Preoperative PET/CT in early-stage breast cancer

Phase II study of uPAR-PET/CT for staging of primary breast cancer in comparison with ultrasound and fine needle biopsies

Accurate initial staging of patients with breast cancer is essential for planning optimal treatment strategies. However, currently, no imaging modality is able to detect lymph node metastases preoperatively with sufficient reliability; therefore, the N status depends on the sentinel node procedure for ~ 70% of patients. In a prospective clinical trial of breast cancer patients, we compared head-to-head uPAR-PET/CT with current standard-of-care, ultrasound (US) and fine needle biopsy (FNB) as staging methods. Forty-nine patients (48 women and 1 man) with biopsy-proven early breast cancer underwent uPAR-PET/CT prior to surgery. All image data were analyzed by two separate teams, each consisting of a highly experienced certified specialist in nuclear medicine and a highly experienced certified specialist in radiology for visualization of primary tumor lesions and detection of lymph node and distant metastases. Histopathological assessment and verification of malignancy in the excised tissues (primary tumors and lymph nodes) were considered standard-of-truth. On a per patient basis, uPAR PET/CT demonstrated a sensitivity of 94% [CI: 83-99%] for detecting the primary tumor (both teams). For the detection of axillary lymph nodes the pooled sensitivity of uPAR PET/CT was 33.3% [CI: 16.5-54.0%], specificity 87.0% [CI: 66.4-97.2%] and accuracy 58.0% [CI: 43.2-71.8%]. In comparison, the standard-of-care preoperative clinical staging algorithm with US and FNB had a sensitivity of 41% [CI: 22-61%] and specificity of 100% [CI: 85-100%] for axillary lymph node metastases. We conclude that the results do not support the use of uPAR PET/CT for staging in breast cancer patients. However, the finding that 94% of primary tumors were uPAR-PET positive may be encouraging for pursuing uPAR theranostics in localized disease. Additionally, other potential applications, such as using uPAR-PET as a prognostic imaging biomarker of tumor aggressiveness, remain to be investigated.

Joint EANM-SNMMI guideline on the role of 2-[18F]FDG PET/CT in no special type breast cancer : (endorsed by the ACR, ESSO, ESTRO, EUSOBI/ESR, and EUSOMA)

INTRODUCTION

There is much literature about the role of 2-[18F]FDG PET/CT in patients with breast cancer (BC). However, there exists no international guideline with involvement of the nuclear medicine societies about this subject.

PURPOSE

To provide an organized, international, state-of-the-art, and multidisciplinary guideline, led by experts of two nuclear medicine societies (EANM and SNMMI) and representation of important societies in the field of BC (ACR, ESSO, ESTRO, EUSOBI/ESR, and EUSOMA).

METHODS

Literature review and expert discussion were performed with the aim of collecting updated information regarding the role of 2-[18F]FDG PET/CT in patients with no special type (NST) BC and summarizing its indications according to scientific evidence. Recommendations were scored according to the National Institute for Health and Care Excellence (NICE) criteria.

RESULTS

Quantitative PET features (SUV, MTV, TLG) are valuable prognostic parameters. In baseline staging, 2-[18F]FDG PET/CT plays a role from stage IIB through stage IV. When assessing response to therapy, 2-[18F]FDG PET/CT should be performed on certified scanners, and reported either according to PERCIST, EORTC PET, or EANM immunotherapy response criteria, as appropriate. 2-[18F]FDG PET/CT may be useful to assess early metabolic response, particularly in non-metastatic triple-negative and HER2+ tumours. 2-[18F]FDG PET/CT is useful to detect the site and extent of recurrence when conventional imaging methods are equivocal and when there is clinical and/or laboratorial suspicion of relapse. Recent developments are promising.

CONCLUSION

2-[18F]FDG PET/CT is extremely useful in BC management, as supported by extensive evidence of its utility compared to other imaging modalities in several clinical scenarios.

High-dose chemotherapy with stem cell rescue to treat stage III homologous deficient breast cancer: factors influencing clinical implementation

BACKGROUND

High-dose chemotherapy with autologous stem cell rescue (HDCT) is a promising treatment for patients with stage III, HER2-negative, homologous recombination deficient (HRD) breast cancer. Clinical effectiveness and cost-effectiveness are currently under investigation in an international multicenter randomized controlled trial. To increase the chance of successful introduction of HDCT into daily clinical practice, we aimed to identify relevant factors for smooth implementation using an early comprehensive assessment framework.

METHODS

This is a qualitative, multi-stakeholder, exploratory research using semi-structured interviews guided by the Constructive Technology Assessment model, which evaluates the quality of a novel health technology by clinical, economic, patient-related, and organizational factors. Stakeholders were recruited by purposeful stratified sampling and interviewed until sufficient content saturation was reached. Two researchers independently created themes, categories, and subcategories by following inductive coding steps, these were verified by a third researcher.

RESULTS

We interviewed 28 stakeholders between June 2019 and April 2021. In total, five overarching themes and seventeen categories were identified. Important findings for optimal implementation included the structural identification and referral of all eligible patients, early integration of supportive care, multidisciplinary collaboration between- and within hospitals, (de)centralization of treatment aspects, the provision of information for patients and healthcare professionals, and compliance to new regulation for the BRCA1-like test.

CONCLUSIONS

In anticipation of a positive reimbursement decision, we recommend to take the highlighted implementation factors into consideration. This might expedite and guide high-quality equitable access to HDCT for patients with stage III, HER2-negative, HRD breast cancer in the Netherlands.

Role of 18F-FDG PET/CT in evaluation of recently diagnosed breast cancer patients

Background

Breast cancer is the most frequent malignant disease in women and usually affects people of all ages, races, socioeconomic classes, and geographic locations. Once breast cancer is diagnosed, tumor staging should be assessed precisely before treatment and prognosis could be determined. The purpose of this study was to determine the diagnostic usefulness of PET/CT in the initial assessment of patients with newly diagnosed breast cancer who were referred for tumor staging, pre-therapeutic or preoperative evaluation.

Results

In the examined 50 patients, PET/CT has higher sensitivity and accuracy compared to CT alone (reaching 100% for PET/CT and 96% for CT) in detecting malignant breast lesions, regional and distant nodal deposits as well as distant deposits, with subsequent upstaging in two patients.

Conclusions

18F-FDG PET/CT is a single valuable technique that detects metastatic illness in newly diagnosed breast cancer patients in an efficient, accurate, and noninvasive manner, resulting in modification of the initial staging, which in turn reflected on the patients' therapeutic plans.

Dual-Mode Tumor Imaging Using Probes That Are Responsive to Hypoxia-Induced Pathological Conditions

Hypoxia in solid tumors is associated with poor prognosis, increased aggressiveness, and strong resistance to therapeutics, making accurate monitoring of hypoxia important. Several imaging modalities have been used to study hypoxia, but each modality has inherent limitations. The use of a second modality can compensate for the limitations and validate the results of any single imaging modality. In this review, we describe dual-mode imaging systems for the detection of hypoxia that have been reported since the start of the 21st century. First, we provide a brief overview of the hallmarks of hypoxia used for imaging and the imaging modalities used to detect hypoxia, including optical imaging, ultrasound imaging, photoacoustic imaging, single-photon emission tomography, X-ray computed tomography, positron emission tomography, Cerenkov radiation energy transfer imaging, magnetic resonance imaging, electron paramagnetic resonance imaging, magnetic particle imaging, and surface-enhanced Raman spectroscopy, and mass spectrometric imaging. These overviews are followed by examples of hypoxia-relevant imaging using a mixture of probes for complementary single-mode imaging techniques. Then, we describe dual-mode molecular switches that are responsive in multiple imaging modalities to at least one hypoxia-induced pathological change. Finally, we offer future perspectives toward dual-mode imaging of hypoxia and hypoxia-induced pathophysiological changes in tumor microenvironments.

