Association between knee osteoarthritis and mortality: a serial propensity score-matched cohort study

Background/Aims@#The association between symptomatic knee osteoarthritis (OA) and higher cardiovascular disease (CVD) mortality is established; however, findings from studies that utilized regression analysis were limited, attributed to the strong association between OA and metabolic risk factors. This study aimed to evaluate the association between knee OA and mortality through propensity score matching. @*Methods@#This was a cohort study including Korean National Health and Nutrition Examination Survey (2010–2013) participants aged ≥ 50 years. By linking the survey data to cause of death data (through 2019) from Statistics Korea, mortality and cause-specific mortality data were obtained. Radiographic knee OA (ROA) was defined as bilateral Kellgren–Lawrence grade ≥ 2. Propensity score matching (1:1) was conducted between asymptomatic ROA, knee pain, and symptomatic ROA groups and normal groups, balancing the confounding factors. Time to death was analyzed using Cox proportional hazard modeling. @*Results@#A higher CVD mortality was observed in the symptomatic ROA group, but not in others; the risk estimates were asymptomatic ROA (hazard ratio [HR] 1.12; 95% confidence interval [CI] 0.77–1.65), knee pain (HR 0.61; 95% CI 0.27–1.38), and symptomatic ROA (HR 1.39; 95% CI 0.89–2.17). No association was found between the all-cause/cancer mortality and other groups. @*Conclusions@#When propensity score matching controls metabolic risk factor imbalances, the association between symptomatic knee OA and higher CVD mortality was weaker compared to results of prior studies that used regression adjustment. The results may be more precise estimates of the total risk of knee OA for mortality in Koreans.

Successful emergency medical service training with virtual field trips using video during the COVID-19 pandemic: the Official Development Assistance Project in Uzbekistan / 한국의학교육

Purpose@#The coronavirus disease 2019 pandemic saw many restrictions on the provision of emergency medical service (EMS) training through actual field trips (AFTs), requiring a search for alternatives. This study aimed to assess trainees’ reactions to virtual field trips (VFTs) and determine the characteristics of instructional design for successful VFTs using edited videos and expert interviews. @*Methods@#This study evaluated Uzbekistan trainees’ reactions to the VFT of EMS training using questionnaires in three categories: satisfaction, relevance, and engagement. Factors of satisfaction and dissatisfaction were identified through open-ended questions. @*Results@#A total of 286 trainees responded to the survey during 15 educational sessions conducted from 2020 to 2022. The trainees’ responses to the VFT were positive. Overall mean scores were 4.65±0.49, 4.63±0.50, and 4.63±0.50 out of 5 points for satisfaction, relevance, and engagement, respectively. The trainees reported that the most interesting and helpful videos concerned the introduction of an EMS training curriculum and the observation of training facilities, such as the simulation centers of educational institutes. The leading causes of satisfaction were (1) authenticity of the VFTs, (2) easy-to-understand content, and (3) relevance to the job. The trainees suggested that Uzbek or Russian voice-overs would be better than subtitles in the video clip for focusing on VFT. @*Conclusion@#In situations where AFTs are not available, VFTs using edited videos and expert interviews are a good alternative to EMS education. Based on these results, it is possible that AFTs could be replaced by VFTs using qualified videos with designed instructions as a distance learning method under specific conditions.

Guselkumab Treatment for Psoriasis in Bio-Naïve and Bio-Experienced Patients:Multicenter Study Based on a 1-Year Follow-Up / 대한피부과학회지

