Inter- and intra-observer variability of qualitative visual breast-composition assessment in mammography among Japanese physicians: a first multi-institutional observer performance study in Japan

BACKGROUND

Visual assessment of mammographic breast composition remains the most common worldwide, although subjective variability limits its reproducibility. This study aimed to investigate the inter- and intra-observer variability in qualitative visual assessment of mammographic breast composition through a multi-institutional observer performance study for the first time in Japan.

METHODS

This study enrolled 10 Japanese physicians from five different institutions. They used the new Japanese breast-composition classification system 4th edition to subjectively evaluate the breast composition in 200 pairs of right and left normal mediolateral oblique mammograms (number determined using precise sample size calculations) twice, with a 1-month interval (median patient age: 59 years [range 40-69 years]). The primary endpoint of this study was the inter-observer variability using kappa (κ) value.

RESULTS

Inter-observer variability for the four and two classes of breast-composition assessment revealed moderate agreement (Fleiss' κ: first and second reading = 0.553 and 0.587, respectively) and substantial agreement (Fleiss' κ: first and second reading = 0.689 and 0.70, respectively). Intra-observer variability for the four and two classes of breast-composition assessment demonstrated substantial agreement (Cohen's κ, median = 0.758) and almost perfect agreement (Cohen's κ, median = 0.813). Assessments of consensus between the 10 physicians and the automated software Volpara® revealed slight agreement (Cohen's κ; first and second reading: 0.104 and 0.075, respectively).

CONCLUSIONS

Qualitative visual assessment of mammographic breast composition using the new Japanese classification revealed excellent intra-observer reproducibility. However, persistent inter-observer variability, presenting a challenge in establishing it as the gold standard in Japan.

Deep learning model to predict Ki-67 expression of breast cancer using digital breast tomosynthesis

BACKGROUND

Developing a deep learning (DL) model for digital breast tomosynthesis (DBT) images to predict Ki-67 expression.

METHODS

The institutional review board approved this retrospective study and waived the requirement for informed consent from the patients. Initially, 499 patients (mean age: 50.5 years, range: 29-90 years) referred to our hospital for breast cancer were participated, 126 patients with pathologically confirmed breast cancer were selected and their Ki-67 expression measured. The Xception architecture was used in the DL model to predict Ki-67 expression levels. The high Ki-67 vs low Ki-67 expression diagnostic performance of our DL model was assessed by accuracy, sensitivity, specificity, areas under the receiver operating characteristic curve (AUC), and by using sub-datasets divided by the radiological characteristics of breast cancer.

RESULTS

The average accuracy, sensitivity, specificity, and AUC were 0.912, 0.629, 0.985, and 0.883, respectively. The AUC of the four subgroups separated by radiological findings for the mass, calcification, distortion, and focal asymmetric density sub-datasets were 0.890, 0.750, 0.870, and 0.660, respectively.

CONCLUSIONS

Our results suggest the potential application of our DL model to predict the expression of Ki-67 using DBT, which may be useful for preoperatively determining the treatment strategy for breast cancer.

Beyond BI-RADS: Nonmass Abnormalities on Breast Ultrasound

Abnormalities on breast ultrasound (US) images which do not meet the criteria for masses are referred to as nonmass lesions. These features and outcomes have been investigated in several studies conducted by Asian researchers. However, the term "nonmass" is not included in the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) 5th edition for US. According to the Japan Association of Breast and Thyroid Sonology guidelines, breast lesions are divided into mass and nonmass. US findings of nonmass abnormalities are classified into five subtypes: abnormalities of the ducts, hypoechoic areas in the mammary glands, architectural distortion, multiple small cysts, and echogenic foci without a hypoechoic area. These findings can be benign or malignant; however, focal or segmental distributions and presence of calcifications suggest malignancy. Intraductal, invasive ductal, and lobular carcinomas can present as nonmass abnormalities. For the nonmass concept to be included in the next BI-RADS and be widely accepted in clinical practice, standardized terminologies, an interpretation algorithm, and outcome-based evidence are required for both screening and diagnostic US.

Nonmass Lesions on Breast US: An International Perspective on Clinical Use and Outcomes

Nonmass lesions (NMLs) on breast US are defined as discrete areas of altered echotexture compared to surrounding breast tissue and lack the 3-dimensionality of a mass. They are not a component of American College of Radiology BI-RADS, but they are a finding type included in the Japan Association of Breast and Thyroid Sonology lexicon. Use of the NML finding is routine in many Asian practices, including the Samsung Medical Center and Seoul National University Hospital, and their features and outcomes have been investigated in multiple studies. Nonmass lesions are most often observed when US is used to evaluate mammographic asymmetries, suspicious calcifications, and nonmass enhancement on MRI and contrast-enhanced mammography. Nonmass lesions can be described by their echogenicity, distribution, presence or absence of associated calcifications, abnormal duct changes, architectural distortion, posterior shadowing, small cysts, and hypervascularity. Malignant lesions, especially ductal carcinoma in situ, can manifest as NMLs on US. There is considerable overlap between the US features of benign and malignant NMLs, and they also must be distinguished from normal variants. The literature indicates that NMLs with linear or segmental distribution, associated calcifications, abnormal duct changes, posterior shadowing, and hypervascularity are suggestive of malignancy, whereas NMLs with only interspersed small cysts are usually benign fibrocystic changes. In this article, we introduce the concepts of NMLs, illustrate US features suggestive of benign and malignant etiologies, and discuss our institutional approach for evaluating NMLs and an algorithm that we use to guide interpretation in clinical practice.

Radiation-induced angiosarcoma of the breast: individual participant meta-analysis of Japanese population

BACKGROUND

Radiation-induced angiosarcoma (RIAS) of the breast is a very rare and poor prognostic disease. According to previous studies, the efficacy of chemotherapy for RIAS is still controversial. However, no study has assessed the prognosis of RIAS and the prognostic impact of preoperative or postoperative chemotherapy in Japanese patients. Our study aimed to assess them in Japanese people using publication data with our three patients.

METHODS

Thirty-nine patients diagnosed with RIAS, including 36 patients from 34 published case series, and three patients from our hospital were used for analysis. Disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) were assessed.

RESULTS

Among the 39 patients, 36 patients (92.3%) underwent surgery. The median DFS and OS periods were 14 months (range 1-75 months) and 23 months (range 4-84 months), respectively. Chemotherapy with taxane-based regimen was administered in 13 cases (33.2%) pre- or post-operatively. DFS was significantly improved with chemotherapy in addition to surgery (p = 0.037). However, addition of chemotherapy to surgery did not improve DDFS (p = 0.09) and OS (p = 0.878). In multivariate analysis, age ≥ 70 years was an independent but poor prognostic factor of DFS. Additionally, a lack of chemotherapy showed a trend to be associated with worse DFS. There was no independent variable contributing to DDFS and OS.

CONCLUSIONS

Chemotherapy may have reduced the recurrence rate of RIAS in Japanese patients but did not improve OS. Further data are needed to confirm the efficacy and proper regimen of chemotherapy.

Deep learning model for predicting the presence of stromal invasion of breast cancer on digital breast tomosynthesis

To develop a deep learning (DL)-based algorithm to predict the presence of stromal invasion in breast cancer using digital breast tomosynthesis (DBT). Our institutional review board approved this retrospective study and waived the requirement for informed consent from the patients. Initially, 499 patients (mean age 50.5 years, age range, 29-90 years) who were referred to our hospital under the suspicion of breast cancer and who underwent DBT between March 1 and August 31, 2019, were enrolled in this study. Among the 499 patients, 140 who underwent surgery after being diagnosed with breast cancer were selected for the analysis. Based on the pathological reports, the 140 patients were classified into two groups: those with non-invasive cancer (n = 20) and those with invasive cancer (n = 120). VGG16, Resnet50, DenseNet121, and Xception architectures were used as DL models to differentiate non-invasive from invasive cancer. The diagnostic performance of the DL models was assessed based on the area under the receiver operating characteristic curve (AUC). The AUC for the four models were 0.56 [95% confidence intervals (95% CI) 0.49-0.62], 0.67 (95% CI 0.62-0.74), 0.71 (95% CI 0.65-0.75), and 0.75 (95% CI 0.69-0.81), respectively. Our proposed DL model trained on DBT images is useful for predicting the presence of stromal invasion in breast cancer.

The Japan Society of Ultrasonics in Medicine guidelines on non-mass abnormalities of the breast

It is possible to appropriately diagnose non-mass abnormalities by elucidating ultrasound non-mass abnormality findings and sharing the concept. If non-mass abnormalities can be diagnosed early, the number of curable cases could increase, leading to fewer breast cancer deaths. The Japan Society of Ultrasonics in Medicine (JSUM) Terminology/Diagnostic Criteria Committee has classified non-mass abnormalities into five subtypes: hypoechoic area in the mammary gland, abnormalities of the ducts, architectural distortion, multiple small cysts, and echogenic foci without a hypoechoic area. We herein define the findings for each of these subtypes and present a summary of the JSUM guidelines on non-mass abnormalities of the breast generated based on those findings.

