Inconsistent radiographic diagnostic criteria for lisfranc injuries: a systematic review

PURPOSE

To evaluate the radiographic diagnostic criteria and propose standardised radiographic criteria for Lisfranc injuries.

METHODS

A systematic review of the PubMed and Embase databases was performed according to the PRISMA guidelines. The various radiographic criteria for the diagnosis of Lisfranc injuries were extracted. Descriptive statistics were presented for all continuous (as mean ± standard deviation) and categorical variables (as frequencies by percentages).

RESULTS

The literature search included 29 studies that totalled 1115 Lisfranc injuries. The risk of bias ranged from "Low" to "Moderate" risk according to the ROBINS-I tool. The overall recommendations according to the GRADE assessment ranged from "Very Low" to "High". 1st metatarsal to 2nd metatarsal diastasis was the most common of the 12 various radiographic diagnostic criteria observed, as was employed in 18 studies. This was followed by 2nd cuneiform to 2nd metatarsal subluxation, as was employed in 11 studies.

CONCLUSION

The radiographic diagnostic criteria of Lisfranc injuries were heterogeneous. The proposition for homogenous radiographic diagnostic criteria is that the following features must be observed for the diagnosis of Lisfranc injuries: 1st metatarsal to 2nd metatarsal diastasis of ≥ 2 mm on anteroposterior view or 2nd cuneiform to 2nd metatarsal subluxation on anteroposterior or oblique views. Further advanced imaging by CT or MRI may be required in patients with normal radiographs but with continued suspicion for Lisfranc injuries.

LEVEL OF EVIDENCE

4, systematic review.

Cardiac phenotypes in the acute-phase of microscopic polyangiitis involves dilatation of the left atrium caused by LV diastolic dysfunction

Background

Microscopic polyangiitis (MPA) is a type of primary systemic vasculitis that affects various organs, especially the lungs and kidneys. However, few reports regarding cardiac features of MPA patients were found.

Purpose

We aim to investigate the echocardiographic parameters of acute-phase MPA.

Methods and results

This single-center retrospective study included 15 patients with MPA (Mean age at 72.2±7.1 years, women 73.3%) who underwent echocardiography within two weeks of commencing steroid therapy for induction or reinduction. The echocardiography parameters of the patients were compared with those of 30 age and sex-matched controls. In the MPA group, the commonly affected organs were kidneys (93.3%) and lungs (46.7%); 5 patients (33.3%) had a history of hypertension, which had a similar frequency as the control group. No significant difference in left ventricular (LV) diameter, LV ejection fraction, e', or inferior vena cava diameter was observed between the two groups. However, the MPA group showed significantly higher left atrial (LA) diameter (p=0.033) and LA volume index (p=0.001), as well as higher early diastolic filling velocity (E-wave, p=0.015; E/A, p=0.043; E/e', p=0.041), diastolic pulmonary venous flow velocity (p=0.013), trans-tricuspid pressure gradient (p=0.019), and shorter deceleration time (p=0.038), associated with mildly thicker ventricular walls of left ventricle (LV) than the control group. Moreover, serum levels of C-reactive protein showed significant correlation between E wave (r=0.58, p=0.023), E/A (r=0.67, p=0.006), and deceleration time (r=−0.69, p=0.005) in the MPA group. These results may indicate that in MPA, increased LV stiffness, rather than impairment of LV relaxation was contributed to LV diastolic function, resulting in LA enlargement.

Conclusion

Patients with acute-phase MPA had LA dilatation associated with LV diastolic dysfunction. This finding indicates the importance of cardiac assessment in patients with MPA.

Funding Acknowledgement

Type of funding sources: None.

Strain patterns in normal anterior talofibular and calcaneofibular ligaments and after anatomical reconstruction using gracilis tendon grafts: A cadaver study

Background

Inversion ankle sprains, or lateral ankle sprains, often result in symptomatic lateral ankle instability, and some patients need lateral ankle ligament reconstruction to reduce pain, improve function, and prevent subsequent injuries. Although anatomically reconstructed ligaments should behave in a biomechanically normal manner, previous studies have not measured the strain patterns of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) after anatomical reconstruction. This study aimed to measure the strain patterns of normal and reconstructed ATFL and CFLs using the miniaturization ligament performance probe (MLPP) system.

Methods

The MLPP was sutured into the ligamentous bands of the ATFLs and CTLs of three freshly frozen cadaveric lower-extremity specimens. Each ankle was manually moved from 15° dorsiflexion to 30° plantar flexion, and a 1.2-N m force was applied to the ankle and subtalar joint complex.

Results

The normal and reconstructed ATFLs exhibited maximal strain (100) during supination in three-dimensional motion. Although the normal ATFLs were not strained during pronation, the reconstructed ATFLs demonstrated relative strain values of 16–36. During the axial motion, the normal ATFLs started to gradually tense at 0° plantar flexion, with the strain increasing as the plantar flexion angle increased, to a maximal value (100) at 30° plantar flexion; the reconstructed ATFLs showed similar strain patterns. Further, the normal CFLs exhibited maximal strain (100) during plantar flexion-abduction and relative strain values of 30–52 during dorsiflexion in three-dimensional motion. The reconstructed CFLs exhibited the most strain during dorsiflexion-adduction and demonstrated relative strain values of 29–62 during plantar flexion-abduction. During the axial motion, the normal CFLs started to gradually tense at 20° plantar flexion and 5° dorsiflexion.

Conclusion

Our results showed that the strain patterns of reconstructed ATFLs and CFLs are not similar to those of normal ATFLs and CFLs.

Three-dimensional analysis of anterior talofibular ligament strain patterns during cadaveric ankle motion using a miniaturized ligament performance probe

Background

Measuring the strain patterns of ligaments at various joint positions informs our understanding of their function. However, few studies have examined the biomechanical properties of ankle ligaments; further, the tensile properties of each ligament, during motion, have not been described. This limitation exists because current biomechanical sensors are too big to insert within the ankle. The present study aimed to validate a novel miniaturized ligament performance probe (MLPP) system for measuring the strain patterns of the anterior talofibular ligament (ATFL) during ankle motion.

Methods

Six fresh-frozen, through-the-knee, lower extremity, cadaveric specimens were used to conduct this study. An MLPP system, comprising a commercially available strain gauge (force probe), amplifier unit, display unit, and logger, was sutured into the midsubstance of the ATFL fibers. To measure tensile forces, a round, metal disk (a “clock”, 150 mm in diameter) was affixed to the plantar aspect of each foot. With a 1.2-Nm load applied to the ankle and subtalar joint complex, the ankle was manually moved from 15° dorsiflexion to 30° plantar flexion. The clock was rotated in 30° increments to measure the ATFL strain detected at each endpoint by the miniature force probe. Individual strain data were aligned with the neutral (0) position value; the maximum value was 100.