The Relationship between Pathological Features and 18F-FDG PET/CT that Changed the Surgeon's Decision as Neoadjuvant Therapy in Breast Cancer

Objective  Patients diagnosed with breast cancer and decided to undergo surgical treatment can undergo neoadjuvant therapy following their 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography/computed tomography ( ¹⁸ F-FDG PET/CT) findings. The present study aims to determine the statistical significance of these patients whose treatment plan was changed and the reasons for the change in the plan.

Materials and Methods  The demographic features and treatment plans of 151 cases who were diagnosed with any stage of breast cancer were evaluated. These patients consist of those who admitted to Mersin University Hospital Breast Outpatient Clinic between January 2016 and December 2019. All of these patients aged between 41 and 85 years were examined with ¹⁸ F-FDG PET/CT after the decision for surgical treatment is made. The analysis included tumor pathology, side, type, subtype, size, and centricity in this study.

Results  About 18.5% ( n  = 28) of patients' treatment plan was changed after ¹⁸ F-FDG PET/CT. They received neoadjuvant therapy. About 81.5% ( n  = 123) of patients did not receive neoadjuvant therapy. Significant differences were observed between patients changed treatment plan and not changed concerning age, lymph node involvement, tumor size, centricity, and subtypes parameters.

Conclusion  Conventional imaging examinations are used in patients with breast cancer. These examinations may not be sufficient to determine advanced disease requiring neoadjuvant treatment. With ¹⁸ F-FDG PET/CT examination, these advanced stage patients are not overlooked. In our study, approximately one in five patients, treatment plan changed after ¹⁸ F-FDG PET/CT examination.

Synchronous Malignancies Identified by PET-CT Scan in Breast Cancer Patients

Breast cancer is a common malignancy and a common cause of cancer-related mortality in women. Pre-treatment workup of breast cancer does not routinely include positron emission tomography scans. We aimed to review cases of women with breast cancer and a synchronous second primary malignancy. We present three cases of women with non-metastatic cancer in whom a synchronous second primary malignancy was found. Synchronous, second primary malignancies which were identified included rectal cancer, gastrointestinal stromal tumor, and non-small cell lung cancer. All second primary malignancies were identified by a PET-CT scan. In conclusion, PET-CT may be used for detection of secondary primary malignancies in select breast cancer patients.

Diagnostic Performance of FDG-PET/CT Scan as Compared to US-Guided FNA in Prediction of Axillary Lymph Node Involvement in Breast Cancer Patients

Purpose

The aim of this study was to evaluate the diagnostic ability of 2-deoxy-2-[fluorine-18]fluoro-d-glucose (¹⁸F-FDG) PET/non-contrast CT compared with those of ultrasound (US)-guided fine needle aspiration (FNA) for axillary lymph node (ALN) staging in breast cancer patients.

Patients and Methods

Preoperative ¹⁸F-FDG PET/non-contrast CT was performed in 268 women with breast cancer, as well as ALN dissection or sentinel lymph node (SLN) biopsy. One hundred sixty-four patients underwent US-guided FNA in combination with ¹⁸F-FDG PET/CT. The diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. The receiver operating characteristic (ROC) curves were compared to evaluate the diagnostic ability of several imaging modalities.

Results

Axillary ¹⁸F-FDG uptake was positive in 180 patients, and 125 patients had axillary metastases according to the final pathology obtained by ALN dissection and/or SLN dissection. Of the patients with positive ¹⁸F-FDG uptake in the axilla, 21% had false-positive results, whereas 79% were truly positive. Eighty-eight patients had negative ¹⁸F-FDG uptake in the axilla, among which 25% were false-negative. ¹⁸F-FDG-PET/CT had a sensitivity of 86.59% and a specificity of 63.46% in the assessment of ALN metastasis; on the other hand, US-guided FNA had a sensitivity of 91.67% and a specificity of 87.50%. The mean primary cancer size (p = 0.04) and tumor grade (p = 0.04) in combination were the only factors associated with the accuracy of ¹⁸F-FDG PET/CT for detecting metastatic ALNs.

Conclusion

The diagnostic performance of ¹⁸F-FDG PET/CT for the detection of axillary node metastasis in breast cancer patients was not significantly different from that of US-guided FNA. Combining ¹⁸F-FDG PET/CT with US-guided FNA or SLN biopsy could improve the diagnostic performance compared to ¹⁸F-FDG PET/CT alone.

Aptamer Embedded Arch-Cruciform DNA Assemblies on 2-D VS2 Scaffolds for Sensitive Detection of Breast Cancer Cells

Arch-cruciform DNA are self-assembled on AuNPs/VS₂ scaffold as a highly sensitive and selective electrochemical biosensor for michigan cancer foundation-7 (MCF-7) breast cancer cells. In the construction, arch DNA is formed using two single-strand DNA sequences embedded with the aptamer for MCF-7 cells. In the absence of MCF-7 cells, a cruciform DNA labeled with three terminal biotin is bound to the top of arch DNA, which further combines with streptavidin-labeled horseradish peroxidase (HRP) to catalyze the hydroquinone-H₂O₂ reaction on the electrode surface. The presence of MCF-7 cells can release the cruciform DNA and reduce the amount of immobilized HRP, thus effectively inhibiting enzyme-mediated electrocatalysis. The electrochemical response of the sensor is negatively correlated with the concentration of MCF-7 cells, with a linear range of 10~1 × 10⁵ cells/mL, and a limit of detection as low as 5 cells/mL (S/N = 3). Through two-dimensional materials and enzyme-based dual signal amplification, this biosensor may pave new ways for the highly sensitive detection of tumor cells in real samples.

Prognostic value of SUVmax in breast cancer and comparative analyses of molecular subtypes: A systematic review and meta-analysis

BACKGROUND

To assess the prognostic capability of the maximum standardized uptake values (SUVmax) measured in the primary tumor and axillary lymph nodes (ALNs) by pretreatment fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography and analyze outcomes according to the molecular breast cancer subtypes.

METHODS

The databases were systematically searched using keywords for breast cancer, positron emission tomography/computed tomography, and SUVmax; the extracted studies reported at least 1 form of survival data, event-free survival (EFS) and overall survival. Comparative analyses of the pooled hazard ratios (HRs) for EFS and overall survival were performed to assess their correlations with SUVmax. The pooled HR was estimated using random-effects model according to the results of heterogeneity.

RESULTS

Thirteen eligible studies comprising 3040 patients with breast cancer were included. The pooled HRs of high SUVmax in the primary tumor and ALN were 3.01 (95% CI 1.83-4.97, P < .00001; I2 = 82%) and 3.72 (95% CI 1.15-12.01; I2 = 92%; P = .03), respectively. Patients with higher SUVmax demonstrated a poorer survival prognosis. Furthermore, comparative analyses according to the molecular subtypes demonstrated that the SUVmax in the primary tumor or ALN can be a predictive parameter in patients with the luminal subtype disease. Subtype analysis results indicated a significant association of the luminal group, with a HR of 2.65 (95% CI 1.31-5.37; I2 = 27%; P = .007).

