Distinct motifs in the E protein are required for SARS-CoV-2 virus particle formation and lysosomal deacidification in host cells

IMPORTANCE

Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), has caused a global public health crisis. The E protein, a structural protein found in this virus particle, is also known to be a viroporin. As such, it forms oligomeric ion channels or pores in the host cell membrane. However, the relationship between these two functions is poorly understood. In this study, we showed that the roles of E protein in virus particle and viroporin formation are distinct. This study contributes to the development of drugs that inhibit SARS-CoV-2 virus particle formation. Additionally, we designed a highly sensitive and high-throughput virus-like particle detection system using the HiBiT tag, which is a useful tool for studying the release of SARS-CoV-2.

Dimerized fusion inhibitor peptides targeting the HR1-HR2 interaction of SARS-CoV-2

Membrane fusion is a critical and indispensable step in the replication cycles of viruses such as SARS-CoV-2 and human immunodeficiency virus type-1 (HIV-1). In this step, a trimer of the heptad repeat 1 (HR1) region interacts with the three HR2 regions and forms a 6-helix bundle (6-HB) structure to proceed with membrane fusion of the virus envelope and host cells. Recently, several researchers have developed potent peptidic SARS-CoV-2 fusion inhibitors based on the HR2 sequence and including some modifications. We have developed highly potent HIV-1 fusion inhibitors by dimerization of its HR2 peptides. Here, we report the development of dimerized HR2 peptides of SARS-CoV-2, which showed significantly higher antiviral activity than the corresponding monomers, suggesting that the dimerization strategy can facilitate the design of potent inhibitors of SARS-CoV-2.

Strong alkaline electrolyzed water efficiently inactivates SARS-CoV-2, other viruses, and Gram-negative bacteria

Air spaces and material surfaces in a pathogen-contaminated environment can often be a source of infection to humans, and disinfection has become a common intervention focused on reducing the contamination levels. In this study, we examined the efficacy of SAIW, a unique electrolyzed water with chlorine-free, high pH, high concentration of dissolved hydrogen, and low oxygen reduction potential, for the inactivation of several viruses and bacteria. Infectivity assays revealed that initial viral titers of enveloped and non-enveloped viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, herpes simplex virus type 1, human coronavirus, feline calicivirus, and canine parvovirus, were reduced by 2.9- to 5.5-log10 within 30 s of SAIW exposure. Similarly, the culturability of three Gram-negative bacteria (Escherichia coli, Salmonella, and Legionella) dropped down by 1.9- to 4.9-log10 within 30 s of SAIW treatment. Mechanistically, treatment with SAIW was found to significantly decrease the binding and subsequent entry efficiencies of SARS-CoV-2 on Vero cells. Finally, we showed that this chlorine-free electrolytic ion water had no acute inhalation toxicity in mice, demonstrating that SAIW holds promise for a safer antiviral and antibacterial disinfectant.

Construction and characterization of an infectious clone generated from Chikungunya virus SL11131 strain

Chikungunya virus (CHIKV) is a mosquito-borne RNA virus that causes Chikungunya fever in humans. In this study, we generated two DNA-based CHIKV infectious clones derived from an Indian Ocean Lineage SL11131 strain and a prototype Ross strain. When the replication capabilities of the infectious CHIKV in various cell lines were evaluated, the SL11131 strain was found to replicate more efficiently than the Ross strain in Aedes albopictus C6/36 cells, whereas SL11131 underwent limited replication in a BHK-21-derivative cell line named BHK-DRV. Infection experiments using chimeric CHIKV between SL11131 and Ross revealed that these different replication activities of SL11131 in C6/36 and BHK-DRV cells were determined by structural and nonstructural genes, respectively. Therefore, the infectious clones created in this study will be a useful tool for investigating the virological features of a recent epidemic strain of CHIKV and benefit the development of effective prevention and treatment of CHIKV infection.

Identification of cellular inhibitors against Chikungunya virus replication by a cDNA expression cloning combined with MinION sequencing

cDNA expression cloning has been shown to be a powerful approach in the search for cellular factors that control virus replication. In this study, cDNA library screening using a pool of cDNA derived from interferon-treated human cells was combined with the MinION sequencer to identify cellular genes inhibiting Chikungunya virus (CHIKV) replication. Challenge infection of CHIKV to Vero cells transduced with the cDNA library produced virus-resistant cells. Then, the MinION sequence of cDNAs extracted from the surviving cells revealed that the open reading frames of TOM7, S100A16, N-terminally truncated form of ECI1 (ECI1ΔN59), and RPL29 were inserted in many of the cells. Importantly, the transient expression of TOM7, S100A16, and ECI1ΔN59 was found to inhibit the replication of CHIKV in Huh7 cells, indicating that these cellular factors were potentially anti-CHIKV molecules. Thus, our study demonstrated that cDNA expression cloning combined with the MinION sequencer allowed a rapid and comprehensive detection of cellular inhibitors against CHIKV.

Abstract P6-02-11: The TILs-US scores based on ultrasonography can predict lymphocyte-predominant breast cancer before surgery

[Purpose]

Tumor-infiltrating lymphocytes (TILs) has been shown to be useful for predicting outcomes after surgery in breast cancer, and while TILs can be evaluated in preoperative biopsy tissue, heterogeneous distribution of TILs requires examination of all biopsied tissue samples.