Results

Throughout the motion required to shift from 15° dorsiflexion to 30° plantar flexion, the ATFL tensed near 20° (plantar flexion), and the strain increased as the plantar flexion angle increased. The ATFL was maximally tensioned at the 2 and 3 o’clock (inversion) positions (96.0 ± 5.8 and 96.3 ± 5.7) and declined sharply towards the 7 o’clock position (12.4 ± 16.8). Within the elastic range of the ATFL (the range within which it can return to its original shape and length), the tensile force was proportional to the strain, in all specimens.

Conclusion

The MLPP system is capable of measuring ATFL strain patterns; thus, this system may be used to effectively determine the relationship between limb position and ATFL ankle ligament strain patterns.

New methods for determination of the keyhole position in the lateral suboccipital approach to avoid transverse-sigmoid sinus injury: Proposition of the groove line as a new surgical landmark

PURPOSE

The asterion is frequently used as an anatomical landmark to determine the location of a keyhole in the lateral suboccipital approach used in craniotomies. However, the asterion may not be ideal because of large individual differences among patients. We examined a simple and safe method for determining an optimal keyhole position (KP) using the digastric groove as a new landmark in the lateral suboccipital approach.

METHODS

Thirty-three patients with trigeminal neuralgia who underwent surgery in our institute between April 2014 and December 2018 were included. The groove line (GL) was designed accurately, extending the digastric groove on the surface of the occipital bone, as the x-axis. The y-axis was depicted from the posterior edge of the digastric groove (the groove point: GP) vertical to the GL. The x-y coordinates represented the distances from GP on each axis. The x-y coordinates of median edge of the transverse-sigmoid sinus (TSJ point), asterion, and the intersection of the GL and transverse sinus (the transverse point: TP) were investigated, based on intraoperative findings and recorded videos.

RESULTS

The x-y coordinated of the TSJ point were (23.9±3.9, 7.2±3.6). In all patients, the TSJ point was located superior to the GL. The x-y coordinates of the asterion were (27.3±6.0, 8.9±4.1), and in 28 of the 33 patients, their coordinates exceeded the TSJ points. The x-coordinate of the TP was 29.5±4.5, and was located behind the TSJ point on the GL in all patients. The shortest distance between the TSJ points and TP was approximately 3mm. According to these measurements, we decided that the optimal KP would be at 20mm from the GP, subjacent to the GL.

CONCLUSIONS

Our methods of using the GL as a new surgical landmark for setting the optimal KP is simple, safe, and useful.

Operative Outcome of Side-Locking Loop Suture Technique Accompanied by Autologous Semitendinosus Tendon Grafting for Chronic Rupture of Achilles Tendon

Background:

The purpose of this retrospective study was to clarify the operative outcomes of the side-locking loop suture (SLLS) technique accompanied by autologous semitendinosus tendon grafting for chronic Achilles tendon rupture.

Methods:

A chart review was conducted of consecutive patients treated with the SLLS technique at our department from 2012 to 2017. Postoperatively, a below-knee splint was applied for 2 weeks in 20 degrees of plantar flexion and then active range of motion exercise was started. Partial weightbearing exercise was allowed at 4 weeks according to patient tolerance, and full weightbearing without crutches was allowed at 8 weeks. The American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score and the Achilles tendon rupture score (ATRS) were used to evaluate clinical outcomes preoperatively and at the final follow-up.

Results:

Ten patients (6 men, 4 women) were included in the analysis. Mean AOFAS ankle-hindfoot scale score increased significantly from 64.2 ± 5.6 points preoperatively to 95.0 ± 5.3 points at the final follow-up ( P < .001). The mean ATRS also increased significantly from 29.8 ± 4.4 points to 86.2 ± 7.7 points, respectively ( P < .001). Mean time between surgery and ability to perform 20 continuous double-leg heel raises of the operated foot was 13.5 ± 3.4 (range 10-18) weeks. One patient complained of postoperative hypoesthesia in the foot, which had spontaneously resolved by 3 months after surgery.

Conclusion:

The SLLS technique accompanied by autologous semitendinosus tendon grafting provided successful operative outcomes for patients with chronic Achilles tendon rupture regardless of the size of the defect, and thus long-term orthotic use was not needed after surgery.

Level of Evidence:

Level IV, retrospective case series.

0205 Remote Collection of Daily Life Information for Japanese Residents

Introduction

Japanese medical students spend their school days under a dense curriculum. It is often difficult to maintain their healthy lifestyle. After graduation, most of them participate in clinical training programs as residents. It is also difficult to maintain a normal life because they are engaged in different specialized departments every few months. Such an environment is considered prone to mental health problems. In fact, one in four residents are reported to be newly depressed two months after the start of clinical training (Maeno T, et al. 2008). These mental health issues are thought to be affected by changes in daily life, but it is difficult to know such changes. In order to investigate changes in their daily lives, we developed a data collection system related to mental health via the Internet.

Methods

The subjects were 22 medical students who graduated from our university in March 2017. They were asked to wear activity tracker wrist bands from December 2016. They were also asked to answer the questionnaire on a web site every week as much as possible, and the responses were collected via the Internet together with the activity data. The first eight months of the observation period, including four months before the start of clinical training and four month after the start of clinical training, are divided into four quarters every two months, and the averaged sleep time and responses to the questionnaire in each period were investigated.

Results

The average number of days that the sleep was effectively recorded during each two months was 28–48. The average number of responses to the questionnaire during each two months was 6.0–7.2.

Conclusion

Residents in the initial clinical training period should be very busy, but the system we have developed seems to have worked well with them for the first four months after the start of clinical training. Whether this system would work as well a longer period is a further problem.

Support

This study is supported by KAKENHI 16K01753.

Strain pattern of each ligamentous band of the superficial deltoid ligament: a cadaver study

BACKGROUND

There are few reports on the detailed biomechanics of the deltoid ligament, and no studies have measured the biomechanics of each ligamentous band because of the difficulty in inserting sensors into the narrow ligaments. This study aimed to measure the strain pattern of the deltoid ligament bands directly using a Miniaturization Ligament Performance Probe (MLPP) system.

METHODS

The MLPP was sutured into the ligamentous bands of the deltoid ligament in 6 fresh-frozen lower extremity cadaveric specimens. The strain was measured using a round metal disk (clock) fixed on the plantar aspect of the foot. The ankle was manually moved from 15° dorsiflexion to 30° plantar flexion, and a 1.2-N-m force was applied to the ankle and subtalar joint complex. Then the clock was rotated every 30° to measure the strain of each ligamentous band at each endpoint.

