Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

INTRODUCTION

The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

METHODS

We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.

RESULTS

A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.

CONCLUSION

A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Triple repeated fetal congenital heart disease linked to PLD1 mutation: a case report

BACKGROUND

Congenital heart disease occurs in approximately 1 in 100 cases. Although sibling occurrence is high (3-9%), the causative genes for this disease are still being elucidated. PLD1 (Phospholipase D1) is a recently discovered gene; however, few case reports have been published on it. In this report, we describe a case of triplicate fetal congenital heart disease that was diagnosed as a PDL1 mutation. Our objective is to explore the clinical manifestations of PLD1 mutations in this particular case.

CASE PRESENTATION

A 32-year-old Japanese woman (gravida, para 0) was introduced since fetus four chamber view was not clear and was diagnosed with ductus arteriosus-dependent left ventricular single ventricle and pulmonary atresia at 21 weeks and 1 day of gestation during her first pregnancy. Artificial abortion using Gemeprost was performed at 21 weeks and 5 days of gestation. The second pregnancy was diagnosed as pulmonary atresia with intact ventricular septum with cardiomegaly, a cardiothoracic area ratio of more than 35%, and a circulatory shunt at 13 weeks and 3 days of gestation. Subsequently, intrauterine fetal death was confirmed at 14 weeks and 3 days of gestation. Regarding the third pregnancy, fetal ultrasonography at 11 weeks and 5 days of gestation showed mild fetal hydrops and moderate tricuspid valve regurgitation. At 16 weeks and 5 days of gestation, the fetus was suspected to have a left ventricular-type single ventricle, trace right ventricle, pulmonary atresia with intact ventricular septum, or cardiomyopathy. Cardiac function gradually declined at 26 weeks of gestation, and intrauterine fetal death was confirmed at 27 weeks and 5 days of gestation. The fourth pregnancy resulted in a normal heart with good progression and no abnormal baby. We submitted the first and second fetuses' umbilical cord, third fetus' placenta, and the fourth fetus' blood to genetic testing using whole exome analysis with next generation sequencing. Genetic analysis identified hemizygous PLD1 mutations in the first, second, and third fetuses. The fourth fetus was heterozygous. In addition, the parents were heterozygous for PLD1. This case is based on three consecutive cases of homozygosity for the PLD1 gene in the sibling cases and the fetuses with recurrent right ventricular valve dysplasia. This will elucidate the cause of recurrent congenital heart disease and intrauterine fetal death and may serve as an indicator for screening the next fetus. To date, homozygous mutations in PLD1 that repeat three times in a row are not reported, only up to two times. The novelty of this report is that it was repeated three times, followed by a heterozygous live birth.

CONCLUSIONS

This report is consistent with previous reports that mutations in PLD1 cause right ventricular valve dysplasia. However, there have been few case reports of PLD1 mutations, and we hope that this report will contribute to elucidate the causes of congenital heart disease, especially right ventricular valve dysplasia, and that the accumulation of such information will provide more detailed information on PLD1 mutations in heart disease.

Hereditary breast and ovarian cancer triggered by occult fallopian tube cancer: a case report

BACKGROUND

At the time of benign gynecological surgery, a prophylactic salpingo-oophorectomy or salpingectomy is increasingly being performed concurrently to reduce the risk of future ovarian and fallopian tube cancer. We herein describe a case of hereditary breast and ovarian cancer syndrome in which a hysterectomy and bilateral adnexectomy were performed with a preoperative diagnosis of benign tumor. A detailed pathological examination revealed occult fallopian tube cancer, and additional staging surgery provided an accurate pathology diagnosis.

CASE PRESENTATION

A 72-year-old Japanese woman with a past history of breast cancer underwent a hysterectomy and bilateral oophoro-salpingectomy for the preoperative diagnosis of uterine myoma and a right para-ovarian cyst. In the detailed pathological examination, high-grade serous carcinoma of the right fallopian tube was detected incidentally, and a subsequent staging laparotomy confirmed single para-aortic lymph node metastasis. Furthermore, a mutation in germline BRCA2 was detected postoperatively, and the patient was finally diagnosed with hereditary breast and ovarian cancer syndrome. She was diagnosed with fallopian tube cancer International Federation of Gynecology and Obstetrics Stage IIIA1(i) and started on adjuvant therapy (six courses of paclitaxel and carboplatin followed by maintenance therapy with olaparib), and 18 months after surgery, she was free of disease.

CONCLUSION

This is a case of fallopian tube cancer that was diagnosed incidentally and then accurately staged with additional advanced staging surgery. Even in the absence of grossly malignant findings, a detailed pathological search of the fallopian tubes and accurate staging surgery are important to make the necessary treatment decisions for the patient.

Clinical perspectives of rare ovarian tumors: clear cell ovarian cancer

Ovarian clear cell carcinoma (OCCC) is a rare and distinct histological type of epithelial ovarian carcinoma in terms of its histopathological, clinical and genetic features. Patients with OCCC are younger and diagnosed at earlier stages than those with the most common histological type-high-grade serous carcinoma. Endometriosis is considered a direct precursor of OCCC. Based on preclinical data, the most frequent gene alternations in OCCC are mutations of AT-rich interaction domain 1A and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha. The prognosis of patients with early-stage OCCC is favorable, whereas patients at an advanced stage or who have the recurrent disease have a dismal prognosis due to OCCC's resistance to standard platinum-based chemotherapy. Despite a lower rate of response due to its resistance to standard platinum-based chemotherapy, the treatment strategy for OCCC resembles that of high-grade serous carcinoma, which includes aggressive cytoreductive surgery and adjuvant platinum-based chemotherapy. Alternative treatment strategies, including biological agents based on molecular characteristics specific to OCCC, are urgently needed. Furthermore, due to its rarity, well-designed collaborative international clinical trials are needed to improve oncologic outcomes and the quality of life in patients with OCCC.

