Role of FDG-PET/CT in evaluating surgical outcomes of operable breast cancer--usefulness for malignant grade of triple-negative breast cancer

An Innovative Non-Linear Prediction Model for Clinical Benefit in Women with Newly Diagnosed Breast Cancer Using Baseline FDG-PET/CT and Clinical Data

Objectives: We aimed to develop a novel non-linear statistical model integrating primary tumor features on baseline [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), molecular subtype, and clinical data for treatment benefit prediction in women with newly diagnosed breast cancer using innovative statistical techniques, as opposed to conventional methodological approaches. Methods: In this single-center retrospective study, we conducted a comprehensive assessment of women newly diagnosed with breast cancer who had undergone a FDG-PET/CT scan for staging prior to treatment. Primary tumor (PT) volume, maximum and mean standardized uptake value (SUVmax and SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were measured on PET/CT. Clinical data including clinical staging (TNM) but also PT anatomical site, histology, receptor status, proliferation index, and molecular subtype were obtained from the medical records. Overall survival (OS), progression-free survival (PFS), and clinical benefit (CB) were assessed as endpoints. A logistic generalized additive model was chosen as the statistical approach to assess the impact of all listed variables on CB. Results: 70 women with newly diagnosed breast cancer (mean age 63.3 ± 15.4 years) were included. The most common location of breast cancer was the upper outer quadrant (40.0%) in the left breast (52.9%). An invasive ductal adenocarcinoma (88.6%) with a high tumor proliferation index (mean ki-67 expression 35.1 ± 24.5%) and molecular subtype B (51.4%) was by far the most detected breast tumor. Most PTs displayed on hybrid imaging a greater volume (12.8 ± 30.4 cm3) with hypermetabolism (mean ± SD of PT maximum SUVmax, SUVmean, MTV, and TLG, respectively: 8.1 ± 7.2, 4.9 ± 4.4, 12.7 ± 30.4, and 47.4 ± 80.2). Higher PT volume (p < 0.01), SUVmax (p = 0.04), SUVmean (p = 0.03), and MTV (<0.01) significantly compromised CB. A considerable majority of patients survived throughout this period (92.8%), while five women died (7.2%). In fact, the OS was 31.7 ± 14.2 months and PFS was 30.2 ± 14.1 months. A multivariate prediction model for CB with excellent accuracy could be developed using age, body mass index (BMI), T, M, PT TLG, and PT volume as predictive parameters. PT volume and PT TLG demonstrated a significant influence on CB in lower ranges; however, beyond a specific cutoff value (respectively, 29.52 cm3 for PT volume and 161.95 cm3 for PT TLG), their impact on CB only reached negligible levels. Ultimately, the absence of distant metastasis M displayed a strong positive impact on CB far ahead of the tumor size T (standardized average estimate 0.88 vs. 0.4). Conclusions: Our results emphasized the pivotal role played by FDG-PET/CT prior to treatment in forecasting treatment outcomes in women newly diagnosed with breast cancer. Nevertheless, careful consideration is required when selecting the methodological approach, as our innovative statistical techniques unveiled non-linear influences of predictive biomarkers on treatment benefit, highlighting also the importance of early breast cancer diagnosis.

Dual-phase FDG PET/CT for predicting prognosis in operable breast cancer

Purpose

We aimed to investigate the role of dual-phase FDG PET/CT in predicting the prognosis of patients with operable breast cancer.

Methods

We retrospectively reviewed the data of 998 patients who underwent radical treatment for breast cancer. Before treatment, PET/CT scans were performed 1 and 2 h after FDG administration. The maximum standardized uptake value (SUVmax) at both time points (SUVmax1 and SUVmax2) in the primary tumor and the retention index (RI) were calculated. PET recurrence risk (PET-RR) was determined based on the SUVmax1 and RI, and disease-free survival (DFS) and overall survival (OS) were evaluated according to the metabolic parameters. Propensity score matching was performed to adjust for biological characteristics.

Results

The cut-off values for SUVmax1 and RI were 3 and 5%, respectively. The 5-year DFS was 94.9% and 86.1% (P < 0.001), and the 5-year OS was 97.6% and 92.7% (P < 0.001) in the low and high PET-RR groups, respectively. In multivariate analysis, high T status, nodal metastasis, the triple-negative subtype, and high PET-RR were independent factors of poor DFS. Propensity score matching revealed similar findings (5-year DFS 91.8% vs. 88.6%, P = 0.041 and 5-year OS 97.1% vs. 94.2%, P = 0.240, respectively).

Conclusion

The combined parameters of SUVmax1 and RI on dual-phase FDG PET/CT were useful for predicting prognosis of patients with breast cancer. Patients with a high SUVmax1 and a negative time course of FDG uptake had a favorable prognosis.

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SUVmax and retention index on FDG PET/CT are related with breast cancer prognosis.

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Breast cancer with high SUVmax but no increase over time has a favorable prognosis.

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Dual-phase FDG PET/CT is useful to predict the prognosis in operable breast cancer.