RESULTS

The tibionavicular ligament (TNL) began to tense at 10° plantar flexion, and the tension becomes stronger as the angle increased; the TNL worked most effectively in plantar flex-abduction. The tibiospring ligament (TSL) began to tense gradually at 15° plantar flexion, and the tension became stronger as the angle increased. The TSL worked most effectively in abduction. The tibiocalcaneal ligament (TCL) began to tense gradually at 0° dorsiflexion, and the tension became stronger as the angle increased. The TCL worked most effectively in pronation (dorsiflexion-abduction). The superficial posterior tibiotalar ligament (SPTTL) began to tense gradually at 0° dorsiflexion, and the tension became stronger as the angle increased, with the SPTTL working most effectively in dorsiflexion.

CONCLUSION

Our results show the biomechanical function of the superficial deltoid ligament and may contribute to determining which ligament is damaged during assessment in the clinical setting.

Simultaneous ossicle resection and lateral ligament repair give excellent clinical results with an early return to physical activity in pediatric and adolescent patients with chronic lateral ankle instability and os subfibulare

PURPOSE

To elucidate surgical outcomes in pediatric/adolescent patients with chronic lateral ankle instability and os subfibulare.

METHODS

A retrospective chart review was conducted of pediatric/adolescent patients with chronic lateral ankle instability and os subfibulare following simultaneous ossicle resection and lateral ligament repair using suture anchors with subsequent immediate full weightbearing and active range of motion exercises for the ankle in our department between 2013 and 2017. Clinical outcomes were evaluated by comparing preoperative and final follow-up American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS) and Karlsson-Peterson ankle function scores. Intervals between surgery and return to physical education in school were determined.

RESULTS

31 feet of 15 male and 16 female patients were examined. Mean postoperative follow-up duration was 40.7 ± 12.7 (range 24-66) months. Mean AOFAS score increased significantly from 66.3 ± 2.5 (range 62-77) preoperatively to 96.5 ± 4.9 (range 87-100) at final follow-up (p < 0.001). Mean Karlsson-Peterson score increased significantly from 51.7 ± 4.0 (range 47-70) preoperatively to 95.3 ± 6.7 (range 80-100) at final follow-up (p < 0.001). Mean interval between surgery and return to physical education in school was 11.4 ± 1.6 (range 10-18) weeks.

CONCLUSION

Simultaneous ossicle resection and lateral ligament repair using suture anchors with subsequent immediate full weightbearing and active ankle range of motion exercises may give excellent clinical outcomes with early return to physical activity for chronic lateral ankle instability with os subfibulare in pediatric/adolescent patients desiring an early return to physical activity. Level of evidence III.

Stress fracture of the posterior talar process in a female long-distance runner treated by osteosynthesis with screw fixation via two-portal hindfoot endoscopy: a case report

Background

Stress fracture of the lateral tubercle of the posterior talar process in runners is extremely rare. Here, we describe a case of a female long-distance runner who sustained a stress fracture of the lateral tubercle of the posterior talar process. Osteosynthesis with screw fixation via two-portal hindfoot endoscopy achieved a good surgical outcome with a less invasive procedure.

Case presentation

An 18-year-old female long-distance runner who belonged to her university’s road running club presented to our institution with a half-year history of persistent left hindfoot pain when running. Radiographs revealed a stress fracture of the lateral tubercle of the posterior talar process. Because the fracture showed no signs of healing 3 months after starting conservative therapy, osteosynthesis with screw fixation was performed via two-portal hindfoot endoscopy. Non-contrast computed tomography at 10 weeks postoperatively revealed consolidation of the stress fracture. At 15 weeks postoperatively, the patient was permitted to jog and return to athletic activity while wearing an orthosis. As of this writing 2 years postoperatively, she remains an active competitive runner.

Conclusions

Osteosynthesis with screw fixation via two-portal hindfoot endoscopy was a less invasive procedure that successfully treated stress fracture of the lateral tubercle of the posterior talar process in this female long-distance runner.

Abstract P1-06-11: Microsatellite instability in triple negative breast cancers

Background:Microsatellite instability (MSI) is a phenotype resulting from defect in mismatch repair genes. The Food and Drug Administration approved anti-programmed death 1 (PD-1) immune checkpoint inhibitor for any solid tumor with MSI-high (MSI-H). Some tumors had good response to PD-1 blockade and it is a promising treatment for a part of refractory breast cancers. Our goal was to determine the frequency of MSI in triple negative breast cancer (TNBC), one of the most clinically aggressive subtypes.

Patients and Methods:This study included 228 patients with primary TNBC underwent resection without neoadjuvant chemotherapy between January 2004 and December 2014. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tissue. Tumor and control DNA were amplified by polymerase chain reaction at the following 5 microsatellite markers: NR-21, BAT-26, BAT-25, NR-24, MONO-27. We classified the tumors as microsatellite stable(MSS), MSI-low or MSI-H.

Results: The mean age of patients was 59 years (range: 30-89) and all were women. T1 tumors were 57.9% and N0 were 67.5%. Meanwhile, the tumors with nuclear grade 3 were 66.2% and high Ki-67 (&gt; 30%) were 66.7%. Among the 228 tumors, 222 tumors (97.4%) revealed MSS, of which 6 (2.6%) revealed MSI and 2 (0.9%) were MSI-H. Among the MSI tumors, T and N factor were showed as follows: T1: 2 tumors, T2: 3 tumors, T3: 1 tumor, N0: 5 tumors and N1: 1 tumor. Of two MSI-H tumors, one showed T1N0 and another showed T2N0. The both of them showed nuclear grade 3, high Ki-67 (&gt; 30%) and had common following instable markers: NR-21, BAT-26 and BAT-25.

Conclusions: Our results demonstrated that the frequency of MSI-H was 0.9% (2/228). MSI might not be useful as a biomarker for immune check point inhibitors. MSI should be combined with another biomarker such as tumor mutational burden in TNBC.

Citation Format: Kurata K, Kubo M, Mori H, Kawaji H, Motoyama Y, Kuroki L, Yamada M, Kaneshiro K, Kai M, Nakamura M. Microsatellite instability in triple negative breast cancers [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 P1-06-11.

Abstract P4-06-22: Transcription factor T-bet and PD-L1 expression in tumor microenvironment of triple-negative breast cancer

Background: Many analyzes regarding immunotherapies using checkpoint blockade has made it clear that tumor infiltrating lymphocytes (TILs) plays an important role in treating cancers with high levels of somatic mutations such as triple-negative breast cancer (TNBC). We reported the relationship between TILs and PD-L1 expression, and revealed that high-TILs/positive-PD-L1 expression population in TNBC was associated with better prognosis (Oncotarget 2017). However, its molecular mechanism is still unclear. Meanwhile, T-box transcription factor 21 (T-bet) which regulates effecter T-cells activation is derived by stimulation of T-cell receptor and IL-12. Activated T-cells work as antitumor lymphocytes by enhancing the production of cytokines such as INFγ. We focused on T-bet and examined the function of activated T-cells.

