Keun Yong Eom
Seoul National University Bundang Hospital
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Featured researches published by Keun Yong Eom.
Cancer Research and Treatment | 2015
Keun Yong Eom; Min Hye Jang; So Yeon Park; Eun Young Kang; Sung-Won Kim; Jee Hyun Kim; Jae-Sung Kim; In Ah Kim
Purpose The aim of study was to test by immunohistochemical (IHC) staining whether carbonic anhydrase (CA) 9 and 12 have an effect on sentinel lymph node (SLN) metastasis in early breast cancer and to find clinicopathologic factors associated with SLN metastasis. Materials and Methods Between June 2003 and June 2011, medical records of 470 patients diagnosedwith breast cancer with pT1-2, pN0-2, and M0 were reviewed. Of these 470, 314 patients who underwent SLN biopsy±axillary dissection were subjects of this study. Using tissue microarray, IHC staining for CA9 and CA12 was performed. Clinicopathologic factors such as patient age, tumour size, lymphatic invasion, hormone receptor status, and the Ki-67 labeling index were analysed together. Results The mean age of all patients was 51.7 years. The mean number of harvested SLN was 3.62, and 212 patients (67.5%) had negative SLN. Lymphatic invasion, the Ki-67 labelling index of primary tumours, and CA9 staining of stromal cells, were independent risk factors for SLN metastasis in the multivariate analysis. In 33 patients (10.5%) without the three risk factors, no patient had SLN metastasis. In 80 patients without lymphatic invasion of primary tumours or CA9 staining of stromal cells, only four patients (5%) had positive SLN. Conclusion CA9 staining of stromal cells is an independent risk factor for SLN metastasis as well as lymphatic invasion and a low Ki-67 labelling index of primary tumours in patients with early breast cancer. IHC staining of primary tumours for CA12was not associatedwith SLN metastasis.
Journal of Breast Cancer | 2017
Jeanny Kwon; Keun Yong Eom; Tae Ryool Koo; Byoung Hyuck Kim; Eunyoung Kang; Sung-Won Kim; Yu Jung Kim; So Yeon Park; In Ah Kim
Purpose Considering the distinctive biology of triple-negative breast cancer (TNBC), this study aimed to identify TNBC-specific prognostic factors and determine the prognostic value of the Nottingham Prognostic Index (NPI) and its variant indices. Methods A total of 233 patients with newly diagnosed stage I to III TNBC from 2003 to 2012 were reviewed. We retrospectively analyzed the patients demographics, clinicopathologic parameters, treatment, and survival outcomes. The NPI was calculated as follows: tumor size (cm)×0.2+node status+Scarff-Bloom-Richardson (SBR) grade. The modified NPI (MNPI) was obtained by adding the modified SBR grade rather than the SBR grade. Results The median follow-up was 67.8 months. Five-year disease-free survival (DFS) and overall survival (OS) were 81.4% and 89.9%, respectively. Multivariate analyses showed that the MNPI was the most significant and common prognostic factor of DFS (p=0.001) and OS (p=0.019). Young age (≤35 years) was also correlated with poor DFS (p=0.006). A recursive partitioning for establishing the prognostic model for DFS was performed based on the results of multivariate analysis. Patients with a low MNPI (≤6.5) were stratified into the low-risk group (p<0.001), and patients with a high MNPI (>6.5) were subdivided into the intermediate (>35 years) and high-risk (≤35 years) groups. Age was not a prognostic factor in patients with a low MNPI, whereas in patients with a high MNPI, it was the second key factor in subdividing patients according to prognosis (p=0.023). Conclusion The MNPI could be used to stratify patients with stage I to III TNBC according to prognosis. It was the most important prognosticator for both DFS and OS. The prognostic significance of young age for DFS differed by MNPI.
