Abstract P3-03-22: Prognostic impact of axillary lymph node status after neoadjuvant chemotherapy for patients with breast cancer

BACKGROUND:

Patients were stratified by final pathological axillary status: ypN0, ypN1, pN0 or pN1.

The prognostic impact of lymph node involvement after neoadjuvant chemotherapy (NAC) for breast cancer is not straightforward. The aim of this study was to compare overall survival (OS) between pathologically

node-positive T1,T2 T3 breast cancer patients treated with NAC, with ypN0 or ypN1 and those treated without NAC with pN0 or pN1.

METHODS:

A total of 3903 consecutive patients with operable breast cancer were prospectively identified at our institution between April 2006 and December 2017. Patients with suspicious axillary LN of breast cancer were assessed using preoperative imaging, underwent fine-needle aspiration cytology or core needle biopsy.

The patients in this study were divided into four groups as follows: the ER(+), the ER(+)/HER2(+) , the HER2(+) and the Triple negative (TN) group.

We evaluate the prognostic impact of the ypN0, ypN1 (with one to three positive lymph nodes after NAC), pN0 and pN1 with no NAC.

The main outcome measures DFS and OS were analyzed using Kaplan–Meier survival analysis.

Result

A number of 270 and 3633 patients were included for NAC and non NAC, respectively. Pathologic nodal status was ypN0 in 58%, ypN1 in 42% for NAC and pN0 in 76%, pN1 in 24% of patients for non NAC.

Overall, 10-year DFS and OS was 81%, 93% in ypN0, 67%, 80% in ypN1, in 90%, 97%, in pN0 and 83%, 94% in pN1 (p <0.001).

In subgroup analysis, 10-year DFS of ypN0, ypN1, pN0 and pN1 was 86%,77%,95% and 80% in the ER group, 91%,56%,93%,and 76% in the ER/HER2 group,89%,55%,91% and 80% in the HER2 group, 85%,59%,92% and 80% in the TN group.

10 years DFS for the ER group were significantly different between ypN0 and pN0 (HR, 2.42 (1.03–4.86, p = 0.04) but were not significantly different between ypN0 and pN0 for the ER/HER2 group (HR 3.58 (0.2–6.88, p = 0.66), for the HER2 group (HR 2.6 (0.78–7.65, p = 0.10) and for the TN group (HR 1.22(0.56–2.38, p = 0.58), respectively).

In all group, DFS for ypN1 was inferior to ypN0.

Conclusions

In the ER group treated with NAC, DFS for ypN0 be inferior to pN0 with adjuvant treatment. In the HER2, the ERHER2 and the TN group treated with NAC, ypN0 is similar to pN0 with adjuvant chemotherapy.

Axillary nodal status ypN1 in each subgroup is associated with a less favorable prognosis compared to ypN0. In conclusion, the HER2 or TN group is highest for predicting ypN0, shown to be most prognostic of long-term survival similar to the patients with pN0. They could be omitted the axillary dissection.

Citation Format: Nakamura R, Yamamoto N, Miyaki T, Itami M. Prognostic impact of axillary lymph node status after neoadjuvant chemotherapy for patients with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-22.

Electron-scale dynamics of the diffusion region during symmetric magnetic reconnection in space

Magnetic reconnection is an energy conversion process that occurs in many astrophysical contexts including Earth's magnetosphere, where the process can be investigated in situ by spacecraft. On 11 July 2017, the four Magnetospheric Multiscale spacecraft encountered a reconnection site in Earth's magnetotail, where reconnection involves symmetric inflow conditions. The electron-scale plasma measurements revealed (i) super-Alfvénic electron jets reaching 15,000 kilometers per second; (ii) electron meandering motion and acceleration by the electric field, producing multiple crescent-shaped structures in the velocity distributions; and (iii) the spatial dimensions of the electron diffusion region with an aspect ratio of 0.1 to 0.2, consistent with fast reconnection. The well-structured multiple layers of electron populations indicate that the dominant electron dynamics are mostly laminar, despite the presence of turbulence near the reconnection site.

How Accurately Can We Measure the Reconnection Rate M for the MMS Diffusion Region Event of 11 July 2017?