Patients and Methods: This study included 242 patients with primary TNBC who underwent resection without neoadjuvant chemotherapy at our three hospitals between January 2004 and December 2014. The immunohistochemistry scoring for CD8 and T-bet expression on TILs was defined as ≥30 per 0.00625mm2. PD-L1 positivity was defined as ≥1% of tumor cells staining positive for PD-L1.

Results: Of the 242 TNBC, CD8 on TILs was expressed as positive in 127 (52.5%) tumors, T-bet on TILs was expressed as positive in 67 (27.7%) tumors, and PD-L1 expression on tumor cells was expressed as positive in 99 (40.9%) tumors. T-bet expression was significantly correlated with CD8 expression (P&lt;0.0001) and PD-L1 expression (P=0.0004). There was no significant difference in recurrence free survival (RFS) and overall survival (OS) regardless of CD8 or PD-L1expression level. Meanwhile, the patients with T-bet-positive tumors had a longer OS, compared to those with T-bet-negative tumors (P = 0.13 in RFS and P = 0.047 in OS). The multivariate analysis revealed that T-bet expression on TILswas an independent and positive prognostic factor for OS(HR = 0.5, 95%CI 0.1-0.9, P = 0.035).

Conclusion: OS was significantly longer among patients with high T-bet expressing TNBC. These results may validate the significance of T-bet as a biomarker for various immunotherapies in TNBC.

Citation Format: Mori H, Kubo M, Kai M, Kurata K, Kawaji H, Kaneshiro K, Motoyama Y, Kuroki R, Yamada M, Nishimura R, Okido M, Oda Y, Nakamura M. Transcription factor T-bet and PD-L1 expression in tumor microenvironment of triple-negative 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 P4-06-22.

Hypersensitivity Reaction to Carboplatin during Treatment for Ovarian Cancer: Successful Resolution by Replacement with Cisplatin

Development of hypersensitivity reactions to carboplatin (CP) during cancer treatment makes optimal chemotherapy difficult to achieve. Many approaches have previously been used following the development of reactions to CP. We report on a patient with ovarian cancer who developed a hypersensitivity reaction to CP. The patient was successfully treated following replacement of carboplatin with cisplatin.

Protein-altering variants of PTPN2 in childhood-onset Type 1A diabetes

AIM

To examine the contribution of PTPN2 coding variants to the risk of childhood-onset Type 1A diabetes.

METHODS

PTPN2 mutation analysis was carried out for 169 unrelated Japanese people with childhood-onset Type 1A diabetes. We searched for coding variants that were absent or extremely rare in the general population and were scored as damaging by multiple in silico programs. We performed mRNA analysis and three-dimensional structural prediction of the detected variants, when possible. We also examined possible physical links between these variants and previously reported risk SNPs as well as clinical information from variant-positive children.

RESULTS

One frameshift variant (p.Q286Yfs*24) and two probably damaging missense substitutions (p.C232W and p.R350Q) were identified in one child each. Of these, p.Q286Yfs*24 and p.C232W were hitherto unreported, while p.R350Q accounted for 2/121,122 alleles of the exome datasets. The p.Q286Yfs*24 variant did not encode stable mRNA, and p.C232W appeared to affect the structure of the tyrosine-protein phosphatase domain. The three variants were physically unrelated to known risk SNPs. The variant-positive children manifested Type 1A diabetes without additional clinical features and invariably carried risk human leukocyte antigen alleles.

CONCLUSIONS

The results provide the first indication that PTPN2 variants contribute to the risk of Type 1A diabetes, independently of known risk SNPs. PTPN2 coding variants possibly induce non-specific Type 1A diabetes phenotypes in individuals with human leukocyte antigen-mediated disease susceptibility. Our findings warrant further validation.

A genome-wide association study identifies two novel susceptibility loci and trans population polygenicity associated with bipolar disorder

Genome-wide association studies (GWASs) have identified several susceptibility loci for bipolar disorder (BD) and shown that the genetic architecture of BD can be explained by polygenicity, with numerous variants contributing to BD. In the present GWAS (Phase I/II), which included 2964 BD and 61 887 control subjects from the Japanese population, we detected a novel susceptibility locus at 11q12.2 (rs28456, P=6.4 × 10-9), a region known to contain regulatory genes for plasma lipid levels (FADS1/2/3). A subsequent meta-analysis of Phase I/II and the Psychiatric GWAS Consortium for BD (PGC-BD) identified another novel BD gene, NFIX (Pbest=5.8 × 10-10), and supported three regions previously implicated in BD susceptibility: MAD1L1 (Pbest=1.9 × 10-9), TRANK1 (Pbest=2.1 × 10-9) and ODZ4 (Pbest=3.3 × 10-9). Polygenicity of BD within Japanese and trans-European-Japanese populations was assessed with risk profile score analysis. We detected higher scores in BD cases both within (Phase I/II) and across populations (Phase I/II and PGC-BD). These were defined by (1) Phase II as discovery and Phase I as target, or vice versa (for 'within Japanese comparisons', Pbest~10-29, R2~2%), and (2) European PGC-BD as discovery and Japanese BD (Phase I/II) as target (for 'trans-European-Japanese comparison,' Pbest~10-13, R2~0.27%). This 'trans population' effect was supported by estimation of the genetic correlation using the effect size based on each population (liability estimates~0.7). These results indicate that (1) two novel and three previously implicated loci are significantly associated with BD and that (2) BD 'risk' effect are shared between Japanese and European populations.

Abstract P5-07-01: LncRNA MIR2052HG regulates ERα level and endocrine resistance through LMTK3 by recruiting early growth response protein 1

BACKGROUND: A GWAS for the MA.27 aromatase inhibitors (AIs) adjuvant trial (4,406 controls and 252 cases) identified variant (V) SNPs in a long noncoding (lnc) RNA, MIR2052HG, that were associated with longer breast cancer free interval (HR= 0.37, P= 2.15E-07). V SNPs (MAF= 0.32 to 0.42) were associated with lower MIR2052HG and ERα expression in the presence of AIs. MIR2052HG maintained ERα both by promoting AKT/FOXO3-mediated ESR1 transcription and by limiting ubiquitin-mediated ERα degradation. (Cancer Res 76:7012-23, 2016). Our goal was to further elucidate MIR2052HG's mechanism of action.