An attempt to establish real-world databases of poly(ADP-ribose) polymerase inhibitors for advanced or recurrent epithelial ovarian cancer: the Japanese Gynecologic Oncology Group

The development of new treatments for gynecological malignancies has been conducted mainly through collaborative international phase III trials led by the United States and Europe. The survival outcomes of many gynecological malignancies have greatly improved as a result. Recent large-scale genome-wide association studies have revealed that drug efficacy and adverse event profiles are not always uniform. Thus, it is important to validate new treatment options in each country to safely and efficiently provide newly developed treatment options to patients with gynecological malignancies. The Japanese Gynecologic Oncology Group (JGOG) is conducting 5 cohort studies (JGOG 3026, 3027, 3028, 3030, and 3031) to establish real-world data (RWD) of poly(ADP-ribose) polymerase (PARP) inhibitor use in patients with advanced or recurrent epithelial ovarian cancer. The RWD constructed will be used to provide newly developed PARP inhibitors for women with advanced or recurrent ovarian cancer in a safer and more efficient manner as well as to develop further treatment options. In 2022, The JGOG, Korean Gynecologic Oncology Group, Chinese Gynecologic Cancer Society, and Taiwanese Gynecologic Oncology Group established the East Asian Gynecologic Oncology Trial Group to collaborate with East Asian countries in clinical research on gynecologic malignancies and disseminate new knowledge on gynecologic malignancies from Asia. The JGOG will conduct a collaborative integrated analysis of the RWD generated from Asian countries and disseminate real-world clinical knowledge regarding new treatment options that have been clinically implemented.

Frequency of thoracic recurrence based on pathological features in patients with ovarian epithelial tumors in stage I versus higher stages

PURPOSE

The aim of this study was to clarify the frequency of thoracic recurrence and identify associated pathological features in postoperative patients with borderline or malignant ovarian epithelial tumors (BMOT) in stage I versus higher stages.

MATERIALS AND METHODS

A total of 368 consecutive patients with a single primary BMOT were treated at our hospital. This study included the 217 patients with no residual disease on the first CT after standard treatment. The timing and pattern of recurrence on follow-up CT images with a scan range from chest to pelvis were evaluated retrospectively. Patient characteristics, tumor histology, and stage were recorded from electronic medical records.

RESULTS

After a median follow-up period of 48 months, recurrence was detected by CT in 9 patients in stage I (n = 159) and 15 in stage II/III (n = 58) (p = 0.0001). Thoracic recurrence was detected in four patients in stage I and four in stage II/III (p = 0.15). Abdominal recurrence was identified as a factor associated with thoracic recurrence (P < 0.001). Clear cell carcinomas accounted for three out of four thoracic recurrences in stage I and two out of four in stage II/III, and had the highest rates of thoracic recurrence (7.7% in stage I and 22.2% in stage II/III) among all histological types associated with thoracic recurrence. Among patients with recurrence, thoracic recurrence-free probability (p = 0.38), median abdominal recurrence-free interval (18 vs 16 months; p = 0.55) and thoracic recurrence-free interval (16.5 vs 23 months; p = 0.89) did not differ significantly between stage I and stage II/III.

CONCLUSION

The frequency and timing of thoracic recurrence did not differ significantly in postoperative patients with BMOT in stage I versus stage II/III. Abdominal recurrence and a histological type of clear cell carcinoma were most often associated with thoracic recurrence in stage I.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

INTRODUCTION

The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.

METHODS

A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.

RESULTS

Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.

CONCLUSIONS

These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Malignant struma ovarii with thyroid-type papillary and poorly differentiated carcinoma: a case report

Background

Malignant struma ovarii is a very rare type of gynecologic cancer. Although its most common histological subtype is a pure type of papillary thyroid carcinoma containing two components, papillary carcinoma and poorly differentiated carcinoma, malignant struma ovarii is still extremely rare. As a result, the optimal treatment for this type of tumor remains uncertain due to its rarity.

Case presentation

A 62-year-old Japanese female presented with a pelvic tumor and clinical diagnosis of malignant tumor of the ovary. She underwent complete debulking surgery, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. The histology of the ovarian tumor revealed malignant struma ovarii with thyroid-type papillary projections and poorly differentiated carcinoma. Because of the complete resection and the absence of distant metastasis, the patient did not receive any adjuvant therapy. At 24 months after surgery, she was free of disease.

Conclusion

This is a rare case report of malignant struma ovarii, without recurrence, in which the component was papillary thyroid carcinoma mixed with poorly differentiated carcinoma. Foregoing adjuvant therapy might be one option for malignant struma ovarii in cases with complete resection and no distant metastasis. In addition, we should consider that long-term follow-up is needed for malignant struma ovarii.

Assessment of Heating on Titanium Alloy Cerebral Aneurysm Clips during 7T MRI

BACKGROUND AND PURPOSE

Patients with cerebral aneurysms often undergo MR imaging after microsurgical clipping. Ultra-high-field MR imaging at 7T may provide high diagnostic capability in such clinical situations. However, titanium alloy clips have safety issues such as adverse interactions with static magnetic fields and radiofrequency-induced heating during 7T MR imaging. The purpose of this study was to quantitatively assess temperature increases on various types of titanium alloy aneurysm clips during 7T MR imaging.

MATERIALS AND METHODS

Five types of titanium alloy aneurysm clips were tested, including combinations of short, long, straight, angled, and fenestrated types. Each clip was set in a phantom filled with gelled saline mixed with polyacrylic acid and underwent 7T MR imaging with 3D T1WI with a spoiled gradient recalled acquisition in the steady-state technique. Temperature was chronologically measured at the tips of the clip blade and head, angled part of the clip, and 5 mm from the tip of the clip head using MR imaging-compatible fiber-optic thermometers.

RESULTS

Temperature increases at all locations for right-angled and short straight clips were <1°C. Temperature increases at the angled part for the 45° angled clip and the tip of the clip head for the straight fenestrated clip were >1°C. Temperature increases at all locations for the long straight clip were >2°C.

CONCLUSIONS

Temperature increases on the right-angled and short straight clips remained below the regulatory limit during 7T MR imaging, but temperature increases on the 45° angled, straight fenestrated, and long straight clips exceeded this limit.

Diagnostic Accuracy of Screening Arterial Spin-Labeling MRI Using Hadamard Encoding for the Detection of Reduced CBF in Adult Patients with Ischemic Moyamoya Disease

BACKGROUND AND PURPOSE

Adult patients with ischemic Moyamoya disease are advised to undergo selective revascularization surgery based on cerebral hemodynamics. The purpose of this study was to determine the diagnostic accuracy of arterial spin-labeling MR imaging using Hadamard-encoded multiple postlabeling delays for the detection of reduced CBF in such patients.