Deep Learning for Differentiation of Breast Masses Detected by Screening Ultrasound Elastography

Recently, deep learning using convolutional neural networks (CNNs) has yielded consistent results in image-pattern recognition. This study was aimed at investigating the effectiveness of deep learning using CNNs to differentiate benign and malignant breast masses identified by elastography on ultrasound screening. A data set of the elastography images of 245 breast masses (146 benign, 99 malignant) in 239 consecutive patients was retrospectively obtained. The data set was randomly split into training (55%), validation (25%) and test (20%) cohorts. A deep learning model predicting the probability of malignancy was constructed using GoogLeNet architectures (pre-trained by ImageNet) with 50 epochs. The model was then applied to the test data, and the results were compared with those obtained by evaluating the fat-to-lesion ratio (FLR) and by a 5-point visual color assessment (elasticity score). The receiver operating characteristic (ROC) curve was calculated to evaluate the performance of the model. The DeLong test was used to compare the areas under the ROC curve (AUCs). The CNN, FLR and elasticity score had a sensitivity of 0.800, 0.800 and 0.350; specificity of 0.966, 0.586 and 0.931; accuracy of 0.898, 0.673 and 0.694; positive predictive value of 0.941, 0.571 and 0.778; negative predictive value of 0.875, 0.810 and 0.675; and AUC of 0.895, 0.693 and 0.641, respectively. The AUC of the CNN was significantly higher than that of the FLR or elasticity score (p < 0.001). A CNN-based deep learning model for predicting benign or malignant breast masses revealed better diagnostic performance than did FLR or elasticity score-based estimations on ultrasound elastography. The CNN-based model also increased the positive predictive value from 57%-78% to 94%. Therefore, this model may reduce unnecessary biopsy recommendations for masses detected on breast ultrasound screening.

Clinicopathological and ultrasound characteristics of breast cancer in BRCA1 and BRCA2 mutation carriers

PURPOSE

BRCA1 and BRCA2 tumors exhibit different characteristics. This study aimed to assess and compare the ultrasound findings and pathologic features of BRCA1 and BRCA2 breast cancers. To our knowledge, this is the first study to examine the mass formation, vascularity, and elasticity in breast cancers of BRCA-positive Japanese women.

METHODS

We identified patients with breast cancer harboring BRCA1 or BRCA2 mutations. After excluding patients who underwent chemotherapy or surgery before the ultrasound, we evaluated 89 cancers in BRCA1-positive and 83 in BRCA2-positive patients. The ultrasound images were reviewed by three radiologists in consensus. Imaging features, including vascularity and elasticity, were assessed. Pathological data, including tumor subtypes, were reviewed.

RESULTS

Significant differences in tumor morphology, peripheral features, posterior echoes, echogenic foci, and vascularity were observed between BRCA1 and BRCA2 tumors. BRCA1 breast cancers tended to be posteriorly accentuating and hypervascular. In contrast, BRCA2 tumors were less likely to form masses. In cases where a tumor formed a mass, it tended to show posterior attenuation, indistinct margins, and echogenic foci. In pathological comparisons, BRCA1 cancers tended to be triple-negative subtypes. In contrast, BRCA2 cancers tended to be luminal or luminal-human epidermal growth factor receptor 2 subtypes.

CONCLUSION

In the surveillance of BRCA mutation carriers, radiologists should be aware that the morphological differences between tumors are quite different between BRCA1 and BRCA2 patients.

Deep learning model for breast cancer diagnosis based on bilateral asymmetrical detection (BilAD) in digital breast tomosynthesis images

The purpose of this study was to develop a deep learning model to diagnose breast cancer by embedding a diagnostic algorithm that examines the asymmetry of bilateral breast tissue. This retrospective study was approved by the institutional review board. A total of 115 patients who underwent breast surgery and had pathologically confirmed breast cancer were enrolled in this study. Two image pairs [230 pairs of bilateral breast digital breast tomosynthesis (DBT) images with 115 malignant tumors and contralateral tissue (M/N), and 115 bilateral normal areas (N/N)] were generated from each patient enrolled in this study. The proposed deep learning model is called bilateral asymmetrical detection (BilAD), which is a modified convolutional neural network (CNN) model of Xception with two-dimensional tensors for bilateral breast images. BilAD was trained to classify the differences between pairs of M/N and N/N datasets. The results of the BilAD model were compared to those of the unilateral control CNN model (uCNN). The results of BilAD and the uCNN were as follows: accuracy, 0.84 and 0.75; sensitivity, 0.73 and 0.58; and specificity, 0.93 and 0.92, respectively. The mean area under the receiver operating characteristic curve of BilAD was significantly higher than that of the uCNN (p = 0.02): 0.90 and 0.84, respectively. The proposed deep learning model trained by embedding a diagnostic algorithm to examine the asymmetry of bilateral breast tissue improves the diagnostic accuracy for breast cancer.

Clinicopathological and imaging features of ductal carcinoma in situ in BRCA1/2 mutation carriers

BACKGROUND

BRCA1/2-associated invasive breast cancer has been extensively studied. However, there are few reports of ductal carcinoma in situ (DCIS).

OBJECTIVE

This study aimed to investigate the clinicopathological and imaging findings of DCIS in patients with BRCA1/2 mutations.

METHODS

This was a single-institution, retrospective study. We identified patients diagnosed with DCIS with BRCA mutations between September 2003 and December 2020. Clinicopathological data and mammography (MG), magnetic resonance imaging (MRI), and ultrasound (US) findings were reviewed.

RESULTS

We identified 30 cancers in 28 patients; 7 (25.0%) patients had BRCA1 mutations, and 21 (75.0%) had BRCA2 mutations. The median patient age was 42 years. Screening was the most common reason for the detection of DCIS (50.0%), followed by occult cancer diagnosed by pathological examination after risk-reducing mastectomy (26.7%). The nuclear grade was most often 1 (46.7%), and 93.3% were estrogen and/or progesterone receptor positive. The detection rates of MG, MRI, and US were 64.3%, 72.0%, and 64.0%, respectively. The most common imaging findings were calcification (100%) on MG, non-mass enhancement (88.9%) on MRI, and hypoechoic area (75.0%) on US.

CONCLUSION

BRCA-associated DCIS was more strongly associated with BRCA2, and imaging features were similar to those of sporadic DCIS. Our results are helpful in informing surveillance strategies based on genotypes in women with BRCA mutations.

An association between mammographic breast density and fine particulate matter among postmenopausal women

Increasing breast density is a risk factor for breast cancer. Geographic variations in breast density may be due to differences in lifestyle and diet, as well as environmental factors such as air pollution exposure. However, these environmental contributors have not been established. In this study, we evaluated an association between air pollution and mammographic breast density. The study population for this study was postmenopausal women who had undergone screening mammography at the Center for Preventive Medicine, St. Luke's International Hospital, from April 2004 to September 2018. Individual mammography results were obtained from electronic charts. The ambient air pollution (PM_2.5) density of the locations of interest, namely, the patients' residential areas during the study period, was obtained. The mean PM_2.5 exposure levels for 1, 3, 5, and 7 years were determined. A generalized estimating equations model was used to examine the association between air pollution density and dense breast. A total of 44,280 mammography results were included in this study, and 29,135 were classified in the non-dense breast group and 15,145 in the dense breast group. There was a 3% increase in the odds of having dense breasts after 1 year (OR = 1.027, 95% confidence interval (CI) 1.019-1.034) and 3 years of PM_2.5 exposure (OR = 1.029, 95% CI 1.022-1.036). This further increased to 4% at 5-year exposure (OR = 1.044, 95% CI 1.037-1.052) and 5% at 7-year exposure (OR = 1.053, 95% CI 1.044-1.063). The risk for dense breasts increased if the factors of smoking, family history of breast and/or ovarian cancer, and history of childbirth were present.

The location of unilateral axillary lymphadenopathy after COVID-19 vaccination compared with that of metastasis from breast cancer without vaccination

PURPOSE

Unilateral axillary lymphadenopathy is known to occur after coronavirus disease (COVID-19) vaccination. Post-vaccination lymphadenopathy may mimic the metastatic lymph nodes in breast cancer, and it is challenging to distinguish between them. This study investigated whether the localization of axillary lymphadenopathy on magnetic resonance imaging (MRI) could be used to distinguish reactive lymphadenopathy after COVID-19 vaccines from metastatic nodes.

MATERIALS AND METHODS

We retrospectively examined preoperative MRI images of 684 axillae in 342 patients who underwent breast cancer surgery from June to October 2021. Lymphadenopathy was defined as cortical thickening or short axis ≥ 5 mm. The axilla was divided into ventral and dorsal parts on the axial plane using a perpendicular line extending from the most anterior margin of the muscle group, including the deltoid, latissimus dorsi, or teres major muscles, relative to a line along the lateral chest wall. We recorded the presence or absence of axillary lymphadenopathy in each area and the number of visible lymph nodes.

RESULTS

Of 80 axillae, 41 and 39 were included in the vaccine and metastasis groups, respectively. The median time from the last vaccination to MRI was 19 days in the vaccine group. The number of visible axillary lymph nodes was significantly higher in the vaccine group (median, 15 nodes) than in the metastasis group (7 nodes) (P < 0.001). Dorsal lymphadenopathy was observed in 16 (39.0%) and two (5.1%) axillae in the vaccine and metastasis groups, respectively (P < 0.001). If the presence of both ventral and dorsal lymphadenopathy is considered indicative of vaccine-induced reaction, this finding has a sensitivity of 34.1%, specificity of 97.4%, and positive and negative predictive values of 93.3％ and 58.5%, respectively.