We gave scores to preoperative ultrasonography (US) images with characteristics indicative of lymphocyte-predominant breast cancer (LPBC) and attempted to apply these for diagnostic prediction of LPBC. In this study, TILs-US scores based on preoperative US were assessed for their usefulness in predicting LPBC, the diagnosis of which was confirmed with postoperative pathology.

[Methods]

We evaluated 161 patients with invasive breast cancer between January 2014 and December 2017. All patients were treated by either mastectomy or breast-conserving surgery. Stromal lymphocytes were evaluated on preoperative biopsy tissues and surgical pathological specimens. Breast cancer samples with ≥ 50% stromal TILs were defined as pre-LPBC (preoperative biopsy tissues) and LPBC (surgical pathological specimens). TILs-US score was calculated from US before curative surgery. Based on clinicopathological factors including TILs-US scores based on preoperative US and pre-LPBC indicators, determinants useful for prediction of LPBC were examined.

[Results]

There were 39 cases of LPBCs and 122 cases of non-LPBCs in surgical pathological specimens. We set TILs-US score cut-offs for predicting LPBC at 4 points based on the receiver operating characteristics (ROC) curves (AUC, 0.88). There were significant predictors for LPBC in maltivariate logistic analysis (TILs-US score: OR26.8, p<0.001; pre- LPBC: 18.6, p=0.002; HER-2: OR9.2, p=0.009) in preoperative clinicopathological factor. The sensitivity, specificity and accuracy of TILs-US score for predicting LPBC were 0.74 (0.62-0.84), 0.89 (0.85-0.92) and 0.85 (0.79-0.90). Those of pre-LPBC were 0.51(0.42-0.55), 0.98 (0.96-1.00) and 0.87 (0.82-0.89), and those of HER2 were 0.28(0.19-0.36), 0.94(0.91-0.97) and 0.78 (0.74-0.82), respectively. The sensitivity of TILs-US score for predicting LPBC was significantly greater than those of pre- LPBC (p=0.04) and HER2 (p<0.001). On the other hand, the specificity of pre- LPBC for predicting LPBC was significantly greater than that of TILs-US score(p=0.002).

The sensitivity, specificity and accuracy of predicting LPBCPerformance measureTILs-US score (95%CI)Preoperative biopsyHER-2P, TILs-US score vs. Preoperative biopsyP, TILs-USscore vs. HER-2Sensitivity0.74 (0.62-0.84)0.51 (0.42-0.55)0.28 (0.19-0.36)0.04<0.001Specificity0.89 (0.85-0.92)0.98 (0.96-1.00)0.94 (0.91-0.97)0.0020.11Accuracy0.85 (0.79-0.90)0.87 (0.82-0.89)0.78 (0.74-0.82)0.230.11

[Conclusions]

TILs-US scores are an important factor that can predict LPBC preoperatively. The TILs-US score has particularly high sensitivity and may be an applicable index in the preoperative evaluation for LPBC.

Citation Format: Kanou A, Masumoto N, Shiroma N, Fukui K, Sasada S, Emi A, Kadoya T, Yokozaki M, Arihiro K, Okada M. The TILs-US scores based on ultrasonography can predict lymphocyte-predominant breast cancer before surgery [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 P6-02-11.

Abstract P6-02-06: Characteristics of lymphocyte-predominant breast cancer in ultrasound images and their application to diagnostic prediction

[Purpose]

Tumor-infiltrating lymphocytes (TILs) is a prognostic factor for breast cancer, however, an accurate and simple evaluation method remains elusive. Therefore, we focused on findings characteristic of lymphocyte-predominant breast cancer (LPBC) in ultrasound (US) images. In this study, the application of preoperative US image assessment to diagnostic prediction of LPBC evaluated from postoperative pathological specimens, was appraised.

[Methods]

We evaluated 191 patients with invasive breast cancer between January 2014 and December 2017. All patients were treated by either mastectomy or breast-conserving surgery. Stromal lymphocytes were evaluated on surgical pathological specimens. Breast cancer samples with ≥ 50% stromal TILs were defined as LPBC. Preoperative US was performed in all cases and images were examined for characteristics indicative of TILs. Scores were given to US images with characteristic TILs and these TILs-US scores were assessed for their application to predict LPBC.

[Results]

There were 39 cases of LPBCs and 122 cases of non-LPBCs in surgical pathological specimens.

The characteristic US image findings predicting LPBC were shape (more lobulated), internal echo level (weaker) and posterior echoes (stronger). The TILs-US scores were given based on these three ultrasound tissue characterizations.We set TILs-US score cut-offs for predicting LPBC at 4 points (Sensitivity, 0.73; specificity, 0.87; accuracy, 0.83) based on the receiver operating characteristics (ROC) curves (AUC, 0.88). There were significant predictors for LPBC in maltivariate logistic analysis (Nuclear Grade (NG): OR3.4, p=0.02; ER: 5.7, p =0.007;HER-2: OR4.1, p=0.04; TILs-US score2: OR14.9, p<0.001) in preoperative clinicopathological factor. The sensitivity, specificity and accuracy of NG for predicting LPBC were 0.75, 0.69 and 0.71. Those of ER and HER2 were 0.33, 0.96 and 0.79.Sensitivity, specificity, and accuracy of NG, ER, and HER2 diagnoses were all lower than the TILs-US score, and the TILs-US score showed the best diagnostic ability.