CONCLUSIONS

SUVmax from pretreatment is a significant prognostic factor for EFS in patients with breast cancer. Despite several limitations, correlation with molecular subtype (luminal type) was demonstrated. Further large-scale studies are required to investigate the precise prognostic capability of SUVmax.

Prognostic value of metabolic tumor volume and total lesion glycolysis in breast cancer: a meta-analysis

OBJECTIVES

PET using F-fluorodeoxyglucose (FDG) has proven to be valuable in staging and monitoring of treatment response in breast cancer. We aimed to assess the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) in patients with breast cancer.

METHODS

A systematic search of MEDLINE and EMBASE was performed using the keywords of breast cancer, PET, and volume. Inclusion criteria were F-FDG PET used as an initial imaging tool; studies limited to patients with breast cancer who had not undergone any treatment before PET scans; and studies reporting survival data. Event-free survival (EFS) and overall survival (OS) were considered markers of outcome.

RESULTS

Nine studies comprising 975 patients were included in this study. The pooled hazard ratio (HR) for adverse events was 33.73 (P < 0.00001; I = 0%) with MTV from primary tumor and 2.89 (P < 0.00001; I = 45%) with TLG from primary tumor, meaning that primary tumors with high volumetric parameters were associated with progression or recurrence. However, the combined HRs for EFS of MTV, and TLG, and those for OS of MTV from whole-body tumor were NS. The pooled HR for OS of TLG from whole-body tumor was 2.95 (P = 0.18; I = 71%).

CONCLUSION

Volumetric parameters from F-FDG PET are significant prognostic factors for outcome in patients with breast cancer. Patients with a high MTV or TLG from primary tumor have a higher risk of adverse events. Patients with a high TLG from whole-body tumor have a higher risk of deaths.

PET/CT in breast cancer staging is useful for evaluation of axillary lymph node and distant metastases

INTRODUCTION

Breast cancer outcome is dependent on disease stage. The aim of the study was to assess the role of PET/CT in the evaluation of axillary lymph node and distant metastases in women with newly diagnosed primary breast cancer.

MATERIALS AND METHODS

We assessed, among patients with newly diagnosed primary breast cancer, associations of [¹⁸F] fluorodeoxyglucose (FDG) uptake (maximum standardized uptake value [SUV_max]) with clinical variables of the primary tumor, including regional nodal status and the presence of distant metastases.

RESULTS

Of 324 patients, 265 (81.8%) had focal uptake of FDG that corresponded with the cancerous lesion, and 21 (6.5%) had no FDG-avid findings. The remaining 38 patients had diffuse or nonspecific uptake of FDG. Among patients with a focal uptake of FDG (n = 265), the mean tumor size was 2.6 ± 1.9 (range 0.5-13.5), and the mean SUV_max was 5.3 ± 4.9 (range 1.2-25.0). In 83 patients (25.6%), PET/CT demonstrated additional suspected foci in the same breast. FDG-avid lymphadenopathy was observed in 156 patients (48.1%). Further assessment of lymph node involvement was available for 55/156 patients (axillary lymph node dissection [n = 21]; core needle biopsy [n = 34]) and confirmed axillary lymph node metastases in 47 (85.5%)). Thirteen patients (4.0%) had FDG-avid supraclavicular lymph nodes and six (1.9%) had FDG-avid internal mammary lymph nodes. Distant FDG-avid lesions were detected in 33 patients (10.2%).

CONCLUSION

PET/CT is a useful diagnostic tool for staging breast cancer patients, but its use should be limited to specific clinical situations; further evaluation is needed.

Impact of 18F-FDG PET, PET/CT, and PET/MRI on Staging and Management as an Initial Staging Modality in Breast Cancer: A Systematic Review and Meta-analysis

OBJECTIVES

We performed a systematic review and meta-analysis to evaluate the impact of 18F-FDG PET, PET/CT, and PET/MRI on staging and management during the initial staging of breast cancer.

METHODS

We searched the PubMed, Embase, Cochrane Library, and KoreaMed databases until March 2020 to identify studies that reported the proportion of breast cancer patients whose clinical stage or management were changed after PET scans. The proportion of changes was pooled using a random-effects model. Subgroup and metaregression analyses were performed to explore heterogeneity.

RESULTS

We included 29 studies (4276 patients). The pooled proportions of changes in stage and management were 25% (95% confidence interval [CI], 21%-30%) and 18% (95% CI, 14%-23%), respectively. When stage changes were stratified according to initial stage, the pooled proportions were 11% (95% CI, 3%-22%) in stage I, 20% (95% CI, 16%-24%) in stage II, and 34% (95% CI, 27%-42%) in stage III. The relative proportions of intermodality and intention-to-treat changes were 74% and 70%, respectively. Using metaregression analyses, the mean age and the proportion of initial stage III to IV and histologic grade II to III were significant factors affecting the heterogeneity in changes in stage or management.

CONCLUSIONS

Currently available literature suggests that the use of 18F-FDG PET, PET/CT, or PET/MRI leads to significant modification of staging and treatment in newly diagnosed breast cancer patients. Therefore, there may be a role for routine clinical use of PET imaging for the initial staging of breast cancer.

Impact of molecular subtype on 1325 early-stage breast cancer patients homogeneously treated with hypofractionated radiotherapy without boost: Should the indications for radiotherapy be more personalized?

Aim

We report molecular subtype impact on 1325 early breast cancer (BCa) patients treated with whole breast hypofractionated (WBH) adjuvant forward-planned intensity modulated radiotherapy (F-IMRT) without boost.

Methods and materials

From 02/2009-05/2017 1325 patients with pTis-pT3, pNx-N1aM0 BCa who underwent breast conservation surgery were treated with WBHF-IMRT in our institute, to a total dose of 40 Gy/15 fractions, without boost. Median age: 62 (interquartile range-IQR-:51.14–70.53) years. Histology: 8% in situ carcinoma (ISC), 92% invasive tumors. Molecular subtypes (invasive tumors): 49.9% Luminal A, 33.1% Luminal B Her2 negative (−), 6.2% Luminal B Her2 positive (+), 3.6% Hormone Receptor (HR)- Her2+, 7.1% Triple negative (TNBC), and 0.2% HR+. Chemotherapy (CT) was prescribed in 28% of patients, hormonal therapy in 80.3%, monoclonal antibodies (MAb) in 86.8% of Luminal B Her2+ and 97.7% of HR- Her2+ patients.

Results

Median follow up was 72.43 (IQR: 44.63–104.13) months. The 5-year Kaplan-Meier estimates of local relapse-free survival (LRFS) was 97.8%, regional-(RRFS) 98.6%, loco-regional- (LRRFS) 96.9%, distant- (DRFS) 96.6%, disease-free survival (DFS) 94.8% and overall survival (OS) 95.5%. Considering molecular subtypes, 5-year LRFS was: 99.8% for Luminal A, 96.7% for Luminal B Her2-, 94.1% for Luminal B Her2+, 87.9% for HR- Her2+, 95.1% for TNBC and 99.1% for in situ carcinoma.

Conclusion

While the overall estimated probability of LR within 5 years after WBHF-IMRT without boost is good (2.2%), molecular subtypes have a strong impact, despite MAb therapy in Her2+ patients, and CT for TNBC patients, and could be used as a parameter in deciding the boost prescription.

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Hypofractionated three-weeks radiotherapy ensures good local control whitout boost.