Background@#Guselkumab is a monoclonal antibody that selectively blocks the p19 subunit of interleukin-23. It has shown good efficacy and safety profile in several clinical trials of plaque psoriasis. However, studies on the efficacy of guselkumab in patients treated with other biologics are lacking. @*Objective@#We aimed to investigate the efficacy and safety profile of guselkumab in patients with moderate-to-severe plaque psoriasis. We also compared the efficacy of guselkumab between biologic-naïve (Bio-Naïve) and biologicexperienced (Bio-Ex) patients. @*Methods@#This multicenter, retrospective study included 72 patients treated with guselkumab. The patients’ clinical characteristics and psoriasis area and severity index (PASI) scores were recorded at each visit. The PASI90 and PASI100 responses and mean PASI scores were compared between the Bio-Naïve and Bio-Ex groups. @*Results@#Fifty-five Bio-Naïve patients and 17 Bio-Ex patients were included in the study. At week 20, there were no significant differences in the PASI90 (64.2% vs. 53.8%) and PASI100 (28.3% vs. 15.4%) responses between the groups. However, at weeks 36 and 44, the PASI90 response (week 36: 89.2% vs. 36.4% and week 44: 97.8% vs. 63.6%) and the PASI100 response (week 36: 64.9% vs. 18.2% and week 44: 68.9% vs. 27.3%) were significantly higher in the Bio-Naïve group (p＜0.05). There were no differences in PASI90 and PASI100 responses between the groups in terms of other clinical characteristics and comorbidities at week 20. @*Conclusion@#The efficacy of guselkumab remained consistent among patients in whom other biologics had failed. However, the efficacy was slightly lower in the Bio-Ex group than in the Bio-Naïve group.

Malignancy risk of thyroid nodules with minimal cystic changes: a multicenter retrospective study

Purpose@#The aim of this multicenter study was to investigate the malignancy risk of minimally cystic thyroid nodules (MCTNs) using cyto-histopathologic diagnoses as the reference standard. @*Methods@#From June 2015 to September 2015, 5,601 thyroid nodules (≥1 cm) from 4,989 consecutive patients who underwent thyroid ultrasonography (US) at 26 institutions were retrospectively analyzed. Each thyroid nodule was categorized according to its cystic proportion: purely solid, minimally cystic (≤10%), and partially cystic (>10%). The malignancy risk of MCTNs was compared with those of purely solid nodules and partially cystic thyroid nodules (PCTNs). The malignancy risk of MCTNs was assessed according to echogenicity and the presence of suspicious US features. @*Results@#The prevalence of MCTNs was 22.5%. The overall malignancy risk of MCTNs was 8.8%, which was significantly lower than that of purely solid nodules (29.5%) (P0.05). MCTNs were associated with a higher risk of malignancy in hypoechoic nodules than in isohyperechoic nodules and in nodules with suspicious US features than in those without suspicious US features (all P<0.001). @*Conclusion@#The malignancy risk of MCTNs was significantly lower than that of purely solid nodules. MCTNs could be categorized as PCTNs rather than as solid nodules to increase the accuracy of the risk stratification system for thyroid nodules.

Serial Short-Term Outcomes of VeryLow-Birth-Weight Infants in the Korean Neonatal Network From 2013 to 2020

Background@#We aimed to determine the current survival rate and short-term outcomes of very-low-birth-weight infants (VLBWIs) in Korea, as well as whether the survival rate and short-term outcomes have improved over time since 2013, which was when the Korean Neonatal Network (KNN) was launched. @*Methods@#This study used data from the annual reports of the KNN from 2013 to 2020. A total of 16,351 VLBWIs born at gestational age (GA) ≥ 22 weeks between January 1, 2013, and December 31, 2020, and who were registered in the KNN were enrolled. Serial outcomes were analyzed according to era (2013–14, 2015–16, 2017–18, and 2019–20). @*Results@#More mothers delivered by cesarean section, had diabetes or hypertension during their pregnancy, and received antenatal steroids when analyzed by era. Fewer infants were intubated at birth and had air leaks when analyzed by era. The overall survival rate of VLBWIs between 2013 and 2020 was 87%. The rate of respiratory distress syndrome was 77% and that of bronchopulmonary dysplasia was 32% between 2013 and 2020. The rates of intraventricular hemorrhage (grade ≥ 3), periventricular leukomalacia, and sepsis decreased over time. The survival rate of infants with a GA of 26 weeks has improved serially according to era. @*Conclusion@#Since the launch of the KNN in 2013, the survival rates of infants with GA 26 weeks and short-term outcomes have improved, which implies a quality improvement in antenatal and delivery room care. Further studies on the long-term neurodevelopmental outcomes of these KNN registrants are warranted.