MATERIALS AND METHODS

Thirty-seven patients underwent brain perfusion SPECT and pseudocontinuous arterial spin-labeling MR imaging using standard postlabeling delay (1525 ms) and Hadamard-encoded multiple postlabeling delays. For Hadamard-encoded multiple postlabeling delays, based on data obtained from the 7 sub-boluses with combinations of different labeling durations and postlabeling delays, CBF corrected by the arterial transit time was calculated on a voxel-by-voxel basis. Using a 3D stereotaxic template, we automatically placed ROIs in the ipsilateral cerebellar hemisphere and 5 MCA territories in the symptomatic cerebral hemisphere; then, the ratio of the MCA to cerebellar ROI was calculated.

RESULTS

The area under the receiver operating characteristic curve for detecting reduced SPECT-CBF ratios (<0.686) was significantly greater for the Hadamard-encoded multiple postlabeling delays-CBF ratios (0.885) than for the standard postlabeling delay-CBF ratios (0.786) (P = .001). The sensitivity and negative predictive value for the Hadamard-encoded multiple postlabeling delays-CBF ratios were 100% (95% confidence interval, 100%-100%) and significantly higher than the sensitivity (95% CI, 44%-80%) and negative predictive value (95% CI, 88%-97%) for the standard postlabeling delay-CBF ratio, respectively.

CONCLUSIONS

ASL MR imaging using Hadamard-encoded multiple postlabeling delays may be applicable as a screening tool because it can detect reduced CBF on brain perfusion SPECT with 100% sensitivity and a 100% negative predictive value in adult patients with ischemic Moyamoya disease.

Prognostic significance of peritoneal cytology in low-risk endometrial cancer: comparison of laparoscopic surgery and laparotomy

Background

There is uncertainty surrounding the prognostic value of peritoneal cytology in low-risk endometrial cancer, especially in laparoscopic surgery. The objective of this retrospective study is to determine the prognostic significance of positive peritoneal cytology among patients with low-risk endometrial cancer and to compare it between laparoscopic surgery and conventional laparotomy.

Methods

From August 2008 to December 2019, all cases of pathologically confirmed stage IA grade 1 or 2 endometrial cancer were reviewed at Osaka Medical College. Statistical analyses used the Chi-square test and the Kaplan–Meier log rank.

Results

A total of 478 patients were identified: 438 with negative peritoneal cytology (232 who underwent laparotomy and 206 who undertook laparoscopic surgery) and 40 with positive peritoneal cytology (20 who underwent laparotomy and 20 who received laparoscopic surgery). Survival was significantly worse among patients with positive peritoneal cytology compared to patients with negative peritoneal cytology. However, there was no significant difference among patients with negative or positive peritoneal cytology between laparoscopic surgery and laparotomy.

Conclusion

This retrospective study suggests that, while peritoneal cytology is an independent risk factor in patients with low-risk endometrial cancer, laparoscopic surgery does not influence the survival outcome when compared to laparotomy.

Bevacizumab-associated events in Japanese women with cervical cancer: a multi-institutional survey of Obstetrical Gynecological Society of Kinki district, Japan

BACKGROUND

The development of perforations or fistulas in the Gastrointestinal (GI) tract or genitourinary (GU) system is a serious adverse effect of bevacizumab. The aim of this study was to investigate the incidences of these GI/GU events as well as their association with previous radiotherapy (RT) in Japanese women with cervical cancer.

METHODS

We conducted a written questionnaire survey among 14 gynecological institutions belonging to the Oncology Research Committee of the Obstetrical and Gynecological Society of Kinki District, Japan. The severity of GI/GU events was classified according to the National Cancer Institute's Common Terminology Criteria for Adverse Events version 5.0. All data were extracted from survey responses and maintained in an Excel spreadsheet and summarized using descriptive statistics.

RESULTS

The information of 224 Japanese women with cervical cancer (152 recurrent and 72 advanced) who were treated with bevacizumab-containing chemotherapy was collected from 14 institutions. Of these, 65% had been previously treated with RT. GI/GU events of any grade developed in 25 (11.2%) patients, leading directly to death in 3 (1.3%) patients. When compared, the incidence of GI/GU events was higher in recurrent disease patients than in advanced disease patients (13.8% vs 5.6%, p = 0.0728). When examined according to the history of RT, the incidence of GI/GU events was greater in patients with a history of RT than in those without (14.5% vs 5.1%, p = 0.044).

CONCLUSION

More than 10% of patients experience GI/GU events during or after receiving bevacizumab-containing chemotherapies. Prior RT is a risk factor for bevacizumab-associated GI/GU events.

Oncologic outcomes for patients with endometrial cancer who received minimally invasive surgery: a retrospective observational study

BACKGROUND

Laparoscopic hysterectomy has been performed for patients with endometrial cancer as minimally invasive surgery; however, the long-term outcomes of high-risk disease compared to open surgery remain unclear.

METHODS

Eight hundred and eighty-three patients with endometrial cancer who underwent laparoscopic or abdominal hysterectomy were categorized into three groups. Low-risk disease was defined as stage IA disease with endometrioid carcinoma of grade 1 or 2. Uterine-confined disease was defined as stage IA disease with high-grade tumors or stage IB and II disease. Advanced disease was defined as stage III or IV disease. The progression-free survival (PFS) and overall survival (OS) rates were compared between laparoscopic and laparotomic hysterectomy.

RESULTS

Among 478 patients with low-risk disease, including 226 with laparoscopy and 252 with laparotomy, the prognosis was not significantly different between the groups (3-year PFS rate, 97.4% vs. 97.1%, p = 0.8; 3-year OS rate, 98.6% vs. 98.3%, p = 0.9). Among the 229 patients with uterine-confined disease, including 51 with laparoscopy and 178 with laparotomy, the prognosis was not significantly different between the groups (3-year PFS rate, 90.5% vs. 85.5%, p = 0.7; 3-year OS rate, 91.3% vs. 92.5%, p = 0.8). Among the 176 patients with advanced disease, including 24 with laparoscopy and 152 with laparotomy, laparoscopic hysterectomy had a higher PFS rate and OS rate than laparotomic hysterectomy (3-year PFS rate, 74.5% vs. 51.5%, p = 0.01; 3-year OS rate, 92.3% vs. 75.1%, p = 0.03).

