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Deep brain stimulation (DBS) of the subthalamic nucleus (STN) represents an effective treatment for severe Parkinson's disease (PD), but little is known about the long-term benefit.To investigate the survival rate and long-term outcome of DBS.We investigated all 81 patients including 37 males and 44 females who underwent bilateral STN DBS from March 2005 to March 2008 at a single institution. The current survival status of the patients was investigated. Preoperative and postoperative follow-up assessments were analyzed.The mean age at the time of surgery was 62 (range 27-82) years, and the median clinical follow-up duration was 145 months. Thirty-five patients (43%) died during the follow-up period. The mean duration from DBS surgery to death was 110.46 ± 40.8 (range 0-155) months. The cumulative survival rate is as follows: 98.8 ± 1.2% (1 year), 95.1 ± 2.4% (5 years), and 79.0 ± 4.5% (10 years). Of the 81 patients, 33 (40%) were ambulatory up to more than 11 years. The Unified Parkinson's Disease Rating Scale (UPDRS) score was significantly improved until 5 years after surgery although it showed a tendency to increase again after 10 years. The patient group with both electrodes located within the STN showed a higher rate of survival and maintained ambulation.STN DBS is a safe and effective treatment for patients with advanced PD. This study based on the long-term follow-up of large patient populations can be used to elucidate the long-term fate of patients who underwent bilateral STN DBS for PD.

Objective: With the development of breast cancer treatment, the prognosis of breast cancer patients is getting better over time. Breast cancer patients want to get accurate information about prognosis according to the treatment pattern. In this study, we investigated the 5-year Conditiona relative survival (CRS) of Korean female breast cancer patients. Materials and Methods: The data from this study was collected from the Korean Central Cancer Registry (KCCR) data, National Health Insurance Service (NHIS) data and Korean Statistical Information Service (KOSIS) data to certify relative survival and conditional relative survival for the female patients of breast cancer in the Korea. We identified 141,779 female breast cancer cases diagnosed between 2002 and 2013. The CRS was estimated for every year after diagnosis, according to age, stage at diagnosis, histologic type, year at diagnosis and treatment patterns within 1year after diagnosis. Results: The 5-year RS at diagnosis was 91.0% and the 10-year RS was 85.9%. The 5-year CRS was 91.1% and 94.3% at 1 year and 5 years after diagnosis, respectively. Very young and very old patients had worse 5-year CRS after 5 years of survival than those of other age groups (89.6% in the Conclusions: This study shows that the improvement pattern of CRS may vary according to age group, treatment pattern, and histologic type. In the group without antihormone therapy, the histologic type seems to be a different aspect of CRS, which is useful information for clinicians and patients. Key words: conditional survival, breast cancer, histology, age, stage, treatment pattern Citation Format: Eun Jin Song, So-Youn Jung, Young Ae Kim, Sun-Young Kong, Eun Sook Lee, Eun-Gyeong Lee, Heein Jo, Jae Hong Han, Seeyoun Lee, Han-Sung Kang. Conditional survival of female breast cancer patients by treatment patterns: Evidence from the Korean nationwide registry [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-13-20.

Bilateral subthalamic nucleus (STN) Deep brain stimulation (DBS) is a well-established treatment in patients with Parkinson’s disease (PD). Traditionally, STN DBS for PD is performed by using microelectrode recording (MER) and/or intraoperative macrostimulation under local anesthesia (LA). However, many patients cannot tolerate the long operation time under LA without medication. In addition, it cannot be even be performed on PD patients with poor physical and neurological condition. Recently, it has been reported that STN DBS under general anesthesia (GA) can be successfully performed due to the feasible MER under GA, as well as the technical advancement in direct targeting and intraoperative imaging. The authors reviewed the previously published literature on STN DBS under GA using intraoperative imaging and MER, focused on discussing the technique, clinical outcome, and the complication, as well as introducing our single-center experience. Based on the reports of previously published studies and ours, GA did not interfere with the MER signal from STN. STN DBS under GA without intraoperative stimulation shows similar or better clinical outcome without any additional complication compared to STN DBS under LA. Long-term follow-up with a large number of the patients would be necessary to validate the safety and efficacy of STN DBS under GA.