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In 1325 early stage breast cancers 5-year local relapse without boost was 2.2%.

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Molecular subtypes have a strong impact on estimated probability of local relapse.

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5-year local control (LC) was 99.8% for Luminal A vs 87.9% for HR- Her2+.

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5-year LC was 96.7% for Luminal B Her2-, 94.1% for Luminal B Her2+, 95.1% for TNBC.

PET-CT upstaging of unilateral operable breast cancer and its correlation with molecular subtypes

Context:

Prognosis and survival rates for breast cancer vary greatly depending on the cancer stage of the patient. Instead of a step-by-step approach using multiple investigations, we can get all the information about the metastatic load of the disease in PET-CT imaging by one single investigation. There is also a correlation between prognosis, FDG uptake, and molecular subtype of breast cancer (Luminal A, Luminal B, Human epidermal growth factor receptor 2 (HER2) positive and Triple-negative). Pre-treatment baseline PET-CT scan was done in 156 unilateral early and operable breast cancer patients from November 2017 to April 2019 in our prospective observational study.

Aims:

To evaluate the utility of PET-CT in staging and upstaging of early and operable breast cancer by detection of unsuspected lymph nodes and distant organ metastases.

To determine the prognostic association between SUVmax of the primary breast lesion in the upstaged cases and the molecular subtypes.

Results:

Thus, PET-CT can serve as one-stop imaging in unilateral operable early breast cancer patients for upstaging and prognostication based on the correlation of SUVmax with molecular subtypes of breast lesions in patients who will surely benefit from whole-body imaging.

Out of 156 patients, approximately 27 patients were upstaged after pre-treatment PET CT.

Six patients were upstaged to stage IIIC and 21 patients were upstaged to IV.

Regional nodes like internal mammary and supraclavicular nodes were detected in 7 patients and 5 patients, respectively, out of 156 patients.

Non-regional distant nodes and organ metastases were detected in 11 and 18 patients out of 156 patients.

Most common molecular subtype detected in the upstaged cases in our study was Luminal A (13 patients) followed by Triple negative (6), Luminal B (3) and HER2-neu-positive subtypes (1).

Conclusions:

FDG PET-CT is a substantial modality to provide information on regional, non regional lymph nodes and distant metastases in early operable breast cancer.

It helps in evaluating the whole body metastatic burden in a single sitting, therefore, reducing the need for multiple investigations.

SUVmax association of the index lesion with molecular subtype in the FDG PET scanning can serve as a prognostication factor in operable early breast cancer patients.

18F-FDG PET is Superior to WHO Grading as a Prognostic Tool in Neuroendocrine Neoplasms and Useful in Guiding PRRT: A Prospective 10-Year Follow-up Study

Accurate grading of patients with neuroendocrine neoplasms (NENs) is essential for risk stratification and optimal choice of therapy. Currently, grading is based on histologically assessed degree of tumor proliferation. The aim of the present study was to assess the long-term prognostic value of ¹⁸F-FDG PET imaging for risk stratification of NENs and compare it with tumor grading (World Health Organization 2010 classification). Methods: We conducted a prospective cohort study evaluating the prognostic value of ¹⁸F-FDG PET imaging and compared it with histologic grading. Enrolled were 166 patients of all grades and with histologically confirmed NENs of gastroenteropancreatic origin. The primary endpoint was overall survival (OS). Progression-free survival (PFS) was a secondary endpoint. In addition, OS in relation to peptide receptor radionuclide therapy (PRRT) was analyzed as an exploratory endpoint. The median follow-up time was 9.8 y. Results: Analysis of the whole cohort revealed that a positive ¹⁸F-FDG PET scan was associated with a shorter OS than a negative ¹⁸F-FDG PET scan (hazard ratio: 3.8; 95% CI: 2.4-5.9; P < 0.001). In G1 and G2 patients (n = 140), a positive ¹⁸F-FDG PET scan was the only identifier of high risk for death (hazard ratio: 3.6; 95% CI, 2.2-5.9; P < 0.001). In multivariate analysis, ¹⁸F-FDG PET, G3 tumor, ≥2 liver metastases, and ≥2 prior therapies were independent prognostic factors for OS, and ¹⁸F-FDG PET, G3 tumor, and ≥3 liver metastases were independent prognostic factors for PFS. For patients receiving PRRT, ¹⁸F-FDG-negative cases had a significantly longer survival than ¹⁸F-FDG-positive cases, whereas no difference was identified for tumor grading. ¹⁸F-FDG-positive patients receiving PRRT had a significantly longer median survival than patients not receiving PRRT (4.4 vs. 1.4 y, P = 0.001), whereas no difference was seen for ¹⁸F-FDG-negative patients. Conclusion: ¹⁸F-FDG PET is useful for risk stratification of all NEN grades and is superior to histologic grading. ¹⁸F-FDG PET could differentiate G1 and G2 tumors into low- and high-risk groups. In the selection of therapy and for risk stratification of NEN patients, ¹⁸F-FDG PET status should be considered.

Correlation Between 18F-FDG PET/CT Findings and BI-RADS Assessment Using Ultrasound in the Evaluation of Breast Lesions: A Multicenter Study

RATIONALE AND OBJECTIVES

To analyze the correlation between ultrasound breast imaging reporting and data system (BI-RADS) category and fluorodeoxyglucose [¹⁸F] (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) findings and their value in breast lesion diagnosis.

MATERIALS AND METHODS

Cases involving hypermetabolic lesions identified by ¹⁸F-FDG PET/CT and ultrasound were retrospectively analyzed. The correlation between the maximum standardized uptake values (SUV_max) of the lesions and the BI-RADS grades was calculated. Histologic diagnosis or evidence at the end of a 2-year follow-up as the standard of truth were analyzed to determine the sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) of the diagnostic methods. Area under the curve (AUC) of BI-RADS, SUV_max, and BI-RADS/SUV_max combined were obtained using receiver-operating characteristic curve (ROC) analysis.

RESULTS

Of 206 cases, 92 were benign and 114 were malignant. The difference between the SUV_max and the BI-RADS grades was statistically significant (p < 0.001). The critical value of the optimal SUV_max was 2.325, and the accuracy, sensitivity, specificity, PPV, and NPV were 84.5%, 91.2%, 76.1%, 82.5%, and 87.5%, respectively. For diagnosis using BI-RADS, these values were 85.9%, 98.2%, 70.7%, 80.6%, and 97.0%, respectively. ROC analysis of 206 breast lesions for distinguishing benign from malignant lesions yielded AUCs of 0.948, 0.896, and 0.977 for BI-RADS, SUV_max, and BI-RADS/SUV_max combined, respectively. The critical value of the optimal SUV_max in grade 3 and 4 lesions (as determined using BI-RADS) was 2.705, and the accuracy, sensitivity, specificity, PPV, and NPV were 82.6%, 77.8%, 85.7%, 77.8%, and 85.7%, respectively. For diagnosis using BI-RADS in cases with grade 3 and 4 lesions, these values were 68.5%, 94.4%, 51.8%, 55.7%, and 93.5%, respectively. In ROC analysis for distinguishing benign from malignant for BI-RADS grade 3-4 lesions, the AUC of BI-RADS, SUV_max, and BI-RADS/SUV_max combined were 0.731, 0.859, and 0.882, respectively.