CONCLUSION

The presence of deep axillary lymphadenopathy may be an important factor for distinguishing post-vaccination lymphadenopathy from metastasis. The number of axillary lymph nodes may also help.

Why is the depth/width ratio of a typical fibroadenoma small in breast ultrasonography?

PURPOSE

Typical myxomatous fibroadenomas have a small depth/width (D/W) ratio on ultrasonography. The small D/W ratio of fibroadenomas is speculated to be caused by the softness of the mass and its orientation along the longitudinal aspect of the ductal elements without adhesion to the surrounding tissue; however, this has not been clearly proven. This study aimed to confirm the reason why fibroadenomas present with a small D/W ratio on ultrasonography.

METHODS

We retrospectively analyzed imaging data from 17 patients who were diagnosed with typical fibroadenomas on ultrasonography and who underwent magnetic resonance imaging (MRI) at our hospital.

RESULTS

The median D/W ratio obtained from ultrasonography images was 0.48 (0.32-0.67), while that obtained from MRI was 1.38 (0.62-1.68). The D/W ratios calculated from MRI were significantly greater than those calculated from ultrasonography images (p < 0.001). The D/W ratio obtained using ultrasonography was not greater than the D/W ratio obtained using MRI in any of the cases.

CONCLUSION

This study revealed that the small D/W ratio of fibroadenomas on ultrasonography may be attributable to the horizontal force acting on the breast against the chest wall in the supine position, the elasticity of the fibroadenoma, and the lack of adhesion between the mass and surrounding tissue.

A prospective ultrasonographic surveillance study on the incidence and recovery period of COVID-19 vaccination-related axillary lymphadenopathy following a booster shot

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Background: COVID-19 vaccination-related lymphadenopathy is a frequent imaging finding that may be indistinguishable from malignant nodes and can lead to diagnostic difficulties in patients with cancer or healthy individuals on cancer screening. However, no prospective trials regarding COVID-19 vaccination-related lymphadenopathy following a booster shot have been conducted. The purpose of this study was to determine the incidence and imaging characteristics of COVID-19 vaccination-related axillary lymphadenopathy and assess the recovery period following a booster shot. Methods: We prospectively enrolled healthy women working at St. Luke’s International Hospital, who would receive the third shot of the Pfizer-BioNTech COVID-19 vaccine between December 6 and 28, 2021. Women with a history of cancer, atopic dermatitis, auto-immune disease, or axillary surgery were excluded. All participants underwent ultrasound (US) examinations for the bilateral axilla at baseline (prior to the third shot), early phase (1–3 days after the shot), and late phase (6 weeks after the shot) if lymphadenopathy was detected at the early phase. We evaluated the incidence and US characteristics of lymphadenopathy. As for US characteristics mimicking a malignant node, focal cortical thickening, absence of the echogenic hilus, and vascularity were examined. In this study, abnormal lymphadenopathy was defined as [1] an increase in the short-axis size by more than 2 mm compared with the baseline, [2] an increase in the number of nodes with short-axis diameter more than 5 mm, and [3] demonstrating US characteristics mimicking malignant nodes. Results: A total of 100 women were enrolled in this study. The median age was 41 years (range 23–63). Abnormal axillary lymphadenopathy on the vaccinated side was observed in 59% of participants in the early phase and 8% in the late phase. In the contralateral axilla, abnormal lymphadenopathy was observed in 1% of participants in the early phase and 2% in the late phase. The median short-axis size of ipsilateral abnormal lymphadenopathy was 7.6 mm in the early phase and 5.7 mm in the late phase. In the early phase, US characteristics mimicking malignant nodes were observed, including focal cortical thickening in 54% of participants, absence of the echogenic hilus in 16%, and hypervascularity in 33%. Conclusions: COVID-19 vaccination-related axillary lymphadenopathy indistinguishable from malignant nodes was observed in more than half of the participants compared with the baseline, which improved in most cases within 6 weeks after the latest booster shot. To avoid a diagnostic conundrum, patients with breast cancer should be vaccinated on the arm contralateral to the cancer side. It is recommended that non-urgent imaging screening for the axilla should be scheduled after 6 weeks following the latest vaccination.

Impact of childbirth history on dense breast in mammographic screening: a cross-sectional study

Background

The evaluation of breast density is important, because dense breast has been shown to be associated with increased risk of breast cancer and a greater risk of a false-negative diagnostic performance due to masking a tumor. Although the relationship between parity and dense breast is under investigation, conclusive evidence is lacking. We aimed to investigate whether parity affects breast density.

Methods

The study design is a cross-sectional study. The subjects are healthy Japanese women who underwent opportunistic mammographic screening at the center for preventive medicine at a single institution from January 2016 to December 2018. Clinical characteristics and lifestyle factors were obtained from questionnaires. Breast density was categorized into 4 groups, namely, almost entirely fatty dense, scattered fibroglandular dense, heterogeneously dense, and extremely dense, according to the Breast Imaging Reporting and Data System. Heterogeneously and extremely dense were considered collectively as dense breast. Multivariate logistic regression analysis was conducted to investigate the relationship between parity and dense breast among premenopausal and postmenopausal women separately.

Results

7612 premenopausal and 9252 postmenopausal women were investigated. Dense breast was shown in 62.6% of nulliparity, 57.3% of single parity, 47.3% of two parity, 37.6% of more than two parity among premenopausal women, and in 41.6% of nulliparity, 31.1% of single parity, 19.3% of two parity, 10.1% of more than two parity among postmenopausal women. For premenopausal women, two parity, single parity and nulliparity showed a higher risk for dense breast with statistically significance (Odds Ratio (OR) adjusted for potential confounding factors: 1.458 (95% Confidence interval (CI); 1.123–1.894), 2.349 (95%CI; 1.801–3.064), 3.222 (95%CI; 2.500–4.151), respectively), compared with more than two parity. For postmenopausal women, two parity, single parity and nulliparity had a higher risk (OR: 1.849 (95%CI; 1.479–2.312), 3.023 (95%CI; 2.385–3.830), 4.954 (95%CI; 3.975–6.174), respectively) with statistically significance, compared with more than two parity.

Conclusions

Parity showed an inverse trend of having dense breast among both premenopausal and postmenopausal women. In particular, nulliparous women need to recognize their higher risk of dense breast. In the future, the declining fertility rate may affect the prevalence of dense breast in the world.

Abstract P1-01-01: Prospective ultrasonographic surveillance study for incidence and recovery period of COVID-19 vaccination-related axillary lymphadenopathy

Background: COVID-19 vaccination-related lymphadenopathy is a frequent imaging finding which may be indistinguishable from malignant nodal involvement and lead to diagnostic difficulties in patients with cancer or healthy individuals on cancer screening. An expert panel of the leading cancer centers in United States recommended routine imaging examinations should be scheduled at least 6 weeks after the final vaccination to allow for any reactive lymphadenopathy to resolve. However, there were no prospective trials regarding COVID-19 vaccination-related lymphadenopathy and the evidence was so limited. The purpose of this study was to determine the incidence and imaging characteristics of COVID-19 vaccination-related axillary lymphadenopathy and assess the recovery period. Methods: We prospectively enrolled healthy women working at the St. Luke’s International Hospital who received Pfizer COVID-19 vaccination within 8 weeks before enrollment between May 10th and 27th, 2021. Women with a history of any type of cancer or axillary surgery, active atopic dermatitis and auto-immune disease were excluded. Participants underwent ultrasound examinations for bilateral axilla at the enrollment. Lymphadenopathy was defined as demonstrating an enlarged node(s) with more than 5mm in short axis by ultrasound imaging in this trial. As for imaging characteristics, status of cortical thickening, echogenic hilus and vascularity of lymph nodes were evaluated. Other side effects by vaccination were assessed by a questionnaire. If lymphadenopathy was detected, we followed the participant by ultrasound examination every three weeks until the lymphadenopathy was resolved. We evaluated the incidence rate and imaging characteristics of lymphadenopathy detected by ultrasound examination, and the recovery period required for improvement of the lymphadenopathy. We also validated the association of the lymphadenopathy with the participant characteristics and other side effects. Results: A total of 135 women were enrolled in this study. Participants' median age was 37 years (range 23-63). Median time from the latest vaccination to the enrollment was 45 days (range 8-56). In the ultrasound examination at enrollment, axillary lymphadenopathy was observed in 67 participants (50%) on the injected (ipsilateral) side. In the contralateral axilla, 13 participants (10%) showed lymphadenopathy. In the ipsilateral axilla, the number of enlarged node(s) was 1 node in 25 cases (19%), 2 nodes in 24 cases (18%), 3 nodes in 13 cases (10%), 4 nodes in 4 cases (3%) and 5 nodes in 1 case (1%). Regarding the ipsilateral enlarged lymph node, focal cortical thickening was observed in 58 cases (43%) and the absence of the echogenic hilus was observed in 15 cases (11%). Hypervascularity was observed in 15 cases (11%). Incidence of the lymphadenopathy was not statistically correlated with participant’s age or incidence of fever due to vaccination. At 6 weeks after the latest vaccination, the rate of ipsilateral axillary lymphadenopathy was 48%, 40% at 8 weeks, and 6% at 12 weeks. In participants with lymphadenopathy, median recovery period to resolve the lymphadenopathy was 75 days from the latest vaccination. Conclusion: A half of participants showed COVID-19 vaccination-related axillary lymphadenopathy and the imaging characteristics were often indistinguishable from malignant nodal involvement. Therefore, patients with breast cancer should be vaccinated on the contralateral arm to the cancer side to avoid diagnostic conundrum. The lymphadenopathy was commonly observed even in 8 weeks, and mostly resolved after 12 weeks from the vaccination. Therefore, non-urgent imaging examinations such as screening would be recommended to be scheduled at least 12 weeks following the latest vaccination.