CONCLUSIONS

Laparoscopic procedures are not associated with a poorer outcome than laparotomy in patients with advanced endometrial cancer or uterine-confined endometrial cancer.

The Diagnostic Accuracy of an Intraoperative Frozen Section Analysis and Imprint Cytology of Sentinel Node Biopsy Specimens from Patients with Uterine Cervical and Endometrial Cancer: a Retrospective Observational Study

Sentinel node biopsy (SNB) may be a decision-making tool for function preservation surgery, including radical trachelectomy and ovary preservation in the treatment of cervical and endometrial cancer. The intraoperative diagnosis is important for guiding treatment decisions for patients with these conditions. Three hundred seventy-one patients with cervical and endometrial cancer received SNB with an intraoperative frozen section analysis and imprint cytology. The sentinel node was cut in half, parallel to the longest axis, to obtain the maximum section area. After performing imprint cytology, one half was used to create a frozen section. The specimen was cut at 2-mm intervals into 5-μm-thick sections, which were subjected to hematoxylin and eosin staining. The diagnostic accuracy of intraoperative frozen section analyses and imprint cytology was compared to the final pathological diagnosis. Among 951 detected sentinel nodes, 51 nodes were found to be positive in the final pathological diagnosis. The sensitivity of a frozen section analysis, imprint cytology and the combination of the two modalities was 76.5%, 72.6%, and 92.2%, respectively. The specificity of a frozen section analysis and imprint cytology was 100%. The negative predictive value of a frozen section analysis and imprint cytology was 98.7% and 98.5%, respectively. In these settings, the accuracy of the frozen section analysis and imprint cytology in the evaluation of SNB specimens was considered acceptable; however, the sensitivity of the combined approach was higher in comparison to when a frozen section analysis or imprint cytology was performed alone.

Serum exosomal microRNA-34a as a potential biomarker in epithelial ovarian cancer

Background

Ovarian cancer (OC) is a leading cause of cancer-related death in women, and thus an accurate diagnosis of the predisposition and its early detection is necessary. The aims of this study were to determine whether serum exosomal microRNA-34a (miR-34a) in ovarian cancer could be used as a potential biomarker.

Methods

Exosomes from OC patients’ serum were collected, and exosomal miRNAs were extracted. The relative expression of miR-34a was calculated from 58 OC samples by quantitative real-time polymerase chain reaction.

Results

Serum exosomal miR-34a levels were significantly increased in early-stage OC patients compared with advanced-stage patients. Its levels were significantly lower in patients with lymph node metastasis than in those with no lymph node metastasis. Furthermore, its levels in the recurrence group were significantly lower than those in the recurrence-free group.

Conclusions

Serum exosomal miR-34a could be a potential biomarker for improving the diagnostic efficiency of OC.

Acetazolamide-Loaded Dynamic 7T MR Quantitative Susceptibility Mapping in Major Cerebral Artery Steno-Occlusive Disease: Comparison with PET

BACKGROUND AND PURPOSE

Dynamic changes in cerebrovascular reactivity after acetazolamide administration vary markedly among patients with major cerebral arterial steno-occlusive disease. MR quantitative susceptibility mapping can dynamically quantify the cerebral magnetic susceptibility. The purpose of this study was to determine whether dynamic changes in susceptibility after administration of acetazolamide on 7T quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in the cerebral hemispheres with major cerebral arterial steno-occlusive disease.

MATERIALS AND METHODS

Sixty-five patients underwent 7T MR imaging at baseline and at 5, 10, 15, and 20 minutes after acetazolamide administration. Differences between the susceptibility of venous structures and surrounding brain tissue were calculated in the quantitative susceptibility mapping images. Susceptibility differences at 5, 10, 15, and 20 minutes after acetazolamide administration relative to baseline were calculated in 97 cerebral hemispheres with major cerebral arterial steno-occlusive disease. CBV and the cerebral metabolic rate of oxygen were also calculated using ¹⁵O-gas PET in the resting state.

RESULTS

Dynamic changes of susceptibility after acetazolamide administration were classified into 3 patterns: abnormally increasing 5 or 10 minutes after acetazolamide administration; abnormally decreasing within 20 minutes after acetazolamide administration; and remaining unchanged after acetazolamide administration. CBV was significantly greater in the first pattern than in the latter 2. The cerebral metabolic rate of oxygen differed significantly in descending order from the first to middle to last pattern.

CONCLUSIONS

Dynamic changes of susceptibility after acetazolamide administration on 7T MR quantitative susceptibility mapping are associated with pre-existing states of CBV and the cerebral metabolic rate of oxygen in major cerebral arterial steno-occlusive disease.

Pharmacokinetic evaluation and antitumor potency of liposomal nanoparticle encapsulated cisplatin targeted to CD24-positive cells in ovarian cancer

CD24, which is upregulated in several human malignancies, is related to Epithelial-mesenchymal-transition (EMT) and has characteristics of cancer stem-like cells, especially in cisplatin-resistant ovarian carcinoma cells. Drug delivery systems represent a promising therapeutic approach for diseases with treatment resistance, and the present study investigated a novel CD24-targeted drug delivery system for advanced ovarian carcinoma. We produced liposomal cisplatin with a red fluorescent substance - cyanine 5.5 (GL-CDDP-Cy5.5). In order to target CD24-positive cells, an anti-CD24 monoclonal antibody was modified to the above drug (CD24-GL-CDDP-Cy5.5). Specific uptake of CD24-GL-CDDP-Cy5.5 was confirmed using a therapeutically resistant ovarian cancer cell line, Caov-3 cells. Antitumor effects of CD24-GL-CDDP-Cy5.5 were then evaluated in Caov-3 ×enograft mice. CD24-GL-CDDP-Cy5.5 showed more specific uptake by flow cytometry than GL-CDDP-Cy5.5. In xenograft mice, GL-CDDP-Cy5.5 and CD24-GL-CDDP-Cy5.5 treatment had significantly higher platinum concentration in disseminated tumor cells than cisplatin (P<0.05). Moreover, CD24-GL-CDDP-Cy5.5 suppressed tumor growth and prolonged survival time compared with other treatments. Median survival times of the control, cisplatin, GL-CDDP-Cy5.5 and CD24-GL-CDDP-Cy5.5 groups were 37, 36, 46 and 54 days after inoculation, respectively. Immunohistochemical analysis showed that CD24-GL-CDDP-Cy5.5 treatment, compared with GL-CDDP-Cy5.5, decreased the number of CD24-positive cells and suppressed the EMT phenomenon significantly (P<0.05). The present study demonstrated that CD24-GL-CDDP-Cy5.5, compared with other treatments, improved therapeutic efficacy. The present results suggested the potential for targeting anticancer therapeutics for CD24-positive cells to prevent disease progression.