Associations between HLA-A, -B, and -C alleles and iodinated contrast media– induced hypersensitivity in Koreans

A common cause of drug hypersensitivity reactions is iodinated contrast media (ICM). ICM-induced hypersensitivity had been considered to be a non-immunological reaction, but evidence for an immunological mechanism has increased recently. Thus, we evaluated whether HLA-A, -B, and -C alleles were associated with ICM-induced hypersensitivity. In total, 126 patients who underwent contrast-enhanced computed tomography studies through outpatient clinics at a tertiary referral hospital between 2008 and 2012 were assessed. Sixty-one patients experienced ICM-induced hypersensitivity and the remainder, 65, were ICM-tolerant patients (control). ICM-induced hypersensitivity patients showed 51 with immediate, 7 with non-immediate, 3 with both or mixed type. HLA-A, -B, and -C genotyping was performed using a PCR sequence-based typing method. Four kinds of ICM were used: iopromide, iohexol, iobitridol, and iodixanol. The most used ICM among the hypersensitivity patients was iopromide. Significant difference in the frequency of HLA-B*58:01 (odds ratios [OR], 3.90; p = 0.0200, 95% confidence interval [CI], 1.16–13.07) was observed between ICM-induced immediate hypersensitivity and control. There were statistically significant differences in the frequencies of the HLA-B*38:02 (OR, 10.24; p = 0.0145; 95% CI, 1.09–96.14) and HLA-B*58:01 (OR, 3.98; p = 0.0348; 95% CI, 1.03–15.39) between iopromide-induced immediate hypersensitivity and control. The mechanism of ICM-induced hypersensitivity remains unknown, but this study showed associations, although weak, with HLA-B*58:01 alleles for ICM-induced immediate hypersensitivity and HLA-B*38:02 and HLA-B*58:01 for iopromideinduced immediate hypersensitivity as risk predictors. Further studies are needed to validate the associations in larger samples and to identify the functional mechanism behind these results.

Adapting an Integrated Program Evaluation for Promoting Competency‐Based Medical Education / 의학교육논단

Educational program evaluation can improve the quality of the curriculum, instructional methods, and resources and provide useful data for making educational decisions and policies. Developing and implementing a program evaluation system is essential in competency-based medical education. The purpose of this study was to explore and establish an educational program evaluation system adapting an integrated program evaluation model to promote competency-based medical education. First, an Educational Evaluation Committee was organized, consisting of faculty, staff members, and students. The committee established an integrated program evaluation model, combining Stufflebeam’s Context, Input, Process, and Product (CIPP) model of a process-oriented approach and Kirkpatrick’s four-level model of an outcome-oriented approach. Kirkpatrick’s model was applied to the product evaluation of the CIPP model. The committee then developed evaluation criteria, indicators, and data collection methods according to the components of the CIPP model and the four levels (reaction, learning, behavior, and results) of Kirkpatrick’s model, and collected and analyzed data. Finally, the committee reported the results of evaluation to a Medical Education Quality Improvement Committee, and the results were used to improve the curriculum and student selection. To enhance the quality of education, identifying educational deficiencies and developing various elements of education in a balanced way through educational evaluation will be needed. Furthermore, it will be necessary to listen to opinions of various stakeholders, work with all members involved in education, and communicate with decision-makers in the process of educational evaluation.

Survey of physicians' views on the clinical implementation of pharmacogenomics-based personalized therapy

Despite quantitative increases and qualitative advances in pharmacogenomics (PGx) research, the clinical implementation of PGx-based personalized therapy has still been limited. The objective of this study was to assess physicians' self-reported knowledge of PGx-based personalized therapy, and to explore the most problematic and highest priority barriers preventing physicians from applying PGx into clinical practice under the Korean healthcare system. A 36-question survey was distributed to 53 physicians with various specialties in Korea. In the physicians' self-perceived knowledge, twenty-eight physicians (53%) reported a lack sufficient knowledge about PGx. The perceived largest barrier to clinical implementation of PGx was the high cost of PGx testing, followed by a lack of PGx education for healthcare providers or lack of clinical PGx experts. Physicians without clinical PGx experience or with indirect experience reported that the largest barrier to clinical implementation of PGx was the high cost of PGx testing, while physicians with clinical PGx experience pointed out that a lack of patients' education was the major concern, followed by a lack of PGx education for healthcare providers or lack of clinical PGx experts. The highest priority problem was reported to be a lack of actionable guidelines for drug selection and dosing using PGx. In conclusion, we should increase and expand extensive educational programs for healthcare providers and patients, and to develop and establish a clinical decision support systems for PGx-based personalized therapy in Korea.