Citation Format: Kumiko Kida, Hiroko Tsunoda, Risa Kasahara, Chika Tsutsumi, Akiko Numata, Yuri Takehara, Atsushi Yoshida, Junko Takei, Naoki Hayashi, Daiki Kobayashi, Hideko Yamauchi. Prospective ultrasonographic surveillance study for incidence and recovery period of COVID-19 vaccination-related axillary lymphadenopathy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-01-01.

Abstract PD7-05: A multicenter prospective study to predict pathologic complete response by vacuum-assisted breast biopsy based on MRI and US findings after neoadjuvant chemotherapy

Background: Surgical excision is still a standard treatment for patients with primary breast cancer because of inaccuracy of clinical complete response (cCR) by radiological findings regardless of high pathologic complete response rate (pCR) after neoadjuvant chemotherapy (NAC). How much vacuum-assisted breast biopsy (VAB) would contribute to improve the accuracy of prediction of pCR depending on the subtype of primary breast cancer has not been well assessed. Method: We conducted a multicenter prospective cohort study to assess the accuracy of prediction of pCR by VAB in combination with MRI and US findings for patients who achieved cCR after NAC in five Japanese hospitals. Patients with cT1-3N+M0 and primary breast cancer who achieved cCR (ycT0/is) in MRI and US findings after NAC were enrolled in this study. Primary outcome was an negative predictive value (NPV) and an false negative rate (FNR) for MRI and US findings, and for VAB in combination with these radiological findings in each subtype of ER-HER2+, ER-HER2-, and ER+HER2+ primary breast cancer. At least five US-guided 10G VAB samples were collected before surgery. Patients received anthracycline and taxane based regimen for NAC. Patients with HER2+ breast cancer received anti-HER2 agent in combination with taxane. Results: A total of 96 patients were enrolled in this study. Eighty-eight patients of them were included in the analysis: ER-HER2+ for 39 patients, ER-HER2- for 29 patients, and ER+HER2+ for 20 patients. A median age was 51 years (range, 26-72 years). Forty-four patients (50.0%) was premenopausal women. Numbers of patients for each tumor stage at diagnosis was cT1 for 25 patients (28.4%), cT2 for 59 patients (67.0%), and cT3 for 3 patients (3.4%). Fifty-six patients (63.6%) were node-negative at diagnosis (cN0) and 82 patients (93.2%) were node-negative after surgery (ycN0). Forty-eight patients (54.5%) had nuclear grade 3. Numbers of patients for each pathological tumor size after NAC was ypT0 for 47 patients (53.4%), ypTis for 19 (21.6%), ypT1 for 22 (25.0%), and ypT2 for one (1.1%). A median number of VAB sample was six (range 5-16). Residual tumor on VAB samples were invasive ductal carcinoma for 7 patients (8.0%), in situ lesion for 11 patients (12.5%). Fifty-nine patients (67.0%) underwent breast-conserving surgery. For radiological findings, NPV of ypT0/is was 84.6% for ER-HER2+, 65.5% for ER-HER2-, and 70.0% for ER+HER2+. VAB in addition to radiological findings yielded an NPV of 63.9% and an FNR of 81.2% for ER-HER2+, an NPV of 72.7% and an FNR of 46.2% for ER-HER2-, and an NPV of 66.7% and an FNR of 33.3% for ER+HER2+. A median size of residual tumor was 0.25cm (range 0.005-1.2cm) for ER-HER2+, 0.25cm (range 0.002-1.2cm) for ER-HER2-, and 0.55cm (range 0.1-0.6cm) for ER+HER2+. For patients with a clip maker, an NPV (90%) and an FNR (33.3%) were improved. Conclusions: Our study showed that VAB in addition to radiological findings was not accurate enough to predict pCR in any subtype of primary breast cancer. We could not support to omit surgery by VAB for patients who achieved cCR after NAC.

Citation Format: Naoki Hayashi, Natsuki Teruya, Takashi Kuwayama, Yasuyuki Kojima, Sachiko Ohde, Sayuka Nakayama, Mizuho Tazo, Hiroyuki Takei, Takayuki Ueno, Takuji Iwase, Shinji Ohno, Hideko Yamauchi, Futoshi Akiyama, Hiroko Tsunoda, Koichiro Tsugawa, Seigo Nakamura. A multicenter prospective study to predict pathologic complete response by vacuum-assisted breast biopsy based on MRI and US findings after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD7-05.

Abstract P3-23-07: Radiation induced angiosarcoma of the breast: Chemotherapy for radiation induced angiosarcoma of the breast - An individual participant data meta-analysis of Japanese population

Background: Radiation-induced angiosarcoma (RIAS) of the breast is a very rare disease. Previous studies from other countries have been reported that patients having RIAS has a poor prognosis, and the efficacy of chemotherapy is still controversial. However, the prognosis of RIAS and the prognostic impact of pre- or postoperative chemotherapy for RIAS in Japanese population are not well known. Our study aimed to assess them in Japanese population using publication data with the cases from our institute. Methods: We obtained 36 Japanese patients data from thirty-four original articles from 2007 to 2020 and 3 patients from our database. Clinicopathological data including age at diagnosis of RIAS, surgery for RIAS, pre- or postoperative chemotherapy for RIAS, regimen of chemotherapy, tumor size, stage for primary breast cancer, and systematic treatment for breast cancer were collected. We assessed disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) using Kaplan-Meier survival curves and log rank test. Hazard ratios were estimated from Cox models. Results: The median age at diagnosis of RIAS was 73.0 years (range, 32-89 years). A median follow-up period was 22 months (range, 6-84 months). RIAS developed on the breast in 36 patients (92.3%) and on chest wall in 3 patients (7.7%). Thirty-six patients (92.3%) underwent surgery. Chemotherapy was administered to 13 cases (33.2%); preoperatively in 3 patients and postoperatively in 10 patients. All patients had received taxane-based chemotherapy. The median size of tumor in pathological examination was 43.5 mm (range, 9-100 mm). There was no difference of patient’s characteristics between patients with or without chemotherapy. The median DFS period was 14 months (range 1-75 months), and the median OS period was 22 months (range, 6-84 months). Chemotherapy in addition to surgery significantly improved DFS period (19 vs 12 months, p=0.027), and DDFS tended to be prolonged by adding chemotherapy (p=0.06). However, chemotherapy did not improved OS (p=0.878). In multivariate analysis, age ≥ 70 years and no chemotherapy for RIAS were the independent poor prognostic factors for DFS. Conclusions: Our study showed that chemotherapy might reduce recurrence rate of RIAS in Japanese patients but did not improve OS. Further studies are warranted to confirm the prognostic impact and proper regimen of chemotherapy for RIAS.

Citation Format: Yuri Takehara, Naoko Matsuda, Daiki Kobayashi, Atsushi Yoshida, Junko Takei, Hiroko Tsunoda, Naoki Kanomata, Hideko Yamauchi, Naoki Hayashi. Radiation induced angiosarcoma of the breast: Chemotherapy for radiation induced angiosarcoma of the breast - An individual participant data meta-analysis of Japanese population [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-23-07.

Evaluation of Axillary Lymph Nodes in Breast Cancer Patients with Atopic Dermatitis

This study assessed the diagnostic accuracy of ultrasound in detecting axillary lymph node metastases in women with breast cancer and atopic dermatitis. We retrospectively reviewed the records of 91 breast cancer patients with a history of atopic dermatitis and compared the dimensions of the lymph nodes on ultrasonographic images of women with and without lymph node metastases diagnosed using histology. Using a major-axis length of ≥5 mm, a short-axis length of ≥5 mm and a cortical thickness of ≥2.3 mm as the criteria for diagnosing axillary lymph node metastases, the specificity was 12.7%, 41.3% and 58.7%, respectively. The low specificity of the ultrasound criteria makes ultrasound unsuitable for diagnosing axillary lymph nodes metastases in breast cancer patients with atopic dermatitis.

Accuracy of morphologic change measurements by ultrasound in predicting pathological response to neoadjuvant chemotherapy in triple-negative and HER2-positive breast cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) is standard therapy in triple-negative breast cancer (TNBC) and HER2-positive breast cancer (HER2 + ve BC). There are concerns about the accurate imaging modalities to measure residual tumor during or after NAC. Up to now no standard imaging method for monitoring the efficacy of NAC has been established, and few reports showed ultrasonographic change. We aimed to assess the echogenicity in ultrasonography (US) as the predictive marker of pathological complete response (pCR) for not only TNBC, but also HER2 + ve BC. Furthermore, we also investigated the change in depth (D) and width (W) of the tumor as the predictive value of pCR.