This study aimed to determine whether the prognosis of breast cancer is affected by muscle or fat volume as measured from computed tomography (CT) images. We identified 1460 patients with chest CT who were diagnosed as having breast cancer at the National Cancer Center, Korea, between January 2001 and December 2009. Using CT images of 10-mm slices, we measured the cross-sectional areas of skeletal muscle and adipose tissue at the 3rd lumbar vertebrae, and derived their volumes. The skeletal muscle volume, fat volume, and muscle-to-fat ratio were evaluated for association with overall survival (OS) and recurrence-free survival (RFS). The median skeletal muscle and fat volumes among the patients were 93.3 cc (range 39.6–236.9) and 420.1 cc (range 19.5–1392.3), respectively. Patients with higher muscle volume had better prognosis than those with lower muscle volume [hazard ratio (HR) 0.56, 95% confidence interval (CI) 0.34–0.92, P = 0.022 for OS; HR 0.72, 95% CI 0.52–0.99, P = 0.046 for RFS]. However, body mass index (BMI) and fat volume were not associated with prognosis. In addition, muscle volume was a significant prognosticator for OS, regardless of BMI (HR 0.55, 95% CI 0.32–0.93, P = 0.034 in BMI

Introduction Annexin A3 (ANXA3) participates in various tumor-associated biological processes, including tumor initiation, progression, and metastasis. The present study was designed to investigate the expression and function of ANXA3 in breast cancer cells. Materials and Methods Annexin A3 protein expression in breast cancer cell lines was evaluated using Western blot analysis. ANXA3 expression in MDA-MB 231 breast cancer cells was silenced by RNA interference, and the effects of RNA silencing on cell proliferation, colony forming ability, wound-healing, and invasiveness were evaluated. Levels of ANXA3 expression in 30 primary breast cancers were assayed using immunohistochemistry and correlated with patient survival. Results Levels of ANXA3 expression were higher in the basal subtype of breast cancer cells, such as MDA-MB 231, HCC-70, and HCC-1954 cells, than in other subtypes. ANXA3 silencing inhibited the activities of MDA-MB 231 and HCC-1954 cells, including their proliferation, invasion across transwell membranes, and wound-healing and colony forming abilities. ANXA3 small interfering RNA (siRNA) also reduced the expression of cycle-dependent kinase protein and increased the expression of E2F1 and p27 proteins compared with control siRNA. Expression of ANXA3 was closely correlated with tumor size, with higher ANXA3 expression associated with reduced disease-free survival in breast cancer patients. Conclusion These findings indicate that ANXA3 is associated with the natural progression of breast cancer and might be a potential prognostic marker of patient survival.

Laparoscopic primary repair is one of the main procedures used for perforated gastric ulcers, and this technique requires reproducible and secure suturing. The aim of this study was to investigate the safety and efficacy of a novel continuous suture method with barbed sutures during laparoscopic repair for perforated peptic ulcers. Clinical data from 116 consecutive patients undergoing laparoscopic repair for perforated peptic ulcers were collected between November 2009 and October 2015. Continuous suturing with 15-cm-long unidirectional absorbable barbed sutures was used for laparoscopic repair in the study group, termed group V (n = 51). Patients who underwent laparoscopic repair with conventional interrupted sutures were defined as group C (n = 65). The complication and operative data were compared between groups. Although there was no difference between group V and group C in the overall complication rate (15.7% vs. 24.6%; p = 0.259), the complication rate related to suturing was lower (3.9% vs. 15.4%; p = 0.04) in group V. Group V showed rates of 0% for leakage, 2% for intra-abdominal fluid collection, and 2% for stricture; the corresponding rates in group C were 3.1, 7.7, and 4.6%, respectively. Regarding operative data, the total operation time (V vs. C, 87.7 min vs. 131.2 min), total suture time (7.1 min vs. 25.3 min), and suture time per stitch (1.2 min vs. 6.2 min) were significantly shorter in group V than in group C (p

We report a unique case of a 67-year-old woman with neurofibromatosis type 1, who was also diagnosed with metaplastic spindle cell carcinoma of the left breast. She had many neurofibromatosis lesions on her body, as well as the mass in the left breast. After the breast mass was diagnosed as a malignant mesenchymal tumor by core needle biopsy, the patient underwent left modified radical mastectomy. Subsequently, the pathological analysis of the tumor showed it to be a metaplastic spindle cell carcinoma. The co-occurrence of neurofibromatosis type 1 and breast cancer, in particular metaplastic spindle cell carcinoma, is very rare.