The sensitivity, specificity and accuracy of predicting LPBCPerformance measureTILs-US score (95%CI)NGER or HER-2P, TILs-US score vs. NG,P, TILs-USscore vs. ER or HER-2Sensitivity0.73 (0.63-0.81)0.75 (0.64-0.84)0.327 (0.24-0.39)0.08<0.001specificity0.87 (0.83-0.90)0.69 (0.65-0.72)0.957 (0.93-0.98)<0.001<0.001accuracy0.83 (0.77-0.88)0.707 (0.65-0.376)0.785 (0.74-0.82)0.0040.25

Conclusions

LPBC has characteristic ultrasound tissue characterizations in US images. Thus, TILs-US scores based on US may be applicable to accurate and convenient preoperative diagnosis of LPBC.

Citation Format: Fukui K, Masumoto N, Shiroma N, Kanou A, Yokozaki M, Sasada S, Emi A, Kadoya T, Arihiro K, Okada M. Characteristics of lymphocyte-predominant breast cancer in ultrasound images and their application to diagnostic prediction [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 P6-02-06.

Abstract P6-02-09: Diagnostic performance of dedicated breast PET for the prediction of pathological response after neoadjuvant chemotherapy

Background: Neoadjuvant chemotherapy (NAC) is a standard treatment for operable breast cancer. However, imaging methods for evaluating treatment response have not been established. Previous studies reported that ring-type dedicated breast positron emission tomography (DbPET) detected residual tumors following NAC more accurately than whole-body PET/CT. This study assessed DbPET parameters for predicting pathological complete response (pCR) in patients with breast cancer.

Patients and Methods: Among patients with breast cancer who underwent surgery after NAC, 61 were examined using ring-type DbPET before and after NAC. The maximum standardized uptake values (SUVmax) and tumor-to-normal-tissue ratio (TNR) were calculated before and after NAC (pre-SUVmax, pre-TNR, post-SUVmax and post-TNR, respectively). Moreover, the reduction rates (ΔSUVmax and ΔTNR) were determined. pCR was defined as complete remission of breast cancer.

Results: The median patient age was 52 years. Forty patients (65.6%) were estrogen receptor (ER)-positive, whereas 25 patients (41.0%) were HER2-positive. Fifteen patients (24.6%) achieved pCR after NAC. The calculated values for the parameters of DbPET are summarized in Table 1. The most promising parameters for predicting pCR were ΔSUVmax (area under the curve [AUC]: 0.506) and post-TNR (AUC: 0.640). Although neither of these two parameters reflected the pathological response to NAC in patients with ER-positive disease, post-TNR showed the highest AUC (i.e., AUC: 0.750) for pCR in patients with ER-negative disease. The sensitivity and specificity of post-TNR in the ER-positive group were 85.7% and 39.4%, respectively. In the ER-negative group, these values were 100% and 58.3%, respectively [Table 2]

Table 1.Diagnostic performance of dedicated breast positron-emission tomography for the prediction of pathological complete response after neoadjuvant chemotherapyParameterspCR Median (IQR)Non-pCR Median (IQR)PAUC (95% CI)Pre-SUVmax14.8 (9.2–17.7)14.4 (10.7–19.8)0.6040.454 (0.285–0.624)Post-SUVmax1.8(1.5–2.1)2.0 (1.6–3.4)0.2370.603 (0.460–0.746)ΔSUVmax (%)87.32 (81.5–91.8)88.6(82.8–91.8)0.9540.506 (0.329–0.682)Pre-TNR8.0 (5.3–9.2)7.3(5.9–10.2)0.7570.472 (0.297–0.647)Post-TNR1.7(1.0–1.1)1.2 (1.0–2.4)0.0980.640 (0.506–0.774)ΔTNR (%)87.3 (78.3–89.1)79.8 (62.7–86.7)0.1130.638 (0.472–0.803)pCR, pathological complete response; IQR, interquartile range; AUC, area under the curve; CI, confidence interval, SUV, standardized uptake value; TNR, tumor-to-normal-tissue ratio.Table 2.Diagnostic accuracy of post-TNR according to estrogen receptor status Sensitivity (%)Specificity (%)Accuracy (%)PPV (%)NPV (%)ER-positive85.739.447.523.192.9ER-negative10058.375.061.5100TNR, tumor-to-normal-tissue ratio; ER, estrogen receptor; PPV, positive predictive value; NPV, negative predictive value

Conclusion: In DbPET, ΔSUVmax and post-TNR were shown to be promising parameters for predicting pathological response to NAC. Post-TNR provided the highest sensitivity for predicting pCR in patients with ER-negative breast cancer.

Citation Format: Suzuki E, Sasada S, Sueoka S, Masumoto N, Goda N, Kajitani K, Emi A, Haruta R, Kadoya T, Kataoka T, Okada M. Diagnostic performance of dedicated breast PET for the prediction of pathological response after neoadjuvant chemotherapy [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 P6-02-09.