METHODS: RNA-Binding Protein Immunoprecipitation (RBPI) assays were performed to demonstrate that the transcription factor, early growth response protein 1 (EGR1), worked together with MIR2052HG to regulate lemur tyrosine kinase-3 (LMTK3) transcription in MCF7/AC1 and CAMA-1 cells. The location of EGR1 on the LMTK3 gene locus was mapped using chromatin immunoprecipitation (ChIP) assays. The co-localization of MIR2052HG RNA and the LMTK3 gene locus was determined using RNA-DNA dual fluorescent in situ hybridization (FISH). SNP effects were evaluated using a panel of human lymphoblastoid cell lines.

RESULTS: TCGA analysis revealed LMTK3 and MIR2052HG expression were highly correlated in ERα-positive breast cancer patients. We found that the MIR2052HG transcript was located in the LMTK3 gene locus by RNA-DNA FISH. Among all of the 12 potential LMTK3 transcription factors identified in the Encode database that were examined by RBPI, only EGR1 showed an interaction with MIR2052HG. CHIP assays confirmed EGR1 binding to the two putative EGR1 binding sites in LMTK3 gene.Depletion of MIR2052HG reduced the binding of EGR1 to the LMTK3 promoter and decreased LMTK3 expression, suggesting that it might function as a scaffold. Mechanistically, decreased LMTK3 levels further increased protein kinase C (PKC) activity and downstream AKT activity, leading to reduced ESR1 mRNA levels via increased pFOXO3. At the protein level, in MIR2052HG depleted cells, increased PKC activity increased the phosphorylation of MEK, ERK, and RSK1, leading to increased ERα phosphorylation at Ser167 and increased ERα degradation. Conversely, overexpression of LMTK3 in MIR2052HG depleted cells reversed these phenotypes. MIR2052HG regulated LMTK3 and ERα expression in a SNP- dependent fashion: the MIR2052HG V SNP, relative to wild-type (WT) genotype, increased LMTK3/ERα expression in response to androstenedione due to increased binding between EGR1 and the LMTK3 promoter in LCLs. However, AI treatment reduced this binding in MIR2052HG variant cells but increased binding in WT cells, resulting in decreased LMTK3/ERα in V cells and increased expression in WT cells.

CONCLUSIONS: Our findings support a model in which the protective MIR2052HG variant genotype regulates LMTK3 via MIR2052HG/EGR1, and LMTK3 regulates ERα stability via the PKC/MEK/ERK/RSK1 axis. This regulation may explain the effect of the MIR2052HG variant genotype on cell proliferation and response to AIs in MA.27. These findings provide new insight into the mechanism of action of MIR2052HG and suggest that LMTK3 may be a new therapeutic target in ERα-positive breast cancer patients treated with AIs.

Citation Format: Cairns J, Ingle JN, Shepherd LE, Kubo M, Goetz MP, Weinshilboum RM, Kalari KR, Wang L. LncRNA MIR2052HG regulates ERα level and endocrine resistance through LMTK3 by recruiting early growth response protein 1 [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 P5-07-01.

New Pharmacogenomics Research Network: An Open Community Catalyzing Research and Translation in Precision Medicine

The goal of pharmacogenomics research is to discover genetic polymorphisms that underlie variation in drug response. Increasingly, pharmacogenomics research involves large numbers of patients and the application of new technologies and methodologies to enable discovery. The Pharmacogenomics Research Network (PGRN) has become a community-driven network of investigators spanning scientific and clinical disciplines. Here, we highlight the activities and types of resources that enable PGRN members to enhance and drive basic and translational research in pharmacogenomics.

Abstract P6-07-05: PD-L1 expression and decreased tumor-infiltrating lymphocytes are associated with poor prognosis in patients with triple negative breast cancer

Background: Tumor microenvironment has been considered to have an active role in determining the aggressiveness of tumor cells. Recently, programmed cell death ligand-1 (PD-L1) expression or tumor-infiltrating lymphocytes (TILs) are known to be an important prognostic factor of breast cancer. However, the correlation of expression of PD-L1 and TILs still remains unclear. Triple-negative breast cancer (TNBC) is a heterogeneous tumor that encompasses many different subclasses. Further identification of these subclasses is necessary in order to predict prognosis and choose appropriate treatments. Our goal was to correlate PD-L1 expression with clinicopathological features including TILs by using a large cohort of TNBCs.

Patients and Methods: This study included 248 patients with primary TNBC who underwent resection without neoadjuvant chemotherapy at our three hospitals between January 2004 and December 2014. The tumor subtypes were routinely determined immunohistochemically by using resected specimens. IHC scoring for PD-L1 expression was defined in reference to that for HER2 expression. PD-L1 positivity was defined as both IHC 2+ and IHC 3+. Cases were defined as high if stromal TILs ≥50% according to recommendations by the International TILs Working Group.

Results: Of the 248 TNBCs, PD-L1 were expressed as positive in 103 (41.5%) tumors, and TILs were highly present in 118 (47.6%) tumors. PD-L1 expression was significantly correlated with higher levels of TILs (P &lt; 0.0001). There was no significant difference when the prognosis of the patients who had PD-L1-positive tumors was compared with that of the patients who had PD-L1-negative tumors (P = 0.56 in recurrence free survival [RFS] and P = 0.13 in overall survival [OS]). Meanwhile, the patients with high-TILs tumors had longer OS, compared to the patients with low-TILs tumors (P = 0.55 in RFS and P = 0.016 in OS). The analysis in the cross effect between PD-L1 expression and TILs using cox proportional hazards model demonstrated that the PD-L1 expression and TILs are not independent factors(P = 0.0018 in RFS and P = 0.015 in OS). The PD-L1-positive group with low-TILs had significantly shorter survival than the PD-L1-positive group with high-TILs (hazard ratio [HR] = 4.7, 95% confidence interval [CI] 1.6–12.7, P = 0.0067 in RFS; HR = 8.4, 95%CI 2.3-30.3, P = 0.0019 in OS).

Conclusions: Our data indicated that PD-L1 expression was related to higher levels of TILs, and PD-L1-positive tumors with low-TILs were associated with poor prognosis in patients with TNBCs. It is proposed that these biomarkers may be of use for predicting their prognosis and essential in the subclassification of TNBCs.

Citation Format: Mori H, Kubo M, Yamaguti R, Nishimura R, Osako T, Arima N, Okumura Y, Okido M, Yamada M, Kai M, Kishimoto J, Oda Y, Nakamura M. PD-L1 expression and decreased tumor-infiltrating lymphocytes are associated with poor prognosis in patients with triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-07-05.

Abstract PD1-04: CSMD1 SNPs selectively affect anastrozole response in postmenopausal breast cancer patients

BACKGROUND: Based on prospective clinical trials, there is no evidence for differences in efficacy between the 3 aromatase inhibitors (AIs) anastrozole, exemestane, and letrozole. The purpose of this study was to identify germline genetic variants associated with response to AIs and to help identify novel mechanisms associated with drug disease efficacy.