Determination of eligibility criteria for salvage hysterectomy after definitive radiotherapy/concurrent chemoradiotherapy for residual cervical disease

5524

Background: Patients with persistent cervical cancer after definitive radiotherapy/concurrent chemoradiotherapy (RT/CCRT) have a poor prognosis. Salvage hysterectomy (HT) is potentially curative, but eligibility criteria therefor have not been determined. Methods: Part 1) Retrospective review of patients with persistent cervical cancer treated with definitive RT/CCRT at 35 institutions of the Japanese Clinical Oncology Group (JCOG) from 2005–2014. Differences between a salvage HT group and a systemic chemotherapy (CT) group after definitive RT/CCRT for residual tumor were evaluated. Clinical variables influencing a salvage HT treatment decision were evaluated using logistic regression analysis. Part 2) Questionnaire-based survey conducted by JCOG gynecologic oncologists assessing treatment choice for patients with residual cervical disease after definitive RT/CCRT. Patients with residual cervical tumor before, during and after definitive RT/CCRT were surveyed for 86 conditions and appropriate candidates for salvage HT were evaluated using heat map analysis. Results: Part 1) We identified 298 patients who underwent salvage HT or systemic CT. Median overall survival was 3.8 and 0.9 year in the HT and CT groups, respectively (HR 0.4341, 95% CI 0.336-0.559, p < 0.01). FIGO stage and lymph node metastasis at initial treatment, performance status (PS) at diagnosis of residual cervical tumor and parametrial invasion of residual cervical tumor significantly influenced a salvage HT treatment decision. Part 2) Heat map analysis showed that surveyed variables segregated into 3 groups: i) in favor of salvage HT, ii) in favor of systemic CT, and iii) either. Conditions such as FIGO stage IB-IIB, PS of 0-1, residual tumor < 4 cm, no parametrial invasion and no residual lymph node metastasis were included in group i, in favor of salvage HT. Conclusions: Eligibility criteria could be determined based on the results of the current study, and a prospective clinical trial evaluating the survival benefit of salvage HT for residual cervical tumor after definitive RT/CCRT is being planned by JCOG.

GPR30 signaling to regulate epithelial-mesenchymal transition and predict survival in ovarian cancer

e17041

Background: G protein-coupled receptor 30 (GPR30) is a 7-transmembrane　estrogen receptor that functions alongside traditional estrogen receptors to regulate the cellular responses to estrogen. Recent studies suggest that the high expression of GPR30 is associated with a poor prognosis in breast cancer or endometrial cancer. Although the role of GPR30 in ovarian cancer was unclear, we revealed that GPR30 is associated with poor prognosis in ovarian cancer. On the other hand, Epithelial-to-Mesenchymal Transition (EMT) is involved in cancer metastasis. The purpose of this study is to reveal how GPR30 was associated with poor prognosis and whether associated with EMT in ovarian cancer. Methods: We examined whether GPR30 signaling activates the EGFR-Akt pathway in an ovarian cancer cell line (Caov-3) by a Western blotting analysis. We also examined the effect of GPR30 on EMT were evaluated in Caov-3, which were cultured both in two-dimensional (2D) culture and three-dimensional (3D) culture model. GPR30 agonist, G1, was used to confirm the regulatory effects of GPR30 on the change of phenotypic modulation and EMT markers expression. Results: The phosphorylation of the EGFR and Akt could be significantly enhanced by G1 (p < 0.05) and inhibited by a Src family kinase inhibitor. In 3D culture, the stimulation of GPR30 leads the floating and sphere formation in Caov-3. G1-induced EMT was observed with related regulation of EMT markers expression at both mRNA and protein level. G1 induced the decrease of E-cadherin level and the increase of Snail and Vimentin in RT-PCR and Western blotting. Knockdown of GPR30, using siRNA, blocked G1-induced EMT. Conclusions: GPR30 increases the phosphorylation of Akt via the EGFR in ovarian cancer cells and changes ovarian cancer cells to the EMT state.GPR30 might be an important molecule related to metastasis process in ovarian cancer.

A rare case of ovarian carcinosarcoma with squamous cell carcinoma

Background

Ovarian carcinosarcoma, which contains sarcomatous and carcinomatous components, is a very rare tumor. The carcinomatous component is often adenocarcinoma, and squamous cell carcinoma is extremely rare. We herein report a case of ovarian carcinosarcoma in which the carcinomatous component was squamous cell carcinoma.

Case presentation

A 68-year-old woman presented with a huge ovarian tumor with a clinical diagnosis of malignant tumor of the ovary. She underwent hysterectomy, bilateral adnexectomy, omentectomy and lymphadenectomy. Histologically, the tumor cells showed undifferentiated pleomorphic sarcoma as the sarcomatous component and squamous cell carcinoma as the carcinomatous component. The final diagnosis was ovarian carcinosarcoma with squamous cell carcinoma in the carcinomatous component, stage IIIA1. Postoperatively, the patient was treated with six cycles of combination chemotherapy with paclitaxel and carboplatin as adjuvant therapy. The patient was free of disease at 45 months’ follow-up consultation.

Conclusion

This is a rare report of ovarian carcinosarcoma with an epithelial component composed of squamous cell carcinoma. Combination chemotherapy with paclitaxel and carboplatin may be an effective choice as adjuvant chemotherapy in cases of ovarian carcinosarcoma including squamous cell carcinoma.

Neoadjuvant intra-arterial chemotherapy using an original four-lumen double-balloon catheter for locally advanced uterine cervical cancer

OBJECTIVE

We report a balloon-occluded arterial infusion therapy with an original four-lumen double-balloon catheter (4L-DB) which allows for the efficient injection of an anticancer agent at a high concentration to the target spot for patients with locally advanced uterine cervical cancer.

