Diagnostic performance of dedicated breast positron emission tomography

Background

Dedicated breast positron emission tomography (dbPET) has been developed for detecting smaller breast cancer. We investigated the diagnostic performance of dbPET in patients with known breast cancer.

Methods

Eighty-two preoperative patients with breast cancer were included in the study (84 tumours: 11 ductal carcinomas in situ [DCIS], 73 invasive cancers). They underwent mammography (MMG), ultrasonography (US), and contrast-enhanced breast magnetic resonance imaging (MRI) before whole-body PET/MRI (WBPET/MRI) and dbPET. We evaluated the sensitivity of all modalities, and the association between the maximum standard uptake value (SUVmax) level and histopathological features.

Results

The sensitivities of MMG, US, MRI, WBPET/MRI and dbPET for all tumours were 81.2% (65/80), 98.8% (83/84), 98.6% (73/74), 86.9% (73/84), and 89.2% (75/84), respectively. For 11 DCIS and 22 small invasive cancers (≤ 2 cm), the sensitivity of dbPET (84.9%) tended to be higher than that of WBPET/MRI (69.7%) (p = 0.095). Seven tumours were detected by dbPET only, but not by WBPET/MRI. Five tumours were detected by only WBPET/MRI because of the blind area of dbPET detector, requiring a wider field of view. After making the mat of dbPET detector thinner, all 22 scanned tumours were depicted. The higher SUVmax of dbPET was significantly related to the negative oestrogen receptor status, higher nuclear grade, and higher Ki67 (p < 0.001).

Conclusions

The sensitivity of dbPET for early breast cancer was higher than that of WBPET/MRI. High SUVmax was related to aggressive features of tumours. Moreover, dbPET can be used for the diagnosis and oncological evaluation of breast cancer.

A genome-wide association study identifies three novel genetic markers for response to tamoxifen: A prospective multicenter study

Purpose

Although association studies of genetic variations with the clinical outcomes of breast cancer patients treated with tamoxifen have been reported, genetic factors which could determine individual response to tamoxifen are not fully clarified. We performed a genome-wide association study (GWAS) to identify novel genetic markers for response to tamoxifen.

Experimental design

We prospectively collected 347 blood samples from patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative, invasive breast cancer receiving preoperative tamoxifen monotherapy for 14 to 28 days. We used Ki-67 response in breast cancer tissues after preoperative short-term tamoxifen therapy as a surrogate marker for response to tamoxifen. We performed GWAS and genotype imputation using 275 patients, and an independent set of 72 patients was used for replication study.

Results

The combined result of GWAS and the replication study, and subsequent imputation analysis indicated possible association of three loci with Ki-67 response after tamoxifen therapy (rs17198973 on chromosome 4q34.3, rs4577773 on 6q12, and rs7087428 on 10p13, P_combined = 5.69 x 10⁻⁶, 1.64 x 10⁻⁵, and 9.77 x 10⁻⁶, respectively). When patients were classified into three groups by the scoring system based on the genotypes of the three SNPs, patients with higher scores showed significantly higher after/before ratio of Ki-67 compared to those with lower scores (P = 1.8 x 10⁻¹²), suggesting the cumulative effect of the three SNPs.

Conclusion

We identified three novel loci, which could be associated with clinical response to tamoxifen. These findings provide new insights into personalized hormonal therapy for the patients with breast cancer.

Abstract 5678: Novel serum microRNAs that enable liquid biopsy for colorectal cancer: validation study of large cohort

Introduction: Recent studies have reported that serum microRNAs (miRNAs) are potentially useful biomarkers for cancer. However, the detection system using serum miRNAs is not established in colorectal cancer (CRC). The aims of this study are 1) to identify specific serum miRNAs and establish the discriminant model for CRC detection and 2) to validate the miRNAs and the discriminant model using a large cohort.

Methods: First, we identified serum miRNAs related with the presence of CRC and constructed the discriminant model for CRC detection using the publicly-released serum miRNA database including 50 patients with CRC and 90 healthy individuals (GSE59856 and GSE73002). Comparing serum miRNA levels between patients with CRC and healthy individuals, we picked up miRNAs (p&lt;0.05 by t-test and fold change &gt; 2). Using these miRNAs, Fisher’s linear discriminant analysis was performed and the diagnostic models were constructed using less than 7 miRNAs. Subsequently, 1117 patients of National Cancer Center Hospital with CRC were enrolled as a validation cohort. Patients with the following criteria were excluded; (i) patients simultaneously or previously diagnosed as the other cancers, (ii) patients who were treated for CRC previously and (iii) patients with familial adenomatous polyposis or Lynch syndrome. Control blood samples were obtained from patients without any history of cancer who were admitted or referred to National Center for Geriatrics and Gerontology or Yokohama Minoru Clinic between 2010 and 2015. A total of 1013 CRC patients and 4384 non-cancerous patients were analyzed. Total RNA was extracted from 300 micro L of serum and comprehensive miRNA expression analysis was performed using a 3D-Gene microarray. ROC analysis was performed to evaluate the previous discriminant models. The sensitivity in each pathological stage and location of CRC was also investigated.This research is partially supported by the “Development of Diagnostic Technology for Detection of miRNA in Body Fluids” grant from the Japan Agency for Medical Research and Development (AMED).

