Under- and Normal-Weight Patients Are More Susceptible to Recurrence of Phyllodes Tumor.

Purpose: Phyllodes tumors (PTs) of the breast are rare fibroepithelial neoplasms, and factors associated with the recurrence of PTs are poorly understood. This study sought to identify clinicopathological factors associated with the recurrence of PTs. Method: From January 2009 to December 2019, we identified 100 patients who underwent definitive surgery for PT. Clinicopathological risk factors associated with the recurrence of PT were assessed. Results: The median age of the patients was 44 y (range, 19-62 y), and the median tumor size was 4 cm (0.8-30 cm). At a median follow-up of 26.7 mo (0-103 mo), 22 of the 100 patients experienced local recurrence. In the univariate and multivariate analyses, body mass index ≥ 23 kg/m2 (P = 0.042 in the univariate analysis; P = 0.039 in the multivariate analysis), tumor size ≥ 5 cm (P = 0.006 in the univariate analysis; P = 0.036 in the multivariate analysis), and the presence of stromal overgrowth (P = 0.032 in the univariate analysis; P = 0.040 in the multivariate analysis) were associated with an increased risk of local recurrence. Resection margins and grade were not associated with local recurrence. Conclusion: Normal- or underweight patients and those with larger tumor sizes were more prone to local recurrence. Further larger, multicenter studies with a long-term follow-up are required.

Slippery and Wear-Resistant Surfaces Enabled by Interface Engineered Graphene.

Friction and wear remain the primary cause of mechanical energy dissipation and system failure. Recent studies reveal graphene as a powerful solid lubricant to combat friction and wear. Most of these studies have focused on nanoscale tribology and have been limited to a few specific surfaces. Here, we uncover many unknown aspects of graphene's contact-sliding at micro- and macroscopic tribo-scales over a broader range of surfaces. We discover that graphene's performance reduces for surfaces with increasing roughness. To overcome this, we introduce a new type of graphene/silicon nitride (SiNx, 3 nm) bilayer overcoats that exhibit superior performance compared to native graphene sheets (mono and bilayer), that is, display the lowest microscale friction and wear on a range of tribologically poor flat surfaces. More importantly, two-layer graphene/SiNx bilayer lubricant (<4 nm in total thickness) shows the highest macroscale wear durability on tape-head (topologically variant surface) that exceeds most previous thicker (∼7-100 nm) overcoats. Detailed nanoscale characterization and atomistic simulations explain the origin of the reduced friction and wear arising from these nanoscale coatings. Overall, this study demonstrates that engineered graphene-based coatings can outperform conventional coatings in a number of technologies.

Comparison of skin-sparing mastectomy using LigaSure™ Small Jaw and electrocautery.

BACKGROUND: Skin-sparing mastectomy (SSM) is increasingly used in patients with breast cancer. We compared the differences between use of electrocautery and LigaSure™ Small Jaw in patients with breast cancer who underwent SSM. METHODS: Between January 2012 and December 2015, 81 patients with breast cancer who underwent SSM were selected and were divided into the electrocautery group and the LigaSure™ Small Jaw group based on the devices that were used. Clinicopathological characteristics, body mass index, operative time, and weight of removed breast were obtained from medical records. Total amount and days of drain use, until removal, and postoperative skin necrosis, requiring debridement, were also analyzed. RESULTS: The study population consisted of 50 patients in the electrocautery group and 31 in the LigaSure™ Small Jaw group. The latter group has significantly shorter operative time (117.5 ± 16.9 vs. 104.0 ± 23.6 min, P = 0.004). The mean total volume of drainage was less (805 ± 278 vs. 694 ± 131 mL, P = 0.017) and mean duration of drainage was also significantly shorter in the LigaSure™ Small Jaw group (11.3 ± 2.5 vs. 10.1 ± 2.0 days, P = 0.029). CONCLUSIONS: The use of LigaSure™ Small Jaw during skin-sparing mastectomy shortened the operative time and duration of drainage and reduced the total volume of drainage.

Thermal injury of the recurrent laryngeal nerve by THUNDERBEAT during thyroid surgery: findings from continuous intraoperative neuromonitoring in a porcine model.