METHODS

We retrospectively reviewed a consecutive 59 patients with TNBC and 41 patients with HER2 + ve BC who received NAC. In all of 100 patients, echogenicity, D and W of the tumor were measured before (pre-NAC) and after NAC (post-NAC). The tumor echogenicity was measured at representative region of interest (ROI), and calculated as the relative comparative assessment with fat echogenicity (ROI ratio).

RESULTS

pCR was significantly associated with higher post-NAC ROI ratio in TNBC (p = 0.010), while there was no association in HER2 + ve BC (p = 0.885). pCR was significantly associated with smaller sizes of post-NAC D and W in TNBC (p = 0.001, 0.003), while no trend was observed in HER2 + ve BC (p = 0.259, 0.435). The area under the curve (AUC) for post-NAC ROI ratio and D were 0.701, 0.755, respectively. Combined with them, AUC became higher up to 0.762.

CONCLUSION

TNBC and HER2 + ve BC showed different morphologic features of residual disease. Echogenicity and tumor size after NAC were both useful to predict pCR for TNBC, but not HER2 + ve BC. In future, radiological imaging needs to be analyzed in terms of breast cancer subtypes.

Long-Term Oncologic Safety of Nipple-Sparing Mastectomy With Immediate Reconstruction

BACKGROUND

We assessed the long-term oncologic safety of nipple-sparing mastectomy (NSM) compared to skin-sparing mastectomy (SSM) for primary breast cancer patients with immediate reconstruction.

PATIENTS AND METHODS

Data of stage 0-III primary breast cancer patients undergoing NSM (n = 190) or SSM (n = 729) from June 2006 to December 2012 were retrospectively collected. Nipple-tumor distance (NTD) was measured on pretreatment mammography, magnetic resonance imaging, or ultrasonography findings. NSM patients with NTD < 1 cm were excluded. Locoregional recurrence (LRR) rates were compared between groups. Disease-free survival (DFS) and overall survival (OS) according to surgical procedure were assessed.

RESULTS

The median (range) follow-up period for NSM and SSM was 71 (10-131) months and 79 (9-140) months, respectively. LRR developed in 11 patients with invasive ductal carcinoma (5.8%) for NSM and 44 (42 in patients with invasive ductal carcinoma and 2 in patients with ductal carcinoma-in-situ) (6.0%) for SSM. Hormone receptor and HER2 status were not associated with LRR in either group. DFS and OS rates did not differ between groups (DFS: 89.3% for NSM, 89.3% for SSM, P = .87; OS: 98.4% for NSM, 94.5% for SSM, P = .43).

CONCLUSION

NSM with immediate reconstruction was as safe as SSM for primary breast cancer with respect to prognosis and local control, regardless of the presence of invasive carcinoma or breast cancer subtype.

B-mode ultrasound diagnostic flowchart for solid breast masses: JABTS BC-01 study

Purpose

Breast ultrasound has been widely used as an essential examination for diagnosing breast cancer. However, standardized diagnostic criteria are as yet lacking. This study aimed to develop a simple diagnostic flowchart for beginners learning breast ultrasonography. The diagnostic flowchart was developed based on the recall criteria widely used in Japan.

Methods

We conducted a multicenter study to examine recall criteria usefulness in the diagnostic phase of breast disease. Women with ultrasound-visible breast masses who underwent B-mode breast ultrasound examination were recruited from 22 hospitals in Japan between September 2009 and January 2010. B-mode images were evaluated by members of the centralized image interpretation committee. We developed the new diagnostic flowchart based on the results. The usefulness of the diagnostic flowchart was assessed by employing datasets from the current study and another study which we conducted (BC-04 study).

Results

We evaluated 1045 solid masses (malignant: 495, benign: 550). Multivariate analysis showed that shape, margin, echogenic halo, interruption of the mammary gland interface, and depth width ratio were significant findings for distinguishing between benign and malignant masses. We modified the recall criteria and developed our novel diagnostic flowchart using these findings. The sensitivity and specificity of the new flowchart (current study: 0.97, 0.45; BC-04 study dataset: 0.95, 0.45) were similar to those of experts (current study: 0.96, 0.54; BC-04 study dataset: 0.98, 0.38).

Conclusion

We developed a simple diagnostic flowchart for breast ultrasound. This flowchart is anticipated to be applicable to educating beginners learning breast ultrasound.

Overall assessment system of combined mammography and ultrasound for breast cancer screening in Japan

Mammography is the only screening method with evidence in support of reduced breast cancer mortality, but yields poor accuracy outcomes in women with dense breast tissue. The Japan Strategic Anti-cancer Randomized Trial (J-START) was conducted as part of the measures implemented to deal with women with dense breast tissue. Although the sensitivity was increased, the specificity was significantly lower in the intervention group because further examination was required in all positive cases classified by either mammography or ultrasound in the J-START. To address the issue, an overall assessment system of combined mammography and adjunctive ultrasound for breast cancer screening has been developed in Japan. The basic concept is based on a comprehensive assessment that includes a mammography assessment followed by an adjunctive assessment for ultrasound similar to the clinical setting. Currently, mammography alone is recommended for population-based breast cancer screening in Japan, but additional ultrasonography is extensively available for women, especially for women with dense breasts with shared decision-making for personalized breast cancer screening. The overall assessment system is recommended for use in Japan when breast cancer screening is conducted using both mammography and ultrasonography. In this article, we summarize the advantages of the overall assessment and the simultaneous mammography/ultrasound method, the basic approach used in Japan to assign the overall assessment category for breast cancer screening, and we outline the future directions of adjunctive screening ultrasound.

Breast cancer screening using digital breast tomosynthesis compared to digital mammography alone for Japanese women

BACKGROUND

The purpose of this study is to confirm the position of DBT in breast cancer screening in Japan, to assess cancer detection rates, recall rates, positive predictive value (PPV), and to evaluate the type of mammographic findings of cancer with the use of digital mammography alone (2DDM) and combined with digital breast tomosynthesis (DBT).

METHODS

11,894 examinations of the opportunistic breast cancer screening using only 2DDM and 2DDM plus DBT were performed from May 1, 2017 to March 31, 2019. The 11,894 women [3535 women who received DBT in addition to 2DDM (3D group) and 8359 who received 2DDM only (2D group)] participated in this study. The study was approved by the Institute's Ethics Committee and all participants provided written informed consent.

RESULTS

The recall rate was 2.6% for the 3D group and 3.6% for the 2D group (p < 0.01). The cancer detection rate was 0.17% in both 3D and 2D groups (p = 0.978). The positive predictive value (PPV) was 6.5% for the 3D group and 4.7% for the 2D group (p = 0.484). The cause of the decrease in recall rate was due to a decrease in the finding of focal asymmetric density (FAD).

CONCLUSION

The recall rate was improved by using DBT for breast cancer screening in Japanese women. Cancer detection rates were exactly the same in DBT and 2DDM groups, so only DBT non-inferiority could be verified. We have verified that breast cancer screening combined with DBT is useful even for Japanese women to reduce unnecessary further examination.

A deep learning-based automated diagnostic system for classifying mammographic lesions

BACKGROUND

Screening mammography has led to reduced breast cancer-specific mortality and is recommended worldwide. However, the resultant doctors' workload of reading mammographic scans needs to be addressed. Although computer-aided detection (CAD) systems have been developed to support readers, the findings are conflicting regarding whether traditional CAD systems improve reading performance. Rapid progress in the artificial intelligence (AI) field has led to the advent of newer CAD systems using deep learning-based algorithms which have the potential to reach human performance levels. Those systems, however, have been developed using mammography images mainly from women in western countries. Because Asian women characteristically have higher-density breasts, it is uncertain whether those AI systems can apply to Japanese women. In this study, we will construct a deep learning-based CAD system trained using mammography images from a large number of Japanese women with high quality reading.

METHODS

We will collect digital mammography images taken for screening or diagnostic purposes at multiple institutions in Japan. A total of 15,000 images, consisting of 5000 images with breast cancer and 10,000 images with benign lesions, will be collected. At least 1000 images of normal breasts will also be collected for use as reference data. With these data, we will construct a deep learning-based AI system to detect breast cancer on mammograms. The primary endpoint will be the sensitivity and specificity of the AI system with the test image set.

DISCUSSION

When the ability of AI reading is shown to be on a par with that of human reading, images of normal breasts or benign lesions that do not have to be read by a human can be selected by AI beforehand. Our AI might work well in Asian women who have similar breast density, size, and shape to those of Japanese women.

TRIAL REGISTRATION

UMIN, trial number UMIN000039009. Registered 26 December 2019, https://www.umin.ac.jp/ctr/.

Characteristics of ultrasonographic images of ductal carcinoma in situ with abnormalities of the ducts

Purpose

Although the number of ductal carcinoma in situ (DCIS) cases has increased with the spread of breast cancer screening in Japan, there are very few reports that summarize ultrasound image features of DCIS. The Japan Association of Breast and Thyroid Sonology (JABTS) investigated the incidence of DCIS with masses and non-mass abnormalities and the characteristics of US images in a retrospective, multicenter, observational study (JABTS BC-02 study). The purpose of this report is to clarify the proportion of DCIS with abnormalities of the ducts with each ultrasound finding and the characteristics of US images.