Temporal Heterogeneity of HER2 Expression and Spatial Heterogeneity of 18F-FDG Uptake Predicts Treatment Outcome of Pyrotinib in Patients with HER2-Positive Metastatic Breast Cancer

Background: This study aimed to evaluate tumor heterogeneity of metastatic breast cancer (MBC) and investigate its impact on the efficacy of pyrotinib in patients with HER2-positive MBC. Methods: MBC patients who underwent 18F-FDG PET/CT before pyrotinib treatment were included. Temporal and spatial tumor heterogeneity was evaluated by the discordance between primary and metastatic immunohistochemistry (IHC) results and baseline 18F-FDG uptake heterogeneity (intertumoral and intratumoral heterogeneity indexes: HI-inter and HI-intra), respectively. Progression-free survival (PFS) was estimated by the Kaplan−Meier method and compared by a log-rank test. Results: A total of 572 patients were screened and 51 patients were included. In 36 patients with matched IHC results, 25% of them had HER2 status conversion. Patients with homogenous HER2 positivity had the longest PFS, followed by patients with gained HER2 positivity, while patients with HER2 negative conversion could not benefit from pyrotinib (16.8 vs. 13.7 vs. 3.6 months, p < 0.0001). In terms of spatial heterogeneity, patients with high HI-intra and HI-inter had significantly worse PFS compared to those with low heterogeneity (10.6 vs. 25.3 months, p = 0.023; 11.2 vs. 25.3 months, p = 0.040). Conclusions: Temporal heterogeneity of HER2 status and spatial heterogeneity of 18F-FDG uptake could predict the treatment outcome of pyrotinib in patients with HER2-positive MBC, which provide practically applicable methods to assess tumor heterogeneity and guidance for treatment decisions.

Associations of adiposity and weight change with recurrence and survival in breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Adiposity and weight change among patients with breast cancer are associated with mortality, but there is limited evidence on the associations with distant recurrence or other causes of death or on central adiposity. Moreover, the relationship with breast cancer subtypes and by menopause status is unclear.

METHODS

We conducted a systematic review and meta-analysis of prospective studies of breast cancer patients investigating the associations of general and central adiposity (body mass index [BMI] and waist circumference [WC], respectively), before and after diagnosis, and weight change, with all-cause mortality, breast cancer-specific mortality (BCSM), and recurrence.

RESULTS

173 studies (519,544 patients, 60,249 deaths overall, and 25,751 breast cancer deaths) were included. For BMI  < 1 year post diagnosis, compared with normal weight women, the summary relative risk (RR) for obese women was 1.21 (1.15-1.27) for all-cause mortality, 1.22 (1.13-1.32) for BCSM, 1.12 (1.06-1.18) for recurrence, and 1.19 (1.11-1.28) for distant recurrence. Obesity was associated with all-cause mortality and BCSM in patients with ER+ or HER2+ tumors, whereas no clear association was observed in patients with triple-negative tumors. Similar associations were observed by menopausal status. Stronger associations were observed in East Asians than Europeans. Central adiposity was associated with all-cause mortality, while large weight gain was associated with all-cause mortality, BCSM, and recurrence.

CONCLUSION

Higher adiposity is associated with all-cause mortality, BCSM, recurrence, and distant recurrence in breast cancer patients, with similar associations by menopausal status and some evidence of heterogeneity by subtypes. Weight gain is also associated with recurrence and survival among breast cancer patients.

Prognostic Value of Metabolic, Volumetric and Textural Parameters of Baseline [18F]FDG PET/CT in Early Triple-Negative Breast Cancer

Simple Summary

The aim of this study was to evaluate PET/CT parameters to determine different prognostic groups in TNBC, in order to select patients with a high risk of relapse, for whom therapeutic escalation can be considered. We have demonstrated that the MTV, TLG and entropy of the primary breast lesion could be of interest to predict the prognostic outcome of TNBC patients.

Abstract

(1) Background: triple-negative breast cancer (TNBC) remains a clinical and therapeutic challenge primarily affecting young women with poor prognosis. TNBC is currently treated as a single entity but presents a very diverse profile in terms of prognosis and response to treatment. Positron emission tomography/computed tomography (PET/CT) with ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) is gaining importance for the staging of breast cancers. TNBCs often show high [¹⁸F]FDG uptake and some studies have suggested a prognostic value for metabolic and volumetric parameters, but no study to our knowledge has examined textural features in TNBC. The objective of this study was to evaluate the association between metabolic, volumetric and textural parameters measured at the initial [¹⁸F]FDG PET/CT and disease-free survival (DFS) and overall survival (OS) in patients with nonmetastatic TBNC. (2) Methods: all consecutive nonmetastatic TNBC patients who underwent a [¹⁸F]FDG PET/CT examination upon diagnosis between 2012 and 2018 were retrospectively included. The metabolic and volumetric parameters (SUV_max, SUV_mean, SUV_peak, MTV, and TLG) and the textural features (entropy, homogeneity, SRE, LRE, LGZE, and HGZE) of the primary tumor were collected. (3) Results: 111 patients were enrolled (median follow-up: 53.6 months). In the univariate analysis, high TLG, MTV and entropy values of the primary tumor were associated with lower DFS (p = 0.008, p = 0.006 and p = 0.025, respectively) and lower OS (p = 0.002, p = 0.001 and p = 0.046, respectively). The discriminating thresholds for two-year DFS were calculated as 7.5 for MTV, 55.8 for TLG and 2.6 for entropy. The discriminating thresholds for two-year OS were calculated as 9.3 for MTV, 57.4 for TLG and 2.67 for entropy. In the multivariate analysis, lymph node involvement in PET/CT was associated with lower DFS (p = 0.036), and the high MTV of the primary tumor was correlated with lower OS (p = 0.014). (4) Conclusions: textural features associated with metabolic and volumetric parameters of baseline [¹⁸F]FDG PET/CT have a prognostic value for identifying high-relapse-risk groups in early TNBC patients.