CONCLUSION

Both ¹⁸F-FDG PET/CT and ultrasound-dependent BI-RADS grading are effective for diagnosing breast lesions. However, in cases of BI-RADS grades 3 and 4, ¹⁸F-FDG PET/CT has better specificity and may be useful for further differential diagnosis.

Baseline staging imaging for distant metastasis in women with stages I, II, and III breast cancer

Background

In Ontario, there is no clearly defined standard of care for staging for distant metastasis in women with newly diagnosed and biopsy-confirmed breast cancer whose clinical presentation is suggestive of early-stage disease. This guideline addresses baseline imaging investigations for women with newly diagnosed primary breast cancer who are otherwise asymptomatic for distant metastasis.

Methods

The medline and embase databases were systematically searched for evidence from January 2000 to April 2019, and the best available evidence was used to draft recommendations relevant to the use of baseline imaging investigation in women with newly diagnosed primary breast cancer who are otherwise asymptomatic. Final approval of this practice guideline was obtained from both the Staging in Early Stage Breast Cancer Advisory Committee and the Report Approval Panel of the Program in Evidence-Based Care.

Recommendations

These recommendations apply to all women with newly diagnosed primary breast cancer (originating in the breast) who have no symptoms of distant metastasis Staging tests using conventional anatomic imaging [chest radiography, liver ultrasonography, chest-abdomen-pelvis computed tomography (ct)] or metabolic imaging modalities [integrated positron-emission tomography (pet)/ct, integrated pet/magnetic resonance imaging (mri), bone scintigraphy] should not be routinely ordered for women newly diagnosed with clinical stage i or stage ii breast cancer who have no symptoms of distant metastasis, regardless of biomarker status. In women newly diagnosed with stage iii breast cancer, baseline staging tests using either anatomic imaging (chest radiography, liver ultrasonography, chest-abdomen-pelvis ct) or metabolic imaging modalities (pet/ct, pet/mri, bone scintigraphy) should be considered regardless of whether the patient is symptomatic for distant metastasis and regardless of biomarker profile.

Impact of 18F-FDG PET/MR on therapeutic management in high risk primary breast cancer patients - A prospective evaluation of staging algorithms

PURPOSE

To investigate whether potential differences in staging between a traditional staging imaging algorithm and ¹⁸F-FDG PET/MR lead to a change in patient management in breast carcinoma and to compare the diagnostic accuracy between the traditional staging algorithm and ¹⁸F-FDG PET/MR for the TNM classification.

METHOD

In this prospective cohort study from two university hospitals 56 women with newly diagnosed, therapy-naive breast cancer and increased pre-test probability for distant metastases were included. All patients were examined by a traditional staging imaging algorithm (X-ray mammography, breast ultrasonography, chest plain radiography, bone scintigraphy, and ultrasonography of the liver and axillary fossa) and whole-body ¹⁸F-FDG PET/MR including dedicated ¹⁸F-FDG PET/MR breast examinations. Each patient was discussed two times in a separate tumor board session to determine a total of three therapy recommendations based on histopathological data of the primary tumor and (1) traditional algorithm only, (2) traditional algorithm and ¹⁸F-FDG PET/MR, and (3) ¹⁸F-FDG PET/MR only. Major changes in therapy recommendations and differences between the traditional staging algorithm and ¹⁸F-FDG PET/MR for the TNM classification were evaluated.

RESULTS

Staging by ¹⁸F-FDG PET/MR led to a difference in treatment compared the traditional staging algorithm in 8/56 cases (14%). Therapy changes included therapy of the breast, locoregional nodes and systemic therapy. A trend to staging superiority was found for ¹⁸F-FDG PET/MRI without statistical significance (p = 0.3827).

CONCLUSION

In conclusion, for breast cancer patients with elevated pre-test probability for distant metastases a change of the therapy regiment occurs in 14 % of patients when staged by ¹⁸F-FDG PET/MR and confirmed by histopathology compared to a traditional staging algorithm. In particular with regard to the amendment of the guideline further assessment of ¹⁸F-FDG-PET/MR in this setting is necessary to assess the true value of this modality.

18F-fluorodeoxyglucose PET/computed tomography in locoregional staging and assessment of biological and clinical aggressiveness of breast cancer subtypes

OBJECTIVE

We aimed to evaluate the availability of fluorine-18-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in initial axillary lymph node (ALN) staging in breast cancer. The secondary objective is to evaluate the role of FDG PET/CT as a pretest in sentinel lymph node biopsy vs. axillary lymph node dissection when predicting disease aggressiveness.

METHODS

The study evaluated retrospectively 194 breast cancer patients who underwent preoperative 18F-FDG. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of FDG PET/CT for ALN metastases were confirmed with histopathology as the gold standard.

RESULTS

The value of the area under curve (AUC), sensitivity and specificity for ALN metastases were determined as 0.847, 78.8% and 92.6%, respectively. The cut-off value of the maximum standardized uptake value (SUVmax) for metastatic ALN detection was calculated as 1.79. PPV, NPV and the accuracy of 18F-FDG PET/CT were 0.933 (93.3%), 0.75 (75%) and 0.837 (83.7%), respectively. The SUVmax value of the primary lesion was significantly correlated with grade, estrogen receptor (ER) status, progesterone receptor (PR) status, SUVmax value of metastatic ALN, Her-2 status and Ki-67 level. Molecular subtypes revealed no statistically significant difference in terms of mean SUVmax value.

CONCLUSION

High values of AUC, sensitivity, specificity, NPV and PPV encourage utilization of PET/CT for locoregional staging of nonmetastatic breast carcinoma. The significant correlation between the primary tumor SUVmax value and grade, ER status, PR status and Ki-67 level increases the prognostic predictive value of the preoperative PET/CT.

Electrochemical cytosensors for detection of breast cancer cells

Breast cancer is one of lethal cancers among women with its metastasis leading to cancer-related morbidity and mortality. Circulating tumor cells (CTCs) derived from a primary tumor can be detected in the venous blood of cancer patients. Monitoring CTCs in blood samples has increased exponentially over the past decades and holds great promise in the diagnosis and treatment of metastatic breast cancer. Electrochemical cytosensors, classified as a class of electrochemical biosensors for sensitive detection and enumeration of targeted cells with minimally invasive methods, have the advantages of electrochemical biosensors, such as simplicity, low cost, and low limit of detection. Here, we review recent progress in the detection of CTCs from breast cancer with a focus on electrochemical cytosensors. This review describes platforms benefiting from these cytosensors to identify cancerous breast cells. Furthermore, strategies for signal amplification and also generation of reusable electrochemical cytosensors are introduced. In addition, breast cancer markers and biorecognition elements for cell capturing are reviewed.

The Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer Screening and Diagnosis, 2018 Edition

This article updates readers as to what is new in the Japanese Breast Cancer Society Clinical Practice Guidelines for Breast Cancer Screening and Diagnosis, 2018 Edition. Breast cancer screening issues are covered, including matters of breast density and possible supplemental modalities, along with appropriate pre-operative/follow-up diagnostic breast imaging tests. Up-to-date clinical practice guidelines for breast cancer screening and diagnosis should help to provide patients and clinicians with not only evidence-based breast imaging options, but also accurate and balanced information about the benefits and harms of intervention, which ultimately enables shared decision making about imaging test plans.