BACKGROUND: Recurrent laryngeal nerve (RLN) palsy is the most common and serious complication of thyroid surgery. The use of energy-based devices (EBDs) has replaced hand-tying methods in many institutions. However, EBD use proximal to the RLN presents risks related to lateral thermal spread and associated nerve damage. THUNDERBEAT (TB) is one of the most widely used EBDs. This study aimed to test the safety of TB during thyroidectomy. METHODS: Four piglets weighing 30-40 kg experienced thyroidectomy while continuous electrophysiologic monitoring (continuous intraoperative neuromonitoring) occurred, using an electromyography endotracheal tube and NIM 3.0 response system. TB was applied at various distances from the RLN, and we assessed the safety of the protocols. RESULTS: Adverse electromyography events did not occur at distances >3 mm from the RLN. Amplitude decreased at 2 mm from the RLN after 8 s. However, immediate loss of signal occurred at 1 mm from the RLN, likely due to immediate shrinkage of surrounding tissue after TB application. CONCLUSIONS: TB can be used safely at 3 mm from the RLN but must be used for <8 s at more proximal locations. This is the first report assessing the safety of TB, and findings indicate that TB should be used at least 1 mm from the RLN to avoid injury.

Pre-ablation stimulated thyroglobulin is a better predictor of recurrence in pathological N1a papillary thyroid carcinoma than the lymph node ratio.

BACKGROUND: Papillary thyroid carcinomas (PTC) with lymph node metastases have a high recurrence rate. We analyzed the potential of lymph node ratio (LNR) and the level of pre-ablation stimulated thyroglobulin (sTg) as risk factors predicting recurrence in patients with pathological N1a PTC. MATERIALS AND METHODS: This study involved 192 patients with pathologically confirmed PTC and central neck lymph node metastases who underwent total thyroidectomy with central lymph node dissection (CLND). The clinico-pathological characteristics, the pre-ablation sTg level and post-treatment recurrences were examined. Univariate and multivariate analyses were performed to identify factors associated with recurrence in these patients. RESULTS: During a median follow-up of 63 months, 17 patients had loco-regional recurrences. Receiver operating characteristic curve analysis showed that the appropriate cut-off values for LNR and the pre-ablation sTg level was 0.48 and 9.3 ng/mL, respectively. Patients with LNR values of ≥0.48 had a significantly worse disease-free survival (DFS) than those with LNR values of <0.48 (P = 0.015), and patients with pre-ablation sTg level values of ≥9.3 ng/mL had significantly worse DFS than those with pre-ablation sTg level values <9.3 ng/mL (P < 0.001). Relative to patients with LNR values of <0.48, those with LNR values of ≥0.48 had higher median pre-ablation sTg level values (0.55 vs. 4.20; P < 0.001). The correlation covariant between the LNR value and the pre-ablation sTg level value was r = 0.454 (P < 0.001). Multivariate analysis showed that a LNR value of ≥0.48 (P = 0.386) was not an independent risk factor for recurrence. To the contrary, a pre-ablation sTg level value of ≥9.3 ng/mL (P < 0.001) was an independent risk factor for recurrence. CONCLUSION: A high pre-ablation sTg level is a better predictor of recurrence in pathological N1a PTC than a high LNR value. Careful follow-up of patients with this risk factor is recommended.

Robotic thyroidectomy using bilateral axillo-breast approach: Comparison of surgical results with open conventional thyroidectomy.

BACKGROUND: The aim of the present study was to compare the surgical outcomes of robotic thyroidectomy using the bilateral axillo-breast approach (BABA) with open conventional thyroidectomy. METHODS: Database of patients who underwent thyroidectomy with cervical lymph node dissection after diagnosed as papillary thyroid carcinoma between July 2008 and February 2013 were examined. Clinicopathologic characteristics, surgical outcomes, and postoperative morbidities of robot group and open group were investigated. RESULTS: The dominant tumor size (P=0.974), body mass index (BMI) (P=0.426), and the mean number of metastatic lymph nodes in central compartment neck dissection (P=0.269) were comparable between the two groups. The mean number of retrieved central lymph nodes was higher in the open group than in the robot group (P=0.001). Postoperative complications were comparable: hypoparathyroidism in 2 weeks (P=0.296) and 3 months (P=0.446) after the surgery; vocal cord palsy in 2 weeks (P=0.363) and 3 months (P=0.312); hematoma (P=0.162); and wound infection (P=0.421). CONCLUSIONS: Robotic thyroidectomy using BABA may be a technically feasible and safe procedure comparable to conventional open surgery especially in node-negative patients.