Value of 18F-FDG PET/CT for predicting axillary pathologic complete response following neoadjuvant systemic therapy in breast cancer patients: emphasis on breast cancer subtype

Background

Neoadjuvant systemic therapy (NST) is a widely accepted initial treatment modality that can lead to pathologic downstaging of the axillary disease burden in breast cancer patients. Axillary response as well as baseline ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake on positron emission tomography with computed tomography (PET/CT) differ between breast cancer subtypes. The value of baseline ¹⁸F-FDG PET/CT in predicting axillary response to NST is not yet established, possibly since breast cancer subtype was not taken into account. The purpose of this study was to investigate the value of baseline ¹⁸F-FDG PET/CT in predicting axillary response to NST with a specific emphasis on subtype.

Methods

PET-parameters derived from the primary tumor as well as the most FDG-avid axillary lymph node were measured on baseline ¹⁸F-FDG PET/CT. Overall imaging findings were compared with the gold standard of histopathology of the axillary surgery specimen. Analyses for ER-positive/HER2-negative were performed separately from HER2-positive and TN patients. In addition, separate analyses for clinically node-positive patients were performed.

Results

Sixty-six patients with 69 primary tumors were included in this study. Thirty-three axillae contained ER-positive/HER2-negative, 16 HER2-positive, and 20 TN breast cancer. No significant difference in PET-parameters between patients with axillary residual disease and axillary pathologic complete response were found for ER-positive/HER2-negative breast cancer. In the combined HER2-positive/TN subgroup, the SUV_max was significantly lower in patients without residual axillary disease in both the entire cohort and in patients with clinically node-positive disease. In this combined subgroup, a cut-off of 4.89 SUV_max measured on the most FDG-avid axillary lymph node could predict residual axillary disease with a sensitivity, specificity, PPV, and NPV of 90%, 69%, 53%, and 95%, respectively.

Conclusions

Predicting axillary response following NST with baseline ¹⁸F-FDG PET/CT can be performed when focusing on breast cancer subtypes. The easily computed PET-parameter SUV_max can predict axillary response in HER2-positive and TN breast cancer. This study adds to the accumulating evidence that studies investigating the value of ¹⁸F-FDG PET/CT in breast cancer should always take subtypes into account.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00861-z.

Breast cancer detection by dedicated breast positron emission tomography according to the World Health Organization classification of breast tumors

OBJECTIVE

Considering the difficulty in detecting primary breast cancers using whole-body positron emission tomography (WBPET) owing to its limited spatial resolution, we aimed to evaluate the detectability of breast cancer by ring-type dedicated breast PET (DbPET) on the World Health Organization (WHO) histological classification in comparison with WBPET.

METHODS

A total of 938 patients with breast cancer underwent WBPET and ring-type DbPET, and 1021 lesions were histologically assessed based on the WHO classification of tumors of the breast. The findings of WBPET and DbPET were retrospectively evaluated and compared.

RESULTS

The size-related sensitivity of DbPET was superior to that of WBPET for subcentimetric tumors (81.9% vs. 52.4%, P < 0.001). The histological distribution was as follows: 11 lobular carcinoma in situ, 158 ductal carcinoma in situ, 738 infiltrating duct carcinoma not otherwise specified (NOS), 12 lobular carcinoma NOS, 40 mucinous adenocarcinoma, 13 tubular carcinoma, 36 invasive breast carcinoma others, and 13 papillary neoplasms. WBPET had low sensitivity for lobular carcinoma in situ, ductal carcinoma in situ, lobular carcinoma NOS, mucinous adenocarcinoma, and tubular carcinoma. DbPET showed improved sensitivity for all the above except lobular and tubular carcinoma. The maximum standardized uptake values (SUVmax) of DbPET were significantly higher than those of WBPET for histological types, excluding lobular carcinoma in situ. The SUVmax of papillary neoplasms was high regardless of low-grade histology and Ki-67 labeling index.

CONCLUSIONS

DBPET was found to have high sensitivity and SUVmax values for all histologic types that showed low sensitivity of detection on WBPET, except lobular carcinoma in situ.

Performance of dedicated breast positron emission tomography in the detection of small and low-grade breast cancer

PURPOSE

This study compares the sensitivity of dedicated breast positron emission tomography (DbPET) and whole body positron emission tomography (WBPET) in detecting invasive breast cancer based on tumor size and biology. Further, we explored the relationship between maximum standardized uptake value (SUVmax) of DbPET and biological features of the tumor.

METHODS

A total of 639 invasive breast cancer lesions subjected to both DbPET and WBPET before surgery, between January 2016 and May 2019, were included in the study. The sensitivity of DbPET and WBPET in detection and the biology of the tumor according to the clinicopathological features were retrospectively evaluated.

RESULTS

The overall sensitivity of DbPET was higher than that of WBPET (91.4% vs. 80.3%, p < 0.001). Subcentimetric tumors were significant (80.9% vs. 54.3%, p < 0.001). Regardless of the nuclear grade, DbPET could detect more lesions than WBPET. The SUVmax was positively correlated with tumor size (R = 0.395, p < 0.001) and the nuclear grade (p < 0.001). Luminal A-like breast cancer had significantly lower SUVmax values than the other subtypes (p < 0.001).