METHODS

One hundred and forty-three patients with locally advanced cervical cancer treated with neoadjuvant intra-arterial chemotherapy (NAIAC) or a primary radical hysterectomy (PRH) were retrospectively assessed. The patients in the NAIAC group received irinotecan 70 mg/m2 intravenously on day 1 and 8 and cisplatin 70 mg/m2 intra-arterially using the 4L-DB on day 2 of a 21-day course, and two courses were performed in principle. The radical hysterectomy was performed within 6 weeks after NAIAC.

RESULTS

Ninety-four patients were treated with NAIAC, and 49 patients undertook a PRH. The response rate of NAIAC on MRI was 92.6%. Fourteen patients (14.6%) had no evidence of cancer cells on pathologic diagnoses. The NAIAC group had a longer disease-free survival than the PRH group (p=0.02); however, the overall survival was not significantly different. The relative risk (RR) for recurrence was higher in patients with lymph node metastasis (RR, 4.31; 95% CI, 2.23-8.43) and lower in those who underwent NAIAC (RR, 0.30; 95% CI, 0.14-0.68).

CONCLUSION

Our results with NAIAC using the 4L-DB catheter in locally advanced cervical cancer indicates beneficial effects on primary lesions and improves disease-free survival.

Preoperative diffusion-weighted magnetic resonance imaging and intraoperative frozen sections for predicting the tumor grade in endometrioid endometrial cancer

Objective

The histological tumor grade is a strong predictor of nodal metastasis in endometrial cancer; as such, an accurate pre- or intraoperative diagnosis is important for performing lymphadenectomy.

Methods

Ninety-one patients with endometrioid endometrial cancer were imaged on DW-MRI with the apparent diffusion coefficient (ADC) calculated and a frozen section (FS) diagnosis made before and at hysterectomy. The diagnostic accuracy for predicting the tumor grade for diffusion weighted magnetic resonance inaging (DW-MRI) and the FS diagnosis compared to the ultimate histologic status was analyzed.

Results

Among 91 patients with endometrioid endometrial cancer, high-grade (endometrioid G3) tumors had lower ADC values than low-grade (endometrioid G1/2) tumors. The cut-off of the mean ADC_mean values for predicting high-grade tumors resulted in 743×10^-6 mm²/sec according to the receiver operating characteristic curve. The true positive rates of ADC values and FSs for the prediction of high-grade tumors did not differ to a statistically significant extent (73.3% vs. 66.7%, p=0.7), however, the true negative rate of ADC values for the prediction of low-grade tumors was significantly lower than that of the FSs (64.5% vs. 98.7%, p=0.01). The kappa statistics of ADC values and FSs were 0.23 and 0.73, respectively. Of note, all five patients with high-grade tumors for whom intraoperative FSs indicated low-grade tumors were predicted to have high-grade tumors on preoperative DW-MRI.

Conclusion

A FS diagnosis is more suitable for predicting high-grade tumors than DW-MRI; however, physicians should pay close attention to tumors with low ADC values on preoperative DW-MRI.

Preoperative Cerebral Oxygen Extraction Fraction Imaging Generated from 7T MR Quantitative Susceptibility Mapping Predicts Development of Cerebral Hyperperfusion following Carotid Endarterectomy

BACKGROUND AND PURPOSE

Preoperative hemodynamic impairment in the affected cerebral hemisphere is associated with the development of cerebral hyperperfusion following carotid endarterectomy. Cerebral oxygen extraction fraction images generated from 7T MR quantitative susceptibility mapping correlate with oxygen extraction fraction images on positron-emission tomography. The present study aimed to determine whether preoperative oxygen extraction fraction imaging generated from 7T MR quantitative susceptibility mapping could identify patients at risk for cerebral hyperperfusion following carotid endarterectomy.

MATERIALS AND METHODS

Seventy-seven patients with unilateral internal carotid artery stenosis (≥70%) underwent preoperative 3D T2*-weighted imaging using a multiple dipole-inversion algorithm with a 7T MR imager. Quantitative susceptibility mapping images were then obtained, and oxygen extraction fraction maps were generated. Quantitative brain perfusion single-photon emission CT was also performed before and immediately after carotid endarterectomy. ROIs were automatically placed in the bilateral middle cerebral artery territories in all images using a 3D stereotactic ROI template, and affected-to-contralateral ratios in the ROIs were calculated on quantitative susceptibility mapping-oxygen extraction fraction images.

RESULTS

Ten patients (13%) showed post-carotid endarterectomy hyperperfusion (cerebral blood flow increases of ≥100% compared with preoperative values in the ROIs on brain perfusion SPECT). Multivariate analysis showed that a high quantitative susceptibility mapping-oxygen extraction fraction ratio was significantly associated with the development of post-carotid endarterectomy hyperperfusion (95% confidence interval, 33.5-249.7; P = .002). Sensitivity, specificity, and positive- and negative-predictive values of the quantitative susceptibility mapping-oxygen extraction fraction ratio for the prediction of the development of post-carotid endarterectomy hyperperfusion were 90%, 84%, 45%, and 98%, respectively.

CONCLUSIONS

Preoperative oxygen extraction fraction imaging generated from 7T MR quantitative susceptibility mapping identifies patients at risk for cerebral hyperperfusion following carotid endarterectomy.

The efficacy of the cyclin-dependent kinase 4/6 inhibitor in endometrial cancer

Background

PD-0332991, the selective cyclin-dependent kinase 4/6 inhibitor palbociclib, causes cell cycle arrest by inhibiting phosphorylation of retinoblastoma (Rb) protein. The aim of this study was to evaluate the therapeutic potential of PD-0332991 in endometrial cancer.