METHODS: A genome-wide association study (GWAS) was performed for 624 patients (Steroids 2015;99:32-38) to identify SNPs associated with estrogen level change in women with estrogen receptor (ER) positive breast cancer treated with anastrozole. Replication of associated SNPs was performed in a GWAS from the MA.27 trial that compared adjuvant anastrozole and exemestane treatment of post-menopausal women with ER+ breast cancer. Functional studies were subsequently performed to determine SNP effects and underlying mechanisms.

RESULTS: Our initial GWAS identified SNPs within CSMD1 that were associated with changes in estrogen levels during anastrozole therapy. An additional SNP in CSMD1 was also associated with breast cancer events in CCTG MA.27. Functionally, we showed that CSMD1 regulates CYP19 expression in a SNP-, and in an anastrozole- dependent fashion. These phenomena were not observed for either letrozole or exemestane. In MA.27, an anastrozole- specific effect was also seen with the minor allele having a protective effect on time to distant metastasis (HR=0.49, p=0.00259), but this was not the case for exemestane (HR=0.71, p=0.111). Our in vitro functional studies indicated that overexpression of CSMD1 sensitized anastrozole or letrozole resistant cells to anastrozole but not to the other two AIs. The SNP in CSMD1 that was associated with increased CSMD1 and CYP19 expression levels increased anastrozole sensitivity, but not letrozole or exemestane in lymphoblastoid cell lines (LCLs) homozygous for either WT or variant CSMD1 SNP genotypes. Based on these observations, we explored whether anastrozole has additional mechanisms beyond its function as a CYP19 inhibitor. Utilizing an estrogen response element (ERE) luciferase reporter assay in a CYP19 CRISPR knockout breast cancer T47D cell line and a surface plasmon resonance (SPR) assay, we found that anastrozole can also function as an ERα agonist, and can bind to, and result in, proteasome dependent ERα degradation, especially in the presence of E2. Treatment of these CYP19 CRISPR knockout cells with anastrozole in the presence of increasing concentrations of E2 results in greater sensitivity compared with anastrozole alone, while the addition of E2, as expected, does not improve letrozole or exemestane sensitivity. These same observations were also seen in letrozole and anastrazole resistant cells.

CONCLUSIONS: Our findings suggest that anastrozole might be more effective than letrozole or exemestane in patients with the CSMD1 SNP. Furthermore, anastrozole can function as an ERα agonist, binding to ERα and resulting in its degradation, especially in the presence of E2. These findings should help to make it possible to develop precision endocrine therapies for women who are candidates for AIs.

Citation Format: Cairns J, Ingle J, Dudenkov T, Kalari K, Buzdar A, Kubo M, Robson M, Ellis M, Goss P, Shepherd L, Goetz M, Weinshilboum R, Wang L. CSMD1 SNPs selectively affect anastrozole response in postmenopausal breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD1-04.

Variants in Pharmacokinetic Transporters and Glycemic Response to Metformin: A Metgen Meta-Analysis

Therapeutic response to metformin, a first-line drug for type 2 diabetes (T2D), is highly variable, in part likely due to genetic factors. To date, metformin pharmacogenetic studies have mainly focused on the impact of variants in metformin transporter genes, with inconsistent results. To clarify the significance of these variants in glycemic response to metformin in T2D, we performed a large-scale meta-analysis across the cohorts of the Metformin Genetics Consortium (MetGen). Nine candidate polymorphisms in five transporter genes (organic cation transporter [OCT]1, OCT2, multidrug and toxin extrusion transporter [MATE]1, MATE2-K, and OCTN1) were analyzed in up to 7,968 individuals. None of the variants showed a significant effect on metformin response in the primary analysis, or in the exploratory secondary analyses, when patients were stratified according to possible confounding genotypes or prescribed a daily dose of metformin. Our results suggest that candidate transporter gene variants have little contribution to variability in glycemic response to metformin in T2D.

TSPAN5, ERICH3 and selective serotonin reuptake inhibitors in major depressive disorder: pharmacometabolomics-informed pharmacogenomics

Millions of patients suffer from major depressive disorder (MDD), but many do not respond to selective serotonin reuptake inhibitor (SSRI) therapy. We used a pharmacometabolomics-informed pharmacogenomics research strategy to identify genes associated with metabolites that were related to SSRI response. Specifically, 306 MDD patients were treated with citalopram or escitalopram and blood was drawn at baseline, 4 and 8 weeks for blood drug levels, genome-wide single nucleotide polymorphism (SNP) genotyping and metabolomic analyses. SSRI treatment decreased plasma serotonin concentrations (P<0.0001). Baseline and plasma serotonin concentration changes were associated with clinical outcomes (P<0.05). Therefore, baseline and serotonin concentration changes were used as phenotypes for genome-wide association studies (GWAS). GWAS for baseline plasma serotonin concentrations revealed a genome-wide significant (P=7.84E-09) SNP cluster on chromosome four 5' of TSPAN5 and a cluster across ERICH3 on chromosome one (P=9.28E-08) that were also observed during GWAS for change in serotonin at 4 (P=5.6E-08 and P=7.54E-07, respectively) and 8 weeks (P=1.25E-06 and P=3.99E-07, respectively). The SNPs on chromosome four were expression quantitative trait loci for TSPAN5. Knockdown (KD) and overexpression (OE) of TSPAN5 in a neuroblastoma cell line significantly altered the expression of serotonin pathway genes (TPH1, TPH2, DDC and MAOA). Chromosome one SNPs included two ERICH3 nonsynonymous SNPs that resulted in accelerated proteasome-mediated degradation. In addition, ERICH3 and TSPAN5 KD and OE altered media serotonin concentrations. Application of a pharmacometabolomics-informed pharmacogenomic research strategy, followed by functional validation, indicated that TSPAN5 and ERICH3 are associated with plasma serotonin concentrations and may have a role in SSRI treatment outcomes.

The Severity of Periodontal Disease is Associated with the Development of Glucose Intolerance in Non-diabetics: The Hisayama Study

Inflammation is hypothesized to play a significant role in the development of type 2 diabetes; however, reports on clinical inflammatory conditions are limited. Studies have suggested that periodontitis affects glucose control in diabetics. This community-based study examined the relationship between periodontitis and glucose tolerance status, including changes in status. The relationship between periodontal condition and the results of a 75-g oral glucose tolerance test was examined in 961 adults in 1998. Deep pockets (mean pocket depth > 2.0 mm) were significantly associated with impaired glucose tolerance and with diabetes as compared with shallow pockets (< 1.3 mm). In the subgroup with normal glucose tolerance 10 years previously, subjects who subsequently developed impaired glucose tolerance were significantly more likely to have deep pockets. Deep pockets were closely related to current glucose tolerance status and the development of glucose intolerance.