CONCLUSIONS

DbPET is superior to WBPET in the detection of subcentimetric, low-grade breast cancers. Further, by using SUVmax, DbPET can distinguish luminal A-like breast cancer from the other subtypes.

A Brief Review on Breast Carcinoma and Deliberation on Current Non Invasive Imaging Techniques for Detection

BACKGROUND

Breast carcinoma is a life threatening disease that accounts for 25.1% of all carcinoma among women worldwide. Early detection of the disease enhances the chance for survival.

DISCUSSION

This paper presents comprehensive report on breast carcinoma disease and its modalities available for detection and diagnosis, as it delves into the screening and detection modalities with special focus placed on the non-invasive techniques and its recent advancement work done, as well as a proposal on a novel method for the application of early breast carcinoma detection.

CONCLUSION

This paper aims to serve as a foundation guidance for the reader to attain bird's eye understanding on breast carcinoma disease and its current non-invasive modalities.

Dual time point 18F-fluorodeoxyglucose positron emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in primary breast cancer

BACKGROUND

To evaluate the clinicopathological and prognostic significance of the percentage change between maximum standardized uptake value (SUV_max) at 60 min (SUV_max1) and SUV_max at 120 min (SUV_max2) (ΔSUV_max%) using dual time point ¹⁸F-fluorodeoxyglucose emission tomography/computed tomography (¹⁸F-FDG PET/CT) in breast cancer.

METHODS

Four hundred and sixty-four patients with primary breast cancer underwent ¹⁸F-FDG PET/CT for preoperative staging. ΔSUV_max% was defined as (SUV_max2 - SUV_max1) / SUV_max1 × 100. We explored the optimal cutoff value of SUV_max parameters (SUV_max1 and ΔSUV_max%) referring to the event of relapse by using receiver operator characteristic curves. The clinicopathological and prognostic significances of the SUV_max1 and ΔSUV_max% were analyzed by Cox's univariate and multivariate analyses.

RESULTS

The optimal cutoff values of SUV_max1 and ΔSUV_max% were 3.4 and 12.5, respectively. Relapse-free survival (RFS) curves were significantly different between high and low SUV_max1 groups (P = 0.0003) and also between high and low ΔSUV_max% groups (P = 0.0151). In Cox multivariate analysis for RFS, SUV_max1 was an independent prognostic factor (P = 0.0267) but ΔSUV_max% was not (P = 0.152). There was a weak correlation between SUV_max1 and ΔSUV_max% (P < 0.0001, R² = 0.166). On combining SUV_max1 and ΔSUV_max%, the subgroups of high SUV_max1 and high ΔSUV_max% showed significantly worse prognosis than the other groups in terms of RFS (P = 0.0002).

CONCLUSION

Dual time point ¹⁸F-FDG PET/CT evaluation can be a useful method for predicting relapse in patients with breast cancer. The combination of SUV_max1 and ΔSUV_max% was able to identify subgroups with worse prognosis more accurately than SUV_max1 alone.

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.

The relationship between ring-type dedicated breast PET and immune microenvironment in early breast cancer

PURPOSE

¹⁸F-fluorodeoxyglucose (FDG) uptake on positron emission tomography (PET) is related to the biological parameters and prognosis of breast cancer. However, whether whole-body PET (WBPET) and dedicated breast PET (DbPET) can reflect the tumor microenvironment is unclear. This study investigated the relationship between stromal tumor-infiltrating lymphocytes (TILs) and maximum standardized uptake value (SUVmax) in WBPET and DbPET.

METHODS

A total of 125 invasive breast cancers underwent WBPET and ring-type DbPET and resected specimens were pathologically assessed. The impact of SUVmax on the tumor biological parameters and TILs was retrospectively evaluated. SUVmax was classified as high and low relative to the median values (WBPET-SUVmax: 2.2 and DbPET-SUVmax: 6.0).

RESULTS

SUVmax correlated with tumor size, nuclear grade, Ki-67 labeling index, and TILs in both WBPET and DbPET (all p < 0.001). In multiple linear regression analysis, tumor size, Ki-67 labeling index, and TILs predicted SUVmax in WBPET and DbPET. The cutoff values of tumor size, Ki-67 labeling index, and TILs predicting high SUVmax were 20 mm, 20%, and 20%, respectively. In multivariate analysis, the predictive factors for high SUVmax were tumor size and Ki-67 labeling index for WBPET and tumor size and TILs for DbPET. High SUVmax in DbPET was related to high numbers of TILs after propensity score matching analysis; however, WBPET was not (p = 0.007 and p = 0.624, respectively).

CONCLUSIONS

Both SUVmax values in WBPET and DbPET predicted TIL concentration of the primary breast cancer. In DbPET, SUVmax represented the immune microenvironment after adjusting for tumor biological factors.

Associations Between PET Parameters and Expression of Ki-67 in Breast Cancer

OBJECTIVES

Numerous studies investigated relationships between positron emission tomography and proliferation index Ki-67 in breast cancer (BC) with inconsistent results. The aim of the present analysis was to provide evident data about associations between standardized uptake value (SUV) and expression of Ki-67 in BC.