Results:First we picked up 30 miRNAs for CRC diagnosis. Fisher’s analysis revealed 107611 candidates of numerical formulas, that showed &gt; 80% of sensitivity and specificity. We could narrow these candidates to 43 formulas with validation analysis. By ROC analysis, the AUC, sensitivity and specificity of the discriminant formula with best performance was 0.904, 79.6% and 86.5%, respectively. The sensitivities of each pathological stage were as follows; pStage 0: 79.0%, pStage I: 90.7%, pStage II: 85.1%, pStage III: 73.7%, pStage IV: 62.2%. The sensitivity of CRC in the right side of the colon was 79.4%, whereas that in the left side was 79.7%.

Conclusions:We identified novel serum miRNAs for CRC detection. Our discriminant using these miRNAs can diagnose CRC including early stage. Furthermore, the sensitivity was high irrespective of the tumor location.

Citation Format: Hiroyuki Takamaru, Yutaka Saito, Taku Sakamoto, Seiichiro Abe, Masayoshi Yamada, Takeshi Nakajima, Kazuki Sudo, Ken Kato, Junpei Kawauchi, Satoko Takizawa, Hiromi Sakamoto, Motohiro Kojima, Atsushi Ochiai, Shumpei Niida, Hideshi Ishii, Tomoko Takamaru, Juntaro Matsuzaki, Takahisa Matsuda, Takahiro Ochiya. Novel serum microRNAs that enable liquid biopsy for colorectal cancer: validation study of large cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5678. doi:10.1158/1538-7445.AM2017-5678

Abstract P4-01-09: γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG) is promising fluorescence probe for rapid diagnosis of breast cancer; - The feasibility study of real time imaging for breast cancer examination -

【Background and Aim】

To date, fluorescence imaging has been used gradually for real time diagnosis in various clinical situations. Evaluation of margin on surgical specimens is essential to decide whether additional resection should be performed for breast cancer surgery. In the same context, rapid assessment of biopsy specimen is crucial because when they do not contain any part of the lesions, re-examination should be need.

A fluorescence probe named γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG) was rapidly activated by an enzyme, γ-glutamyltransferase (GGT). It was overexpressed in variety of cancers so promising for clinical use. The aim of this study is to examine the usefulness of the probe for breast cancer detection.

【Material and Methods】

We investigated the patients of breast cancer or benign disease who received examination consecutively from March 2015 to February 2016 in our hospital. The samples were obtained by core needle biopsy (CNB) or vacuum-assisted breast biopsy (VAB).We sprayed the probe on these samples immediately after examination and shoot images by CCD camera. To evaluate the fluorescence intensity along the time, we used a filtered CCD camera that could detect specifically gGlu-HMRG color (Discovery® INDEC Medical Systems Inc.). The images were automatically obtained every 30 seconds for 10 minutes after adding the probe on the specimens.

The average value of the image in each region of interest (ROI) was analyzed using image analysis program Image J (https://imagej.nih.gov/ij/).

We investigated the change of fluorescence intensity with the passage of time. We also compared the fluorescence intensity of malignant lesions with benign ones, and analyzed whether the fluorescence intensity could distinguish the malignant lesions from benign ones.

【Result】

We obtained 362 samples from96 tumors. Fifty-six tumors with 215 samples were benign, while 40 tumors with 147samples are malignant histologically.

The fluorescence was immediately observed after sprayed the probe. The intensity had been increasing in proportion to time. The malignant specimens were rapidly increasing; in contrast, the benign ones were slowly. For example, when it took 60 seconds after spraying the probe that the intensity increase up to some level in malignant specimens, while benign one took 240 seconds up to the same level on average.

Comparing the malignant lesions with benign ones after sprayed 120 seconds, the fluorescence intensity was higher in malignant specimens than benign ones (average fluorescence intensity; benign 0.9, malignant 2.3 p=0.0138). By ROC analysis whether the fluorescence intensity could distinguish the malignant lesions from benign, AUC, sensitivity and specificity was 0.63, 70% and 57%, respectively (cut off 0.2).