We investigate the accuracy with which the reconnection electric field E M can be determined from in situ plasma data. We study the magnetotail electron diffusion region observed by National Aeronautics and Space Administration's Magnetospheric Multiscale (MMS) on 11 July 2017 at 22:34 UT and focus on the very large errors in E M that result from errors in an L M N boundary normal coordinate system. We determine several L M N coordinates for this MMS event using several different methods. We use these M axes to estimate E M. We find some consensus that the reconnection rate was roughly E M = 3.2 ± 0.6 mV/m, which corresponds to a normalized reconnection rate of 0.18 ± 0.035. Minimum variance analysis of the electron velocity (MVA-v e), MVA of E, minimization of Faraday residue, and an adjusted version of the maximum directional derivative of the magnetic field (MDD-B) technique all produce reasonably similar coordinate axes. We use virtual MMS data from a particle-in-cell simulation of this event to estimate the errors in the coordinate axes and reconnection rate associated with MVA-v e and MDD-B. The L and M directions are most reliably determined by MVA-v e when the spacecraft observes a clear electron jet reversal. When the magnetic field data have errors as small as 0.5% of the background field strength, the M direction obtained by MDD-B technique may be off by as much as 35°. The normal direction is most accurately obtained by MDD-B. Overall, we find that these techniques were able to identify E M from the virtual data within error bars ≥20%.

Size of recurrent laryngeal nerve as a new risk factor for postoperative vocal cord paralysis

Recurrent laryngeal nerve paralysis (RLNP) is a frequent and serious complication following esophageal cancer surgery. Therefore, this study aims to evaluate the correlation between recurrent laryngeal nerve (RLN) size and RLNP. This was a retrospective study of esophageal cancer patients who underwent thoracoscopic esophagectomy from January 2012 to December 2014. Eighty-four patients were included in the primary analysis. Diameter of the RLN was measured using the digital video recording of surgical procedures by the ratio between scissor and RLN. For evaluation of vocal cord paralysis or paresis, indirect laryngoscopy was performed. Because RLNP more frequently occurs on the left side than the right, we evaluated the correlation between size of the left RLN and left RLNP. The median size of the left RLN was 1.51 mm. We found that the incidence of postoperative left RLNP (Clavien-Dindo classification ≥1) was significantly higher (71% vs. 24%; P < 0.001) in thin RLNs (≤1.5 mm) than in thick RLNs (>1.5 mm). Thin RLN (P < 0.001), female sex (P = 0.025), and being overweight (P = 0.034) were identified as significant independent risk factors for postoperative RLNP. RLNP more easily occurred when the RLN was thin. It is difficult to confirm occurrence of postoperative RLNP before and at extubation. Therefore, it is helpful to know its risk factors including size of RLN.

Meta-analysis of the impact of postoperative complications on survival after oesophagectomy for cancer

Background

Oesophagectomy has a high risk of postoperative morbidity. The impact of postoperative complications on overall survival of oesophageal cancer remains unclear. This meta‐analysis addressed the impact of complications on long‐term survival following oesophagectomy.

Methods

A search of PubMed and Cochrane Library databases was undertaken for systematic review of papers published between January 1995 and August 2016 that analysed the relation between postoperative complications and long‐term survival. In the meta‐analysis, data were pooled. The main outcome was overall survival (OS). Secondary endpoints included disease‐free (DFS) and cancer‐specific (CSS) survival.

Results

A total of 357 citations was reviewed; 21 studies comprising 11 368 patients were included in the analyses. Overall, postoperative complications were associated with significantly decreased 5‐year OS (hazard ratio (HR) 1·16, 95 per cent c.i. 1·06 to 1·26; P = 0·001) and 5‐year CSS (HR 1·27, 1·09 to 1·47; P = 0·002). Pulmonary complications were associated with decreased 5‐year OS (HR 1·37, 1·16 to 1·62; P < 0·001), CSS (HR 1·60, 1·35 to 1·89; P < 0·001) and 5‐year DFS (HR 1·16, 1·00 to 1·33; P = 0·05). Patients with anastomotic leakage had significantly decreased 5‐year OS (HR 1·20, 1·10 to 1·30; P < 0·001), 5‐year CSS (HR 1·81, 1·11 to 2·95; P = 0·02) and 5‐year DFS (HR 1·13, 1·02 to 1·25; P = 0·01).

Conclusion

Postoperative complications after oesophagectomy, including pulmonary complications and anastomotic leakage, decreased long‐term survival.