METHODS

MEDLINE library, SCOPUS and EMBASE data bases were screened for relationships between SUV and Ki-67 in BC up to April 2018. Overall, 32 studies with 1802 patients were identified. The following data were extracted from the literature: authors, year of publication, number of patients, and correlation coefficients. Associations between SUV and Ki-67 were analyzed by Spearman's correlation coefficient.

RESULTS

Associations between SUV_max derived from ¹⁸F-FDG PET and Ki-67 were reported in 25 studies (1624 patients). The pooled correlation coefficient was 0.40, (95% CI = [0.34; 0.46]). Furthermore, 7 studies analyzed associations between SUV_max derived from ¹⁸F-fluorthymidin (FLT) PET and Ki-67 (178 patients). The pooled correlation coefficient was 0.54, (95% CI = [0.37; 0.70]).

CONCLUSION

SUV_max correlated moderately with expression of Ki-67 and, therefore, cannot be used as a surrogate marker for tumor proliferation. Further studies are needed to evaluate associations between PET parameters and histopathological findings like hormone receptor status in breast cancer.

Pretreatment 18F-FDG Uptake Heterogeneity Predicts Treatment Outcome of First-Line Chemotherapy in Patients with Metastatic Triple-Negative Breast Cancer

BACKGROUND

Intratumoral heterogeneity of 18F-fluorodeoxyglucose (18F-FDG) uptake in primary tumor has proven to be a surrogate marker for predicting treatment outcome in various tumors. However, the value of intraindividual heterogeneity in metastatic diseases remains unknown. The aim of this study was to evaluate pretreatment positron emission tomography/computed tomography (PET/CT) 18F-FDG-based heterogeneity for the prediction of first-line treatment outcome in metastatic triple-negative breast cancer (mTNBC).

MATERIALS AND METHODS

mTNBC patients from three clinical trials (NCT00601159, NCT01287624, and NCT02341911) with whole-body 18F-FDG PET/CT scan before first-line gemcitabine/platinum were included. Heterogeneity index (HI) and the maximum of FDG uptake (MAX) across total metastatic lesions (-T) on baseline PET/CT scans were assessed. HI was measured by MAX divided by the minimum FDG uptake across metastatic lesions. Optimal cutoffs were determined by time-dependent receiver operator characteristics (ROC) analysis. Progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method and compared by log-rank test.

RESULTS

A total of 42 mTNBC patients were included in this study. The median PFS of patients with high HI-T (>1.9) and high MAX-T (>10.5) was significantly shorter than patients with low HI-T (<1.9; p = .049) and low MAX-T (<10.5; p = .001). In terms of OS, only high MAX-T was significant for poorer outcome (p = .013). ROC curve analysis confirmed the predictive value of MAX and HI in mTNBC patients. Area under the ROC curve for MAX-T and HI-T was 0.75 and 0.65, indicating a higher predictive accuracy than conventional clinical risk factors.

CONCLUSION

HI and MAX measured among metastatic lesions on pretreatment 18F-FDG PET/CT scans could be potential predicators for first-line treatment outcome in patients with mTNBC.

IMPLICATIONS FOR PRACTICE

Intratumoral heterogeneity of 18F-fluorodeoxyglucose (FDG) uptake in primary tumor has proven to be a robust surrogate predictive marker. A novel positron emission tomography/computed tomography (PET/CT) parameter-heterogeneity index (HI) to quantify the heterogeneous characteristics of metastatic disease is proposed. Triple-negative breast cancer (TNBC) is a highly heterogeneous disease and remains a clinical challenge. The predictive performance of HI, along with the maximum FDG uptake (MAX), measured on pretreatment PET/CT scans in patients with metastatic TNBC was evaluated. Results indicate that HI and MAX may serve as applicable imaging predicators for treatment outcome of metastatic TNBC in clinical practice.

A hierarchical prognostic model for risk stratification in patients with early breast cancer according to 18 F-fludeoxyglucose uptake and clinicopathological parameters

This study was to investigate a hierarchical prognostic model using clinicopathological factors and 18 F-fludeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) for recurrence-free survival (RFS) in patients with early breast cancer who underwent surgery without neoadjuvant chemotherapy. A total of 524 patients with early breast cancer were included. The Cox proportional hazards model was used with clinicopathological variables and maximum standardized uptake value (SUVmax) on PET/CT. After classification and regression tree (CART) modeling, RFS curves were estimated using the Kaplan-Meier method and differences in each risk layer were assessed using the log-rank test. During a median follow-up of 46.2 months, 31 (5.9%) patients experienced recurrence. The CART model identified four risk layers: group 1 (SUVmax ≤6.75 and tumor size ≤2.0 cm); group 2 (SUVmax ≤6.75 and Luminal A [LumA] or TN tumor >2.0 cm); group 3 (SUVmax ≤6.75 and Luminal B [LumB] or human epidermal growth factor receptor 2 [HER2]-enriched] tumor >2.0 cm); group 4 (SUVmax >6.75). Five-year RFS was as follows: 95.9% (group 1), 98% (group 2), 82.8% (group 3), and 85.4% (group 4). Group 3 or group 4 showed worse prognosis than group 1 or group 2 (group 1 vs. group 3: P = 0.040; group 1 vs. group 4: P < 0.001; group 2 vs. group 3: P = 0.016; group 2 vs. group 4: P < 0.001). High SUVmax (>6.75) in primary breast cancer was an independent factor for poor RFS. In patients with low SUVmax, LumB or HER2-enriched tumor >2 cm was also prognostic for poor RFS, similar to high SUVmax.

