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Purpose Adjuvant chemotherapy (AC) is recommended for patients with stage II colorectal cancer with adverse features. However, the effect of adjuvant treatment in elderly patients with high-risk stage II colorectal cancer remains controversial. This study aimed to investigate the oncologic outcomes in elderly high-risk stage II colorectal cancer patients who underwent curative resection with or without AC. Methods Patients aged over 70 years having stage II colorectal adenocarcinoma with at least 1 adverse feature who underwent radical surgery between 2008 and 2017 at a single center were included. We compared recurrence-free survival (RFS) and overall survival (OS) between patients who received more than 80% of the planned AC cycle (the AC+ group) and those who did not receive it (the AC− group). Results The AC+ and AC– group contained 46 patients and 50 patients, respectively. The log-rank test revealed no significant intergroup differences in RFS (P=0.083) and OS (P=0.122). In the subgroup of 27 patients with more than 2 adverse features, the AC+ group (n=16) showed better RFS (P=0.006) and OS (P=0.025) than the AC− group. In this subgroup, AC was the only significant factor affecting RFS in the multivariate analysis (P=0.023). AC was significantly associated with OS (P=0.033) in the univariate analysis, but not in the multivariate analysis (P=0.332). Conclusion Among elderly patients with stage II high-risk colorectal cancer, the AC+ group did not show better RFS or OS than the AC− group. However, selected patients with more than 2 adverse features might benefit from AC.

Purpose It is known that as the T stage of a carcinoma progresses, the prognosis becomes poorer. However, there are few studies about factors that affect the prognosis of T4 advanced colon cancer. This study aimed to identify the prognostic factors associated with disease-free survival (DFS) and overall survival (OS) in T4 colon cancer. Methods Patients diagnosed with stage T4 on histopathology after undergoing curative surgery for colon cancer between March 2009 and March 2018 were retrospectively analyzed for factors related to postoperative survival. Primary outcomes were DFS and OS. Results Eighty-two patients were included in the study. DFS and OS of the pathologic (p) T4b group were not inferior to that of the pT4a group. Multivariate analysis showed that differentiation (hazard ratio [HR], 4.994; P = 0.005), and laparoscopic surgery (HR, 0.323; P = 0.008) were significant prognostic factors for DFS, while differentiation (HR, 7.904; P ≤ 0.001) and chemotherapy (HR, 0.344; P = 0.038) were significant prognostic factors for OS. Conclusion Tumor differentiation, laparoscopic surgery, and adjuvant chemotherapy were found to be significant prognostic factors in patients with T4 colon cancer. Adjuvant chemotherapy and curative resections by laparoscopy might improve the prognosis in these patients.

Abstract Decision to undergo risk-reducing mastectomy (RRM) needs to consider several factors, including patient’s preference, surgeon’s preference, family history, and genetic predisposition. The aim of this study was to examine whether preoperative diagnosis of BRCA1/2 mutation status could influence surgical decision-making in newly diagnosed breast cancer patients. We retrospectively reviewed ipsilateral breast cancer patients with BRCA1/2 mutation who underwent primary surgery between January 2008 and November 2019 at a single institution in Korea. Of 344 eligible patients, 140 (40.7%) patients were aware of their mutation status ‘prior to surgery’, while 204 (59.3%) did not. Contralateral RRM rate was significantly higher in the group with BRCA1/2 mutation status identified ‘prior to surgery’ compared to the group with mutation status identified ‘after surgery’ [45.0% (63/140) vs. 2.0% (4/204)] (p