Abstract P6-02-17: Hand-held impulse-radar detector for breast cancer: development and a pilot study

Background: Microwave breast imaging, which using the difference in the dielectric properties between breast cancer and normal breast tissue, is a painless and non-radiation method. We have created a novel hand-held prototype of breast cancer detector using impulse-radar based imaging system, and conducted a pilot clinical study.

Methods: The detector consists of complementary metal-oxide-semiconductor (CMOS) integrated circuits covering the ultrawideband width from 3.1 to 10.6 GHz, which enable the generation and transmission of Gaussian monocycle pulse (GMP) trains and single port eight throw switching matrices (SP8T-SW) for controlling a 4×4 cross-shaped dome antenna array. The size of the detector was 19.1 × 17.7 × 18.8 cm. After evaluation using a breast tumor phantom and the resected breast specimens obtained through mastectomy, we recruited 5 patients with histologically confirmed breast cancers in the clinical study. The detector was placed on the breast with the patient in a supine position. The primary endpoint was a detection rate of breast cancers, and the secondary endpoints were positional accuracy and adverse event. This study was registered with the UMIN Clinical Trials Registry (UMIN000026181).

Results: The three-dimensional positions of the tumors in the imaging results using a phantom and resected specimens are consistent with the results of histopathology analysis. In the clinical study, all 5 targeted breast cancers were detected and were visualized at the sites confirmed by other diagnostic modalities. Among 5 tumors, one was not detected via mammography because of heterogeneously dense breast and another was a microinvasive carcinoma of invasive tumor size 0.5 mm. No study-related adverse events occurred.

Conclusions: We succeeded in creating a new device of hand-held impulse-radar detector for breast cancer. The detector has sufficient detective capability, is safe for clinical use, and might detect an early stage breast cancer. In the future, we will proceed with the development to clinical application.

Citation Format: Sasada S, Masumoto N, Song H, Goda N, Kajitani K, Emi A, Kadoya T, Arihiro K, Kikkawa T, Okada M. Hand-held impulse-radar detector for breast cancer: development and a pilot study [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 P6-02-17.

Abstract P5-02-03: Evaluation of pathological malignancy grade and neoplastic progress of breast cancer using dedicated breast positron emission tomography

Background: Dedicated breast positron emission tomography (DbPET)provides detailed high resolution images of the breast and enables quantitative assessment using standard uptake values (SUVs). We aimed to determine whether DbPET can predict the pathological malignancy grade and neoplastic progress of breast cancer compared with whole body (WB) PET.

Methods: We investigated 196 consecutive patients with invasive breast cancerwho underwent concurrent Db- and WB-PET from January 2016 to March 2017. All Db- and WB-PET were quantified based on SUVs. We also investigated pathological features of breast cancer who had a ring-like uptake (RU) without central FDG accumulation on DbPET.

Results:

The associations between the SUVs for DB- and WB-PET and the pathological factors in breast cancerCharacteristicSUV WBPETDbPET Mean ± SDpMean ± SDpall3.6 ± 3.4 9.4±7.9 Tumor size    ≤2.0 cm2.2±1.6<0.0016.5±5.2<0.001>2.0 cm5.5±4.1 13.3±9.2 LN    Negative3.1±3.3<0.0018.4±7.8<0.001Positive4.9±3.2 11.8±7.7 NG    1 or 22.4±2.1<0.0016.6±5.9<0.00135.1±4.0 12.7±8.7 Ki67    < 201.8±1.1<0.0015.2±3.3<0.001≥ 204.4±3.7 11.4±8.6 ER    positive3.4±3.30.028.8±7.60.006negative5.2±3.6 13.5±8.6 HER-2    positive4.6±3.10.0911.8±7.60.04negative3.4±3.4 9.0±7.9 Sub type vs Lumnal A vs Lumnal ALuminal A1.8±1.1 5.2±3.3 Luminal B4.0±3.8<0.00110.1±8.5<0.001HER24.6±3.1<0.00111.8±7.6<0.001Triple negative5.3±3.8<0.00113.8±9.2<0.001

summarizes the association between SUVs for Db- and WB-PET and pathological factors inbreast cancer.SUVs on PET were significantly higher for the tumor size of >2.0 cm than for tumor size ≤2.0 cm (p<0.001), for LN-positive than for LN-negative (p<0.001), for NG3 than for NG1-NG2 (p<0.001), for higher Ki67 expression than for lower Ki67 expression (p<0.001), and for ER-negative than for ER-positive (WBPET, p=0.02; DbPET, p=0.006). SUVs were significantly lower for Luminal A than for Luminal B, HER2, and triple-negative cancer (p<0.001 for all three).SUVs for DbPET was significantly higher for HER2-positive than for HER2-negative (p=0.02).

The association between SUVs for breast cancer with and without RU on DbPETCharacteristicRU(-), nRU(+), npall17323 Tumor size   ≤2.0 cm1095<0.001>2.0 cm6418 LN   Negative1299<0.001Positive4414 NG   1 or 210070.0237316 Ki67   < 206130.03≥ 2011220 ER   positive152190.49negative214 HER-2   positive2620.38negative14721 Sub type  vs Lumnal ALuminal A493 Luminal B84150.02HER22620.81Triple negative1430.04

summarizes the association between SUVs for breast cancer with and without RU on DbPET. SUVs for breast cancer with RU on DbPET were significantly higher for the tumor size of >2.0 cm than for tumor size ≤2.0 cm, for LN -positive than for LN-negative (p<0.001), for NG3 than for NG1-2 (p=0.02), and for higher Ki67 expression than for lowerKi67 expression (p=0.03). SUVs were significantly lower for Luminal A than for Luminal B (p=0.02) and triple-negative cancer (p=0.04).