The usefulness of fluorodeoxyglucose-PET/CT for preoperative evaluation of ductal carcinoma in situ

Purpose

PET/CT is useful in preoperative evaluation of invasive breast cancer (IBC) to predict axillary metastasis and staging workup. The usefulness is unclear in cases of ductal carcinoma in situ (DCIS) diagnosed at biopsy before surgery, which sometimes is upgraded to IBC after definitive surgery. The aim of this study is to find out the usefulness of PET/CT on DCIS as a preoperative evaluation tool.

Methods

We investigated 102 patients preoperatively diagnosed with DCIS who subsequently underwent definitive surgery between 2010 and 2015. The uptake of ¹⁸F-fluorodeoxyglucose was graded by visual and semiquantitative methods. We analyzed the maximum standardized uptake value (SUVmax) of each patient with clinicopathologic variables. We determined optimal cutoff values for SUVmax by receiver operating characteristic curve analysis.

Results

Fifteen cases out of 102 cases (14.7%) were upgraded to IBC after surgery. The SUVmax was higher in patients upgraded to IBC (mean: 2.56 vs. 1.36) (P = 0.007). The SUVmax was significantly higher in patients who had symptoms, palpable masses, lesions over 2 cm in size and BI-RAD category 5. Both visual and semiquantitative analysis were significant predictors of IBC underestimation. SUVmax of 2.65 was the theoretical cutoff value in ROC curve analysis in predicting the underestimation of IBC. The underestimation rate was significantly higher in patients with SUVmax >2.65 (P < 0.001), over the moderate enhanced uptake on visual analysis (P < 0.001).

Conclusion

PET/CT can be used as a complementary evaluation tool to predict the underestimation of DCIS combined with the lesion size, palpable mass, symptomatic lesion, and BI-RAD category.

Tumor characteristics and metabolic quantification in carcinoma breast: An institutional experience

BACKGROUND

In India, carcinoma breast is the most common cancer among urban women population and second most common cancer after carcinoma cervix in rural areas. One in 22 women in India develops carcinoma of the breast in their lifetime. Fluorine-18-fluoro-2-deoxy-D-glucose (18F-FDG) uptake in breast cancer usually indicates the degree of tumor metabolism and hence can predict its behavior and prognosis. On the other hand, the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2) or neu state of breast cancer is a biomarker that provides important prognostic information in addition to predicting response to therapy.

AIMS

The main objective of this study is to assess whether a correlation exists between 18F-FDG uptake in untreated cases of breast cancer, their receptor status (ER, PR, and HER-2 or neu), tumor histology, and tumor size.

SUBJECTS AND METHODS

Sixty consecutive female patients, with biopsy-proven primary breast cancer, were enrolled in this prospective study for whom 18F-FDG positron emission tomography-computed tomography scan was done in the Department of Nuclear Medicine. Results obtained were analyzed using appropriate statistical tests (t-test and Pearson Chi-square tests), and interpretation was made with 95% confidence level.

RESULTS

In our series, a positive correlation between tumor size, high tumor grade, and standardized uptake value (SUV) was found. Tumors with positive receptor status for estrogen, progesterone, and HER-2/neu receptors had statistically insignificant lower maximum SUV (SUVmax) values than their negative counterparts. Triple-negative breast tumors (ER-, PR-, and no overexpression of HER-2/neu) are currently a subject of major interest because of their aggressiveness, poor prognosis, and lack of targeted therapy. Based on receptor status when the SUVmaxof the group with triple-negative receptor status (ER-/PR-/HER-2/neu-) was compared to rest of the patient group, it was seen that patients with negative receptor status had significantly higher mean SUVmaxvalues.

CONCLUSIONS

We have inferred that in patients with breast cancer, various biological parameters such as tumor size, grade, histology, and hormonal receptor status have different impact on tumor metabolic activity.

Reliability of 18F-FDG PET Metabolic Parameters Derived Using Simultaneous PET/MRI and Correlation With Prognostic Factors of Invasive Ductal Carcinoma: A Feasibility Study

OBJECTIVE

The objective of our study was to correlate semiquantitative PET parameters-standardized uptake value (SUV) and total lesion glycolysis (TLG)-derived in simultaneous PET/MRI using MRI-based attenuation correction with clinical and histopathologic prognostic factors in patients with breast cancer.

MATERIALS AND METHODS

Eighty-two invasive ductal carcinomas in 69 women were included in the study. All the subjects underwent whole-body (WB) PET/MRI (supine WB mode) and dedicated PET/MRI of the breast (prone breast imaging mode) for staging on a simultaneous PET/MRI system. The SUV and TLG values were calculated from ¹⁸F-FDG PET data using MRI-based attenuation correction (2-point Dixon sequence for tissue segmentation). Relationships between SUV and TLG values and clinical and histopathologic parameters (i.e., tumor size, tumor grade, Ki-67 status, and hormonal receptor expression status) were evaluated using Spearman correlation coefficient analysis.

RESULTS

A significant correlation was observed between mean SUV (SUV_mean) and maximum SUV (SUV_max) values derived with WB PET and regional PET of the breasts performed simultaneously with MRI (r = 0.88 and 0.89, respectively). A significant difference (p < 0.05) was observed in SUV_mean, SUV_max, and TLG values between the grades and molecular subtypes of breast cancer. High SUV_mean, SUV_max, and TLG values were found to correlate with larger tumor size (p < 0.01), higher proliferation index (p < 0.05), higher grade (p < 0.01), and triple-negative hormonal receptor status (p < 0.01, p < 0.05).