Transoral periosteal thyroidectomy: cadaver to human.

BACKGROUND: Although endoscopic thyroid surgery is gaining wide acceptance, existing endoscopic methods for thyroidectomy are blamed for the increased frequency of flap dissections and longer surgical times. More recently, transoral endoscopic thyroidectomy has overcome the limitations of previous approaches. Herein, we present our initial experience with transoral periosteal thyroidectomy (TOPOT) in cadaver and porcine models. Using these models, the surgical view was improved and had greater freedom of motion; the technique was then performed in human subjects using robotic TOPOT, which has not previously been reported. METHOD: TOPOTs were performed in seven fresh human cadavers and ten live pigs. Total thyroidectomies were performed in all cadavers and pigs. After the cadaver and animal trials, four human patients underwent robotic TOPOT performed using the da Vinci® surgical system at Korea University Anam Hospital. Recurrent laryngeal nerve function, intra- and postoperative complications, and postoperative outcomes were assessed in all patients. RESULT: One left lobectomy for follicular adenoma, two right lobectomies for nodular hyperplasia, and one left lobectomy with a central neck dissection for papillary thyroid microcarcinoma were performed in the human subjects using a robotic transoral periosteal approach. In three cases, paresthesia occurred in the mental nerve, but this improved within 4 weeks in all cases. No local infections occurred at the incision site or anterior neck, and no recurrent laryngeal nerve cord palsies occurred postoperatively. CONCLUSION: TOPOT may be an effective and safe approach for robotic thyroid surgery.

YKL-40 expression could be a poor prognostic marker in the breast cancer tissue.

YKL-40 is a glycoprotein involved in cellular growth, migration, and the inflammatory process. Elevation in serum levels of YKL-40 has been associated with worse prognosis in various cancers, including breast cancer. Given that the clinical significance of YKL-40 expression in breast cancer tissue is unclear, we aimed to determine the prognostic value of YKL-40 expression in breast cancer tissue using immunohistochemistry. We performed tissue microarray (TMA) analysis of 425 breast cancer tissues collected during operation. Immunohistochemical staining was performed to measure expression of YKL-40 and several breast cancer biomarkers, such as aldehyde dehyadrogenase1, TGF-beta, and Gli-1 as well as hormonal receptor and Her-2/neu status. Statistical analysis of the relationship of YKL-40 expression with clinicopathological characteristics was performed for 390 TMA samples. YKL-40 was expressed to varying degrees in 84.9% of breast cancer tissues. YKL-40 expression was correlated with estrogen receptor and progesterone receptor negativity and was positively correlated with TGF-beta and Gli-1 expression. Strong YKL-40 expression was associated with a larger proportion of Her-2/neu-enriched and basal-like tumors. The results of this study demonstrate that YKL-40 expression in breast cancer tissues is associated with hormone receptor negativity and Her-2/neu-enriched molecular subtypes of breast cancer, and therefore could be considered a poor prognostic predictor.

Safe and successful pregnancy following breast cancer treatment in young patients 35 years old or under without invasive fertility preservation: a retrospective study.

Purpose: Recent advances in the treatment of breast cancer have led to the improvement of breast cancer patient's survival. With the prolonged survival of these patients, pregnancy became an important issue, especially in young cancer patient aged 35 years or under. Increased hormone levels during pregnancy, however, raise concerns about elevating the risk of cancer recurrence. The aim of this study was to validate the notion of increased risk associated with pregnancy after breast cancer treatment in young patients. Methods: From January 2009 to December 2020, newly diagnosed breast cancer patients 35 years old or under who underwent optimal surgery in Korea University Guro Hospital were enrolled in this study. Patients were categorized into 3 groups: nulliparous, pregnancy prior to treatment of breast cancer, and patients with pregnancy after breast cancer treatment. Their overall survival and disease-free survival were evaluated. Results: A total of 107 patients were enrolled in this study. Thirteen patients (12.1%) conceived and successfully delivered. The mean follow-up period after surgery was 58.9 (± 33.5) months. There was no significant difference in overall survival (P = 0.608) and disease-free survival (P = 0.591) among different groups. Conclusion: In young patients, pregnancy after treatment for breast cancer did not affect their overall survival or diseasefree survival as compared to nullipara or previously delivered groups. Therefore, pregnancy counseling should not be prevented in young breast cancer patients 35 years old or under.