Purpose To identify factors significantly associated with the mortality of patients with left colonic perforation, and to compare the outcome of Hartmann’s procedure (HP) and primary repair (PR) or primary anastomosis (PA) in patients with left colonic perforation without factors associated with mortality. Methods This retrospective study included patients who underwent surgery for left colonic perforation from January 2009 to February 2018. Preoperative factors related to postoperative mortality, including vital signs, laboratory findings, and intraoperative findings, were analyzed by type of operation. The chi-square, Fisher exact, and Mann-Whitney U-tests were used to analyze the data. Results Ninety-one patients were included (36 men, 55 women), and 15 (16.5%) died postoperatively. Prognostic factors were age, leukopenia, thrombocytopenia, bleeding tendency, acute kidney injury, hemodynamic instability, and the existence of feculent ascites. Leukopenia and longer operative time were independent risk factors for mortality. Seventy-nine patients did not have leukopenia and 30 of these patients who underwent PR without diversion were excluded from the subanalysis. HP was performed in 30 patients, and PR with diversion and PA with or without diversion were performed in 19. Compared to the other operative methods, HP had no advantage in reducing hospital mortality (P=0.458) and morbidity. Conclusion Leukopenia could be an objective prognostic factor for left colonic perforation. Although HP is the gold standard for septic left colonic perforation, it did not improve the hospital mortality of the patients without leukopenia. For such patients, PR or PA may be suggested as an alternative option for left colonic perforation.

Summary: Background/Objective: Axillary lymph node staging (ALNS) is an important step in the treatment of breast cancer and sentinel lymph node biopsy (SLNB) is a standard procedure for ALNS. Recently, the use of positron emission tomography/computed tomography (PET/CT) for whole body staging in patients with breast cancer has been increasing. The negative predictive value (NPV) of the specific diagnostic modality is the crucial value for excluding axillary lymph node metastasis (ALNM) and guiding the decision not to proceed with axillary lymph node dissection. The aim of this study was to identify patient groups in which PET/CT yields a high NPV for ALNS. Methods: We reviewed data from the records of 262 patients with breast cancer who underwent PET/CT before surgery between February 2009 and March 2018. We searched for factors associated with pathological axillary lymph node metastasis in patients with negative ALNM on PET/CT. Then, we calculated the NPV of PET/CT for ALNS in the patient group without the identified factors and in all patients. Results: Age ≥75 years and tumor size on ultrasonography (US) ≥ 15 mm were the associated factors; the NPV of PET/CT in patients without these factors compared to all patients was 97.2% versus 88.7%. Conclusion: The NPV of PET/CT for ALNS in patients younger than 75 years and with tumor size on US

PurposeThe aim of this study was to evaluate whether the perioperative carcinoembryonic antigen (CEA) ratio could be used as a determinant for adjuvant therapy after curative surgery in stage II colorectal cancer.MethodsData for 119 patients with stage II colorectal cancer who underwent radical surgery between 2010 and 2013 were collected. The perioperative CEA ratio was defined as the postoperative/preoperative serum CEA level, and the patients were grouped according to their perioperative CEA ratios: high ratio (≥0.5) and low ratio (

PurposeThe aim of this study is to determine the predictable factors that affect the clinical course, especially the hospital stay, the operation performed, and to determine factors that will be helpful in deciding whether in-hospital or outpatient treatment is appropriate.MethodsWe retrospectively collected medical data for patients who had been diagnosed with acute diverticulitis at Inje University Sanggye Paik Hospital between January and December 2016. In total, 117 patients were enrolled in this study. We examined clinical factors, including age, sex, body mass index, pain, body temperature, white blood cell count, C-reactive protein, nil per os (NPO) time, hospital duration, computed tomography (CT) findings, location of diverticulitis, operation performed, and presence of comorbidity (e.g., hypertension and diabetes mellitus).ResultsIn the multivariate analysis, the statistically significant factor related with hospital duration was the presence of perforation on the CT scan (P < 0.001). Longer NPO time was related with pain score (>7) (P = 0.011). Operations were mainly performed in patients with left-sided colonic diverticulitis (P = 0.012).ConclusionWe suggest a perforation finding on the CT scan, a severe pain score at least above 7 on a numeric rating pain scale, and a left-sided lesion are absolute indications for in-hospital management.