CONCLUSION

Semiquantitative FDG parameters derived with MRI-based attenuation correction in simultaneous PET/MRI are reliable and correlate with clinicopathologic features such as grade as well as subtype and thus could be used in the prognostication of breast cancer.

Relationship between primary tumour 18F-FDG uptake and immunohistochemical and clinical prognostic parameters in breast carcinoma

OBJECTIVE

The objective of this study was to investigate the relationship between level of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) accumulation in primary breast tumour assessed by positron emission tomography/computed tomography (PET/CT) and histopathological and clinical prognostic factors.

MATERIAL AND METHODS

A retrospective analysis was performed using the medical records of 58 female patients (age range: 31-86 years, mean age: 56) with biopsy of proven breast carcinoma, and who had undergone ¹⁸F-FDG PET/CT examination before chemotherapy/surgery. The ¹⁸F-FDG uptake of breast tumours was calculated as tumour to background ratio (TBR), which was compared with histopathological and clinical prognostic parameters.

RESULTS

The histology of the breast tumour in the 58 patients was ductal type in 52 (90%), lobular in 4 (7%), and mucinous in 2 (3%). Tumour size was ≤ 2cm in 31 (53%) patients, and>2cm in 27 (47%). The levels of TBRs were not significantly different between the patients groups with tumours of 2cm or less and greater than 2cm (P=0.131). No significant difference between levels of TBR was observed neither with regards to axillary lymph node involvement (P=0.065) nor in terms of distant metastases (p=0.123). No statistically significant difference was found in levels of TBRs between patients with c-erbB-2 receptor positive and negative ones (P=0.107). Progesterone receptor (PR) expression was observed in 33 patients (57%), and 25 patients (43%) were PR negative. As regards progesterone receptor status, a statistically significant difference was observed in mean TBR levels between patients with and without progesterone receptor expression (P=0.020). Oestrogen receptor expression was positive in 41 (71%) patients, and negative in 17 (29%) patients. The difference in the levels of TBRs between patients with and without oestrogen receptor expression was at the level of significancy (P=0.050).

CONCLUSIONS

It is concluded that ¹⁸F-FDG uptake correlates with progesterone negativity of the tumour. However, a significant association with clinical prognostic parameters and level of ¹⁸F-FDG uptake levels could not be demonstrated.

The clinical significance of standardized uptake value in breast cancer measured using 18F-fluorodeoxyglucose positron emission tomography/computed tomography

OBJECTIVE

The objective of this study was to investigate the clinical and biological significance of F-fluorodeoxyglucose (F-FDG) uptake levels in breast cancer patients.

PATIENTS AND METHODS

F-FDG PET/computed tomography was performed in 206 women with breast cancer, and the standardized uptake value (SUV) in breast cancer was analyzed to test associations with prognostic parameters.

RESULTS

PET/computed tomography sensitivity for primary tumor detection was 90.4% (206/228) and sensitivity and specificity for metastatic axillary lymph node were 72.6% (45/62) and 84.7% (122/144), respectively. A high SUV was significantly associated with large tumor size (>2 cm, P<0.001), positive axillary lymph node metastasis (P<0.001), distant metastasis (P=0.016), higher tumor node metastasis stage (P<0.001), higher histologic grade (P<0.001), higher nuclear grade (P<0.001), estrogen receptor negativity (P<0.001), progesterone receptor negativity (P<0.001), triple negativity (P=0.006), B-cell lymphoma/leukemia-2 negativity (P=0.031), cytokeratin 5/6 positivity (P=0.001), epidermal growth factor receptor positivity (P=0.005), and Ki67 positivity (P=0.003). Multivariate analysis showed that tumor size (>2 cm, P=0.001), positive axillary lymph node metastasis (P=0.028), and estrogen receptor negativity (P<0.001) were significantly associated with the SUV.

CONCLUSION

High levels of F-FDG uptake in primary breast cancer were correlated with poor prognostic factors and aggressive biologic markers such as triple negativity, markers of basal-type cancer, and Ki67. The SUV might be predictive of biologic markers and assist therapeutic decision making.

Prognostic impact of progesterone receptor status combined with body mass index in breast cancer patients treated with adjuvant aromatase inhibitor

Aromatase inhibitors have played a central role in endocrine therapy for the treatment of estrogen receptor (ER)-positive breast cancer in postmenopausal patients. However, prognostic factors for recurrence following such treatment have not been identified. The current study aimed to validate the prognostic value of endocrine-related progesterone receptor (PgR) status combined with body mass index (BMI). Among 659 consecutive patients with primary breast cancer who underwent curative surgery between 2002 and 2012, 184 postmenopausal patients with ER-positive (ER+) and human epidermal growth factor receptor type 2-negative (HER2-) breast cancer who were treated with adjuvant aromatase inhibitor therapy were assessed. The patients were assigned to groups based on BMI, according to the WHO cut-off value: ≥25 kg/m² (high, H) or <25 kg/m² (low, L). Positive nodal status, negative PgR status, BMI-H and a high Ki-67 labeling index (≥20%) were found to be significantly associated with a short recurrence-free interval (RFI) upon univariate analysis (P=0.048, 0.007, 0.027, and 0.012, respectively). The patients were further grouped based on their combined PgR/BMI status. The RFI was significantly shorter in the PgR- and/or BMI-H group compared with that of the PgR+/BMI-L group (P=0.012). Multivariate analysis revealed PgR- tumors and/or BMI-H and positive nodal status to be independent prognostic factors (P=0.012 and 0.020, respectively). The present findings indicate that PgR/BMI status may serve as a practical tool in the management of ER+ and HER2- breast cancer in patients treated with adjuvant aromatase inhibitors.