The relationship between preeclampsia, pregnancy-induced hypertension and maternal risk of breast cancer: a meta-analysis.

BACKGROUND: It has long been recognized that some human breast cancers are hormone dependent. Preeclampsia is a syndrome of pregnancy defined by the onset of hypertension and proteinuria and characterized by dysfunction of the maternal endothelium. Many hormonal changes occur with preeclampsia, and we hypothesize that these changes may influence the risk of maternal breast cancer. We also analyzed the relation between pregnancy-induced hypertension (PIH) and maternal risk of breast cancer. METHODS: Among 13 relevant publications about preeclampsia and six relevant publications about PIH, some studies find preeclampsia associated with a lower risk of breast cancer, but others did not. Therefore, these results are inconclusive. We conducted meta-analysis to evaluate more precisely the relationship between preeclampsia, PIH and maternal risk of breast cancer. RESULTS: The pooled estimate of the hazard ratio (HR) associated with preeclampsia was 0.86 (95% CI 0.73-1.01), and that associated with PIH was 0.83 (0.66-1.06), both based on the random effects model. CONCLUSION: Some suggestive but not entirely consistent nor conclusive evidence was found on the association between the history of preeclampsia or PIH with the subsequent risk of breast cancer.

Plasma-discharge-integrated slot structure for microwave power limiter.

A slot structure was combined with a discharge electrode to limit incident high-power microwaves via the integration of plasma discharge. At the target resonating frequency of 9.45 GHz, the surface current was concentrated at an electrode, and the electric field was enhanced by the proposed design to lower the response power level of the incident signal. When a low-power signal is injected, plasma is not generated, and the incident wave travels without insertion loss. Double-stage slot structures were utilized to broaden the band-pass characteristics in the frequency domain, and the demonstrated plasma limiter exhibited an insertion loss of 1.01 dB at 9.45 GHz. The xenon gas pressure was optimized with the shortest distance of 100 µm between the upper and lower electrodes to reduce the discharge power of the plasma. In the case of a high-power signal input, as xenon-gas breakdown occurred, the transmitted signal was close to zero, and most of the high-power signal was reflected with a blocking efficiency of 40.55 dB. The demonstrated result will be useful to protect the receiver of a radio detection and ranging system from the high power microwave.

Transparent and Flexible Graphene Pressure Sensor with Self-Assembled Topological Crystalline Ionic Gel.

This study demonstrates transparent and flexible capacitive pressure sensors using a high-k ionic gel composed of an insulating polymer (poly(vinylidene fluoride-co-trifluoroethylene-co-chlorofluoroethylene), P(VDF-TrFE-CFE)) blended with an ionic liquid (IL; 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide, [EMI][TFSA]). The thermal melt recrystallization of the P(VDF-TrFE-CFE):[EMI][TFSA] blend films develops the characteristic topological semicrystalline surface of the films, making them highly sensitive to pressure. Using optically transparent and mechanically flexible graphene electrodes, a novel pressure sensor is realized with the topological ionic gel. The sensor exhibits a sufficiently large air dielectric gap between graphene and the topological ionic gel, resulting in a large variation in capacitance before and after the application of various pressures owing to the pressure-sensitive reduction of the air gap. The developed graphene pressure sensor exhibits a high sensitivity of 10.14 kPa-1 at 20 kPa, rapid response times of <30 ms, and durable device operation with 4000 repeated ON/OFF cycles. Furthermore, broad-range detections from lightweight objects to human motion are successfully achieved, demonstrating that the developed pressure sensor with a self-assembled crystalline topology is potentially suitable for a variety of cost-effective wearable applications.

The relationship between twin births and maternal risk of breast cancer: a meta-analysis.