Conclusions: SUVs for DbPET were equal or superiorto WBPET in predicting the pathological malignancy grade and neoplastic progress in tumors. Furthermore, the presence of RU on DbPET can provide excellent predictive value for high-grade malignancy and might help to determine appropriate therapeutic strategies.

Citation Format: Masumoto N, Kadoya T, Nishina M, Kimura Y, Suzuki E, Sueoka S, Goda N, Sasada S, Kajitani K, Emi A, Haruta R, Kataoka T, Okada M. Evaluation of pathological malignancy grade and neoplastic progress of breast cancer using dedicated breast positron emission tomography [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 P5-02-03.

Abstract P6-03-08: Detection ability of dedicated breast positron emission tomography for small-sized breast cancer

Background: Whole body (WB) 18F-fluorodeoxyglucose positron emission tomography (PET) has a relatively poor spatial resolution (>1 cm), which limits the capability to detect small lesions. Therefore, small-sized breast cancers (≤1 cm) may not be visible on WBPET. To overcome these limitations, dedicated breast PET (DbPET) has been developed to improve spatial resolution. DbPET enables detailed high-resolution images within the breast. We aimed to determine whether DbPET can detect small-sized breast cancer compared to WBPET.

Methods: We investigated 203 consecutive patients (217 tumors) (T1–3, N0–3a, M0) with breast cancer who underwent concurrent DbPET and WBPET between January 2016 and March 2017. All DbPET and WBPET images were semi-quantified based on standard uptake values. The diagnostic performance of each scanner was assessed in DbPET and WBPET. Tumors were classified based on pathological classification as follows: Tis, ductal carcinoma in situ (DCIS); T1a, ≤0.5 cm; T1b, 0.5–1 cm; and T1c, 1–2 cm; T2, 2–5 cm; T3, >5 cm. The sensitivities of DbPET and WBPET were compared in each size group.

Results: Table 1 shows the detection rate of breast cancer in WBPET and DbPET

The detection rate of breast cancer in WB- and Db-PET DbPETWBPETpTumor sizeDetection (-) n(%)Detection (+) n(%)Detection (-) n(%)Detection (+) n(%) Tis6(14.6)35(85.4)18(43.9)23(56.1)0.0030T1a2(8)23(92)7(28)18(72)0.0594T1b2(6.5)29(93.5)10(32.3)21(67.7)0.0077T1c5(8.2)56(91.8)11(18)50(82)0.1038T20(0)57(100)1(1.8)56(98.2)0.2375T30(0)2(100)0(0)2(100)-total15(6.9)202(93.1)47(21.7)170(78.3)<0.0001

. The overall detection rate in DBPET [93.1% (202/217)] was significantly higher than that of WBPET [78.3% (170/217)] (P < 0.001). For smaller tumors, DbPET was more sensitive than WBPET: Tis (85.4% vs. 56.1%), T1a (92% vs. 72%), T1b (93.5% vs. 67.7%), T1c (91.8% vs. 82%), T2 (100% vs. 98.2%), and T3 (100% vs. 100%). The sensitivity of DbPET was significantly higher than that of WBPET in Tis (P = 0.003) and T1b (P = 0.008) and tended to be higher than that of WBPET in T1a (P = 0.059). Conversely, no significant differences were observed in T1c (P = 0.103) and T2 (P = 0.238).

Conclusion: The imaging sensitivity of DbPET was higher than that of WBPET. DbPET showed significant sensitivity in DCIS and tumors ≤1 cm, which is a weak point for WBPET. DbPET may serve as a new diagnostic modality to detect small-sized breast cancer.

Citation Format: Sueoka S, Masumoto N, Nishina M, Kimura Y, Suzuki E, Goda N, Sasada S, Kajitani K, Emi A, Haruta R, Kadoya T, Kataoka T, Okada M. Detection ability of dedicated breast positron emission tomography for small-sized 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 P6-03-08.

Abstract P4-02-06: Evaluation of contrast-enhanced ultrasonography for early prediction of response to neoadjuvant chemotherapy in triple negative breast cancer

Objectives

We aimed to determine whether contrast-enhanced ultrasonography (CEUS) can predict the early effects of neoadjuvant chemotherapy on triple negative breast cancer.

Methods

The clinical responses of 20 consecutive patients with breast cancer (T1–2, N0–1, M0) to neoadjuvant chemotherapy between October 2012 and Feb 2016 were assessed using ultrasonography and contrast-enhanced ultrasonography before starting the therapy and after the treatment of 2 courses. Ascending slope (AS) of perfusion parameters for contrast-enhanced ultrasonography were created from time–intensity curves based on enhancement intensity and temporal changes to objectively evaluate contrast-enhanced ultrasonography findings.We investigated whether rate of change of ascending slope (ΔAS) and tumor size (Δ US) could predict pCR.