Methods

The JABTS BC-02 study population was comprised of patients who were examined by ultrasonography, underwent surgery, and were histopathologically diagnosed with DCIS at each study site between January 2008 and December 2012. The US images of DCIS and pathology and clinical information were retrospectively collected from 16 institutions in Japan. The US images were evaluated by 22 experts on the Central Image Interpretation Committee of JABTS.

Results

Abnormalities of the ducts were noted in 78 (10.5%) of 705 US images of DCIS. Of the 78 cases, the distribution of abnormalities of the ducts was focal or segmental. The second characteristic was the presence of internal echoes in dilated ducts. All cases were accompanied by intraductal solid echoes, and 40 cases (51.3%) were accompanied by echogenic foci. In addition, intraductal solid echoes were continuous or multiple in 72 cases (92.4%), and the shape of the solid echoes was broad-based and/or irregular in 62 cases (79.5%).

Conclusion

DCIS cases with duct abnormalities on ultrasound were investigated in this study. The important characteristics were as follows: (1) the distribution of ductal dilatation was focal or segmental, (2) solid parts were present in the dilated ducts, (3) the distribution of internal echoes was continuous or multiple, (4) the shape of solid echoes was broad-based and/or irregular, and (5) internal echoes were sometimes accompanied by echogenic foci. Accurate evaluation of these findings may be useful for diagnosing DCIS. Although the duct abnormalities are included in “ASSOCIATED FEATURES” in ACR BI-RADS ATLAS (USA), we emphasize that this concept is very important for understanding US characteristics of DCIS.

Multicenter Prospective Study of Color Doppler Ultrasound for Breast Masses: Utility of Our Color Doppler Method

The use of color Doppler ultrasound (CD) for distinguishing between benign and malignant breast lesions remains controversial. This study (JABTS BC-04 study) was aimed at confirming the usefulness of our CD diagnostic criteria. We evaluated ultrasound images of 1408 solid breast masses from 16 institutions in Japan (malignant: 839, benign: 569). Multivariate analysis indicated that vascularity (amount of blood flow), vascular flow pattern ("surrounding marginal flow" or "penetrating flow") and the incident angle of penetrating flow were significant findings for distinguishing between benign and malignant lesions. However, the sensitivity and specificity of B-mode alone did not improve significantly with CD addition (97.6% → 97.9%, 38.3% → 41.5%, respectively). We explored the causes of these negative results and found that age should have been considered when evaluating vascularity. Simulation experiments suggested that specificity is significantly improved when age is taken into consideration (38.3% → 46.0%, p < 0.001) and we thereby improved our diagnostic criteria.

The Loss of Lymph Node Metastases After Neoadjuvant Chemotherapy in Patients With Cytology-proven Axillary Node-positive Primary Breast Cancer

BACKGROUND

Axillary lymph node (LN) dissection after neoadjuvant chemotherapy (NAC) still remains a standard treatment of initially LN-positive primary breast cancer because of the difficulty of assessment of LN status. The aim of this study was to assess the LN status after NAC in initially LN-positive primary breast cancer patients who were assessed as clinically LN-negative after NAC (ycN0) and identify factors associated with loss of LN metastasis.

PATIENTS AND METHODS

The study cohort comprised 279 patients with cytology-proven LN-positivity before NAC. LN status was assessed by ultrasonography. Regional recurrence-free survival and overall survival according to pathologic LN after NAC (ypN) status were assessed in patients with ycN0.

RESULTS

Of the 279 patients, 179 patients (64.2%) had ycN0. High nuclear grade, estrogen receptor-negative (ER^-), and human epidermal growth factor receptor 2-positive (HER2⁺), were significant predictors of ycN0/ypN0 (P < .001, .007, and .046, respectively). Metastases persisted in 1 or 2 LNs for 5 (20.0%) of 25 patients with ER^-/HER2⁺ and for 4 (21.1%) of 19 patients with ER^-/HER2^-, and in 3 or more LNs for 0 (0%) of 25 patients with ER^-/HER2⁺ and for 1 (5.3%) of 19 patients with ER^-/HER2^-. Patients with ER⁺ tumors had more numerous residual LN metastases than those with ER^- tumors (P < .001). Among patients with ycN0, ypN status was not associated with regional recurrence-free survival or overall survival.

CONCLUSIONS

Three or more residual LN metastases were rare in patients with ER^- tumors if assessed as ycN0 by ultrasonography. Prospective studies are needed to confirm the prognostic impact of not performing axillary lymph node dissection in such patients.

Abstract P2-14-17: Long-term oncologic safety of nipple-sparing mastectomy with immediate reconstruction

Background

Nipple-sparing mastectomy (NSM) is an alternative procedure to skin-sparing mastectomy (SSM) for selected patients who undergo immediate reconstruction. However, the evidence of long-term oncologic safety of NSM has not been established. In this study, we aimed to compare the prognosis of breast cancer patients who underwent NSM to those who underwent SSM with immediate reconstruction.

Methods

The clinicopathological factors including recurrence site, pathologic stage, nipple-tumor distance, histological type, lymphovascular invasion, margin status, ER, PgR and HER2 status of stage 0–III primary breast cancer patients who underwent NSM or SSM with immediate primary reconstruction with tissue expander from our breast center database was retrospectively assessed. Patients with a nipple tumor distance of &lt;1 cm who underwent NSM were excluded. 190 patients who underwent NSM and 729 patients who underwent SSM were included in the analysis. All patients underwent MRI or US before treatment. Nipple-tumor distance was mainly measured by MRI.

Results

The median follow-up period was 71 months (range: 10 - 131 months) for the NSM group and 79 months (range: 9 - 140 months) for the SSM group. There were no significant difference of clinicopathological factors between the NSM group and the SSM group, except of the larger diameter of tumor in the SSM group. NSM was performed for 60 patients (32%) with stage 0, 71 patients (37%) with stage I, and 59 patients (31%) with stage II/III. SSM was performed for 185 patients (26%) with stage 0, 268 patients (37%) with stage I, and 276 patients (37%) with stage II/III. Local recurrence was found in 11 (5.8%) patients in the NSM group and in 44 (6.0%) patients in the SSM group. In the NSM group, only one (0.5%) patient had local recurrence in the nipple areola complex. In terms of DFS and overall survival (OS) rate, there was no difference between the NSM group and the SSM group (DFS; 89.5% vs 89.2%, HR, 1.044; p = 0.8992; 95% CI, 0.5116–1.9519, and OS; 98.4% vs 96.4%, HR, 0.963; p = 0.9116; 95% CI, 0.473–1.793). According to breast cancer subtype, in the NSM group, all of the 11 patients (100%) who developed local recurrence in the NSM group was hormone receptor (HR)-positive/HER2-negative breast cancer. 29 of the 44 patients (65.9%) who developed local recurrence in the SSM group was HR-positive/HER2-negative, 6 patients (13.6%) was HR-negative/HER2-positive, and 7 patients (15.9%) was triple-negative breast cancer. Among patients who had received neoadjuvant chemotherapy, the NSM group (3 of 14 patients, 21.4%) had a trend for higher local recurrence rate than the SSM group 7 of 116 patients (6.0%) (p = 0.0813). However, no local recurrence in the nipple areola complex was observed for the NSM group. In addition, there was no difference of OS between the NSM group (92.9%) and the SSM group (90.5%) (HR, 0.903; p = 0.9943; 95% CI, 0.049-4.739).

Conclusions

Our results suggested that NSM with immediate reconstruction might be safe as well as SSM for breast cancer with the nipple–tumor distance of &gt;1 cm with respect to their prognosis and local control regardless of breast cancer subtype or invasiveness. Further studies with a large sample size to assess the risk of local recurrence for NSM after neoadjuvant chemotherapy.

Citation Format: Yamashita Y, Hayashi N, Nagura N, Kajiura Y, Yoshida A, Takei J, Suzuki K, Tsunoda H, Yamauchi H. Long-term oncologic safety of nipple-sparing mastectomy with immediate reconstruction [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 P2-14-17.