Cervical lymph node metastasis is common in patients with papillary thyroid carcinoma (PTC).Salmonellaspecies are rarely reported as causative agents in focal infections of the head and neck. The cooccurrence of lymph node metastasis from PTC and a bacterial infection is rare. This report describes a 76-year-old woman with a cervical lymph node metastasis from PTC andSalmonellainfection of the same lymph node. The patient presented with painful swelling in her left lateral neck region for 15 days, and neck ultrasonography and computed tomography showed a cystic mass along left levels II–IV. The cystic mass was suspected of being a metastatic lymph node; modified radical neck dissection was performed. Histopathological examination confirmed the presence of PTC in the resected node and laboratory examination of the combined abscess cavity confirmed the presence ofSalmonella Typhi. Following antibiotic sensitivity testing of the culturedSalmonella Typhi, she was treated with proper antibiotics. Cystic lesions in lymph nodes with metastatic cancer may indicate the presence of cooccurring bacterial infection. Thus, culturing of specimen can be option to make accurate diagnosis and to provide proper postoperative management.

The mesoporous TiO2 nanoparticle-based scaffold structure is the best electron transport layer (ETL) for perovskite solar cells (PSCs) and is still used in most PSCs with optimal photovoltaic characteristics. However, the high sintering temperature of TiO2 nanoparticles required to remove binders from the TiO2 paste limits PSC application to flexible electronics. In this study, a simple interface modification process involving ethanol rinsing is developed to enhance the photovoltaic characteristics of low-temperature processed PSCs. This easy and fast technique could enable remarkable performance by PSCs by significantly increasing the fill factor and current density, leading to a power conversion efficiency more than four times that of untreated solar cells.

Background/purpose: The number of long-term breast cancer survivors is increasing rapidly due to the growing rates of detection, incidence and improved survival. Quality of life (QOL) of physical and psychosocial health outcomes vary across the breast cancer survivors including diagnosis at different stages of breast cancer. There is little data regarding the psychosocial health of disease-free breast cancer survivors compared with those of general population. We conducted to assess the QOL, especially psychosocial health, of disease-free female survivors over 2 year after breast cancer diagnosis compared with cancer-free control women. Methods: We used baseline data from the health examinee cohort, a part of the Korea Genome Epidemiology Study which is a large scaled cohort study established since 2001. This cohort has collected data of past medical history, socioeconomical factors (income, education, marital status and current employment status) and health behavioral factors (smoking, drinking, physical activity, BMI, menopausal status and subjective health status) of participants while they underwent regular health examination. The disease-free breast cancer survivors were defined as those who answered that they were ≥2 years from the initial diagnosis of breast cancer without recurrence and current treatment. Among the participants female subjects without history of any type cancer were randomly selected at 1:4 ratio by 5-year age groups, educational attainment level and household income as a comparison group. We analyzed Psychosocial Well-being Index-Short Form (PWI-SF) in these two groups. Subjects with score ≤8, 9–26, and 27 were classified as the 'healthy group', 'latent stress group', and 'stress group,' respectively. Results: Total 347 survivors of breast cancer and 1,388 matched participants without cancer history were selected for analysis. Even after being matched for education and household income status, breast cancer survivors showed better psychosocial health status and health behaviors compared with matched comparison group. The prevalence of latent stress and stress group (vs healthy group) by PWI-SF score was 88.2% in breast cancer survivors and 89.9% in the matched female controls, showing borderline significant differences (p = 0.057). The prevalence rates of ever drinkers and smokers or obese women were lower and of those who exercised ≥150 min/week were higher in breast cancer survivors (p < 0.05). The total PWI-SF score was lower in breast cancer survivors, suggesting lower level of psychosocial stress level in breast cancer survivors. After adjusting for effects of other sociodemographic variables, breast cancer survivors were less likely to be included in stress group by 36% (OR = 0.64; 95% confidence interval [CI], 0.42–0.98). Conclusions: The disease-free breast cancer survivors with regular health examination showed better psychosocial health status compared with matched general population. The better health behaviors in cancer survivors such as less alcohol drinking, low BMI, less history of smoking and more regular exercise, which have been identified in several previous cancer survivors studies might be attributed to their better psychosocial health status. Citation Format: Lee MH, Park B, Song EJ, Park SJ, Kong S-Y, Lee ES. Psychosocial health of disease-free breast cancer survivors compared with cancer-free general population: Korean health examinee cohort study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-10-12.