Correlation between Performance-Based and Interview-Based Cognitive Measurements in Patients with Schizophrenia

Objective@#The Measurement and Treatment Research to improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB) is used to measure the cognitive function of patients with schizophrenia. In some situations, interview-based measures such as the Schizophrenia Cognition Rating Scale (SCoRS) may be appropriate. In this study, we analyzed the correlation between performance- and interview-based measurements in patients with schizophrenia. @*Methods@#Fifty-six clinically stable patients were recruited. To evaluate cognitive function, we used the MCCB performance-based measure and the SCoRS interview-based measure. Measurements were taken at baseline, and 2 weeks and 3 months later. Spearman correlations were computed between each SCoRS item’s interviewer rating and each MCCB score. @*Results@#The correlation between the MCCB overall T score and the SCoRS global score was the strongest (r=-0.52), while the SCoRS total score and the MCCB Speed of Processing score also correlated (r=-0.48). The SCoRS global score showed statistically significant correlations with all seven MCCB domains and the overall T score. @*Conclusion@#This study reveals correlations between MCCB domains and SCoRS items. Since we find that interview-based measurements are highly correlated with performance-based measurements, we suggest them as a useful cognitive function evaluation tool that can easily be applied in clinical settings.

Effect of dexamethasone gargle, intravenous dexamethasone, and their combination on postoperative sore throat: a randomized controlled trial

Background@#Postoperative sore throat (POST) is a complication that decreases patient satisfaction and increases postoperative complaints. The present study was conducted to investigate effects of gargling with dexamethasone, intravenous dexamethasone injection and the combination of the two on the incidence and severity of POST. @*Methods@#Study participants were 96 patients who had undergone laparoscopic cholecystectomy, randomly allocated into three groups. Group G gargled with 0.05% dexamethasone solution and were infused intravenous 0.9% normal saline before general anesthesia; group I gargled with 0.9% normal saline and were infused intravenous 0.1 mg/kg dexamethasone; group GI gargled with 0.05% dexamethasone solution and were infused intravenous 0.1 mg/kg dexamethasone. The incidence and severity of POST, hoarseness and cough were evaluated and recorded at 1, 6, and 24 h after the surgery. @*Results@#There were no significant differences in the total incidence of POST up to 24 postoperative hours among Group G, Group I and Group GI (P = 0.367, Group G incidence = 34.38%, [95% confidence interval, 95% CI = 17.92–50.83], Group I incidence = 18.75%, [95% CI = 5.23–32.27], Group GI incidence = 28.13%, [95% CI = 12.55–43.70]). The other outcomes were comparable among the groups. @*Conclusions@#In patients who had undergone laparoscopic cholecystectomy, gargling with 0.05% dexamethasone solution demonstrated the same POST prevention effect as intravenous injection of 0.1 mg/kg dexamethasone. The incidence and severity of POST were not significantly different between the combination of gargling with 0.05% dexamethasone solution and intravenous injection of 0.1 mg/kg dexamethasone and use of each of the preventive methods alone.