Abstract P3-13-03: NEOS: A randomized, open label, phase 3 trial of adjuvant chemotherapy for postmenopausal breast cancer patients who responded to neoadjuvant letrozole: First report of long-term outcome and prognostic value of response to neoadjuvant endocrine therapy

Background: Whether adjuvant chemotherapy is required for patients (pts) with intermediate-risk endocrine-responsive postmenopausal breast cancer (BC) remains unknown. Sufficient data have not been available about the long-term prognosis of patients with neoadjuvant endocrine therapy (ET). NEOS is a randomized phase III study that assessed the long-term prognosis of estrogen receptor positive (ER+) primary breast cancer (PBC) pts who received neoadjuvant ET with/without adjuvant chemotherapy.

Methods: Postmenopausal BC pts with ER +/HER2 negative, T1c-2, clinically node negative, under 76 years old were enrolled at primary registration. Pts were treated by leterozole (LET) in weeks 24-28 after primary enrollment. Pts experienced progression (PD) during neoadjuvant phase were excluded at randomization and received any systemic therapy driven by investigators before or after surgery. The long-term prognosis was followed in all registered pts including PD pts. Response to neoadjuvant ET was evaluated as complete response (CR), partial response (PR) or stable disease (SD) using calipers, ultrasound and MRI (or CT) at the baseline and end of treatment before surgery. Pts who met eligibility criteria were randomized 1:1 to LET for 4.5-5 years after chemotherapy or LET alone for 4.5-5 years without chemotherapy after surgery. Pts excluded at second registration were treated any systemic therapies driven by investigators. The primary endpoint was disease-free survival (DFS) and secondary endpoints included overall survival (OS), clinical response rate in neoadjuvant phase, pathological response, and breast-conserving surgery rate. The randomization code have been blinded to the investigators.

Results: Between May 2008 and June 2013, 904 patients were enrolled at primary registration from 100 institutions in Japan (median follow-up: 4.0 years) and 24 pts were withdrawn during neoadjuvant phase. The median age was 63 years, T1c:37%, T2:63%, and PgR+:78%. Clinical response rates (CR, PR, SD and PD) were2% (16pts), 48% (421pts), 45% (400pts) and 5% (43pts), respectively and, in each response category, 0% (0/16), 5.5% (23/421), 7.8% (31/400), and 20.9% (9/43) experienced DFS events. DFS in PD pts to neoadjuvant ET were statistically significantly worse than CR, PR, SD pts (p&lt;0.0001, hazard ratio 4.7 (95% CI:2.3-9.5). The prognosis after surgery in 669 randomized pts was good regardless with/without chemotherapy, forty four pts (6.6%) experienced DFS events after surgery. The predictive markers of PD for neoadjuvant ET were yet unclear among evaluated clinical factors.

Conclusion: This is the first report of DFS in the largest neoadjuvant ET trial (NEOS). The DFS of postmenopausal, ER+/HER2-, PBC pts excluding PD pts to neoadjuvant ET is highly good regardless with/without chemotherapy. Neoadjuvant ET with utilization of PD response as a prognostic marker can be considered as a standard treatment option for these patients. Clinical trial information: UMIN000001090.

Citation Format: Iwata H, Masuda N, Fujisawa T, Toyama T, Ohtani S, Yamamoto Y, Kashiwaba M, Taira N, Sakai T, Hasegawa Y, Nakamura R, Akabane H, Shibahara Y, Sasano H, Yamaguchi T, Ohashi Y. NEOS: A randomized, open label, phase 3 trial of adjuvant chemotherapy for postmenopausal breast cancer patients who responded to neoadjuvant letrozole: First report of long-term outcome and prognostic value of response to neoadjuvant endocrine therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-13-03.

Abstract P3-02-01: Impact of prognoses on the discrepancies in histological grade of breast cancer between core needle biopsy and surgical excision specimen

Purpose: The high reliability and utility of core needle biopsy (CNB) have been previously described. Histological grade in CNB is one of the main determinants of the need for neoadjuvant systemic therapy. Our aim in this study was to clarify the host and histopathological factors influencing the discrepancies in histological grade (HG) between CNB and surgically excision specimen (SES).

Methods: A total of 1342 operable invasive breast carcinoma biopsies were assessed and compared with surgical specimens in our hospital. Patients who required neoadjuvat chemotherapy were excluded. Histological grade (tubule formation, nuclear pleomorphism and mitotic index) was assessed between paired CNB and SET samples.

ER and PgR status were determined using immunohistochemistry(IHC). HER2 status was determined using IHC and scored from 0 to 3+. Fluorescence in-situ hybridization analysis was carried out in HER2 2+ cases. The cut off point for ER and PgR positivity was set at 1%.