Journal of Breast Cancer | 2013
Tae Ryool Koo; Keun Yong Eom; Eun Young Kang; Yu Jung Kim; Sung-Won Kim; Jee Hyun Kim; Jae-Sung Kim; In Ah Kim
Purpose This pilot study aimed to evaluate prognostic factors of postmastectomy radiotherapy (PMRT) for breast cancer patients undergoing systemic therapy in either preoperative or postoperative setting. Methods Between 2003 and 2009, 113 patients received PMRT: 61 underwent preoperative systemic therapy (PST subgroup) and 52 received postoperative systemic therapy (non-PST subgroup). Results The median follow-up time was 72.3 months (range, 34.0-109.4 months) for surviving patients. In univariate analysis of all patients, disease-free survival (DFS) was associated with age, nodal ratio (NR), and Ki-67 expression; overall survival (OS) was associated with NR and Ki-67 expression. Pathologic N stage and HER2 expression were marginally associated with DFS and OS. In the non-PST subgroup, DFS was associated with age, NR, venous invasion, and Ki-67 expression; OS was associated with age. In the PST subgroup, DFS was associated with ypN stage and NR; OS was associated with ypN, histologic grade, HER2 expression, and p53 expression. In multivariate analysis of all patients, DFS and OS were significantly associated with NR (p=0.003 and p=0.019, respectively) and Ki-67 expression (p=0.002 and p=0.015, respectively). Patients were classified into low-risk (NR ≤0.2 and Ki-67 ≤20%; n=34), intermediate-risk (NR >0.2 or Ki-67 >20%; n=63), and high-risk (NR >0.2 and Ki-67 >20%; n=16) subgroups. All low-risk patients were alive at the time of analysis. High-risk (p<0.001 and p=0.001, respectively) and intermediate-risk (p=0.022 and p=0.008, respectively) patients had significantly shorter DFS and OS than low-risk patients. This prognostic model was statistically significant for DFS when applied to the PST (p=0.001) and non-PST (p=0.016) subgroups separately. Conclusion For breast cancer patients undergoing PMRT, NR and Ki-67 are potential prognostic factors. A model using these factors might help predict a poor prognosis. Whether NR and Ki-67 are also prognostic for different setting of systemic therapy, preoperative or postoperative, warrants further study.
International Journal of Gynecological Cancer | 2017
Jinhong Jung; Young Seok Kim; Ji Hyeon Joo; Won Park; Jong Hoon Lee; Jin Hee Kim; Won Sup Yoon; Seok Ho Lee; Keun Yong Eom; Yong Bae Kim
Objective The aim of this study was to investigate the survival, patterns of failure, and prognostic factors in patients with stage II endometrial carcinoma treated with adjuvant radiotherapy. Methods We reviewed the medical records of patients who underwent total hysterectomy, bilateral salpingo-oophorectomy, and pelvic lymph node dissection followed by adjuvant radiotherapy in 10 participating hospitals of the Korean Radiation Oncology Group. Most patients received adjuvant external beam radiation therapy, with a median dose of 50.4 Gy; approximately 50% of these patients received an additional brachytherapy boost, with a median dose of 18 Gy. Adjuvant chemotherapy was administered to 19 patients. Results A total of 122 patients were examined. Over a median follow-up period of 62.7 months (range, 1.9–158.8 months), the 5-year overall survival (OS) and disease-free survival rates were found to be 91.1% and 85.1%, respectively. Recurrence was observed in 14 patients (11.5%), including 3 with local recurrence and 11 with distant metastases as the first site of recurrence. Univariate analysis indicated that lymphovascular invasion was related to an unfavorable OS. An age of 60 years or above, histologic grade 3, and lymphovascular invasion were identified as risk factors for OS. Because there were several risk factors related to OS, we assigned patients to a high-risk group (defined as cases with ≥1 risk factors) and a low-risk group. The 5-year OS rate of the high-risk group was significantly inferior to that of the low-risk group (82.9% vs 100%, P = 0.003). Conclusions The high-risk group had a significantly poorer survival rate than the low-risk group, and distant metastasis was the main pattern of recurrence, thus indicating that further adjuvant chemotherapy should be considered in high-risk patients.
Radiation oncology journal | 2014
Keun Yong Eom; Sung W. Ha; Eunsik Lee; Cheol Kwak; Sang Eun Lee
Purpose To determine whether neoadjuvant androgen deprivation therapy (NADT) improves clinical outcomes in patients with prostate cancer treated with definitive radiotherapy. Materials and Methods We retrospectively reviewed medical records of 201 patients with prostate cancer treated with radiotherapy between January 1991 and December 2008. Of these, 156 patients with more than 3 years of follow-up were the subjects of this study. The median duration of follow-up was 91.2 months. NADT was given in 103 patients (66%) with median duration of 3.3 months (range, 1.0 to 7.7 months). Radiation dose was escalated gradually from 64 Gy to 81 Gy using intensity-modulated radiotherapy technique. Results Biochemical relapse-free survival (BCRFS) and overall survival (OS) of all patients were 72.6% and 90.7% at 5 years, respectively. BCRFS and OS of NADT group were 79.5% and 89.8% at 5 years and those of radiotherapy alone group were 58.8% and 92.3% at 5 years, respectively. Risk group (p = 0.010) and radiation dose ≥70 Gy (p = 0.017) affected BCRFS independently. NADT was a significant prognostic factor in univariate analysis, but not in multivariate analysis (p = 0.073). Radiation dose ≥70 Gy was only an independent factor for OS (p = 0.007; hazard ratio, 0.261; 95% confidence interval, 0.071-0.963). Conclusion NADT prior to definitive radiotherapy did not result in significant benefit in terms of BCRFS and OS. NADT should not be performed routinely in the era of dose-escalated radiotherapy.