Background Mucinous carcinoma of the breast is an indolent tumors with a favorable prognosis; however, micropapillary features tend to lead to aggressive behavior. Thus, mucinous carcinoma and micropapillary carcinoma exhibit contrasting biologic behaviors. Here, we review invasive mucinous carcinoma with a focus on micropapillary features and correlations with clinicopathological factors. Methods A total of 64 patients with invasive breast cancer with mucinous or micropapillary features were enrolled in the study. Of 36 pure mucinous carcinomas, 17 (47.2%) had micropapillary features and were termed mucinous carcinoma with micropapillary features (MUMPC), and 19 (52.8%) had no micropapillary features and were termed mucinous carcinoma without micropapillary features. MUMPC were compared with 15 invasive micropapillary carcinomas (IMPC) and 13 invasive ductal and micropapillary carcinomas (IDMPC). Results The clinicopathological factors of pure mucinous carcinoma and MUMPC were not significantly different. In contrast to IMPC and IDMPC, MUMPC had a low nuclear grade, lower mitotic rate, higher expression of hormone receptors, negative human epidermal growth factor receptor 2 (HER2) status, lower Ki-67 proliferating index, and less frequent lymph node metastasis (p < .05). According to univariate analyses, progesterone receptor, HER2, T-stage, and lymph node metastasis were significant risk factors for overall survival; however, only T-stage remained significant in a multivariate analysis (p < .05). Conclusions In contrast to IMPC and IDMPC, the micropapillary pattern in mucinous carcinoma does not contribute to aggressive behavior. However, further analysis of a larger series of patients is required to clarify the prognostic significance of micropapillary patterns in mucinous carcinoma of the breast.

A smart regenerative braking system, which is an advanced driver assistance system of electric vehicles, automatically controls the regeneration torque of the electric motor to brake the vehicle by recognizing the deceleration conditions. Thus, this autonomous braking system can provide driver convenience and energy efficiency by suppressing the frequent braking of the driver brake pedaling. In order to apply this assistance system, a deceleration planning algorithm should guarantee the safety deceleration under diverse driving situations. Furthermore, the planning algorithm suppresses a sense of heterogeneity by autonomous braking. To ensuring these requirements for deceleration planning, this study proposes a multi-level deceleration planning algorithm which consists of the two representative planning algorithms and one planning management. Two planning algorithms, which are the driver model-based planning and optimization-based planning, generate the deceleration profiles. Then, the planning management determines the optimal planning result among the deceleration profiles. To obtain an optimal result, planning management is updated based on the reinforcement learning algorithm. The proposed algorithm was learned and validated under a simulation environment using the real vehicle experimental data. As a result, the algorithm determines the optimal deceleration vehicle trajectory to autonomous regenerative braking.

To preserve the fun of driving and enhance driving convenience, a smart regenerative braking system (SRS) is developed. The SRS provides automatic regeneration that is appropriate for the driving conditions, but the existing technology has a low level of acceptability and comfort. To solve this problem, this paper presents an automatic regenerative control system based on a deceleration model that reflects the driver’s characteristics. The deceleration model is designed as a parametric model that mimics the driver’s behavior. In addition, it consists of parameters that represent the driver’s characteristics. These parameters are updated online by a learning algorithm. The validation results of the vehicle testing show that the vehicle maintained a safe distance from the leading car while simulating a driver’s behavior. Of all the deceleration that occurred during the testing, 92% was conducted by the automatic regeneration system. In addition, the results of the online learning algorithm are different based on the driver’s deceleration pattern. The presented automatic regenerative control system can be safely used in diverse car-following situations. Moreover, the system’s acceptability is improved by updating the driver characteristics. In the future, the algorithm will be extended for use in more diverse deceleration situations by using intelligent transportation system information.