Results: The clinicopathological characteristics of tumors showed in

Clinico-pathological characteristics of 1342 patients and tumors by discordance group between CNB and SES for histological grade  LL groupHH groupHL groupLLHgroupp valupTT1a31 (94%)0(0%)2(6%)0(0%)0.001 T1b162(92%)4(2%)1(1%)10(6%)  T1c421(79%)43(8%)14(3%)52(10%)  T2335(68%)63(13%)10(2%)82(17%)  T352(68%)8(10%)2(3%)15(19%)  T425(71%)4(11%)0(0%)6(17%) pNnegtive668(78%)73(9%)13(2%)101(12%)0.08 positive358(74%)49(10%)16(3%)64(13%) lynegative600(79%)6(4(8%)14(2%)85(11%)0.18 positive426(74%)58(10%)15(3%)80(14%) vnegative799(80%)81(5%)23(2%)98(10%)0.001 positive227(67%)41(12%)6(2%)67(20%) ER/PgRmegative82(33%)83(33%)13(5%)72(29%)0.001 positive944(86%)39(4%)16(1%)93(9%) HER2negative932(80%)86(7%)22(2%)121(10%)0.001 positive94(52%)36(20%)7(4%)44(24%) CNB;core needle biopsy, SES;surgical excision specimen, HH group (high grade in CNB/high grade in SES), LL group (low grade in CNB/low grade in SES), HL group (high grade in CNB/low grade in SES) and LH group (low grade in CNB/high grade in SES)

. The concordance rates of HG of luminal type, HER2 type luminal HER2 type and Triple negative type in CNB and SES were 91%, 64%, 73% and 66%, respectively (p&gt;0.001). Factors of discrepancy were T size, vessel invasion and ER/HER2 status for HG. The discrepancy factors were assessed with univariate and multivariate analysis. The underestimate and overestimate rates of HG in CNB compared to SES were7.5% and 1.3% in ER(+)HER2(-) type, 32%, and 3.1% in HER2 type, 22% and 4.3% in ER(+) HER2(+) type and 29% and 5.5% in Triple negative type(TN), respectively. The concordance rates of tubule formation, nuclear pleomorphism and mitotic index in CNB and SES were 81%, 97% and 93% in luminal type, 85%, 66% and 33% in HER2 type, 77%, 87% and 83% in luminal HER2 type and 82%, 67% and 73% in TN type respectively.

Conclusions: Using the largest known dataset to date of paired samples from a single institution, we evaluated the accuracy of CNB and the discrepancy factors between CNB and SES in breast cancer patients.

We conclude that CNB for histological grade assessment in patients with HER2 positive or TN breast cancer before neoadjuvant treatment should be used with caution.

Citation Format: Nakamura R, Yamamoto N, Miyaki T, Teranaka R, Itami M. Impact of prognoses on the discrepancies in histological grade of breast cancer between core needle biopsy and surgical excision specimen [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-02-01.

Abstract PD5-03: TransNEOS: Validation of the oncotype DX recurrence score (RS) testing core needle biopsy samples from NEOS as predictor of clinical response to neoadjuvant endocrine therapy for postmenopausal estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer patients

Background: Neoadjuvant therapy for locally advanced breast cancer has the potential to improve surgical therapeutic outcomes without sacrificing the survival advantages of adjuvant therapy. However, determining whether ER+ patients (pts) will respond to neoadjuvant (NA) chemotherapy (CT) or hormone therapy (HT) can be difficult. Not all ER+ pts respond to NACT, while response to NAHT can vary across ER+ pts. Thus, the ability to select pts more likely to benefit from NAHT would represent progress in clinical management of breast cancer. NEOS is a randomized phase III study assessinglong-term prognosis of ER+ primary breast cancer with/without adjuvant CT following NAHT (UMIN 000001090, http://www.umin.ac.jp/). We used archived core biopsy tumor samples from the NEOS study to validate the RS result as a predictor of clinical response and its association with successful breast conserving surgery (BCS) in pts treated with 6 months of NAHT.

Methods: NEOS enrolled 904 postmenopausal pts with ER+, HER2-, clinically node negative (cN0) breast cancer to evaluate whether adjuvant CT was necessary for pts who responded to NAHT. In this current study, we enrolled pts with tumors ≥2cm from the NEOS study. Biopsy samples of 333 pts were assessed for the Oncotype DX assay. Response to NAHT was recorded as complete/partial response (CR/PR), or stable/progressive disease (SD/PD).