Women who undergo a greater number of menstrual cycles may be at increased risk of breast cancer, possibly due to cumulative exposure to ovarian hormones. Pregnancy reduces the lifetime number of menstrual cycles and also influences the levels of ovarian hormones. Twin pregnancies differ from singleton pregnancies in both hormone levels and perinatal changes. To date, a meta-analysis on the effects of twin birth on the risk of maternal breast cancer has not been conducted. Among 17 relevant publications identified in a systematic search, some suggest that twin births may be associated with lower breast cancer risk but others do not; therefore, the results are inconclusive. Although our pooled results of all 17 published studies did not show a reduced maternal risk of breast cancer for twin births (HR 0.94; 95% CI = 0.87-1.02; P = 0.127), a trend toward reduced maternal risk of breast cancer was identified in a subgroup analysis of cohort studies (HR 0.91; 95% CI = 0.83-1.01; P = 0.068). The results of this meta-analysis suggest that twin pregnancy does not significantly decrease the maternal risk of breast cancer.

Association of a vascular endothelial growth factor gene 936 C/T polymorphism with breast cancer risk: a meta-analysis.

Published studies on the association between the vascular endothelial growth factor (VEGF) gene 936 C/T polymorphism and breast cancer risk are inconclusive, and a meta-analysis is required to verify the association. Nine studies, including a total of 4,973 cases and 5,035 controls, were subjected to meta-analysis. When all eligible subjects were pooled for meta-analysis, the CT + TT genotypes were not associated with a significant decrease in breast cancer risk (odds ratio = 0.87; 95% confidence interval 0.75-1.02; P = 0.087). We also categorized by ethnicity (Caucasian, Asian, or mixed) for subgroup analysis, however, according to this subgroup analysis, we found no significant association between the CT and TT versus CC genotype with breast cancer risk reduction in any of the subgroups. We conclude that the VEGF gene 936 C/T polymorphism does not affect breast cancer risk.

Bevacizumab for salvage treatment of metastatic breast cancer: a systemic review and meta-analysis of randomized controlled trials.

Although various new agents have been developed for the treatment of patients with metastatic breast cancer (MBC), overall survival rates have changed little in the last half century. We conducted meta-analysis to verify the clinical efficacy of bevacizumab for the salvage treatment of MBC. Event-based hazard ratios (HR) with 95% confidence intervals (95% CIs) were derived, and a test of heterogeneity was applied. Four studies, with a total of 2,860 patients, met the inclusion criteria for analysis. The pooled results of clinical efficacies were: HR for progression free survival 0.69 (95% CI, 0.58-0.81, z = 4.54, P <0.001); HR for overall survival 0.92 (95% CI, 0.82-1.03, z =1.44, P = 0.15); and HR for the clinical objective response rate 1.53 (95% CI, 1.37-1.71, z = 7.37, P < 0.001). In terms of overall survival, subgroup analysis demonstrated statistically significant improvement for the bevacizumab combination in the initial therapy subgroup (HR, 0.878; 95% CI, 0.771-0.999, z = 1.98, P = 0.048). Hypertension and proteinura were more common in the bevacizumab combination arm; however, these toxicities were managed with therapy. In conclusion, meta-analysis suggested benefits of a carefully managed bevacizumab-containing salvage regimen for patients with histologically or cytologically confirmed Her-2 negative MBC who have not received previous cytotoxic therapy. This treatment could improve both progression free survival and overall survival rates.

Phase II study of vinorelbine monotherapy in anthracycline and taxane pre-treated metastatic breast cancer.

We performed a single-institution phase II study to evaluate the efficacy and toxicities of vinorelbine monotherapy in patients previously treated with anthracyclines and taxanes. Vinorelbine was administered at a dose level of 25 mg/m² intravenously on days 1, 8, 15 and 22, every four weeks, and responses were assessed after every two cycles of treatment. All of the patients had previously been treated with anthracyclines and taxanes. A total of 26 patients were enrolled in this study between April 2004 and August 2009. The median age of the patients was 47 years (range, 37 to 71 years), and 80.8% had an Eastern Cooperative Oncology Group performance status of 0 or 1. Out of 24 evaluable patients, five partial responses were observed, giving an overall response rate of 20.8%, with a median response duration of 2.8 months. The median time to progression was 3.7 months (range, 0.5 to 22.6 months), and median overall survival duration was 10.4 months (range, 1.3 to 57.6 months). The major toxicities observed were neutropenia, anemia and peripheral neuropathy. Grade 3 or 4 hematologic toxicities included neutropenia in 18 patients (69.2%) and anemia in four patients (15.3%). Grade 1 or 2 peripheral neuropathy was observed in 11 patients (42.3%), however there were no cases of grade 3 or 4 peripheral neuropathy. The results of this study indicate that vinorelbine monotherapy was feasible regimen with manageable toxicities in patients with metastatic breast cancer who were previously exposed to anthracyclines and taxanes.