【Conclusion】

The probe was contributory to distinguish malignant and benign lesions and may be useful for the rapid diagnosis of CNB in practice. We are now trying to seek a more accurate probe to differentiate benign and malignant lesion as a next step.

Citation Format: Takamaru T, Akashi ST, Kuwayama T, Sawada T, Hirota Y, Urano Y, Nakamura S. γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG) is promising fluorescence probe for rapid diagnosis of breast cancer; - The feasibility study of real time imaging for breast cancer examination - [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 P4-01-09.

Abstract 2031: Association between CYP2D6 genotype and response to tamoxifen in a prospective multicenter study in Japan

Purpose:

CYP2D6 is key enzyme responsible for the generation of the potent active metabolite of tamoxifen, “endoxifen”. We previously reported that reduced- or null-function alleles of CYP2D6 were significantly associated with poor clinical outcome of breast cancer patients treated with tamoxifen. However, there are still discrepant reports questioning the association between CYP2D6 genotype and tamoxifen efficacy. Hence, we carried out prospective multicenter studies to evaluate the value of CYP2D6 genotyping in tamoxifen therapy.

Patients and Methods:

We studied 279 patients with hormone receptor-positive and Her-2 negative, invasive breast cancer receiving preoperative tamoxifen monotherapy for 14 - 28 days. Ki-67 response in breast cancer tissues after tamoxifen therapy was used as a surrogate marker of response to tamoxifen. We investigated the effects of allelic variants of CYP2D6 on Ki-67 change in breast cancer tissues, histological response, breast conservative operation and hot flash.

Results:

Ki-67 labeling index in breast cancer tissues significantly decreased after preoperative tamoxifen monotherapy for 14-28 days (P = 0.00000000024). Moreover, proportion of estrogen receptor positive cells in breast cancer tissues were significantly associated with Ki-67 change after tamoxifen therapy (P = 0.0099). CYP2D6 variants were not significantly associated with histological response, breast conservative operation and hot flash (P = 0.25, P = 0.28 and P = 0.34, respectively). However, CYP2D6 variants were significantly associated with Ki-67 decrease after the preoperative tamoxifen therapy (P = 0.000014; in patients with two variant alleles v patients carrying one or two wild-type alleles).

Conclusion:

Our result suggest that genetic variation in CYP2D6 is a key predictor for the prognosis of patients with breast cancer treated with tamoxifen.

Citation Format: Hitoshi Zembutsu, Seigo Nakamura, Sadako Akashi-Tanaka, Takashi Kuwayama, Chie Watanabe, Tomoko Takamaru, Hiroyuki Takei, Kana Miyahara, Hiroshi Matsumoto, Yoshie Hasegawa, Goro Kutomi, Hiroaki Shima, Fukino Satomi, Hideki Maeda, Minoru Okazaki, Hisamitsu Zaha, Mai Onomura, Ayami Matsukata, Yasuaki Sagara, Shinichi Baba, Akimitsu Yamada, Kazuhiro Shimada, Daisuke Shimizu, Koichiro Tsugawa, Arata Shimo, Tan Ern Yu, Mikael Hartman, Chan Ching Wang, Soo Chin Lee, Yusuke Nakamura. Association between CYP2D6 genotype and response to tamoxifen in a prospective multicenter study in Japan. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2031.

Risk of node metastasis of sentinel lymph nodes detected in level II/III of the axilla by single-photon emission computed tomography/computed tomography

In breast cancer, single-photon emission computed tomography/computed tomography (SPECT/CT) shows the exact anatomical location of sentinel nodes (SN). SPECT/CT mainly exposes axilla and partly exposes atypical sites of extra-axillary lymphatic drainage. The mechanism of how the atypical hot nodes are involved in lymphatic metastasis was retrospectively investigated in the present study, particularly at the level II/III region. SPECT/CT was performed in 92 clinical stage 0-IIA breast cancer patients. Sentinel lymph nodes are depicted as hot nodes in SPECT/CT. Patients were divided into two groups: With or without hot node in level II/III on SPECT/CT. The existence of metastasis in level II/III was investigated and the risk factors were identified. A total of 12 patients were sentinel lymph node biopsy metastasis positive and axillary lymph node dissection (ALND) was performed. These patients were divided into two groups: With and without SN in level II/III, and nodes in level II/III were pathologically proven. In 11 of the 92 patients, hot nodes were detected in level II/III. There was a significant difference in node metastasis depending on whether there were hot nodes in level II/III (P=0.0319). Multivariate analysis indicated that the hot nodes in level II/III and lymphatic invasion were independent factors associated with node metastasis. There were 12 SN-positive patients followed by ALND. In four of the 12 patients, hot nodes were observed in level II/III. Two of the four patients with hot nodes depicted by SPECT/CT and metastatic nodes were pathologically evident in the same lesion. Therefore, the present study indicated that the hot node in level II/III as depicted by SPECT/CT may be a risk of SN metastasis, including deeper nodes.