Background & Objective: The ACOSOG Z0011 trial announced in 2010, has been proved of successful local therapy with oncological safety by performing sentinel lymph node biopsy(SLBx) only, instead of traditional axillary lymph node dissection(ALND) for clinically node negative breast cancer patients. According to this result, paradigm of axilla surgery was changed and it was also reflected in updated NCCN guidelines. In 2017, A 10-year follow up of Z0011 was published. In terms of overall survival and disease free survival, there was no difference in the results between the SLBx only group and the ALND group. We retrospectively reviewed all breast cancer patients to ascertain paradigm shift of breast cancer surgery after applying the Z0011 criteria for 15 years. Materials & Method: All women who underwent breast conserving surgery at the National Cancer Center between January 1, 2000 and December 31, 2015 were enrolled and classified according to the Z0011 criteria. Finally, total 361 patients enrolled the study. The primary outcome of the study was to confirm the difference in mortality and recurrence rates among the SLBx only group, SLBx + sampling (picking up additional axilla lymph nodes) group and the ALND group, and the secondary outcome was to identify the complication among three groups. Results: After the Z0011 guideline has adopted in our institute, the rate of ALND had rapidly decreased and lymph node sampling has replaced ALND. Of the 361 patients, 271 patients underwent formal ALND. 66 patients had SLBx only and 24 patients had further axillary node sampling in addition of SLBx. The number of retrieval total node was 13.02 in ALND group compared with 2.61 in SLBx only group and 5.71 in SLBx+sampling group with statistically significant(p=0.000). But there was no difference of the mean number of positive sentinel node among these groups. Mean follow up period was 94.38 months(ALND 101.38months, SLBx only 77.61months, SLBx+sampling 61.54months, P=0.367). During follow-up, total 25 patients experienced disease recurrence. Twenty two patients were from ALND group and Three patients were from SLBx only group (p=0.787). Most common recurrence site was bone(4%), followed by Lung (3.7%), Liver(2.2%) and Brain(0.7%). Only six patients were dead by cause of breast cancer and all of them were from ALND group but there was no significant difference(p=0.574). One hundred five patients (29.1%) experience the complication from operation. arm edema in the ALND group occurred about 40 times more than the SLBx only group (80 vs. 2) and 26 times more than the SLBx + sampling group(80 vs. 3), but there was no statistically significant(p=0.065). Conclusion: From single center cohort for 15 years, we concluded that SLBx can be used safely in Z0011 eligible cohort without any increase of the risk of locoregional and distant recurrence. Also, we suggest omission of ALND can reduce some serious complication such as arm lymphedema. Keyword: Z0011 criteria, Arm lymphedema, locoregional recurrence, sentinel lymph node biopsy, axillar lymph node dissection Citation Format: Heein Jo, JooHwa Kwak, Eun-Gyeong Lee, Jai Hong Han, So-Youn Jung, Eun Jin Song, Han-Sung Kang, EunSook Lee, Seeyoun Lee. The clinical outcomes between sentinel lymph node biopsy and axillary lymph node dissection in Z0011 eligible cohort in single center for 15 years [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-02-20.

Objective: This study aimed to evaluate the outcomes between sentinel lymph node biopsy (SLNB) and axillar lymph node dissection (ALND) on recurrence and survival in clinically node positive breast cancer patients who showed conversion into pN0 after neoadjuvant chemotherapy (NAC) from 10 years cohort in single center. Materials & Method: This study enrolled total 225 patients, from January 2006 to December 2015 who underwent breast cancer surgery and axillar lymph node approach in clinically axillar lymph node metastasis with conversion into node negative after neoadjuvant chemotherapy. One hundred patients had only SLNB and 125 patients had ALND finally. Results: The median follow-up time was 58 months (range, 12-147 months) in only SLNB group and 103 months (range 9-174 months) in ALND group and the median number of retrieved SLNs was 2 (range, 1-6) and 11 (2-31). The 5 years overall survival rate of SLNB and ALND group is 94%, 95.7% (P=0.786), disease free survival rate 91.9%, 91.6%, (p=0.753) which was not statistically significant. Three patients (3%) and 6 patients (4.8%) showed loco-regional recurrence respectively. All they showed ipsilateral axillary lymph node recurrence. Seven patients (7%) and 6 patients (4.8%) in SLNB group and ALND group showed distant metastasis. However, there were more complications in the ALND group than in the SLNB group. Among them, ALND group showed the higher rate of shoulder stiffness than SLNB group (7% vs 10.4%, p=0.384, respectively). Especially, the incidence of lymphedema was 6 times higher in ALND group. (4 patients (4%) vs 29 patients (23.2%), p=0.271) Conclusion: We found the SLNB only group did not increase the recurrence or metastatic rate from the patients, but reduced the incidence of complications such as lymphedema from the 10 years single center cohort. Therefore, we suggest SLNB can be considered as a reliable as an alternative to ALND when the complete response is achieved by re-staging with imaging study after neoadjuvant chemotherapy. Keyword: neoadjuvant chemotherapy, sentinel lymph node biopsy, axillar lymph node dissection Citation Format: Joo Hwa Kwak, Heein Jo, Eun-Gyeong Lee, Eun Jin Song, Jai Hong Han, So-Youn Jung, Han-Sung Kang, Eun Sook Lee, Seeyoun Lee. What happened to clinically node positive breast cancer patients who showed conversion into pN0 after neoadjuvant chemotherapy?: Single center for 10 years [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-02-08.