Results

Eight (40.0%) of the 20 patients achieved pathological complete response. ΔAS were significantly higher (-25.5 ± 35.5 vs. 14.7 ± 33.2; P < 0.02) in patients who achieved pCR than in those who did not. On the other hand, ΔUS of pCR and non-pCR did not significantly differ among tumors (-40.8 ± 22.4 vs. -21.4 ± 20.6; P = 0.06). The AUC values for ΔAS and ΔUS were 0.792 (95% CI, 0.579 -1.000, P = 0.03) and 0.729 (95% CI, 0.501 - 0.957;p = 0.09), respectively. We set ΔAS and Δ US cut-offs for predicting pCR at-20.08 and - 33.75 based on the ROC curves. Clinical and pathological characteristics of the 20 patients are summarized in Univariate (odds ratio, 2.71; p= 0.02) and multivariate (odds ratio, 2.88; p= 0.03) analysis showed that ΔAS was the sole independent predictor of pCR.

Clinical and pathological characteristics of patients with breast cancer.CharacteristicpCR (n)Non pCR (n)pClinical T status   T1110.71T2711 Clinical N status   Negative570.85Positive35 Nuclear Grade   1 or 2340.85358 ΔUS (%)   < -33.75390.09≥ -33.7553 ΔAS (%)   < -20.082100.009≥ -20.0862 

Univariate and multivariate logistic analysis of significant predictive factors for pCR in triple negative subtype Univariate analysisMultivariate analysis OR, 95% CI, pOR, 95% CI, pΔUS  > -33.751.61, 0.72-34.7, 0.101.85, 0.51-79.1, 0.15≤-33.75  ΔAS  > -20.082.71, 1.65-136.1, 0.022.88, 1.44-218.7, 0.03≤ -20.08  

Conclusion

ΔAS assessed with CEUS can help the physician to early predict the probability of achieving pCR or not.

Citation Format: Masumoto N, Kadoya T, Murakami C, Gouda N, Sasada S, Emi A, Haruta R, Kataoka T, Okada M. Evaluation of contrast-enhanced ultrasonography for early prediction of response to neoadjuvant chemotherapy in 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 P4-02-06.

Abstract P1-15-03: Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial

Background

Prevention of letrozole–induced bone loss using oral risedronate has not been proved in the Japanese women. The aim of this study was to assess the effect of risedronate 17.5mg/week on bone mineral density (BMD) in postmenopausal, early breast cancer patients scheduled to receive adjuvant letrozole.

Patients and Methods

Postmenopausal women with hormone receptor–positive early breast cancer were assigned to one of two strata according to their baseline BMD T-score as being at low and high risk of osteoporosis. Patients with low risk (-2.5 ≤ T score) were randomly assigned to letrozole and risedronate (L+R) or to letrozole alone (L). Patients with high risk (-2.5 > T score) received letrozole and risedronate (L+R). Letrozole was given at a dosage of 2.5 mg/day while oral risedronate was given at 17.5mg/week. The primary end point was the change in lumbar spine (LS) BMD at 12 months. The secondary end points included change in total hip (HP) BMD and bone turnover markers.

Results

In the low risk group (N=103), treatment with L+R resulted in a significant increase in BMD at LS and at HP compared to treatment with L only at 12 months (1.8% vs -2.2%, P < 0.001, and -0.3% vs -2.9%, P = 0.001, respectively). In the L+R group, significant decreases in bone turnover makers, NTX and PINP, were recognized compared with L only at 12months (-11.1% vs. 27.5%, P<0.001, -42.3% vs. 15.2%, P<0.001, respectively). In the high risk group (N=28), treatment with L+R resulted in a significant increase in BMD at LS and prevention of decrease in BMD at HP (3.6%; 95%CI, 1.8% to 5.3%, p=0.003, 0.3%; 95%CI, -1.3% to 1.8%, p=0.47, respectively).

Estimated Percentage Change From Baseline to 6 and 12 Months in Lumbar Spine and Total Hip BMD   From Baseline to 6 MonthsFrom Baseline to 12 MonthsBMD areaRisk GroupTreatmentChange in BMD (%), 95% CIPChange in BMD (%), 95% CIPLumbar spineLow riskL+R1.7 (-1.3 to 4.7)<0.0011.8 (-2.1 to 5.7)<0.001  L-1.6 (-4.3 to 1.1) -2.2 (-5.7 to 1.3)  High riskL+R1.8 (0.4 to 3.2)0.043.6 (1.8 to 5.3)0.003Total hipLow riskL+R-0.2 (-2.7 to 2.3)0.001-0.3 (-3.2 to 2.6)0.001  L-2.2 (-5.4 to 1.0) -2.9 (-7.2 to 1.4)  High riskL+R0.1 (-1.3 to 1.6)0.610.3 (-1.3 to 1.8)0.47BMD: bone mineral density, L: Letrozole, R: risedronate

Four patients (14.3%) improved from osteoporotic region to the osteopenic region with L+R treatment. Letrozole and risedronate were well tolerable and there was no serious adeverse event including osteonecrosis of jaw.

Conclusions

At 12 months, 17.5mg/week risedronate therapy prevented bone loss in postmenopausal women with breast cancer who were receiving adjuvant letrozole, of which results were compatible with previous findings of western populations.