Effects of topical dexamethasone in postoperative sore throat / 대한마취과학회지

BACKGROUND: Postoperative sore throat (POST) is a complication that undermines patient satisfaction and increases discomfort in the postoperative period. The present study examined the effects of dexamethasone gargle and endotracheal tube cuff soaking on the incidence and severity of POST. METHODS: Ninety patients undergoing laparoscopic cholecystectomy were randomly allocated into three groups: 0.9% normal saline gargling and tube soaking (group C), 0.05% dexamethasone solution gargling and 0.9% normal saline tube soaking (group G), 0.9% normal saline gargling and 0.05% dexamethasone tube soaking (group S). The incidence and severity of POST were then assessed and recorded at 24 hours after surgery. RESULTS: The total incidence of POST was significantly different among the groups (P < 0.05), and group S exhibited a significantly lower incidence of POST than group C (P < 0.0167). In addition, the POST intensity of group G and group S was less severe than those of group C (Both P < 0.0167). CONCLUSIONS: Among patients undergoing laparoscopic cholecystectomy, those who gargled with 0.05% dexamethasone solution exhibited lower severity of POST than the control group, and those whose endotracheal tube cuff was soaked in the dexamethasone solution before intubation exhibited significantly lower incidence and severity of POST than the control group.

The Prevalence of Colonic Neoplasm in Cryptogenic Pyogenic Liver Abscess: A Prospectively Enrolled Cross-sectional Study / 대한소화기학회지

BACKGROUND/AIMS: Several studies suggest that pyogenic liver abscess (PLA) is associated with colon neoplasm. A colonoscopic exam for cryptogenic PLA might detect a hidden colon neoplasm, through which intestinal flora can be transmitted into the liver. However, there are no prospectively enrolled cross-sectional data for colonic neoplasm in cryptogenic PLA. METHODS: Patients with PLA were prospectively enrolled from two university hospitals. Among them, all the patients with cryptogenic PLA were recommended for colonoscopic exam to check for colonic neoplasm. RESULTS: One hundred eighty-three patients with PLA were enrolled in the study for 22 months. One hundred and one (55.2%) patients did not have a definite cause of liver abscess at initial evaluation. The median diameter of the largest lesion was 5.7 cm (1.0-14.0 cm), and 74.3% of the patients were treated by percutaneous abscess drainage. Ninety-one percent of the patients who had an identified pathogen yielded Klebsiella. Sixty-two patients underwent colonoscopic exams, and no one had a colonic cancer, one had an adenomatous polyp with high grade dysplasia (1.6%), and 27 had adenomatous polyps with low grade dysplasia (43.5%; 41.0% in male and 43.5% in female). Of fifty patients who underwent an esophagogastroduodeno-scopic exam, nine had gastric ulcers, one had an esophageal ulcer, and one had hemorrhagic gastritis. CONCLUSIONS: The prevalence of colonic neoplasm among the patients with cryptogenic PLA was not as high as that in previous studies. Further well-designed, large-scale studies are required to assess the association of the colon neoplasm and cryptogenic PLA.

Efficacy of Surfactant-TA, Calfactant and Poractant Alfa for Preterm Infants with Respiratory Distress Syndrome: A Retrospective Study

PURPOSE: To compare the efficacy of the new drug calfactant with the commonly used drugs surfactant-TA and poractant alfa. MATERIALS AND METHODS: A total of 332 preterm infants at 24-31 weeks' gestation with respiratory distress syndrome (RDS) were enrolled and allocated to three groups according to the surfactant instilled; Group 1 (n=146, surfactant-TA), Group 2 (n=96, calfactant), and Group 3 (n=90, poractant alfa). The diagnosis of RDS and the decision to replace the pulmonary surfactant were left to the attending physician and based on patient severity determined by chest radiography and blood gas analysis. Data were collected and reviewed retrospectively using patient medical records. RESULTS: Demographic factors including gestational age, birth weight, Apgar score, clinical risk index for babies II score, and maternal status before delivery were not different between the study groups. Instances of surfactant redosing and pulmonary air leaks, as well as duration of mechanical ventilation, were also not different. Rates of patent ductus arteriosus, intraventricular hemorrhage (> or =grade III), periventricular leukomalacia, high stage retinopathy of prematurity, necrotizing enterocolitis (> or =stage II), and mortality were also similar, as was duration of hospital stay. Cases of pulmonary hemorrhage and moderate to severe bronchopulmonary dysplasia were increased in Group 3. CONCLUSION: Calfactant is equally as effective as surfactant-TA and poractant alfa. This was the first study comparing the efficacy of surfactant-TA, calfactant, and poractant alfa in a large number of preterm infants in Korea. Further randomized prospective studies on these surfactants are needed.