For achieving improved electrical conductivity through surface passivation of crystalline silicon, we investigated TiON films by combining TiO2 and TiN deposition cycles in plasma-enhanced atomic layer deposition. To control the composition of the TiON films, a super-cycle—composed of one cycle of TiO2 and x-cycles of TiN—was adopted. The thickness of the films could be precisely controlled on the nanometer and sub-nanometer scale, regardless of the TiO2:TiN sub-cycle ratio. The chemical state, crystalline phase, and interface characteristics of the TiON films were examined. For the TiO2:TiN = 1:20 film, the carrier lifetime was increased from 30 to 243 μs, while the resistivity decreased from 3.1 × 108 to 7.1 × 10 − 1 Ω•cm compared to the TiO2 film.

Highly transparent and conductive oxide-metal-oxide (OMO) electrodes comprising aluminum-doped zinc-oxide (AZO) and ultrathin Ag or oxygen (O2)-doped Ag (AgOx) metal layers were fabricated for use in thin-film silicon solar cells. The surface morphologies of the metal layers and the transparencies and conductivities of OMO electrodes were investigated near the percolation thickness values of the metal layers. The percolation metal thickness, which means the metal layer is morphologically continuous, could be used to optimize the transparent OMO electrode. Additionally, thin Ag-based OMO (AgOx OMO) with superior performance could be fabricated by adding O2. The optimized AgOx OMO electrodes yielded the highest average transmittance (Tavg) of 93.5% and the lowest average optical loss (OLavg) of 1.01% within 500–800 nm at the percolation thickness of ~6 nm, thus, maintaining low conductivity. These outcomes were superior to the responses of the percolated Ag OMO (Tavg = 87.2%; OLavg = 1.01%). Using the OMO structure at the rear electrode, transparent hydrogenated amorphous silicon thin-film solar was fabricated for building integrated photovoltaic windows. The best figure-of-merit (FOM; equal to the product of Tavg and efficiency η) values of the OMO-based transparent solar cells could be obtained for percolated OMO structures. The cells using AgOx OMO (AgOx cells) performed better than the Ag cells; the best FOMs of AgOx and Ag cells were 140.8 (Tavg = 27.8%; η = 5.51%) and 104.6% (Tavg = 18.9%; η = 5.54%), respectively. These results could contribute to the development of high-performance transparent solar cells or optoelectronic devices.

Purpose This study evaluated the association of serum HER2 (sHER2) levels at diagnosis with clinicopathologic parameters and disease free survival (DFS) in operable breast cancer patients according to intrinsic subtype. Methods The sHER2 levels were measured using a chemiluminescence immunoassay. The HER2 status in all tumor tissues was determined by immunohistochemistry, and confirmed in equivocal cases by fluorescence in situ. Results There were 436 consecutive stage I-III breast cancer patients with sHER2 result at diagnosis between Nov 2004 and Dec 2011. High sHER2 levels (≥ 15 ng/ml) were reported in 52 patients (11.9%) and HER2 overexpression in tumor tissue was observed in 111 patients (25.5%). High sHER2 levels were associated significantly with advanced stage (P < 0.001), mastectomy (P = 0.012), neoadjuvant chemotherapy (P < 0.001), anti-HER2 therapy (P < 0.001) and hormone therapy (P = 0.022). The patients with high sHER2 levels had a worse DFS (P < 0.001). In multivariate analysis, high sHER2 levels were associated significantly with worse DFS (HR = 2.25, 95% CI 1.27–3.99, P = 0.005). High sHER2 levels were associated with worse DFS in the HR+/HER2-, HR+/HER2+ and HR-/HER2+ subtypes (P = 0.043, 0.003 and 0.041, respectively). Conclusions These results show that the sHER2 level at diagnosis is a useful prognostic factor in patients with operable breast cancer, especially in the HR+/HER2-, HR+/HER2+ and HR-/HER2+ subtypes.