The Evolving Role of FDG-PET/CT in the Diagnosis, Staging, and Treatment of Breast Cancer

The applications of 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/X-ray computed tomography (PET/CT) in the management of patients with breast cancer have been extensively studied. According to these studies, PET/CT is not routinely performed for the diagnosis of primary breast cancer, although PET/CT in specific subtypes of breast cancer correlates with histopathologic features of the primary tumor. PET/CT can detect metastases to mediastinal, axial, and internal mammary nodes, but it cannot replace the sentinel node biopsy. In detection of distant metastases, this imaging tool may have a better accuracy in detecting lytic bone metastases compared to bone scintigraphy. Thus, PET/CT is recommended when advanced-stage disease is suspected, and conventional modalities are inconclusive. Also, PET/CT has a high sensitivity and specificity to detect loco-regional recurrence and is recommended in asymptomatic patients with rising tumor markers. Numerous studies support the future role of PET/CT in prediction of response to neoadjuvant chemotherapy (NAC). PET/CT has a higher diagnostic value for prognostic risk stratification in comparison with conventional modalities. With the continuing research on the treatment planning and evaluation of patients with breast cancer, the role of PET/CT can be further extended.

18F-FDG PET/CT in breast cancer: Evidence-based recommendations in initial staging

Current guidelines do not systematically recommend 18F-FDG PET/CT for breast cancer staging; and the recommendations and level of evidence supporting its use in different groups of patients vary among guidelines. This review summarizes the evidence about the role of 18F-FDG PET/CT in breast cancer staging and the therapeutic and prognostic impact accumulated in the last decade. Other related aspects, such as the association of metabolic information with biology and prognosis are considered and evidence-based recommendations for the use of 18F-FDG PET/CT in breast cancer staging are offered. We systematically searched MEDLINE for articles reporting studies with at least 30 patients related to clinical questions following the Problem/Population, Intervention, Comparison, and Outcome framework. We critically reviewed the selected articles and elaborated evidence tables structuring the summarized information into methodology, results, and limitations. The level of evidence and the grades of recommendation for the use of 18F-FDG PET/CT in different contexts are summarized. Level III evidence supports the use of 18F-FDG PET/CT for initial staging in patients with recently diagnosed breast cancer; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a weak recommendation in this population. In patients with locally advanced breast cancer, level II evidence supports the use of 18F-FDG PET/CT for initial staging; the diagnostic and therapeutic impact of the 18F-FDG PET/CT findings is sufficient for a strong recommendation in this population. In patients with recently diagnosed breast cancer, the metabolic information from baseline 18F-FDG PET/CT is associated with tumor biology and has prognostic implications, supported by level II evidence. In conclusion, 18F-FDG PET/CT is not recommended for staging all patients with early breast cancer, although evidence of improved regional and systemic staging supports its use in locally advanced breast cancer. Baseline tumor glycolytic activity is associated with tumor biology and prognosis.

Preoperative [18]fluorodeoxyglucose-positron emission tomography/computed tomography in early stage breast cancer: Rates of distant metastases

AIM

To investigate rates of distant metastases (DM) detected with [18]fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT) in early stage invasive breast cancer.

METHODS

We searched the English language literature databases of PubMed, EMBASE, ISI Web of Knowledge, Web of Science and Google Scholar, for publications on DM detected in patients who had 18FDG-PET/CT scans as part of the staging for early stages of breast cancer (stage I and II), prior to or immediately following surgery. Reports published between 2011 and 2017 were considered. The systematic review was conducted according to the PRISMA guidelines.

RESULTS

Among the 18 total studies included in the analysis, the risk of DM ranged from 0% to 8.3% and 0% to 12.9% for stage I and II invasive breast cancer, respectively. Among the patients with clinical stage II, the rate of occult metastases diagnosed by 18FDG-PET/CT was 7.2% (range, 0%-19.6%) for stage IIA and 15.8% (range, 0%-40.8%) for stage IIB. In young patients (< 40-year-old), 18FDG-PET/CT demonstrated a higher prevalence of DM at the time of diagnosis for those with aggressive histology (i.e., triple-negative receptors and poorly differentiated grade).

CONCLUSION

Young patients with poorly differentiated tumors and stage IIB triple-negative breast cancer may benefit from 18FDG-PET/CT at initial staging to detect occult DM prior to surgery.

Initial Fludeoxyglucose (18F) Positron Emission Tomography-Computed Tomography (FDG-PET/CT) Imaging of Breast Cancer - Correlations with the Primary Tumour and Locoregional Metastases

BACKROUND

We aimed to evaluate initial PET/CT features of primary tumour and locoregional metastatic lymph nodes (LNs) in breast cancer and to look for potential relationships between several parameters from PET/CT.

MATERIAL/METHODS

Twenty-three women (mean age; 48.66±12.23 years) with a diagnosis of primary invasive ductal carcinoma were included. They underwent PET/CT imaging for the initial tumour staging and had no evidence of distant metastates. Patients were divided into two groups. The LABC (locally advanced breast cancer) group included 17 patients with ipsilateral axillary lymph node (LN) metastases. The Non-LABC group consisted of six patients without LN metastases. PET/CT parameters including tumour size, axillary LN size, SUV_max of ipsilateral axillary LNs (SUV_max-LN), SUV_max of primary tumour (SUV_max-T) and NT ratios (SUV_max-LN/SUV_max-T) were compared between the groups. Correlations between the above-mentioned PET/CT parameters in the LABC group as well as the correlation between tumour size and SUV_max-T within each group were evaluated statistically.

RESULTS

The mean values of the initial PET/CT parameters in the LABC group were significantly higher than those of the non-LABC group (p<0.05). The correlation between tumour size and SUV_max-T value within both LABC and non-LABC groups was statistically significant (p<0.05). In the LABC group, the correlations between the size and SUV_max-LN values of metastatic axillary LNs, between tumour size and metastatic axillary LN size, between SUV_max-T values and metastatic axillary LN size, between SUV_max-T and SUV_max-LN values, and between tumour size and SUV_max-LN values were all significant (p<0.05).

CONCLUSIONS

We found significant correlations between PET/CT parameters of the primary tumour and those of metastatic axillary LNs. Patients with LN metastases had relatively larger primary tumours and higher SUV_max values.

Is PET/CT Necessary in the Management of Early Breast Cancer?

PURPOSE

Advanced imaging methods in early breast cancers are not recommended before surgery. In contrast to the accepted guidelines, some recent studies have shown some benefits with the use of PET/CT in early-stage breast cancer. In this study, we aimed to document the efficacy of PET/CT in detection of distant metastasis as well as other primary cancers.

PATIENTS AND METHODS

In this retrospective study, we reviewed the records of all women patients diagnosed with early breast cancer between March 2012 and December 2014. Besides demographics, we recorded the clinical TNM stage, histology of the tumor, and hormone receptor status. As PET/CT imaging is a routine procedure in our center for early breast cancer, tumor size, lymph node status, distant metastasis, and possible other primary malignancies detected by PET/CT were also recorded.

RESULTS

Of the 419 women included in the study, 24.8% were clinically staged as stage I while the rest were stage II. Distant metastases were detected in 42 patients (10%). The yield of PET/CT in detecting metastasis was significant in stage II patients compared with stage I patients (12.4% vs 2.9%). In subgroup analysis of stage II patients, the performance of PET/CT in detecting metastasis was still evident in stage IIA patients (9.5%). In logistic regression analysis of the significant and near-significant factors (as detected by univariate analysis) effecting PET/CT detected distant metastasis, only nodal status (P = 0.053) was found to be significant.

CONCLUSIONS

We suggest the use of PET/CT in investigating metastasis in axilla positive and clinically stage II early breast cancer patients.