Efficacy of Surfactant-TA, Calfactant and Poractant Alfa for Preterm Infants with Respiratory Distress Syndrome: A Retrospective Study

PURPOSE: To compare the efficacy of the new drug calfactant with the commonly used drugs surfactant-TA and poractant alfa. MATERIALS AND METHODS: A total of 332 preterm infants at 24-31 weeks' gestation with respiratory distress syndrome (RDS) were enrolled and allocated to three groups according to the surfactant instilled; Group 1 (n=146, surfactant-TA), Group 2 (n=96, calfactant), and Group 3 (n=90, poractant alfa). The diagnosis of RDS and the decision to replace the pulmonary surfactant were left to the attending physician and based on patient severity determined by chest radiography and blood gas analysis. Data were collected and reviewed retrospectively using patient medical records. RESULTS: Demographic factors including gestational age, birth weight, Apgar score, clinical risk index for babies II score, and maternal status before delivery were not different between the study groups. Instances of surfactant redosing and pulmonary air leaks, as well as duration of mechanical ventilation, were also not different. Rates of patent ductus arteriosus, intraventricular hemorrhage (> or =grade III), periventricular leukomalacia, high stage retinopathy of prematurity, necrotizing enterocolitis (> or =stage II), and mortality were also similar, as was duration of hospital stay. Cases of pulmonary hemorrhage and moderate to severe bronchopulmonary dysplasia were increased in Group 3. CONCLUSION: Calfactant is equally as effective as surfactant-TA and poractant alfa. This was the first study comparing the efficacy of surfactant-TA, calfactant, and poractant alfa in a large number of preterm infants in Korea. Further randomized prospective studies on these surfactants are needed.

No association between the IL28B SNP and response to peginterferon plus ribavirin combination treatment in Korean chronic hepatitis C patients

BACKGROUND/AIMS: There are few available data regarding the association between the single nucleotide polymorphisms (SNPs) of the gene encoding interleukin 28B (IL28B) and a sustained virologic response (SVR) to peginterferon (PEG-IFN) plus ribavirin (RBV) therapy in Korean chronic hepatitis C patients. METHODS: This was a retrospective cohort study of 156 patients with chronic hepatitis C virus (HCV) infection who received combination treatment of PEG-IFN plus RBV. Blood samples from these patients were analyzed to identify the IL28B SNPs at rs12979860, rs12980275, rs8099917, and rs8103142. Association analyses were performed to evaluate the relationships between each IL28B SNP and SVRs. RESULTS: Seventy six patients with HCV genotype 1 and 80 with genotype non-1 were enrolled. The frequencies of rs12979860 CC and CT genotypes were 90.4% and 9.6%, respectively; those of rs12980275 AA and AG genotypes were 87.2% and 12.8%, respectively; those of rs8099917 TT and TG genotypes were 92.3% and 7.7%, respectively; and those of rs8103142 TT and CT genotypes were 90.4% and 9.6%, respectively. Among the patients with HCV genotype 1, the SVR rates were 69.7% and 80.0% for rs12979860 CC and CT, respectively (P=0.71). Among the HCV genotype non-1 patients, SVR rates were 88.0% and 100% for rs12979860 CC and CT (P=1.00), respectively. CONCLUSIONS: Genotypes of the IL28B SNP that are known to be favorable were present in most of the Korean patients with chronic hepatitis C in this study. Moreover, the IL28B SNP did not influence the SVR rate in either the HCV genotype 1 or non-1 patients. Therefore, IL28B SNP analysis might be not useful for the initial assessment, prediction of treatment outcomes, or treatment decision-making of Korean chronic hepatitis C patients.