Abstract P5-18-05: Clinicopathological characteristics and prognosis of young patients with ductal carcinoma in situ

Background: The peak age at diagnosis of breast cancer differs between patients in Asian countries (40 - 50 years), and those in Western countries (60 - 70 years). With the increasing use of screening mammography, the incidence of ductal carcinoma in situ (DCIS) has increased significantly in younger Asian women. Nevertheless, our knowledge of the clinicopathological features and prognosis in young patients with DCIS is relatively limited. We aimed to compare the clinicopathological features of younger patients with that of older patients with DCIS and to evaluate their prognostic factors.Methods: A total of 1445 women were diagnosed with DCIS between the years 2005 and 2015. Patients with the past history of breast cancer and managed without surgery were excluded. The young age group included patients &lt;50 years of age, whereas the old age group included patients ≥50 years of age at diagnosis. We compared the clinicopathological characteristics [tumor size, surgery type, estrogen receptor (ER) and progesterone receptor (PgR) status, HER2 status, nuclear grade, margin status, radiotherapy, endocrine therapy, family history of breast cancer, and screening presentation or presentation with symptoms] and prognosis [disease-free survival (DFS), and overall survival (OS)] between the groups. DFS included the following events: contralateral breast cancer, loco-regional, and distant recurrences. DFS and OS were estimated using the Kaplan–Maier method. The risk factors associated with events were estimated using the log-rank test for univariate analysis. P values &lt; 0.05 were considered statistically significant.Result: Among the 1445 patients diagnosed with DCIS, 1281 were included in this study. The median age at diagnosis was 47 years (range, 22-87 years). The median follow-up time was 72 months (range, 1-162 months). ER and/or PgR status was positive in 1133 patients (88%). HER2 status was positive in 289 patients (23%). Premenopausal status was noted in 867 patients (68%). The median tumor size was 3.0 cm. Of 1281, 202 (18%) patients received endocrine therapy, 846 (66%) received breast conserving surgery, and 724 (86%) received radiation therapy. There were 765 patients (60%) in the young group. Significantly more patients in the young group had low nuclear grades, were ER and/or PgR positive, were HER2 receptor negative, underwent mastectomy, presented with symptoms, and had close/positive margins. Fifty-eight (4.5%) events occurred: 41 (3.2%) contralateral breast cancers, 19 (1.5%) loco-regional recurrences, and one (0.1%) distant metastasis. No death due to breast cancer was reported. On multivariate analysis, the young group (hazard ratio: 2.24, 95% CI: 1.01 - 4.95, P = 0.04), and presentation with clinical symptoms (hazard ratio: 2.09, 95% CI: 1.07-4.10, P = 0.03) significantly correlated with worse DFS. OS was not significantly different between the groups.Conclusion: This was the largest study with young patients with DCIS in the Asian population. We found that age at diagnosis was a significant independent factor associated with DFS. While genetic background also requires consideration, women with DCIS at &lt;50 year of age may require intensive surveillance. This result requires confirmation with longer follow-up.

Citation Format: Seki A, Matsuda N, Kajiura Y, Kobayashi D, Hayashi N, Tsunoda H, Suzuki K, Yoshida A, Takei J, Yamauchi H. Clinicopathological characteristics and prognosis of young patients with ductal carcinoma in situ [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 P5-18-05.

Magnetic Resonance Imaging Combined With Second-look Ultrasonography in Predicting Pathologic Complete Response After Neoadjuvant Chemotherapy in Primary Breast Cancer Patients

BACKGROUND

Magnetic resonance imaging (MRI) or ultrasonography (US) alone is limited in the ability to predict the pathologic complete response (pCR) accurately after neoadjuvant chemotherapy (NAC). The aim of the present study was to predict the pCR using MRI combined with second-look US in primary breast cancer patients.

MATERIALS AND METHODS

A total of 1274 consecutive primary breast cancer patients who were examined by MRI and second-look US before and after NAC and had undergone breast-conserving surgery from 2004 to 2014 were included. The positive predictive value (PPV) of a clinical complete response (cCR) by MRI alone and MRI plus US was assessed. A CR was defined as no residual invasive carcinoma. The presence of a residual in situ component was also assessed (ypTis).

RESULTS

Of the 1274 patients, 333 (26.1%) had a pCR (ypT0/is), and 102 (8.0%) had a residual in situ component (ypTis). A cCR was found in 247 patients (19.4%) using MRI alone and in 182 patients (14.3%) using MRI plus US. The PPV for a cCR using MRI alone was 79.4% and the PPV for MRI plus US was 86.8%. The PPV for a cCR by MRI plus US was the greatest at 98.1% in the estrogen receptor-negative (ER^-)/human epidermal growth factor receptor-positive (HER2⁺) group (86.5% in the ER⁺/HER2⁺, 83.0% in the ER^-/HER2^-, and 64.7% in the ER⁺/HER2^- groups). The PPV for residual in situ component was as low as 72.2%.

CONCLUSION

Our results have shown that MRI combined with second-look US in predicting for a pCR was useful compared with MRI alone, especially for ER^-/HER2⁺. However, it was difficult to predict for the presence of a residual in situ component. Our ongoing prospective multi-institutional study has shown that adding vacuum-assisted biopsy to MRI plus second-look US is warranted to improve the prediction of pCR for omitting breast surgery.

Ductal Carcinoma in situ of the breast in sclerosing adenosis encapsulated by a hamartoma: A case report

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Ductal Carcinoma in situ in sclerosing adenosis encapsulated by a hamartoma is rare.

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The diagnosis is difficult due to the appearance of these combined lesions.

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Atypical appearance of a hamartoma may suggest a co-existing malignancy.

Introduction

Ductal Carcinoma in situ (DCIS) of the breast can develop in areas of sclerosing adenosis. The radiographic finding of sclerosing adenosis is a spiculated mass and can look like invasive ductal carcinoma. We report a patient with DCIS in sclerosing adenosis encapsulated by a hamartoma, with imaging findings quite different from the typical findings of sclerosing adenosis.

Presentation of case

A 73-year old woman, with no previous mammography, presented with a palpable mass in the left breast. Mammography showed a 36 mm well-defined mass with fat density in the middle outer quadrant of the left breast. Ultrasonography showed a well-defined mass in the same area which was composed of hypoechoic and hyperechoic areas. The histological diagnosis by core needle biopsy was sclerosing adenosis. We considered the patient’s age and tumor size and performed a partial mastectomy for both diagnosis and treatment. Final pathology showed DCIS in sclerosing adenosis in a hamartoma.

Discussion

This patient had DCIS in an area of sclerosing adenosis, encapsulated by a hamartoma. DCIS can develop in areas of sclerosing adenosis, and can appear similar to invasive ductal carcinoma, so we must avoid misdiagnosis or over-treatment. Malignant transformation of a hamartoma is rare, but can occur since it contains epithelial tissue. Definitive biopsy should be performed due to the possibility of a malignancy inside the hamartoma.

Conclusions

When diagnosing a hamartoma, the presence of atypical findings on imaging studies, should suggest the possibility of malignancy. Although rare, a malignant tumor may be present inside the hamartoma.

Abstract P3-01-03: The loss of lymph node metastasis after neoadjuvant chemotherapy in patients with cytologically proven node-positive primary breast cancer

Purpose:While the sensitivity to neoadjuvant chemotherapy (NAC) depends on breast cancer subtype, it has been reported that over 30% of patients with node-positive breast cancer achieved an axillary pathologic complete response (pCR) after NAC. However, axillary lymph node dissection (ALND) still remains as a standard treatment because of the difficulty of assessment of lymph node (LN) status after NAC. ALND will be omitted if axillary LN status is accurately assessed. Our purpose of this study was to predict the loss of axillary LN metastasis after NAC in primary breast cancer patients.

Patients and Methods: Among 997 consecutive patients who underwent surgery after NAC from January 2006, to December 2016, 279 patients with cytologically proven node-positive were included in this analysis. All patients were assessed using CT or PET-CT, and ultrasonography (US) before NAC. LN status after NAC was assessed by US. Patients with cT4 tumor, and supra/subclavicular and parasternal LN metastasis were excluded. Clinical LN status after NAC (ycN) was compared to pathological LN status (ypN) on surgical specimen. The association between LN status and clinicopathological factors including nuclear grade (NG), tumor size, the use of trastuzumab, and breast cancer subtypes, was assessed.

Result: Of the 279 patients with LN-positive before NAC, 166 patients (59.5%) had ER+/HER2- tumor, 51 patients (18.3%) had ER+/HER2+ tumor, 33 patients (11.8%) had ER-/HER2- tumor, and 29 patients (10.4%) had ER-/HER2+ tumor. 179 patients (64.2%) had ycN0 and 102 patients (36.6%)had ypN0. There was significant difference of rate of the loss of LN metastasis after NAC; 37 of 166 patients (22.3%) with ER+/HER2- tumor, 24 of 51 patients (47.1%) with ER+HER2+ tumor, 19 of 33 patients (57.6%) with ER-HER2- tumor, and 22 of 29 patients (75.9%) with ER-HER2+ tumor, (p&lt;0.01).The accuracy of assessment of the loss of LN metastasis by US (ycN0/ypN0) was high in 20 of 25 patients (80.0%) with ER-/HER2+ tumor and in 14 of 19 patients (73.4%) ER-/HER2- tumor compared to ER+ tumor; 21 of 39 patients (53.8%) with ER+/HER2+ tumor and 34 of 96 patients (35.4%) with ER+/HER2- tumor (p&lt;0.01). For patients with ycN0/ypN+, the median number of residual LN metastasis was 1 in ER-/HER2+ tumor (range:1-2) and ER-/HER2- tumor (range:1-3), and 2 in ER+/HER2+ tumor (range:1-6) and ER+/HER2- tumor (range:1-14). Among patients with ER-/HER2+ tumor, there was association between the loss of LN metastasis and the use of trastuzumab (p&lt;0.01). There was no association between the loss of LN metastasis and NG or tumor size.

Conclusion: Our results showed patients with ER-/HER2+ tumor and cytologically proven LN metastasis who received NAC with trastuzumab might have the loss of LN metastasis if assessed as ycN0 by US after NAC, whereas, the patients in ER+ tumor have a high risk to have residual LN metastases after NAC even if assessed as ycN0. Further studies are warranted the prognostic impact of the omission of ALND for these populations.

Citation Format: Namura M, Hayashi N, Tsunoda H, Yoshida A, Takei J, Suzuki K, Nakamura S, Yamauchi H. The loss of lymph node metastasis after neoadjuvant chemotherapy in patients with cytologically proven node-positive primary 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 P3-01-03.