Methods and findings

Four human endometrial cancer cell lines, ECC, HEC1A, HEC108 and TEN, were treated with PD-0332991 and their function was evaluated. In vivo, the therapeutic efficacy was evaluated in a model of subcutaneous endometrial cancer. An immunohistochemical analysis was performed in 337 endometrial cancer specimens. A proliferation assay revealed that 2 of the 4 cell lines that expressed Rb were sensitive to PD-0332991 with an IC50 of 0.65 μM (HEC1A) and 0.58 μM (HEC108), respectively. Both cell lines had G0/G1 cell cycle arrest after treatment with PD-0332991 according to flow cytometry. In vivo, PD-0332991 had antitumoral efficacy with a reduction in the activity of Ki67 and phosphorylation of Rb. Immunohistochemical analyses revealed that the positive rate of Rb was 67.7%, however, there was no significant relationship between the expression levels of Rb and the tumor grade.

Conclusions

PD-0332991 had therapeutic potential against endometrial cancer cell lines expressing Rb protein. Our immunohistochemical analysis revealed that approximately 70% of patients with endometrial cancer might have therapeutic indications for PD-0332991. Of note, the tumor grade had no impact on the indications for treatment.

The effects of administration of the Lactobacillus gasseri strain CP2305 on quality of life, clinical symptoms and changes in gene expression in patients with irritable bowel syndrome

AIMS

To clarify the effects of Lactobacillus gasseri CP2305 (CP2305) on quality of life and clinical symptoms and its functional mechanisms in patients with irritable bowel syndrome (IBS).

METHODS AND RESULTS

After the patients were administered CP2305 daily for 4 weeks, the IBS-severity index score was significantly improved compared with that of the placebo group, and this improvement was accompanied by a reduction in health-related worry and changes in intestinal microbiota. The gene expression profiling of the peripheral blood leucocytes showed that CP2305 treatment significantly up-regulated genes related to eukaryotic initiation factor 2 (EIF2) signalling. Eighty-two genes were down-regulated in IBS patients compared with healthy controls. The expression of 23 of these genes exhibited a CP2305-dependent increase associated with an improvement in IBS severity. The majority of the restored genes were related to EIF2 signalling.

CONCLUSIONS

CP2305 administration is a potential candidate therapeutic option for patients with IBS.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although probiotics have been proposed to benefit IBS patients, objective clinical evidence and elucidation of the functional mechanism remain insufficient. Our study demonstrated that CP2305 administration beneficially influences IBS patients in both subjective and objective evaluations, and gene expression profiling provided insights into the functional mechanism.

CD24 expression is a marker for predicting clinical outcome and regulates the epithelial-mesenchymal transition in ovarian cancer via both the Akt and ERK pathways

The degree of peritoneal dissemination and chemotherapy-resistant tumors is related to the prognosis in patients with advanced-stage ovarian cancer. The epithelial-mesenchymal-transition (EMT) is a multifaceted pathological program that endows cancer cells with the ability to invade and disseminate. CD24 is frequently overexpressed in various human cancers and is correlated with a poor prognosis. We herein examined the functions of CD24 in human ovarian cancer cell lines and evaluated how it contributes to the molecular mechanism underlying the regeneration of cancer stem-like cells (CSCs) through the EMT mechanism in ovarian carcinoma. We demonstrated that CD24 was expressed in 70.1% of primary ovarian carcinoma tissues, which were obtained from 174 patients, and that the expression of CD24 was an independent predictor of survival in patients with ovarian cancer. The expression of CD24 has been found to be correlated with the FIGO stage, presence of peritoneal and lymph node metastasis. CD24 induces the EMT phenomenon, which is involved in cell invasion, the highly proliferative phenotype, colony formation and which is associated with cisplatin resistance and the properties of CSCs, via the activation of PI3K/Akt, NF-κB and ERK in Caov-3 cisplatin-resistant cell lines. CD24-positive ovarian carcinomas have been shown to have a greater potential for intra-abdominal tumor cell dissemination in in vivo models. Our findings suggest that CD24 induced the EMT phenomenon in ovarian cancer, and that CD24 amplified cell growth-related intracellular signaling via the PI3K/Akt and MAPK pathways by affecting the EMT signal pathways. We believe that CD24 is a key molecule of metastatic progression in the EMT phenomenon and a promising therapeutic target for advanced ovarian cancer.

Controlling joint instability delays the degeneration of articular cartilage in a rat model

OBJECTIVE

Joint instability induced by anterior cruciate ligament (ACL) transection is commonly considered as a predisposing factor for osteoarthritis (OA) of the knee; however, the influence of re-stabilization on the protection of articular cartilage is unclear. The aim of this study was to evaluate the effect of joint re-stabilization on articular cartilage using an instability and re-stabilization ACL transection model.

DESIGN

To induce different models of joint instability, our laboratory created a controlled abnormal joint movement (CAJM) group and an anterior cruciate ligament transection group (ACL-T). Seventy-five Wistar male rats were randomly assigned to the CAJM (n = 30), ACL-T (n = 30), or no treatment (INTACT) group (n = 15). Cartilage changes were assessed with soft X-ray analysis, histological and immunohistochemistry analysis, and real-time polymerase chain reaction (PCR) analysis at 2, 4, and 12 weeks.

RESULTS

Joint instability, as indicated by the difference in anterior displacement between the CAJM and ACL-T groups (P < 0.001), and cartilage degeneration, as evaluated according to the Osteoarthritis Research Society International (OARSI) score, were significantly higher in the ACL-T group than the CAJM group at 12 weeks (P < 0.001). Moreover, joint re-stabilization maintained cartilage structure (thickness [P < 0.001], surface roughness [P < 0.001], and glycosaminoglycan stainability [P < 0.001]) and suppressed tumor necrosis factor-alpha (TNF-α) and caspase-3 at 4 weeks after surgery.

CONCLUSION

Re-stabilization of joint instability may suppress inflammatory cytokines, thereby delaying the progression of OA. Joint instability is a substantial contributor to cartilage degeneration.

Hypofibrinolytic Activity after Total Joint Replacement

Tissue-type plasminogen activator (t-PA), tissue-type plasminogen activator inhibitor (t-PAI), and other factors (platelets, fibrinogen, fibrinogen degrada tion products, antithrombin-III, plasminogen, and α2-plasmin inhibitor [α2-PI]) related to the fibrinolytic system were studied in 21 patients undergoing total joint replacement.

Seventeen of the 21 patients revealed an impaired fibrinolytic activity from the first to seventh postoperative day and a subsequent return to the preopera tive level by the fourteenth postoperative day. There were accompanying increases in the level of α2-PI and in the t-PAI/t-PA ratio, and there was decrease in plas minogen level. Such hypofibrinolytic states may be related to a higher incidence of postoperative thrombosis in total joint replacement patients.

