk of secondary primary malignant occurrence after 1:1 matching was analyzed. Results: Among 27,078 patients with breast cancer, there was no significant difference in the risk of secondary cancer following radiotherapy in 4,426 patients after 1:1 propensity-score matching. Further, there were no significant differences in the sensitivity analysis according to age, latency period, and number of radiation treatments. Conclusion There was no difference in the risk of secondary cancer in the patients diagnosed with breast cancer depending on whether or not radiotherapy was performed after surgery. In the future, it is necessary to analyze including data generated during cancer treatment.

Background: Posttransplant diabetes mellitus (PTDM) complicates kidney transplant recipients (KTRs) in morbidity and mortality. This study aimed to predict PTDM risk in KTRs using machine learning and deep learning models. Methods: Data were obtained from the Korea Organ Transplantation Registry, a nationwide cohort study of KTRs. Four machine learning algorithms, including eXtreme Gradient Boosting (XGBoost), CatBoost, light gradient boosting machine and logistic regression, and deep learning were implemented on 41 pretransplant and 31 posttransplant variables to predict PTDM. Model performance was assessed using the area under the curve (AUC) of the receiver operating characteristic curve, accuracy, precision, recall, and F1 score. Results: Among 3,213 KTRs, 497 patients (15.5%) developed PTDM within 1 year. The PTDM group had higher age, body mass index (BMI), triglyceride level, and prevalence of hypertension and cardiovascular disease, and lower total cholesterol level at baseline than the No-PTDM group. The XGBoost model showed the highest AUC (0.738) and F1 score (0.42), and modest accuracy (0.86), while the CatBoost model exhibited the highest accuracy (0.87) and precision (0.79). Feature importance in XGBoost was highest for recipient age, followed by baseline BMI, triglyceride level at posttransplant 6 months, baseline glycated hemoglobin and high-density lipoprotein cholesterol level, white blood cell (WBC) count and serum uric acid level at 6 months, baseline WBC count, and tacrolimus trough level at discharge. Conclusion The XGBoost model demonstrated the best performance for predicting PTDM within 1 year, offering an accurate tool for early identification and personalized care of high-risk KTRs for PTDM.

Purpose: To compare the prognosis of patients with axillary adenocarcinoma from an unknown primary (ACUPax) origin with negative MRI results and those with MRI-detected primary breast cancers. Materials and Methods: The breast MRI images of 32 patients with ACUPax without signs of primary breast cancer on mammography and ultrasound (US) were analyzed. Spot compression-magnification mammography and second-look US were performed for the area of MRI abnormality in patients with positive results; any positive findings corresponding to the MRI abnormality were confirmed by biopsy. If suspicious MRI lesions could not be localized on mammography or US, MR-guided biopsy or excision biopsy after MR-guided localization was performed. We compared the prognosis of patients with negative breast MRI with that for patients with MRI-detected primary breast cancers. Results: Primary breast cancers were confirmed in 8 (25%) patients after breast MRI. Primary breast cancers were not detected on MRI in 24 (75%) patients, including five cases of false-positive MRI results. Twenty-three patients underwent axillary lymph node dissection (ALND) followed by whole breast radiation therapy (WBRT) and chemotherapy (n=17) or subsequent chemotherapy only (n=2). Recurrence or distant metastasis did not occur during follow up in 7/8 patients with MRI-detected primary breast cancers and 22/24 patients with negative MRI results. Regional recurrence or distant metastasis did not occur in any MR-negative patient who received adjuvant chemotherapy after ALND and WBRT. Conclusion The prognoses of MR-negative patients with ACUPax who received ALND and WBRT followed by chemotherapy were as good as those of patients with MRI-detected primary breast cancers.