Primary endpoint of this study was to evaluate clinical response (CR/PR) to NA letrozole between pts with low (&lt;18) and high (≥31) RS result. Secondary endpoints include evaluating the relationships between clinical response and continuous RS results, and other covariates including age, tumor size, grade, Ki67 by IHC, ER and PR single gene scores, and ER and proliferation gene group scores by RT-PCR.

Results: The analysis included 294 pts with median age of 63 yrs, median tumor size of 25mm, and 66% were nuclear grade 1. 156 (53.0%), 83 (28.6%) and 54(18.4%) cases were low, intermediate, and high RS groups by Oncotype DX, respectively. Six (2%), 126 (42.8%), 149 (50.3%), 13 (4.4%) cases experienced CR, PR, SD, PD as clinical response, respectively, similar to that of all NEOS pts. Clinical response rate was 54%, 42% and 22% in low, intermediate, and high RS groups, respectively. The proportion of pts with clinical response was significantly higher in the low RS group vs the high RS group (p&lt;0.001). In univariate analyses, continuous RS was significantly associated with clinical response (p&lt;0.001), along with ER (p=.02), PR (p&lt;0.001), and ER gene group score (p&lt;0.001). Other covariates were not associated with clinical response.

Conclusion: The Oncotype DX RS test in core biopsy samples is validated as a predictive assay for clinical response of NAHT in postmenopausal, ER+/HER2-, cN0, primary early breast cancer pts. Further results on the association of RS results with BCS outcomes following NAHT will be presented. These results when combined with previously published data on RS in NACT studies help guide pts with ER+, HER2- breast cancer with NAHT vs NACT treatment options to maximize clinical response.

Citation Format: Yamamoto Y, Iwata H, Masuda N, Fujisawa T, Toyama T, Kashiwaba M, Ohtani S, Taira N, Sakai T, Hasegawa Y, Nakamura R, Akabane H, Shibahara Y, Sasano H, Yamaguchi T, Sakamaki K, Chao C, McCullough D, Sugiyama N, Ohashi Y. TransNEOS: Validation of the oncotype DX recurrence score (RS) testing core needle biopsy samples from NEOS as predictor of clinical response to neoadjuvant endocrine therapy for postmenopausal estrogen receptor positive (ER+), HER2 negative (HER2-) breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD5-03.

Abstract P5-21-07: Phase II study of eribulin in combination with pertuzumab plus trastuzumab for human epidermal growth factor receptor 2 (HER2)-positive advanced or metastatic breast cancer

Background: Pertuzumab provided overall and progression-free survival (PFS) benefits in HER2-positive metastatic breast cancer patients (pts) in the CLEOPATRA (Clinical evaluation of docetaxel, pertuzumab and trastuzumab) study. However, few studies have described the efficacy of other drugs in combination with pertuzumab plus trastuzumab. Here, we present a pre-specified analysis of eribulin in combination with pertuzumab plus trastuzumab as first- and second-line therapy for advanced or metastatic breast cancer (AMBC) in a multicenter, open-label phase II study (UMIN000012232, JBCRG-M03).

Methods: HER2-positive AMBC with no or single prior chemotherapy for AMBC were enrolled. All pts were administered trastuzumab and taxane as adjuvant or first-line chemotherapy. Treatment consisted of eribulin 1.4 mg/m2 on days 1 and 8 of a 21-day cycle and trastuzumab (8 mg/kg loading dose, then 6 mg/kg) plus pertuzumab (840 mg/body loading dose, then 420 mg/ body) once every 3 weeks, all administered intravenously. The primary endpoint was PFS, and secondary endpoints included overall response rate (ORR) and safety. PFS was determined using Kaplan–Meier analysis. Tumor response was assessed according to RECIST ver. 1.1.