Abstract P3-05-10: Non-coding RNAs derived from near the ESR1 gene acts as a transcriptional regulator during estrogen deprivation adaptation of ER positive breast cancer cells

Endocrine therapies that blocks estrogen production are effective for estrogen receptor (ER)-positive breast cancer. However, endocrine therapy treated patients eventually experience relapse after a long period of estrogen deprivation. The mechanism underlying acquisition of estrogen independent growth by ER positive breast cancer cells remains unclear.

To understand such molecular mechanism, we used a cell model LTED (long term estrogen deprivation) which MCF7 cells were cultured under estrogen deprivation for 4-10 months. In LTED cells, we found that ER encoded gene ESR1 was up-regulated and ER overproduction was essential for estrogen-independent cell growth. We also revealed that RNA transcriptions of the ESR1 and several neighbor genes were co-induced from both coding and non-coding regions in LTED cells, using RNA-sequence. These highly transcribed regions were corresponded to active histone modifications and transcription factor bindings according to publically available genome-wide analyses data. Fluorescence in situ hybridization (FISH) analyses indicated that RNA from the chromatin domain region nearby ESR1 were co-localized and made foci in nucleus.

We found non-coding regions that are particularly highly transcribed. FISH analyses indicated that RNAs from these regions might interact with the parental ESR1 gene locus. Recent studies have shown that non-coding RNAs are involved in transcriptional regulation and chromatin regulation. To understand the role of the non-coding RNA, we have generated MCF7 cells lines that lack the non-coding site, using CRISPR/CAS9 system. We found that mRNA transcription of multiple genes including ESR1 were impaired by the deletion. These findings suggested that these non-coding RNAs may be involved in chromatin regulation of the chromatin domain nearby ESR1.

In this study, we found non-coding RNAs that control transcription of chromatin domain genes in ER positive breast cancer cells. Such non-coding RNA mediated transcriptional regulation might be critical for endocrine therapy resistance adaptation.

Citation Format: Fujiwara S, Saitoh N, Tomita S, Abdalla MO, Iwase H, Nakao M. Non-coding RNAs derived from near the ESR1 gene acts as a transcriptional regulator during estrogen deprivation adaptation of ER positive breast cancer cells. [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 P3-05-10.

Abstract P6-07-07: Clinical significance of ESR1 mutations using droplet digital polymerase chain reaction assay in 325 breast cancer samples

Purpose: We aimed to develop a droplet digital Polymerase Chain Reaction (ddPCR)-based method for the sensitive detection of estrogen receptor (ER) α (ESR1) mutations in the primary and recurrent/metastatic tumor tissues of breast cancer.

Experimental Design: We studied a total of 325 tumor specimens (270 primary breast cancer specimens and 55 ER-positive recurrent/metastatic tumor specimens). Because the recurrent/metastatic tumor specimens had much inflammatory and stromal cells, we captured only tumor cells using laser microdissection. We investigated the quantification of rare ESR1 mutations, four representative types, Y537S, Y537N, Y537C, and D538G in extracted genomic DNA using ddPCR system that simultaneously performed thousands of PCRs on a nanoliter scale.

Results: In 270 primary breast cancer samples, we analyzed each ESR1 alteration percentage in each subtype. ESR1 Y537C tended to be higher in hormone receptor-positive (HR+)/ human epidermal growth factor receptor 2-negative (HER2-) group (P = 0.06) and higher percentage of ESR1 D538G was statistically significant in HR+/ HER2- group (P = 0.027), compared with HER2+ group. There was no statistically different in each ESR1 alteration percentage between HR+/ HER2- group and HR-/ HER2- group. Whether each ESR1 alteration was dichotomized as positive or not, we used the percentage which HER2+ group and HR-/ HER2- were not identified, as a cutoff point. ESR1 mutations occurred in 7 samples (2.5%) out of 270 primary samples, but ESR1 mutations occurred in 11 samples (20%) out of 55 metastatic/ recurrent breast cancer samples.

Table 1 Patients characteristics of 11 metastatic ER-positive breast cancer cases with ESR1 mutationsCaseAge (years)HER2 statusKi67 LIER HSPgR HSBiopsy siteMutation472-102051Lymph nodeY537C 1610 A&gt;G only665-518218Lymph nodeY537S 1610 A&gt;C Y537N 1609 T&gt;A D538G 1613 A&gt;G1555-201105SkinY537C 1610 A&gt;G only1863-10162130Lymph nodeD538G 1613 A&gt;G only3354-417015Lymph nodeY537S 1610 A&gt;C Y537N 1609 T&gt;A D538G 1613 A&gt;G4268-516950SkinY537C 1610 A&gt;G only4466-24270159Lymph nodeY537N 1609 T&gt;A only4673-20224110Lymph nodeY537N 1609 T&gt;A and D538G 1613 A&gt;G4952-20275138SkinY537S 1610 A&gt;C and Y537C 1610 A&gt;G5040-101740Lymph nodeY537S 1610 A&gt;C only5140-101895IBTRY537S 1610 A&gt;C onlyAbbreviations: HER2, human epidermal growth factor receptor 2; LI, labeling index; ER, estrogen receptor; HS, histoscore; PgR, progesteron receptor; ET, endocrine therapy; IBTR, ipsilateral breast tumor recurrence; SD, stable disease; PD, progressive disease; MPA, medroxyprogesterone acetate

Two biopsies were performed in 8 women, in which four women had primary and recurrent/metastatic samples. Four out of these 8 women acquired ESR1 mutation, whereas no ESR1 mutation could be identified at first biopsy.

Conclusions: We demonstrated the sensitive detection and accurate quantification of low frequency ESR1 mutations in 270 primary breast cancer samples and 55 recurrent/metastatic samples using ddPCR assay. This technique could prove a useful method for the precise detection of ESR1 mutations in endocrine therapy resistant cases.

Citation Format: Takeshita T, Yamamoto Y, Yamamoto-Ibusuki M, Inao T, Sueta A, Fujiwara S, Iwase H. Clinical significance of ESR1 mutations using droplet digital polymerase chain reaction assay in 325 breast cancer samples. [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 P6-07-07.