A Longitudinal HbA1c Model Elucidates Genes Linked to Disease Progression on Metformin

One-third of type-2 diabetic patients respond poorly to metformin. Despite extensive research, the impact of genetic and nongenetic factors on long-term outcome is unknown. In this study we combine nonlinear mixed effect modeling with computational genetic methodologies to identify predictors of long-term response. In all, 1,056 patients contributed their genetic, demographic, and long-term HbA1c data. The top nine variants (of 12,000 variants in 267 candidate genes) accounted for approximately one-third of the variability in the disease progression parameter. Average serum creatinine level, age, and weight were determinants of symptomatic response; however, explaining negligible variability. Two single nucleotide polymorphisms (SNPs) in CSMD1 gene (rs2617102, rs2954625) and one SNP in a pharmacologically relevant SLC22A2 gene (rs316009) influenced disease progression, with minor alleles leading to less and more favorable outcomes, respectively. Overall, our study highlights the influence of genetic factors on long-term HbA1c response and provides a computational model, which when validated, may be used to individualize treatment.

Genome-wide association study identifies pharmacogenomic loci linked with specific antihypertensive drug treatment and new-onset diabetes

We conducted a discovery genome-wide association study with expression quantitative trait loci (eQTL) annotation of new-onset diabetes (NOD) among European Americans, who were exposed to a calcium channel blocker-based strategy (CCB strategy) or a β-blocker-based strategy (β-blocker strategy) in the INternational VErapamil SR Trandolapril STudy. Replication of the top signal from the SNP*treatment interaction analysis was attempted in Hispanic and African Americans, and a joint meta-analysis was performed (total 334 NOD cases and 806 matched controls). PLEKHH2 rs11124945 at 2p21 interacted with antihypertensive exposure for NOD (meta-analysis p=5.3×10⁻⁸). rs11124945 G allele carriers had lower odds for NOD when exposed to the β-blocker strategy compared with the CCB strategy [OR=0.38 (0.24-0.60), p=4.0×10⁻⁵], while A/A homozygotes exposed to the β-blocker strategy had increased odds for NOD compared with the CCB strategy [OR=2.02 (1.39-2.92), p=2.0×10⁻⁴]. eQTL annotation of the 2p21 locus provides functional support for regulating gene expression.

Influence of Nonenzymatic Glycation in Dentinal Collagen on Dental Caries

Advanced glycation end-products (AGEs) are generated via nonenzymatic glycation of dentinal collagen, resulting in accumulation of AGEs in dentin tissue. Since accumulated AGEs cause crosslinking between amino acid polypeptides in the collagen molecule and modify mechanical properties of dentinal collagen, the authors assumed that there would be a significant interaction between the generation of AGEs and progression of caries in dentin. To confirm such an interaction, spectroscopic imaging analyses (i.e., nanosecond fluorescence lifetime imaging and second harmonic generation light imaging) were performed in addition to biochemical and electron microscopic analyses in the present study. Seven carious human teeth were fixed in paraformaldehyde and cut longitudinally into 1-mm sections using a low-speed diamond saw for the following analyses. In transmission electron microscopy (TEM) analysis, nondecalcified specimens were embedded in epoxy resin and sliced into thin sections for observation. For the immunohistochemical analysis, the specimens were paraffin embedded after decalcification for 2 wk and sectioned with a microtome. Resultant sections were stained with anti-AGE and anticollagen antibodies. The demineralized specimens were used for spectroscopic analyses without additional treatment. For Western blotting analysis, specimens were separated into carious and sound dentin. Each specimen was homogenized with a bead crusher and an ultrasonic homogenizer and then treated with hydrochloric acid. In carious dentin, the collagen fibers showed an amorphous structure in the TEM image, and the AGEs were localized in the areas of bacterial invasion in the immunostaining image. The total amount of AGEs in carious dentin was higher than in sound dentin in Western blotting. The ultrastructure of type I collagen and total amount of AGEs varied markedly in the dentinal caries region. The fluorescence lifetime was shorter in the carious area than that in the sound areas, indicating an increase of AGEs in the carious area. The increase of AGEs could influence the progression of dentinal caries.

Genomewide Association Studies in Pharmacogenomics: Meeting Report of the NIH Pharmacogenomics Research Network-RIKEN (PGRN-RIKEN) Collaboration

Genomewide association studies (GWAS) have resulted in the identification of many heritable genetic factors that underlie risk for human disease or variation in physiologic traits. In contrast, there are fewer GWAS of drug response phenotypes, despite extensive unexplained interindividual variability. To address this urgent need, the NIH Pharmacogenomics Research Network (PGRN) and the Center for Integrative Medical Sciences (IMS) at RIKEN support a collaboration, PGRN-RIKEN, with the goal of accelerating GWAS of drug response phenotypes.

Treatment of an Arteriovenous Shunt Draining into a Venous Angioma by Selective Embolisation

We treated a 62-year-old woman who suffered from intraventricular haemorrhage. Angiography revealed an arteriovenous shunt draining into a venous angioma. She was successfully treated by obliteration of the arteriovenous shunt with transarterial embolisation.

Angiography performed after embolisation demonstrated that the persisting venous angioma served as the draning vein for normal middle cerebral artery perfusion.

We believe that selective arterial occlusion with preservation of the venous component is the best treatment for this type of mixed vascular malformation.

Treatment of Intracranial (Dural) Arteriovenous Fistulas in Unusual Locations

We evaluated retrospectively the treatment modalities and clinical outcome of 14 patients with intracranial dural arteriovenous fistula (AVF) involving cortical veins and dural sinuses except the cavernous and lateral sinuses. The location of arteriovenous shunt was the confluence of the sinuses and superior sagittal sinus (in 2 patients), superior petrosal sinus (1), marginal sinus (1), parasigmoid sinus (1), cortical vein at the anterior fossa (2), cortical vein of the parietal lobe (2), petrosal vein (2), and the cortical vein around the craniocervical junction (3). Of 12 patients who underwent endovascular and/or surgical treatment, five patients were treated only with microsurgery, six only with endovascular therapy, and one with combined surgical and endovascular procedure.

Angioanatomical result was complete occlusion of the lesion in all the cases treated with surgery, and 80 to 100% occlusion in cases with endovascular treatment. Clinical outcome was GR in nine patients, MD in two, SD in one, VS in one, and D in one. The natural history of the lesion at each location and angioanatomical feature including the hemodynamic condition in each case should be precisely evaluated to select endovascular, surgical, or a combined procedure for the management of these unusual types of intracranial dural AVF.