Results: Fifty pts were enrolled from November 2013 to April 2016. Forty-nine pts were eligible for safety analysis and the full analysis set (FAS) included 46 pts. The median age was 56 years (23–70), and 8 (16%) and 41 (84%) pts were treated in first- and second-line settings, respectively. Eleven pts (23.9%) were de-novo Stage 4, and 35 pts (76.1%) had progressed in metastatic disease after completion of local therapy. Median PFS was 9.3 months (M) (95% confidence interval [CI]: 6.4–12.3). Table 1 shows the efficacy data for each treatment line and includes ORR, complete response rate (CR), partial response rate (PR), stable disease rate (SD), progressive disease rate (PD), not evaluable rate (NE) and PFS in the FAS. The median relative dose intensities of eribulin, trastuzumab, and pertuzumab were 93.3% (77.0%–100%), 100% (96.0%–100%), and 100% (89.7%–100%), respectively, in the FAS. The grade 3/4 adverse events (AE) were neutropenia in 5 pts (10.2%), including 2 pts (4.1%) with febrile neutropenia; hypertension in 3 pts (6.1%), and other AEs in only one patient. The average of the ejection fraction did not decrease significantly. Symptomatic left ventricular systolic dysfunction was not observed.

Conclusion: In pts with HER2-positive AMBC, first- and second-line therapy of eribulin in combination with pertuzumab plus trastuzumab demonstrated substantial antitumor activity with an acceptable safety profile. We are planning a phase III study comparing eribulin with taxanes in combination with pertuzumab plus trastuzumab for the treatment of HER2-positive AMBC.

Efficacy data for each treatment lineTreatment LineTotal (n=46)First line (n=8)Second line (n=38)PFS (95% CI), months9.3 (6.4-12.3)20.8 (2.8-38.7)8.7 (7.2-10.2)ORR (%)28 (60.9)7 (87.5)21 (55.3)CR (%)8 (17.4)3 (37.5)5 (13.2)PR (%)20 (43.5)4 (50.0)16 (42.1)SD (%)11 (23.9)1 (12.5)10 (26.3)PD (%)5 (10.9)05 (13.2)NE (%)2 (4.3)02 (5.3)

Citation Format: Kawaguchi H, Yamashita T, Masuda N, Kitada M, Narui K, Hattori M, Yoshinami T, Matsunami N, Yanagihara K, Kawasoe T, Nagashima T, Bando H, Yano H, Hasegawa Y, Nakamura R, Kashiwaba M, Morita S, Ohno S, Toi M. Phase II study of eribulin in combination with pertuzumab plus trastuzumab for human epidermal growth factor receptor 2 (HER2)-positive advanced or metastatic breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-07.

Turbulent mass transfer caused by vortex induced reconnection in collisionless magnetospheric plasmas

Magnetic reconnection is believed to be the main driver to transport solar wind into the Earth's magnetosphere when the magnetopause features a large magnetic shear. However, even when the magnetic shear is too small for spontaneous reconnection, the Kelvin-Helmholtz instability driven by a super-Alfvénic velocity shear is expected to facilitate the transport. Although previous kinetic simulations have demonstrated that the non-linear vortex flows from the Kelvin-Helmholtz instability gives rise to vortex-induced reconnection and resulting plasma transport, the system sizes of these simulations were too small to allow the reconnection to evolve much beyond the electron scale as recently observed by the Magnetospheric Multiscale (MMS) spacecraft. Here, based on a large-scale kinetic simulation and its comparison with MMS observations, we show for the first time that ion-scale jets from vortex-induced reconnection rapidly decay through self-generated turbulence, leading to a mass transfer rate nearly one order higher than previous expectations for the Kelvin-Helmholtz instability.

Simultaneous Remote Observations of Intense Reconnection Effects by DMSP and MMS Spacecraft During a Storm Time Substorm

During a magnetic storm on 23 June 2015, several very intense substorms took place, with signatures observed by multiple spacecraft including DMSP and Magnetospheric Multiscale (MMS). At the time of interest, DMSP F18 crossed inbound through a poleward expanding auroral bulge boundary at 23.5 h magnetic local time (MLT), while MMS was located duskward of 22 h MLT during an inward crossing of the expanding plasma sheet boundary. The two spacecraft observed a consistent set of signatures as they simultaneously crossed the reconnection separatrix layer during this very intense reconnection event. These include (1) energy dispersion of the energetic ions and electrons traveling earthward, accompanied with high electron energies in the vicinity of the separatrix; (2) energy dispersion of polar rain electrons, with a high-energy cutoff; and (3) intense inward convection of the magnetic field lines at the MMS location. The high temporal resolution measurements by MMS provide unprecedented observations of the outermost electron boundary layer. We discuss the relevance of the energy dispersion of the electrons, and their pitch angle distribution, to the spatial and temporal evolution of the boundary layer. The results indicate that the underlying magnetotail magnetic reconnection process was an intrinsically impulsive and the active X-line was located relatively close to the Earth, approximately at 16-18 R_E.