Citation Format: Kadoya T, Masumoto N, Shigematsu H, Emi A, Kajitani K, Kobayashi Y, Funakoshi M, Kawabuchi Y, Ohara M, Matsuura K, Noma M, Sasada T, Okada M. Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial. [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 P1-15-03.

Abstract P4-09-17: Wnt5a expression is associated with high-grade malignancy in ER-positive breast cancer

Background: Wnt5a is a representative ligand that activates the β-catenin-independent pathways. The purpose of our study is to elucidate the implication of Wnt5a expression in breast cancer.

Materials and methods: One hundred seventy eight breast cancer patients (mean age ± SD: 59.6 ± 13.2 years) with clinical Stage I∼III between January 2011 and February 2014, were prospectively evaluated. Patients who underwent operation without neoadjuvant therapy were enrolled to this study. The immunohistochemical analyses of Wnt5a protein was performed to evaluate relationships between Wnt5a expression and clinicopathological factors. MCF7 cells that stably express Wnt5a were generated and used for cDNA microarray analyses to investigate Wnt5a-dependent gene expression.

Results: Wnt5a expression was significantly more frequent when estrogen receptor (ER) was present, 68/153 (44%) than when ER was absent, 1/25 (4%) (p<0.001). Wnt5a expression was also related with progesterone receptor (PgR) (P<0.001), but not with HER2 status (P=0.496). In ER-positive breast cancer, a significant interaction between expression of Wnt5a with lymph node metastasis (P<0.001), nuclear grade (P=0.004), lymphatic invasion (P=0.002), vessel invasion (P=0.050), and pStage (P<0.001). Microarray analyses identified several genes induced by Wnt5a (>3.0 fold), involving activated leukocyte cell adhesion molecule (ALCAM). ALCAM is known to be related with apoptosis, invasion and prognosis of breast cancer. Wnt5a expression levels correlated with those of ALCAM in ER-positive tumor samples from patients by immunohistochemical analyses (P<0.001).

Relationship between Wnt5a expression and clinicopathological featureClinicopathological featuretotalWnt5a expressionP value (n=153)Negative (n=85)Positive (n=68) Age (median, range) 63, 35-8657.5, 34-870.065Age, n (%)    ≤4528 (18)13 (46)15 (54) >45125 (82)72 (58)53 (42)0.282Menopausal status, n (%)    Premenopausal58 (38)27 (47)31 (53) Postmenopausal95 (62)58 (61)37 (39)0.080Tumor size, n (%)    pT1 ≤20mm104 (44)63 (61)41 (39) pT2/pT3 >20mm49 (56)22 (45)27 (55)0.069lymph node metastasis, n (%)    Negative103 (67)72 (70)31 (30) Positive50 (33)13 (26)37 (74)<0.001Nuclear grade, n (%)    1/285 (56)56 (66)29 (34) 368 (44)29 (43)39 (57)0.004Lymphatic invasion, n (%)    Negative101 (66)65 (64)36 (36) Positive52 (34)20 (38)32 (62)0.002Vessel invasion, n (%)    Negative142 (93)82 (58)60 (42) Positive11 (7)3 (27)8 (73)0.050Ki-67, n (%)    0-2067 (44)43 (64)24 (36) 21-10086 (56)42 (49)44 (51)0.058pStage, n (%)    pStage I80 (52)58 (73)22 (28) pStage II64 (42)27 (42)37 (58) pStage III9 (6)0 (0)9 (100)<0.001ALCAM, n (%)    Negative85 (56)64 (75)21 (25) Positive68 (44)21 (31)47 (69)<0.001

Conclusions: Wnt5a express in ER-positive breast cancer and are associated with high-grade malignancy. Wnt5a could be a prognostic factor of ER-positive breast cancer. These results have implications that Wnt5a may become a preoperative and postoperative assessment tool for tumor malignancy grade and a potential therapeutic target except endocrine therapy in ER-positive breast cancer. In future studies, further research on Wnt5a are required to develop a novel treatment for more improved outcomes in a great variety of breast cancer.

Citation Format: Kobayashi Y, Kadoya T, Gouda N, Kajitani K, Emi A, Shigematsu H, Masumoto N, Okada M. Wnt5a expression is associated with high-grade malignancy in ER-positive 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 P4-09-17.

Abstract P2-03-07: Prediction of the pathological response to neoadjuvant chemotherapy in patients with breast cancer using sonazoid-enhanced ultrasonography

Background:

Altered blood flow in malignant tumors is evidenced by contrast-enhanced ultrasonography (CEUS) because of its image perfusion capabilities.

This study aimed to investigate the value of CEUS in the evaluation of the response of breast cancer lesions to neoadjuvant chemotherapy (NAC). We evaluated whether the prediction of a pathological complete response (pCR) using CEUS was more precise than that using other standard evaluation methods such as magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT).

Methods:

Ten patients (mean age, 50.2 years) who underwent NAC for invasive breast cancer between September 2012 and April 2013 were eligible for this cohort study. Clinical tumor response was evaluated using contrast-enhanced MRI, PET/CT, and CEUS following NAC. A pCR was defined as the absence of invasive cancer in the breast and lymph nodes according to the Japanese Breast Cancer Society criteria.