Background: Purse-string suture is a simple technique to reduce wound size and to achieve complete or partial closure of skin defects. Objective: To classify situations in which purse-string sutures can be utilized and to assess the long-term size reduction and cosmetic outcome of the final scar. Methods: Patients (93 from Severance hospital and 12 from Gangnam Severance hospital) in whom purse-string sutures were used between January 2015 and December 2019 were retrospectively reviewed. Wound site, final reconstruction method, repair duration, final wound size, and Vancouver scar scale were assessed. Results: A total of 105 patients were reviewed. Lesions were located on the trunk (48 [45.7%]), limbs (32 [30.5%]), and face (25 [23.8%]). Mean ratio of wound length/primary defect length was 0.79±0.30. Multilayered purse-string suture showed the shortest duration from excision to final repair (p<0.001) and most effectively minimized the scar size (scar to defect size ratio 0.67±0.23, p=0.002). The average Vancouver scar scale measured at the latest followup visit at least 6 months postoperatively was 1.62, and the risk of hypertrophic scarring was 8.6%. There was no significant difference in the Vancouver scar scale and the risk of hypertrophic scarring between the different surgical method groups. Conclusion Purse-string sutures can be utilized in many stages of reconstruction to effectively reduce scar size without compromising the final cosmetic outcome.

Mucinous borderline tumors (MBT) of the ovary with mild to moderately atypical epithelial cells that produce mucin rarely recur and very rarely become malignant after surgery. Due to their low malignant potential and large tumor size, most cases are diagnosed in stage I and have a good prognosis. The authors reported a case of MBT, which had been left untreated after diagnosis, progressed to stage IV, and caused massive pleural effusion (>3,000 mL) resulting in death. Grossly, severe abdominal swelling, a huge multiloculated cystic mass in the left ovary, and a metastatic mucinous mass in the pleura and peritoneum were observed. Histological findings include gastrointestinal type epithelial cells with mucin secretion, degenerative and autolytic nuclei, and occasional infiltration of inflammatory cells. Because sufficient sections cannot be made according to the clinical pathology criteria in forensic autopsy, efficient decisions are required during autopsy for diagnosis.

Background: We developed an assay to measure DNA-incorporated 6-thioguanine (DNATG) and validated its clinical applicability in Korean pediatric patients with acute lymphoblastic leukemia (ALL) in order to improve individualized thiopurine treatment and reduce the life-threatening cytotoxicity. Methods: The DNA-TG assay was developed based on liquid chromatography-tandem mass spectrometry, with isotope-labeled TG-d3 and guanine-d3 as internal standards.This method was applied to 257 samples of pediatric ALL patients. The DNA-TG level was compared with erythrocyte TG nucleotide (RBC-TGN) level in relation to the TPMT and NUDT15 genotypes, which affect thiopurine metabolism, using Spearman’s rank test and repeated measure ANOVA. Results: For DNA-TG quantification, a linearity range of 10.0-5,000.0 fmol TG/µg DNA;bias for accuracy of –10.4% –3.5%; coefficient of variation for intra- and inter-day precision of 3.4% and 5.8% at 80 fmol TG/µg DNA and of 4.9% and 5.3% at 800 fmol TG/µg DNA, respectively; and recovery of 85.7%–116.2% were achieved without matrix effects or carry-over. The median DNA-TG level in the 257 samples was 106.0 fmol TG/µg DNA (interquartile range, 75.8–150.9). There was a strong correlation between DNA-TG and RBC-TGN levels (ρ = 0.68,ρ < 0.0001). The DNA-TG/RBC-TGN ratio was significantly higher in NUDT15 intermediate metabolizers (*1/*2 and *1/*3) than in patients with wildtype alleles (ρ < 0.0001). Conclusions This simple and sensitive method for measuring DNA-TG level can improve therapeutic drug monitoring for thiopurine treatment.