Oncologic Outcomes and Risk Factors for Recurrence after Tumor-specific Mesorectal Excision of Rectal Cancer: 782 Cases

PURPOSE: The aim of this study was to analyze the oncologic outcomes and the risk factors for recurrence after a tumor-specific mesorectal excision (TSME) of resectable rectal cancer in a single institution. METHODS: A total of 782 patients who underwent a TSME for resectable rectal cancer between February 1995 and December 2005 were enrolled retrospectively. Oncologic outcomes included 5-year cancer-specific survival and its affecting factors, as well as risk factors for local and systemic recurrence. RESULTS: The 5-year cancer-specific survival rate was 77.53% with a mean follow-up period of 61 +/- 31 months. The overall local and systemic recurrence rates were 9.2% and 21.1%, respectively. The risk factors for local recurrence were pN stage (P = 0.015), positive distal resection margin, and positive circumferential resection margin (P < 0.001). The risk factors for systemic recurrence were pN stage (P < 0.001) and preoperative carcinoembryonic antigen level (P = 0.005). The prognostic factors for cancer-specific survival were pT stage (P < 0.001), pN stage (P < 0.001), positive distal resection margin (P = 0.005), and positive circumferential resection margin (P = 0.016). CONCLUSION: The oncologic outcomes in our institution after a TSME for patients with resectable rectal cancer were similar to those reported in other recent studies, and we established the risk factors that could be crucial for the planning of treatment and follow-up.

Clinical Outcome after Breast Conserving Surgery and Radiation Therapy for Early Breast Cancer / 대한방사선종양학회지

PURPOSE: This study was performed to evaluate the disease-free survival and risk factors of recurrence in early breast cancer patients who have undergone breast conserving surgery and radiation therapy. MATERIALS AND METHODS: From March 1997 to December 2002, 77 breast cancer patients who underwent breast conserving surgery and radiation therapy were reviewed retrospectively. The median follow-up time was 58.4 months (range 43.8~129.4 months) and the mean subject age was 41 years. The frequency distribution of the different T stages, based on the tumor characteristics was 38 (49.3%) for T1, 28 (36.3%) for T2, 3 for T3, 7 for Tis and 1 for an unidentified sized tumor. In addition, 52 patients (67.5%) did not have axillary lymph metastasis, whereas 14 patients (18.1%) had 1~3 lymph node metastases and 3 (0.03%) had more than 4 lymph node metastases. The resection margin was negative in 59 patients, close (< or =2 mm) in 15, and positive in 4. All patients received radiation therapy at the intact breast using tangential fields with a subsequent electron beam boost to the tumor bed at a total dose ranging from 59.4 Gy to 66.4 Gy. Patients with more than four positive axillary lymph nodes received radiation therapy (41.4~60.4 Gy) at the axillary and supraclavicular area. Chemotherapy was administered in 59 patients and tamoxifen or fareston was administered in 29 patients. RESULTS: The 5 year overall survival and disease-free survival rates were 98.08% and 93.49%, respectively. Of the 77 patients, a total of 4 relapses (5.2%), including 1 isolated supraclavicular relapse, 1 supraclavicular relapse with synchronous multiple distant relapses, and 2 distant relapses were observed. No cases of local breast relapses were observed. Lymph node metastasis or number of metastatic lymph nodes was not found to be statistically related with a relapse (p=0.3289) nor disease-free survival (p=0.1430). Patients with positive margins had a significantly shorter disease-free survival period (p<0.0001) and higher relapse rates (p=0.0507). However, patients with close margins were at equal risk of relapse and disease-free survival as with negative margins (p=1.000). Patients younger than 40 years of age had higher relapse rates (9.3% vs. 0%) and lower disease-free survival periods, but the difference was not statistically significant (p=0.1255). The relapse rates for patients with tumors was 14% for tumor stage T2, compared to 0% for tumor stage T1 tumors (p=0.0284). A univariate analysis found that disease-free survival and relapse rates, T stage, positive resection margin and mutation of p53 were significant factors for clinical outcome. CONCLUSION: The results of this study have shown that breast conservation surgery and radiation therapy in early breast cancer patients has proven to be a safe treatment modality with a low relapse rate and high disease-free survival rate. The patients with a positive margin, T2 stage, and mutation of p53 are associated with statistically higher relapse rates and lower disease-free survival.