A clinically complete response (cCR) was defined as the absence of residual disease on MRI and PET/CT. The HI VISION ASCENDUS (Hitachi Aloka Medical Corp.) was used for ultrasonography. Tumors were observed 50 s after Sonazoid injection at a dose of 0.01 ml/kg. A time-intensity curve of tumor signal intensity was drawn. The brightness of the tumor was digitized and the curve was created on the basis of brightness changes over time. The intensity of brightness of the breast cancer lesions was calculated as the increased rate of brightness (IRB) using the following formula: maximal intensity/intensity before contrast.

Results:

Four (40%) of the 10 patients were diagnosed with pCR by NAC. Among 4 (40%) patients diagnosed with cCR by MRI, 1 (25%) achieved pCR. All patients were diagnosed with pCR by PET/CT. The IRB values of the 10 patients who received CEUS before surgery were 1.0, 1.1, 1.2, 1.2, 1.3, 1.6, 1.8, 1.9, 2.5, and 4.2. The IRB values of the 4 patients diagnosed with pCR were 1.0, 1.1, 1.2, and 1.2. IRB values were significantly lower in patients who achieved pCR than in those who did not (pCR vs. no pCR, 1.1 ± 0.9 vs. 2.2 ± 1.0, P < 0.05). Furthermore, among the patients who achieved pCR, the IRB values of 2 patients with no residual ductal carcinoma in situ (DCIS) were 1.0 and 1.1, whereas those of 2 patients with residual DCIS were both 1.2.

In the 4 patients who achieved cCR as diagnosed by MRI and PET/CT, 3 with pathological residual disease had detectable IRB by CEUS.

table 1caseageStageSub typeMRIPET-CTpathological responseIncrease rate of brightness (IRB)167T2N1 IIBLuminal HER2PRCRCR1237T2N0 IIAHER2 positivePRCRCR1.1346T3N1 IIIAHER2 positiveCRCRCR1.2446T2N3c IIICLuminal HER2PRCRCR1.2564T2N0 IIAHER-2 positiveCRCRPR1.3658T2N1 IIBLuminal BCRCRPR1.6738T2N0 IIALuminal BPRCRPR1.8857T1cN0 ILuminal HER-2PRCRPR1.9939T2N1 IIBLuminalBSDCRSD2.51050T2N1 IIBTriple negativePRCRSD4.2

Conclusions:

The prediction of pCR after NAC in patients with breast cancer is more precise with Sonazoid-enhanced ultrasonography than with standard methods such as MRI and PET/CT. Furthermore, CEUS may be useful for predicting residual DCIS on the basis of brightness intensity.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-03-07.

Abstract P6-07-26: Prognostic significance of the maximal value of the baseline standardized uptake value on fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for predicting pathologic malignancy of operable breast cancer with neoadjuvant chemotherapy

PURPOSE: [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is potentially useful in predicting pathological complete response (pCR), disease free survival (DFS) and overall survival (OS) of breast cancer patients with neoadjuvant chemotherapy.

MATERIALS AND METHODS: 77 breast cancer patients (mean age ± SD: 52.6 ± 11.2 years) with clinical Stage I∼III between January 2006 and December 2011, were prospectively evaluated (median follow up period:26.5 months). Neoadjuvant chemotherapy of an anthracycline-based regimen and taxane was performed, and patients underwent a whole-body FDG PET/CT before and after chemotherapy. The maximal value of the baseline standardized uptake values (SUVmax) were assessed for predicting pCR, DFS and OS. For the evaluation of relationship between SUVmax values and prognosticators such as hormone receptors, human epidermal growth factor receptor 2 (HER2), nuclear grade, lymph node metastasis and tumor size, statistical analyses were performed using Student t test and log-rank test, and p values of less than 0.05 were considered to indicate statistically significant differences.

RESULTS: Clinical Stage included were I (n = 2, 2.6%), II (n = 62, 80.5%) and III (n = 12, 15.6%). Tumors with estrogen receptor positive were 52 (67.5%) and negative were 24 (31.2%). Therapeutic response by neoadjuvant chemotherapy was obtained in 15 patients (19.5%) with pCR and 60 (77.9%) without pCR. Patients were divided into two groups according to cut-off SUVmax established on the basis of receiver operating characteristic (ROC) analysis (<6.0 vs. ≥6.0, AUC=0.721). When related to the biologic parameters, estrogen receptor (OR:3.75, 95%Cl:1.36–10.35, p = 0.02), but not progesterone receptor (OR:2.31, 95%Cl:0.89–6.00, p = 0.08) nor HER2 status (OR:1.51, 95%Cl:0.47–4.85, p = 0.70) were found strong relation to SUVmax values.

Cloning and expression analysis of takeout/JHBP family genes of silkworm, Bombyx mori

A Bombyx EST cDNA database was searched using the Drosophila takeout gene and nine cDNAs were obtained. The homology search suggested that these genes are widespread in insects and organize a large gene family, and that they have hydrophobic ligands. A phylogenetic tree indicated that the genes are first divided into two large groups, juvenile hormone binding protein and other protein genes, and the latter group diversified within a short time at an early stage. The expression study of five Bombyx genes indicated that they are expressed in various tissues and are regulated by development and feeding conditions. The Bombyx genes might have roles related to the regulation of metabolism, growth or development related to nutritional conditions.