Detailed comparison of the da Vinci Xi and S surgical systems for transaxillary thyroidectomy.

ABSTRACT: Robotic surgical systems have evolved over time. The da Vinci Xi system was developed in 2014 and was expected to solve the shortcomings of the previous S system. Therefore, we conducted this study to compare these 2 systems and identify if the Xi system truly improves surgical outcomes.In this retrospective study, a total of 86 patients with unilateral papillary thyroid carcinoma without central lymph node involvement underwent gasless transaxillary hemithyroidectomy using 2 robotic systems, the da Vinci S and Xi. Forty patients were in the da Vinci S group and 46 patients were in the da Vinci Xi group. All surgeries were performed by 1 surgeon (YWC). All surgery video files were analyzed to compare the duration of each surgical step.The total operation time was significantly shorter in the Xi group than in the S group (153.0 minutes vs 105.7 minutes, P < .01). Time for robot docking was shorter in the Xi group (19.8 minutes vs 10.6 minutes, P < .01), and all procedures performed in the console also required a shorter time in this group. The overall complication rate did not differ significantly (P = .464).The da Vinci Xi system made robotic thyroidectomy easier and faster without increasing the complication rate. It is a safe and valuable system for robotic thyroidectomy.

Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional Nipple-Sparing Mastectomy for Breast Cancer Based on Initial Experience.

PURPOSE: Endoscopic breast surgery for patients with breast cancer was introduced for its superior cosmetic outcomes; it was initially studied in the field of breast-conserving surgery and, more recently, in robotic-assisted nipple-sparing mastectomy (NSM). The main purpose of this study was to investigate the feasibility and safety of endoscopic NSM (E-NSM) in patients with breast cancer by comparing E-NSM and conventional NSM (C-NSM). METHODS: Between May 2017 and October 2020, we retrieved the records of 45 patients who underwent NSM with permanent silicone implants and divided them into the E-NSM group (20 patients) and the C-NSM group (25 patients), depending on the use of the endoscopic device. We also analyzed demographic information, pathology, operative time, and complications. RESULTS: No significant differences were observed between the 2 groups based on demographic information, postoperative pathological data, mean length of hospital stay, and total number of complications. The mean preparation time for surgery was comparable between both groups. Compared to the C-NSM group, the E-NSM group had a significantly longer mean operative time and, subsequently, a significantly longer mean total operative time and number of complications. CONCLUSION: The results showed that E-NSM was feasible and safe with a more inconspicuous incision in patients with breast cancer.

Association of a TGF-ß1 gene -509 C/T polymorphism with breast cancer risk: a meta-analysis.

Transforming growth factor-ß1 (TGF-ß1) is negative regulator of cell proliferation and the cell cycle, and plasma levels of TGF-ß1 are twice as high in TGF-ß1 -509 T homozygotes as in -509 C homozygotes. Published studies on the association between the TGF-ß1 gene -509 C/T polymorphism and breast cancer risk are inconclusive, and a meta-analysis is required to verify the association. We performed a meta-analysis of four studies, including a total of 5,986 cases and 6,829 controls. Our pooled results indicate that the TGF-ß1 gene -509 C/T polymorphism is not associated with breast cancer risk in a TT versus CC codominant (OR = 1.08; 95% CI = 0.87-1.34; P = 0.494), in a CT versus CC codominant (OR = 1.02; 95% CI = 0.94-1.10; P = 0.686), recessive (OR = 0.92; 95% CI = 0.83-1.03; P = 0.157), and dominant (OR = 1.03; 95% CI = 0.96-1.11; P = 0.439) models. Conclusively, this meta-analysis suggests that the TGF-ß1 gene -509 T allele polymorphism does not decrease breast cancer risk.