Additional Prone 18F-FDG PET/CT Acquisition to Improve the Visualization of the Primary Tumor and Regional Lymph Node Metastases in Stage II/III Breast Cancer

PURPOSE

To prospectively compare prone and supine acquired 18F-FDG PET/CT for visualization of primary tumors and regional lymph nodes in stage II/III breast cancer patients.

MATERIALS AND METHODS

One hundred ninety-eight patients were included consecutively from August 2010 to April 2012. One hour after administration of 180-240 MBq 18F-FDG, PET/CT images of the thorax were firstly acquired in prone position. Subsequently, a standard PET/CT in supine position from skull base to thighs was made. Both sets of images were tested in a univariate and a multivariate analysis for the number of lesions per breast or lymph node (LN) region and anatomical mismatch between PET and CT images.

RESULTS

Images in prone position showed less compression of breast tissue, more primary tumor (PT) multifocality (P < 0.001) and more avid axillary LNs (P < 0.001) compared with supine position. Anatomical mismatch of the axillary LN metastases was found more often on supine PET/CT images compared with prone (P = 0.004). Prone images showed a smaller PT functional volume compared with supine position (P < 0.001).

CONCLUSIONS

Prone position PET/CT improved the visualization of PT multifocality and the number of detected axillary lymph nodes. Therefore, it is a valuable addition to standard supine PET/CT in the protocol for locoregional assessment in stage II/III breast cancer patients.

PET/CT with 18F-FDG predicts short-term outcome in stage II/III breast cancer patients upstaged to N2/3 nodal disease

INTRODUCTION

¹⁸F-FDG PET/CT has high positive predictive value for the detection of avid lymph node metastases in breast cancer patients. We analysed the effect of upstaging lymph nodes by PET/CT on short-term outcome in stage II/III breast cancer patients.

PATIENTS AND METHODS

A total of 278 stage II/III primary breast cancer patients (mean age 48.9 years, range 19-75 years) were re-staged with ¹⁸F-FDG PET/CT before start of pre-operative systemic treatment (PST). Patients were divided in three groups based on risk for local recurrence: a low - (T2N0), intermediate - (T0-2N1 and T3N0) and a high-risk group (T0-3N2-3, T3N1 and T4). Within these groups we looked at local recurrence-free survival (LRFS), recurrence-free survival (RFS) and overall survival (OS) within the first 3 years of follow-up.

RESULTS

With a median follow-up (FU) of 50 months the RFS, LRFS and OS were 87%, 88% and 92% respectively for the whole group. PET/CT upstaged 43 patients from the low- and intermediate risk group to the high-risk group, based on detection of ≥4 avid axillary nodes or occult N2/3-disease. Patients upstaged with PET/CT had more events for all three analyses compared to the original risk groups, which resulted in a significantly worse RFS (69.8%; p = 0.03) a nearly significantly worse LRFS (p = 0.052) and no effect in OS (p = 0.433).

DISCUSSION

Additional PET/CT staging allows breast cancer patients to be treated according to the true stage, still stage II/III breast cancer patients upstaged to N2/3 by PET/CT have worse short-term outcome, despite adjustment of treatment, than patients staged high-risk with conventional imaging.

PET/MR in Breast Cancer

Breast cancer is an international public health concern in which an optimal treatment plan requires a precise staging. Both MRI and PET imaging techniques have made significant progress in the last decades with constant improvements that made both modalities clinically relevant in several stages of breast cancer management and follow-up. On one hand, specific breast MRI permits high diagnostic accuracy for local tumor staging, and whole-body MRI can also be of great use in distant staging, eventually accompanied by organ-specific MRI sequences. Moreover, many different MRI sequences can be performed, including functional MRI, letting us foresee important improvements in breast cancer characterization in the future. On the contrary, (18)F-FDG-PET has a high diagnostic performance for the detection of distant metastases, and several other tracers currently under development may profoundly affect breast cancer management in the future with better determination of different types of breast cancers allowing personalized treatments. As a consequence PET/MR is a promising emerging technology, and it is foreseeable that in cases where both PET and MRI data are needed, a hybrid acquisition is justified when available. However, at this stage of deployment of such hybrid scanners in a clinical setting, more data are needed to demonstrate their added value beyond just patient comfort of having to undergo a single examination instead of two, and the higher confidence of diagnostic interpretation of these co-registered images. Optimized imaging protocols are still being developed and are prone to provide more efficient hybrid protocols with a potential improvement in diagnostic accuracy. More convincing studies with larger number of patients as well as cost-effectiveness studies are needed. This article provides insights into the current state-of-the-art of PET/MR in patients with breast cancer and gives an outlook on future developments of both imaging techniques and potential applications in the future.

(18) F-FDG PET/CT for initial staging in breast cancer patients - Is there a relevant impact on treatment planning compared to conventional staging modalities?

OBJECTIVE

To evaluate the impact of whole-body (18) F-FDG PET/CT on initial staging of breast cancer in comparison to conventional staging modalities.

METHODS

This study included 102 breast cancer patients, 101 patients were eligible for evaluation. Preoperative whole-body staging with PET/CT was performed in patients with clinical stage ≥ T2 tumours or positive local lymph nodes (n = 91). Postoperative PET/CT was performed in patients without these criteria but positive sentinel lymph node biopsy (n = 10). All patients underwent PET/CT and a conventional staging algorithm, which included bone scan, chest X-ray and abdominal ultrasound. PET/CT findings were compared to conventional staging and the impact on therapeutic management was evaluated.

RESULTS

PET/CT led to an upgrade of the N or M stage in overall 19 patients (19 %) and newly identified manifestation of breast cancer in two patients (2 %). PET/CT findings caused a change in treatment of 11 patients (11 %). This is within the range of recent studies, all applying conventional inclusion criteria based on the initial T and N status.

CONCLUSIONS

PET/CT has a relevant impact on initial staging and treatment of breast cancer when compared to conventional modalities. Further studies should assess inclusion criteria beyond the conventional T and N status, e.g. tumour grading and receptor status.

KEY POINTS

• PET/CT may be relevant in staging breast cancer patients at higher risk for metastases • PET/CT may modify the N and M stage in multiple patients • PET/CT may impact treatment planning in breast cancer patients.

Role of FDG PET-CT in evaluation of locoregional nodal disease for initial staging of breast cancer

Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is not indicated or recommended in the initial staging of early breast cancer. Although it is valuable for detecting distant metastasis, providing prognostic information, identifying recurrence and evaluating response to chemotherapy, the role of FDG PET/CT in evaluating locoregional nodal status for initial staging of breast cancer has not yet been well-defined in clinical practice. FDG PET/CT has high specificity but compromised sensitivity for identifying axillary nodal disease in breast cancer. Positive axillary FDG PET/CT is a good predictor of axillary disease and correlates well with sentinel lymph node biopsy (SLNB). FDG PET/CT may help to identify patients with high axillary lymph node burden who could then move directly to axillary lymph node dissection (ALND) and would not require the additional step of SLNB. However, FDG PET/CT cannot replace SLNB or ALND due to unsatisfactory sensitivity. The spatial resolution of PET instruments precludes the detection of small nodal metastases. Although there is still disagreement regarding the management of internal mammary node (IMN) disease in breast cancer, it is known that IMN involvement is of prognostic significance, and IMN metastasis has been associated with higher rates of distant metastasis and lower overall survival rates. Limited clinical observations suggested that FDG PET/CT has advantages over conventional modalities in detecting and uncovering occult extra-axillary especially IMN lesions with upstaging the disease and an impact on the adjuvant management.