Lymph node shape in computed tomography imaging as a predictor for axillary lymph node metastasis in patients with breast cancer

The aim of the present study was to evaluate whether preoperative computed tomography (CT) is a useful modality for the diagnosis of axillary lymph node metastasis. The axillary lymph node status was examined in patients with primary breast cancer who had undergone surgery. In total, 75 patients were analyzed with preoperative contrast CT images, following which the patients underwent an intraoperative sentinel lymph node biopsy to determine possible predictors of axillary lymph node metastasis. The lymph node shape was classified into three groups, which included fat-, clear-and obscure-types. Multivariate analysis revealed that clear-type lymph nodes in preoperative contrast CT imaging may be an independent predictor of lymph node metastasis (odds ratio, 15; P=0.003). Therefore, the results indicated that preoperative CT examination is useful to predict axillary lymph node metastasis.

Use of the dye-guided sentinel lymph node biopsy method alone for breast cancer metastasis to avoid unnecessary axillary lymph node dissection

For sentinel lymph node biopsy (SLNB), a combination of dye-guided and γ-probe-guided methods is the most commonly used technique. However, the number of institutes in which the γ-probe-guided method is able to be performed is limited, since special equipment is required for the method. In this study, SLNB with the dye-guided method alone was evaluated, and the clinicopathological characteristics were analyzed to identify any factors that were predictive of whether the follow-up axillary lymph node dissection (ALND) was able to be omitted. A total of 374 patients who underwent SLNB between 1999 and 2009 were studied. The SLN identification rate was analyzed, in addition to the false-positive and false-negative rates and the correlation between the clinicopathological characteristics and axillary lymph node metastases. The SLN was identified in 96.8% of cases, and, out of the patients who had SLN metastasis, 63.0% did not exhibit metastasis elsewhere. The sensitivity was 96.4% and the specificity was 100%. The false-negative rate was 3.6%. Univariate analyses revealed significant differences in the lymph vessel invasion (ly) status, nuclear grade (NG), maximum tumor size and the percentage of the area occupied by the tumor cells in the SLN (SLN occupation ratio) between the patients with and without non-SLN metastasis, indicating that these factors may be predictive of axillary lymph node metastasis. Multivariate analysis revealed that ly status was an independent risk factor for non-SLN metastasis. In conclusion, SLN with the dye-guided method alone provided a high detection rate. The study identified a predictive factor for axillary lymph node metastasis that may improve the patients’ quality of life.

Human endoplasmic reticulum oxidoreductin 1-α is a novel predictor for poor prognosis of breast cancer

Human endoplasmic reticulum oxidoreductin 1-α (hERO1-α) is an oxidizing enzyme that exists in the endoplasmic reticulum and its expression is augmented under hypoxia. It regulates a redox state of various kinds of protein through reoxidation of "client" protein disulfide isomerase. Interestingly, although the expression of hERO1-α in normal tissues was comparatively limited, various types of cancer cells expressed it in large amounts. Therefore, we examined the role of ERO1-α in tumor growth using murine breast cancer line 4T1 and found that knockdown of murine ERO1-α inhibited in vivo tumor growth and decreased lung metastasis compared with wild-type 4T1. Moreover, we investigated the relationship between expression of hERO1-α and prognosis in breast cancer patients. Seventy-one patients with breast cancer who underwent surgery between 2005 and 2006 in Sapporo Medical University Hospital (Sapporo, Japan) were analyzed in this study. Significant differences were found between the hERO1-α-positive group (n = 33) and hERO1-α-negative group (n = 38) in nuclear grade (P < 0.001) and intrinsic subtype (P = 0.021) in univariate analysis. More importantly, in multivariate analysis of disease-free survival by Cox regression, expression of hERO1-α was the only independent prognosis factor (P = 0.035). Finally, in univariate survival analysis, patients positive for hERO1-α had significantly shorter disease-free survival and overall survival than those patients negative for hERO1-α. These findings indicate that the expression of hERO1-α in cancer cells is associated with poorer prognosis and thus can be a prognostic factor for patients with breast cancer.