Purpose: Breast cancer diagnosis and treatment often produce stress in patients. Anxiety is one of the most prevalent psychological symptoms perceived by breast cancer patients. This study aims to evaluate the temporal patterns of anxiety and find factors associated with persistent anxiety during breast cancer treatment. Methods: This is prospective cohort study. Between July 2010 and July 2011, we recruited patients with nonmetastatic breast cancer who were expected to receive adjuvant chemotherapy (n = 411) from 2 cancer hospitals in Seoul, Korea. Anxiety was measured using the Hospital Anxiety and Depression Scale. Results: The mean age of the participants was 46.4 ± 7.9 years. Preoperatively, 44.5% (183 of 411) of the patients showed abnormal anxiety. The proportion of the abnormal anxiety group significantly decreased after surgery (P < 0.01) and this phenomenon continued until the 12-month follow-up point. Patients experienced renewed anxiety at 12 months when the main adjuvant therapies were finished. Socioeconomic factors were not associated with persistent anxiety. Pain, breast, and arm symptoms were significantly higher in the persistently abnormal group, especially at postoperative months 6 and 12. Conclusion Surgery was a major relieving factor of anxiety, and patients who finished their main adjuvant treatment experienced renewed anxiety. Surgeons should be the main detectors and care-givers with respect to psychological distress in breast cancer patients. To reduce persistent anxiety, caring for the patient’s physical symptoms is important.

Purpose: Fluorodeoxyglucose positron emission tomography–computed tomography (PET-CT) is gaining evidence as a predictive factor in non-small cell lung cancer (NSCLC). Stereotactic ablative radiotherapy (SABR) is the standard treatment in early-stage NSCLC when a patient is unsuitable for surgery. We performed a study to assess the prognostic clinical significance of PET-CT after SABR in early-stage NSCLC. Materials and Methods: Seventy-six patients with stage I NSCLC treated with SABR were investigated. Total radiation dose ranged from 36 to 63 Gy in three to eight fractions depending on tumor location and size. Respiratory motion control was implemented at simulation and during treatment. PET-CT prior to SABR was performed in 66 patients (86.8%). Results: Median follow-up time was 32 months (range, 5 to 142 months). Local control rate at 1, 2, and 5 years were 95.9%, 92.8%, and 86.7%, respectively. Overall survival (OS) at 1, 2, and 5 years were 91.0%, 71.3%, and 52.1% respectively. Cause-specific survival at 1, 2, and 5 years were 98.6%, 93.1%, and 84.3% respectively. Tumor size and pre-SABR maximal standardized uptake value (SUVmax) demonstrated statistical significance in the Kaplan-Meier survival analyses with log-rank test. In multivariate analyses pre-SABR SUVmax remained statistically significant in correlation to OS (p=0.024; hazard ratio [HR], 3.2; 95% confidence interval [CI], 1.2 to 8.8) and with marginal significance in regards to regional progression-free survival (p=0.059; HR, 32.5; 95% CI, 2.6 to 402.5). Conclusion Pre-SABR SUVmax demonstrated a predictive power in statistical analyses. Tumors with SUVmax above 6 at diagnosis were associated with inferior outcomes.

Purpose: The purpose of this study was to identify the clinical utility of circulating tumor DNA (ctDNA) from ascites and serial plasma samples from epithelial ovarian cancer (EOC) patients. Materials and Methods: Using targeted next-generation sequencing, we analyzed a total of 55 EOC samples including ctDNA from ascites and serial plasma and gDNA from tumor tissues. Tumor tissues and ascites were collected during debulking surgeries and plasma samples were collected before and after the surgeries. Because one EOC patient underwent secondary debulking surgery, a total of 11 tumor tissues, 33 plasma samples, and 11 ascites samples were obtained from the 10 patients. Results: Of the 10 patients, nine (90%) contained somatic mutations in both tumor tissues and ascites ctDNA. This mutational concordance was confirmed through correlation analysis. The mutational concordance between ascites and tumor tissues was valid in recurrent/progressive ovarian cancer. TP53 was the most frequently detected gene with mutations. ctDNA from serial plasma samples identified EOC progression/recurrence at a similar time or even more rapidly than cancer antigen 125, an established serum protein tumor marker for EOC. Conclusion Our data suggest that ascites ctDNA can be used to identify the mutational landscape of ovarian cancer for therapeutic strategy planning.