Purpose : The safety and feasibility of laparoscopic colonic resection in elderly colorectal cancer patients remains to be verified. The aim of this study was to determine the safety and feasibility of laparoscopic colonic resection compared to open colonic resection for colorectal cancer in patients older than 80 years of age. Methods : One hundred ninety two patients older than 80 years of age underwent curative resection for colorectal cancer. Twenty-four (12.4%) patients who had been operated by laparoscopic surgery were compared with 168 (87.6%) patients who had undergone open colonic resection. Results : The mean age of the 192 patients was 81.9 years. The postoperative complication and mortality were 17.1% and 1.5%, respectively. The preoperative clinical parameters were similar between the two groups. The surgery time was longer in the laparoscopic group, but not significantly. The intraoperative blood loss was less in the laparoscopic group (p=0.025). The major postoperative complications in the laparoscopic group and the open groups were significantly different (0% vs 19.0%, p=0.018). There was no postoperative mortality in the laparoscopic group, but 3 cases (1.7%) of mortality were seen in the open group (p=0.594). Conclusion : Laparoscopic colonic resection in elderly colorectal cancer patients is safe and feasible. Therefore, laparoscopic colonic resection can be recommended as an alternative treatment for colorectal cancer in patients over 80 years of age.

The process of precise silicon etching on the atomic scale was investigated by examining the formation of an (NH4)2SiF6 thin film as an intermediate phase followed by the removal of this layer by sublimation. An amorphous (NH4)2SiF6 thin film was formed on a Si substrate via a two-step plasma process consisting of an oxidation step involving an O2 plasma and a modification step to form an (NH4)2SiF6 thin film using an NH3/NF3 plasma, where the formed thin film was removed by a sublimation process. Because the thickness of the (NH4)2SiF6 thin film could be linearly controlled by altering the number of two-step plasma process cycles, the etching depth could be successfully controlled on the sub-nanometer scale.

Background/purpose: Increased serum HER2 levels have been shown to correlate with higher tumor burden and poorer clinical outcomes in metastatic breast cancer, but there is little data regarding the significance of serum HER2 levels at diagnosis in the operable breast cancer. We evaluated the association between baseline serum HER2 levels and clinicopathologic parameters, and the correlation of baseline serum HER2 levels with clinical outcome by molecular subtype in operable breast cancer patients. Methods: We included patients with stage I-III breast cancer diagnosed at our center between October 2004 and December 2011. Baseline serum HER2 levels were measured by chemiluminescence immunoassay at diagnosis. Patients were categorized into 4 molecular subtype groups by their hormone receptor (HR) status and HER2 status: HR+/HER2-, HR+/HER2+, HR-/HER2+ and HR-/HER2-. HR and HER2 status were determined by immuhohistochemistry (IHC) in all tumors, and fluorescence in situ hybridization (FISH) assay was performed whenever the HER2 status was equivocal. Results: There were 439 consecutive stage I-III breast cancer patients, of which 271 (61.7%) were HR+/HER2-, 75 (17.1%) were HR+/HER2+, 30 (6.8%) were HR-/HER+ and 63 (14.4%) were HR-/HER2-. A total of 192 patients underwent neoadjuvant chemotherapy and the remaining 235 patients did not. Of these 235 patients, 204 underwent adjuvant chemotherapy. High serum HER2 levels (≥15 ng/ml) were reported in 51 patients (11.6%) and HER2-positive status in tumor tissue was observed in 105 patients (23.9%). High serum HER2 levels were significantly associated with tumor size > 2cm (p=0.032), high histologic grade (0.048), negative HR status and neoadjuvant chemotherapy usage. Patients who had high baseline serum HER2 levels had a worse disease free survival (DFS) (p Conclusions: This is the largest study in the evaluation of serum HER2 levels at diagnosis on the prognosis of patients with operable breast cancer. Our results showed that baseline serum HER2 level is a good prognostic marker in patients with operable breast cancer. High serum HER2 levels at diagnosis were associated with worse DFS, especially in patients of HR+/HER2-, HR+/HER2+ and HR-/HER2+ subtypes. Citation Format: Moo Hyun Lee, Siew Kuan Lim, Ji Young You, Eun Jin Song, So-Youn Jung, See Youn Lee, Han-Sung Kang, Eun Sook Lee. The significance of serum HER2 levels at diagnosis on outcome of breast cancer patients by molecular subtype [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-02-04.