Abstract P5-05-04: MALDI mass spectrometry imaging profile of low molecular metabolites in breast carcinoma tissues embedded in frozen tissue microarray

[Background]

Metabolomics is now widely utilized for searching disease markers or identification of new drug targets. In common method, tissue samples originated in human resected specimens are stored by formalin-fixed, paraffin-embedded (FFPE) blocks. However, these samples are inadequate to measure low molecular metabolites or lipids. Furthermore, extraction process that is required for conventional mass-spectrometry causes the loss of information on the spatial localization of the metabolites. In this study, we directly analyzed breast carcinoma tissues embedded in frozen tissue microarray (fTMA) using MALDI mass spectrometry imaging (MALDI-MSI). With our original method, we could obtain profiles of low molecular metabolite and mapping images of several tissues at one time.

[Method]

Six fTMA blocks were constructed by 119 breast tissues (carcinoma 84, normal 35) from 99 patients and sectioned at 10 um thickness. MADLI-MSI were performed by AXIMA Confidence (Shimadzu, Japan) with 9-aminoacridine as a matrix (m/z range:50∼1000, Negative Ion mode). Carcinoma and normal area in individual tissues were confirmed by H&E staining of slide grasses after MADLI-MSI analysis. Acquired MSI data were processed with the freely available software BioMap (Novartis, Switzerland).

[Result]

We could detected 1,915 peaks derive from endogenous metabolite by direct tissue MALDI-MSI analysis of breast carcinoma fTMA. Among them, 185 peaks that could be commonly detected were subjected to further analysis. Among these peaks, we could identify 18 metabolites related to energy metabolism such as ATP. By comparison of metabolite profiles obtained from carcinoma with normal tissues, we found that the energy charge (EC; which is related to ATP, ADP and AMP concentrations) and the sum of adenosine phosphate compound intensities (AXP) were significantly higher than that of normal tissue (EC; T : N = 0.56 : 0.35, AXP; 17453 : 2066, p&lt;0.0001), but there were no significant difference with lymph node metastasis, tumor histological type and tumor size. In comparison with tumor subtype, higher EC was observed in ER(+)/ Her2(-) tumor than others but AXP showed no significant among all subtypes including Ki-67 labeling index.

[Conclusion]

A combination of fTMA and MALDI-MSI is promising approach for biomarker discovery because it can achieve high throughput metabolic mapping without obvious artifact or other problem. In this study, even though high EC value were indicated in carcinoma tissue than normal but newly biomarker candidate was indeterminate at this moment. Identification of the candidates of novel carcinoma tissue biomarker is now underway.

Citation Format: Torata N, Kubo M, Miura D, Ohuchida K, Miyazaki T, Fujimura Y, Hayakawa E, Kai M, Oda Y, Mizumoto K, Hashizume M, Nakamura M. MALDI mass spectrometry imaging profile of low molecular metabolites in breast carcinoma tissues embedded in frozen tissue microarray. [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 P5-05-04.

Abstract P4-09-15: BRCAness and PD-L1 expression of basal-like and not basal-like triple negative breast cancer

Background: Triple Negative Breast Cancer (TNBC) subtype occurs in approximately 20% of all patients with breast cancer and is associated with rapid growth, early metastasis and poor prognosis compared with other subtypes. TNBCs are a heterogeneous disease entity and further subclassification is needed, but still ongoing. In this study, we assessed BRCAness, defined as shared characteristics between sporadic and BRCA1-mutated tumors, in a cohort of basal-like and non-basal-like TNBCs.

Patients and Methods: DNA was isolated from formalin-fixed paraffin-embedded tumor tissues and BRCAness status was analyzed in 262 patients with primary TNBCs resected at our three hospitals between 2004 and 2014. Classification of BRCAness was performed by using Multiple Ligation-dependent Probe Amplification (MLPA) with the probemix P376 BRCA1ness by MRC (Amsterdam, Holland). The tumor subtypes were routinely determined immunohistochemically by using resected specimens. Basal-like phenotype was defined as being positive for Epidermal Growth Factor Receptor (EGFR) and/or Cytokeratin 5/6 (CK5/6). Moreover, TNBCs were stained and analyzed for programmed cell death ligand-1 (PD-L1) expression as a target of new immune therapies.

Results: Of 262 TNBCs, 232 tumors (88.5%) was a basal-like phenotype. The results of MLPA assay showed that 159 (68.5%) of 232 tumors had a BRCAness profile. Patients with basal-like BRCAness tumors were younger than patients with basal-like non-BRCAness tumors (p&lt;0.0001). There was no significant difference between the two groups regarding pathological stage. The basal-like BRCAness group had shorter relapse-free survival (RFS) and overall survival (OS) than the basal-like non-BRCAness group (p=0.028 and p=0.13, respectively), and anthracycline-based regimens provided greater benefit to the basal-like BRCAness group significantly (p=0.01 in RFS and p=0.007 in OS). PD-L1 was expressed in 71 (44.7%) of 159 basal-like TNBCs with BRCAness.

Conclusion: We reported the majority of basal-like TNBCs showed a BRCAness profile and PD-L1 expressed in approximately 50% of BRCAness tumors. It is known that about 30% of BRCAness tumors are BRCA1-mutated tumors. Those biomarkers are essential for subclassification of TNBCs and may offer not only platinum-based chemotherapy but also novel therapies, such as immune-targeted therapies of PD-1/PD-L1 inhibitors and PARP inhibitors, to patients with basal-like TNBCs with BRCAness.

Citation Format: Mori H, Kubo M, Yamada M, Kai M, Osako T, Nishimura R, Arima N, Okido M, Kuroki S, Oda Y, Nakamura M. BRCAness and PD-L1 expression of basal-like and not basal-like triple negative breast cancer. [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 P4-09-15.

Gender differences of muscle and crural fascia origins in relation to the occurrence of medial tibial stress syndrome

Although women reportedly have a higher prevalence of medial tibial stress syndrome (MTSS) than men, the possible role of gender-based anatomical differences has not been investigated. The aim of the present study was to investigate the presence of gender-based differences in the range of muscle attachments along the entire medial tibia, the proportion of muscle attachment at the middle and distal thirds of the medial margin of the tibia, the structure of the crural fascia, and chiasm position. The specimens were 100 legs of 55 Japanese cadavers. Statistical analysis was carried out using a chi-square test to compare anatomical features between the sexes. The flexor digitorum longus (FDL) had a higher proportion of attachment to the middle and distal thirds of the medial margin of the tibia than the soleus (SOL; P < 0.001). The proportion of the SOL attachment to the middle and distal thirds of the medial margin of the tibia was 33.3% in men and 72.5% in women (P < 0.001). The soleal aponeurosis was not observed in any specimen. In all specimens the FDL formed the top layer of both chiasms. These results suggest that the higher prevalence of MTSS reported among women may be the result of gender-based anatomical differences.