Radiology and Oncology | 2017
Sang Won Kang; Jin Beom Chung; Jae-Sung Kim; In Ah Kim; Keun Yong Eom; Changhoon Song; Jeong-Woo Lee; Jin-Young Kim; Tae Suk Suh
Abstract Background The aim of this study was to determine the optimal strategy among various arc arrangements in prostate plans of stereotactic body radiotherapy with volumetric modulated arc therapy (SBRT-VMAT). Patients and methods To investigate how arc arrangements affect dosimetric and biological metrics, SBRT-VMAT plans for eighteen patients were generated with arrangements of single-full arc (1FA), single-partial arc (1PA), double-full arc (2FA), and double-partial arc (2PA). All plans were calculated by the Acuros XB calculation algorithm. Dosimetric and radiobiological metrics for target volumes and organs at risk (OARs) were evaluated from dosevolume histograms. Results All plans were highly conformal (CI<1.05, CN=0.91) and homogeneous (HI=0.09-0.12) for target volumes. For OARs, there was no difference in the bladder dose, while there was a significant difference in the rectum and both femoral head doses. Plans using 1PA and 2PA showed a strong reduction to the mean rectum dose compared to plans using 1FA and 2FA. Contrastively, the D2% and mean dose in both femoral heads were always lower in plans using 1FA and 2FA. The average tumor control probability and normal tissue complication probability were comparable in plans using all arc arrangements. Conclusions The use of 1PA had a more effective delivery time and produced equivalent target coverage with better rectal sparing, although all plans using four arc arrangements showed generally similar for dosimetric and biological metrics. However, the D2% and mean dose in femoral heads increased slightly and remained within the tolerance. Therefore, this study suggests that the use of 1PA is an attractive choice for delivering prostate SBRT-VMAT.
Gynecologic Oncology | 2017
Jong Hoon Lee; Sea-Won Lee; Ju Ree Kim; Yeon Sil Kim; Mee Sun Yoon; Songmi Jeong; Jin Hee Kim; Ja Young Lee; Keun Yong Eom; Bae Kwon Jeong; Seok Ho Lee
OBJECTIVEnThe aim of this multi-institutional study was to determine the prognostic impact of tumour parameters, such as tumour size (TS), tumour volume (TV), and marker expression, on survival during radiation therapy (RT) for cervical cancer patients.nnnMETHODSnA total of 231 patients with histologically confirmed cervical cancer, classified as Federation of Gynecology and Obstetrics (FIGO) Ib2-IVa, were enrolled in this study. Pre- and mid-RT pelvic magnetic resonance imaging (MRI) and squamous cell carcinoma antigen (SCC-ag) analysis were performed twice, during RT and just before brachytherapy.nnnRESULTSnThe median follow-up time was 27.8months (range, 2-116months). Multivariate analysis revealed that stage (odds ratio [OR], 2.936 and 95% confidence interval [CI], 1.119-7.707; P=0.029), tumour volume reduction rate (TVRR) (OR, 3.435 and 95% CI, 1.062-11.106; P=0.039), and SCC-ag reduction rate (SCCRR) (OR, 5.104 and 95% CI, 1.769-14.727; P=0.003) were independently associated with overall survival (OS), while pre-RT TS (OR, 2.148 and 95% CI, 1.221-3.810; P=0.009), mid-RT TV (OR, 3.106 and 95% CI, 1.685-5.724; P<0.0001) and SCCRR (OR, 1.954 and 95% CI, 1.133-3.369; P=0.016) were associated with progression-free survival (PFS). Based on the prognostic factor analysis, patients with the highest prognostic risk score of 3 showed poorer overall survival and progression free survival than patients with lower prognostic risk scores.nnnCONCLUSIONnWe identified that tumour parameters such as TVRR, SCCRR, pre-RT TS, and mid-RT TV areindependent and strong prognostic parameters for patients with cervical cancer receiving RT. This scoring system-based prognostic factor analysis could be used to help develop optimized treatment plans for cervical cancer patients during RT.
Progress in Medical Physics | 2014
Jin Beom Chung; Keun Yong Eom; In Ah Kim; Jae-Sung Kim; Jeong-Woo Lee; Semie Hong; Yon Lae Kim; Byung Moon Park; Sang Won Kang; Tae Suk Suh
Brachytherapy | 2016
Keun Yong Eom; In Ah Kim; Hak Jae Kim; Hong-Gyun Wu; Wan Jun
Journal of Thoracic Oncology | 2007
Hong-Gyun Wu; Keun Yong Eom; Do Hoon Oh; Il Han Kim; Mi Yeon Lee; Eui Kyu Chie; Charn Il Park