This paper presents a simplified decoupler-based multivariable controller with a gain scheduling strategy in order to deal with strong nonlinearities and cross-coupled characteristics for exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) systems in diesel engines. A feedback controller is designed with the gain scheduling strategy, which updates control gains according to engine operating conditions. The gain scheduling strategy is implemented by using a proposed scheduling variable derived from indirect measurements of the EGR mass flow, such as the pressure ratio of the intake, exhaust manifolds, and the exhaust air-to-fuel ratio. The scheduling variable is utilized to estimate static gains of the EGR and VGT systems; it has a large dispersion in various engine operating conditions. Based on the estimated static gains of the plant, the Skogestad internal model control (SIMC) method determines appropriate control gains. The dynamic decoupler is designed to deal with the cross-coupled effects of the EGR and VGT systems by applying a simplified decoupler design method. The simplified decoupler is beneficial for compensating for the dynamics difference between two control loops of the EGR and VGT systems, for example, slow VGT dynamics and fast EGR dynamics. The proposed control algorithm is evaluated through engine experiments. Step test results of set points reveal that root-mean-square (RMS) error of the gain-scheduled feedback controller is reduced by 47% as compared to those of the fixed gain controller. Furthermore, the designed simplified decoupler decreased the tracking error under transients by 14-66% in various engine operating conditions. [ABSTRACT FROM AUTHOR]

Background: The luminal subtype of breast cancer is sensitive to anti-estrogen therapy and shows a better prognosis than that of human epidermal growth factor receptor2 (HER2)-enriched or triple-negative breast cancer. However, the luminal type of breast cancer is heterogeneous and can have aggressive clinical features. We investigated the clinical implications of single hormone receptor negativity in a luminal B HER2- negative group. Methods: We collected luminal B HER2-negative breast cancer data that were estrogen receptor (ER) and/or progesterone receptor (PR) positive, Ki 67 high (>14%), and HER2 negative and divided them into the ERand PR-positive group and the ER- or PR-negative group. We analyzed the clinical and pathological data and survival according to ER or PR loss. Results: There were no statistical differences in TNM stage, breast and axillary operative methods, or number of tumors between the ER- and PR-positive group and ER- or PR-negative group. However, the ER- or PR-negative group was associated with older age (≥45 years), higher histological grade, lower Bcl-2 expression, and far higher Ki 67 (>50%). Disease-free survival (DFS) and overall survival (OS) were shorter in the ER- or PR-negative group than that in the ER- and PR-positive group (p = 0.0038, p = 0.0071). Conclusions: ER- or PR-negative subgroup showed worse prognosis than ER- and PR-positive subgroup in the luminal B HER2-negative group. We could consider the negativity of ER or PR as prognostic marker in luminal B HER2-negative subtype of breast cancer. [ABSTRACT FROM AUTHOR]

This paper proposes a model-based gain scheduling strategy of a Skogestad internal model control (SIMC)-based boost pressure controller for passenger car diesel engines. This gain scheduling strategy is proposed with a new scheduling variable to handle the nonlinear variable geometric turbocharger (VGT) plant characteristics. The scheduling variable is derived from the pressure ratio between the exhaust and intake manifolds and the exhaust air-to-fuel ratio to estimate the static gain of the VGT plant, which varies widely with change in the engine operating conditions. The proposed static gain model was designed with the scheduling variable, engine speed, and fuel injection quantity. Compared to the steady-state experimental data, the static gain model showed an Rsquared value of 0.91. The boost pressure controller had the proportional-integral (PI) structure to allow for online calibration, and the PI gains were determined using the SIMC method. The proposed static gain model for the VGT plant was integrated into the SIMC control structure to obtain the appropriate control gains under wide engine operating area. The proposed control algorithm was compared with a fixed gain boost pressure controller through various step tests of the desired boost pressure. The fixed gain controller showed a large overshoot of 64% when the exhaust gas recirculation (EGR) operating condition was changed. In contrast, the proposed gain scheduled boost pressure controller reduced the overshoot to 12%. The model-based gain scheduling strategy successfully adjusted the control gains to achieve consistent control performance under various engine operating conditions. [ABSTRACT FROM AUTHOR]

This paper investigates the design of model-based feedforward compensators for exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) systems using air path models for a common-rail direct injection (CRDI) diesel engine to cope with the nonlinear control problem. The model-based feedforward compensators generate set-positions of the EGR valve and the VGT vane to track the desired mass air flow {MAE) and manifold absolute pressure (MAP) with consideration of the current engine operating conditions. In the best case, the rising time to reach 90% of the MAE set-point was reduced by 69.8% compared with the look-up table based feedforward compensators. [ABSTRACT FROM AUTHOR]