Positron Emission Tomography (PET) in Oncology

Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%-15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.

Retrospective analysis of 18F-FDG PET/CT for staging asymptomatic breast cancer patients younger than 40 years

National Comprehensive Cancer Network guidelines consider (18)F-FDG PET/CT for only clinical stage III breast cancer patients. However, there is debate whether TNM staging should be the only factor in considering if PET/CT is warranted. Patient age may be an additional consideration, because young breast cancer patients often have more aggressive tumors with potential for earlier metastases. This study assessed PET/CT for staging of asymptomatic breast cancer patients younger than 40 y.

METHODS

In this Institutional Review Board-approved retrospective study, our hospital information system was screened for breast cancer patients younger than 40 y who underwent staging PET/CT before any treatment. Patients with symptoms or conventional imaging findings suggestive of distant metastases or with prior malignancy were excluded. Initial stage was based on physical examination, mammography, ultrasound, and breast MR imaging. PET/CT was then evaluated to identify unsuspected extraaxillary regional nodal and distant metastases.

RESULTS

One hundred thirty-four patients with initial breast cancer stage I to IIIC met inclusion criteria. PET/CT findings led to upstaging to stage III or IV in 28 patients (21%). Unsuspected extraaxillary regional nodes were found in 15 of 134 patients (11%) and distant metastases in 20 of 134 (15%), with 7 of 134 (5%) demonstrating both. PET/CT revealed stage IV disease in 1 of 20 (5%) patients with initial clinical stage I, 2 of 44 (5%) stage IIA, 8 of 47 (17%) stage IIB, 4 of 13 (31%) stage IIIA, 4 of 8 (50%) stage IIIB, and 1 of 2 (50%) stage IIIC. All 20 patients upstaged to stage IV were histologically confirmed. Four synchronous thyroid and 1 rectal malignancies were identified.

CONCLUSION

PET/CT revealed distant metastases in 17% of asymptomatic stage IIB breast cancer patients younger than 40 y. Although guidelines of the National Comprehensive Cancer Network recommend against systemic staging in patients with stage II disease, our data suggest that PET/CT might be valuable in younger patients with stage IIB and III disease. Use of PET/CT in younger patients has the potential to reduce the morbidity and cost of unnecessary therapies in young breast cancer patients.

Additional value of F-18 FDG PET/CT for initial staging in breast cancer with clinically negative axillary nodes

The aim of this study was to evaluate the clinical impact of the preoperative ¹⁸F-FDG PET/CT in the initial workup of breast cancer with clinically negative axillary nodes. Whether the status of the clinical axillary nodal involvement can be considered a parameter for making a decision to omit the preoperative ¹⁸F-FDG PET/CT in the situation reported herein was also determined. A total of 178 patients who had newly diagnosed breast cancer and for whom the conventional diagnostic modalities showed no sign of axillary node metastasis were retrospectively enrolled in this study. All the patients underwent preoperative ¹⁸F-FDG PET/CT. The images and histologic results that were obtained were analyzed. ¹⁸F-FDG PET/CT detected primary lesions in 156 of the 178 patients, with an overall sensitivity of 87.6 %, and false negative results were obtained for 22 patients (12.4 %). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ¹⁸F-FDG PET/CT in the detection of axillary nodes were 20.8, 86.9, 37.0, 74.8, and 69.1 %, respectively. Extra-axillary node metastasis was identified in two patients (1.1 %) who had internal mammary nodes. There was no distant metastasis, but coexisting primary tumor was detected in five patients (2.8 %). In total, the therapeutic plan was changed based on ¹⁸F-FDG PET/CT in seven (3.9 %) of the 178 patients, but considering only the cases confined to breast cancer, the change occurred in only two patients (1.1 %). ¹⁸F-FDG PET/CT almost did not affect the initial staging and treatment plan in breast cancer with clinically negative axillary node. If the axillary node is clinically negative in the preoperative workup of breast cancer, then ¹⁸F-FDG PET/CT can be omitted.

Role of positron emission tomography/computed tomography in breast cancer

Although positron emission tomography (PET) imaging may not be used in the diagnosis of breast cancer, the use of PET/computed tomography is imperative in all aspects of breast cancer staging, treatment, and follow-up. PET will continue to be relevant in personalized medicine because accurate tumor status will be even more critical during and after the transition from a generic metabolic agent to receptor imaging. Positron emission mammography is an imaging proposition that may have benefits in lower doses, but its use is limited without new radiopharmaceuticals.

Clinical application of 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography in breast cancer

Positron emission tomography (PET)/computed tomography (CT) is not suited for primary diagnostics of breast tumours and it cannot replace sentinel lymph node technique in determining metastases to the axilla. PET/CT has a high sensitivity and specificity regarding the detection of loco-regional recurrence and metastases to mediastinal and internal mammary lymph nodes, as well as distant metastases. Whether the method can replace conventional methods, or be a supplement when this is non-conclusive, remains unresolved. PET/CT cannot be recommended for routine follow-up but is recommended in patients with suspected relapse when conventional imaging has given equivocal results. PET/CT can be applied to confirm isolated loco-regional relapse or metastatic lesion detected by conventional imaging. PET/CT has a high sensitivity for detecting response to treatment, but a low specificity calls for cautions. Further investigations into the use of PET/CT to predict and monitor response are warranted, before this approach may find its way into a clinical setting. In the future, PET/CT will probably find increasing use in treatment planning and evaluation of patients with breast cancer.

¹⁸F-FDG PET/CT provides powerful prognostic stratification in the primary staging of large breast cancer when compared with conventional explorations

PURPOSE

The objective of this study was to assess the impact on management and the prognostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT for initial staging of newly diagnosed large breast cancer (BC) when compared with conventional staging.

METHODS

We prospectively included 142 patients with newly diagnosed BC and at least grade T2 tumour. All patients were evaluated with complete conventional imaging (CI) procedures (mammogram and/or breast ultrasound, bone scan, abdominal ultrasound and/or CT, X-rays and/or CT of the chest), followed by FDG PET/CT exploration, prior to treatment. The treatment plan based on CI staging was compared with that based on PET/CT findings. CI and PET/CT findings were confirmed by imaging and clinical follow-up and/or pathology when assessable. Progression-free survival (PFS) was analysed using the Cox proportional hazards regression model.

RESULTS

According to CI staging, 79 patients (56%) were stage II, 46 (32%) stage III and 17 (12%) stage IV (distant metastases). Of the patients, 30 (21%) were upstaged by PET/CT, including 12 (8%) from stage II or III to stage IV. On the other hand, 23 patients (16%) were downstaged by PET/CT, including 4 (3%) from stage IV to stage II or III. PET/CT had a high or medium impact on management planning for 18 patients (13%). Median follow-up was 30 months (range 9-59 months); 37 patients (26%) experienced recurrence or progression of disease during follow-up and 17 patients (12%) died. The Cox model indicated that CI staging was significantly associated with PFS (p = 0.01), but PET/CT staging provided stronger prognostic stratification (p < 0.0001). Moreover, Cox regression multivariate analysis showed that only PET/CT staging remained associated with PFS (p < 0.0001).

CONCLUSION

FDG PET/CT provides staging information that more accurately stratifies prognostic risk in newly diagnosed large BC when compared with conventional explorations alone.