Discrepancies Between Pathological Tumor Responses and Estimations of Complete Response by Magnetic Resonance Imaging After Neoadjuvant Chemotherapy Differ by Breast Cancer Subtype

INTRODUCTION

The influence of breast cancer (BC) subtype in discrepancies between pathologic complete response (pCR) and complete response by magnetic resonance imaging (MRI-CR) after neoadjuvant chemotherapy (NAC) have not been discussed well. We evaluated the association between BC subtype and pCR or only residual in situ lesion without invasive cancer (pCR/in situ⁺) in patients with MRI-CR (positive predictive value [PPV]).

MATERIAL AND METHODS

From the data of 716 patients with primary BC who were diagnosed with invasive cancer and treated with NAC and then surgery from January 2009 to May 2014 at St. Luke's International Hospital, 180 patients were determined to have MRI-CR by retrospective chart review. BC subtypes at baseline were classified into 6 subtypes, as strong estrogen receptor (ER⁺⁺), moderately positive ER (ER⁺), negative ER (ER^-), and HER2 status expression.

RESULTS

Three subtypes had PPV (pCR) ≥ 50%: ER^-/HER2⁺ (56.3%, 27/48), ER^-/HER2^- (57.6%, 34/59), and ER⁺/HER2⁺ (56.2%, 9/16). However, PPV (pCR) for the ER⁺⁺/HER2^- and ER⁺⁺/HER2⁺ subtypes was < 30%; notably, only 12.0% (3/25) for the ER⁺⁺/HER2^- subtype, which was significantly low (P < .001) compared with ER⁺⁺/HER2^- and other subtypes. PPV (pCR/in situ⁺) was significantly low at 20.0% in the ER⁺⁺/HER2^- subtype (P < .001 compared with other subtypes). PPV (pCR/in situ⁺) in other subtypes was collectively greater than 60%, and was 91.7% in the ER^-/HER2⁺ subtype.

CONCLUSION

We should interpret carefully MRI-CR of NAC to evaluate residual disease for ER⁺⁺/HER2^- BC.

BMI change and abdominal girth as risk factors of breast cancer

e13082

Background: While obesity is considered the risk factors of breast cancer, Asian women are tends to be lower BMI compared with Western populations and there are not much reports that studied association between obesity and risk of breast cancer in Asian women. In this study, we analyzed the associations of breast cancer incidence and body mass index at age 18-20 (BMI 18-20y), BMI at research entry (BMI at entry), change of the BMI from BMI 18-20y to BMI at entry (BMI change), abdominal girth at research entry (AG), HbA1c [N] at research entry (HbA1c). Methods: We used data of the women who had undergone medical check-ups and opportunistic breast cancer screening at least twice at the Center for Preventive Medicine of St. Luke’s International Hospital between April 1, 2005 and March 31, 2014. Statistical analysis was done by using multivariate Cox proportional hazards model to investigate the hazard ratio (HR) at 95% confidence intervals (95% CI). Results: In this 10 year period, 30,109 women (20,043 women were premenopausal and 10,066 women were postmenopausal women) received opportunistic breast cancer screening at least twice. After analysis of 131656.6 person-years follow up during 10 years, 325 initial breast cancer cases were identified 202 cases in premenopausal women, and 123 cases in postmenopausal women. Among postmenopausal women, BMI change and AG were positively associated with breast cancer incidence. Women whose BMI change were major gain group (> +5.0) were significantly likely to develop breast cancer compared with stable group (BMI change were between -2.5 to +2.5) [HR: 1.902 (95% CI = 1.202-3.009)]. Large AG ( > 90cm) was significant risk to develop breast cancer versus less than 70cm [HR: 2.500 (95% CI = 1.091-5.730)]. In the analysis classified BMI18-20y more and less than 20 kg/m2, large BMI18-20y ( > 20 kg/m2) postmenopausal women with high HbA1c ( > 6.5) was more likely to develop breast cancer compared with low HbA1c ( < 5.5) [HR: 3.325(95% CI = 1.307-8.460)]. Conclusions: Increase of BMI after age of 18-20 years and large AG in postmenopausal women have positive association with breast cancer development. High HbA1c women whose BMI18-20y was over 20 kg/m2 are significantly to develop breast cancer.

Ultrasound Image Classification of Ductal Carcinoma In Situ (DCIS) of the Breast: Analysis of 705 DCIS Lesions

The Japan Association of Breast and Thyroid Sonology (JABTS) proposed, in 2003, a conceptual classification system for non-mass abnormalities to be applied in addition to the conventional concept of masses, to facilitate detecting ductal carcinoma in situ (DCIS) lesions. The aim of this study was to confirm the utility of this system and to clarify the distribution of these findings in DCIS lesions. Data on 705 surgically treated DCIS lesions from 16 institutions in Japan were retrospectively reviewed. All 705 DCIS lesions could be classified according to the JABTS classification system. The most frequent findings were hypo-echoic areas in the mammary gland (48.6%), followed by solid masses (28.0%) and duct abnormalities (10.2%) or mixed masses (8.1%). Distortion (1.3%), clustered microcysts (1.4%) and echogenic foci without a hypo-echoic area (2.5%) were uncommon. These results suggest that the concept of non-mass abnormalities is useful in detecting DCIS lesions.

Abstract P2-08-28: Association between rim enhancement on magnetic resonance imaging and response of chemo therapy

Background: Triple-negative breast cancers (TNBC) are defined as tumors that lack expression of estrogen receptor (ER), progesterone receptor (PR), and HER2. TNBC is characterized as a cancer with a high malignancy potential and a poor prognosis. Systemic therapy that is effective in TNBC is only chemotherapy. On magnetic resonance imaging (MRI), rim enhancement was frequently seen in TNBC. It is reported that rim enhancement on MRI may associated with long-term outcome of patients with triple-negative breast cancer and may potentially serve as a prognostic biomarker in these patients. It is not well known about the relationship of rim enhancement on the MRI and treatment effectiveness of TNBC.

Purpose: We investigated the relationship between rim enhancement on MRI and response of chemo therapy and outcome in patients with TNBC.

Methods: MRI findings of 144 consecutive female TNBC patients, who underwent surgery from 2007 to 2012 in our hospital, were retrospectively reviewed. All patients have taken the MRI in our hospital before treatment, and had undergone chemotherapy before or after surgery. Presence of rim enhancement on MRI was assessed. Rim enhancement was defined more pronounced at the periphery of the mass at early phase.

Association of the presence of rim enhancement on MRI and the pathological complete response (pCR) rate in patients who underwent neo adjuvant chemotherapy (NAC) was assessed using two-sided Pearson's Chi squared tests. Disease free survival (DFS) rates were calculated by the Kaplan-Meier method. Univariate analysis was performed using the log rank test. pCR was defined as the disappearance of invasive cancer.

Results: The median age was 51yo (26-82), and the median observation period was 49 months (5-92). Eighty-one patients (56.2%) underwent NAC and 63 patients (43.7%) underwent adjuvant chemotherapy. Twenty-six cases (18.0%) occurred recurrence or distance metastasis. The presence of rim enhancement were observed 68 cases (42.3%), and non-rim enhancement were 66 cases (57.6%). DFS were not significantly different according to the presence of rim enhancement on MRI(P=0.31).

In NAC patients, 28 patients (34.5%) were led to pCR and 53 (63.4%) were non-pCR. The presence of rim enhancement were observed 44 cases (54.3%), and non-rim enhancement were 37 cases (45.6%). In pCR rate, rim enhancement is higher than non-rim enhancement (40.9%, 27.0%, respectivrly). However, the presence of rim enhancement on MRI was not significantly associated with pCR in TNBC patients (p= 0.190).

Table1. Association between rim enhancement and pCR pCR(%)non-PCR (%)P-valuerim enhancement18 (40.9)26 (59.1) non-rim enhancement10 (27.0)27 (72.9)0.19

Conclusion: The presence of rim enhancement on MRI showed high pCR rate. While, it is not a significant predictor of pCR in TNBC patients.

Citation Format: Motonari T, Yoshida A, Tsunoda H, Hayashi N, Yagata H, Yamauti H. Association between rim enhancement on magnetic resonance imaging and response of chemo therapy. [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 P2-08-28.

Malignant phyllodes tumor metastasized to the right ventricle: a case report

Cardiac metastasis of malignant phyllodes tumor is very rare. We herein report a rare case that developed cardiac metastasis from malignant phyllodes tumor. A 38-year-old woman underwent lumpectomy, and the final pathological findings showed the 5-cm malignant phyllodes tumor partially containing 1 cm of squamous cell carcinoma. Four months after the first surgery, a local recurrence of malignant phyllodes tumor and distant metastases to the bone, lung, pulmonary main trunk, and right ventricle were detected. Mass reduction surgery of cardiac metastasis of the malignant phyllodes tumor was performed to avoid sudden death. In immunohistochemical findings, the tumor was suspected to be originated in myoepithelial cells because of the expression of smooth muscle lineage including α-smooth muscle actin and Calponin1 and highly malignant characteristics showing MIB-1 and p53 highly positive with angiogenesis. Further studies are needed to clarify the effective treatment to these tumors.