Maximum standardized uptake value of fluorodeoxyglucose positron emission tomography/computed tomography is a prognostic factor in ovarian clear cell adenocarcinoma

BACKGROUND

Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) is useful for diagnosing malignant tumors. Intracellular FDG uptake is measured as the standardized uptake value (SUV), which differs depending on tumor characteristics. This study investigated differences in maximum SUV (SUVmax) according to histologic type in ovarian epithelial cancer and the relationship of SUVmax with prognosis.

METHODS

This study included 80 patients with ovarian epithelial cancer based on histopathologic findings at surgery and who had undergone PET/CT before treatment. Maximum SUV on PET/CT of primary lesions and histopathology were compared based on histologic type, and the prognosis associated with different SUVmax was evaluated.

RESULTS

Clinical tumor stage was I in 35 patients, II in 8, III in 25, and IV in 12. Histologic type was serous adenocarcinoma (AC) in 33 patients, clear cell AC in 27, endometrioid AC in 15, and mucinous AC in 5. Median SUVmax was lower in mucinous AC (2.76) and clear cell AC (4.9) than in serous AC (11.4) or endometrioid AC (11.4). Overall, median SUVmax was lower in clinical stage I (5.37) than in clinical stage ≥II (10.3). However, in both clear cell AC and endometrioid AC, when histologic evaluation was possible, no difference was seen between stage I and stage ≥II. Moreover, in clear cell AC, the 5-year survival rate was significantly higher in the low-SUVmax group (100%) than in the high-SUVmax group (43.0%, P = 0.009).

CONCLUSIONS

Maximum SUV on preoperative FDG-PET/CT in ovarian epithelial cancer differs according to histologic type. In clear cell AC, SUVmax may represent a prognostic factor.

Axillary Lymph Node-to-Primary Tumor Standard Uptake Value Ratio on Preoperative (18)F-FDG PET/CT: A Prognostic Factor for Invasive Ductal Breast Cancer

Purpose

This study assessed the axillary lymph node (ALN)-to-primary tumor maximum standard uptake value (SUV_max) ratio (ALN/T SUV ratio) in invasive ductal breast cancer (IDC) on preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to determine the effectiveness in predicting recurrence-free survival (RFS).

Methods

One hundred nineteen IDC patients (mean age, 50.5±10.5 years) with pathologically proven ALN involvement without distant metastasis and preoperative FDG PET/CT were enrolled in the study. SUV_max values of the ALN and primary tumor were obtained on FDG PET/CT, and ALN/T SUV ratio was calculated. Several factors were evaluated for their effectiveness in predicting RFS. These included several parameters on FDG PET/CT as well as several clinicopathological parameters: pathologic tumor/node stage; nuclear and histological grade; hormonal state; status with respect to human epidermal growth factor receptor 2, mindbomb E3 ubiquitin protein ligase 1 (MIB-1), and p53; primary tumor size; and ALN size.

Results

Among 119 patients with breast cancer, 17 patients (14.3%) experienced relapse during follow-up (mean follow-up, 28.4 months). The ALN/T SUV ratio of the group with disease recurrence was higher than that of the group without recurrence (0.97±1.60 and 0.45±0.40, respectively, p=0.005). Univariate analysis showed that the primary tumor SUV_max, ALN SUV_max, ALN/T SUV ratio, ALN status, nuclear and histological grade, estrogen receptor (ER) status, and MIB-1 status were predictors for RFS. Among these variables, ALN/T SUV ratio with hazard ratio of 4.20 (95% confidence interval [CI], 1.74-10.13) and ER status with hazard ratio of 4.33 (95% CI, 1.06-17.71) were predictors for RFS according to multivariate analysis (p=0.002 and p=0.042, respectively).

Conclusion

Our study demonstrated that ALN/T SUV ratio together with ER status was an independent factor for predicting relapse in IDC with metastatic ALN. ALN/T SUV ratio on preoperative FDG PET/CT may be a useful marker for selecting IDC patients that need adjunct treatment to prevent recurrence.

Correlation between (18)F-FDG uptake on PET/CT and prognostic factors in triple-negative breast cancer

OBJECTIVES

The purpose of this study was to investigate whether a correlation exists between (18)F-fluorodeoxyglucose (FDG) uptake and prognostic factors in triple-negative breast cancer (TNBC).

METHODS

Between January 2009 and December 2013, 103 patients (mean age, 50.6 years) with primary TNBC (mean, 2.6 cm; range, 1.0-6.5 cm) underwent (18)F-FDG PET/CT for initial staging. Correlations between maximum standardized uptake value (SUVmax) on PET/CT and prognostic factors including tumour size, nodal status, histological grade, Ki-67 proliferation index, tumour suppressor p53, and 'basal-like' markers (epidermal growth factor receptor and CK 5/6) were assessed.

RESULTS

The mean SUVmax of the 103 tumours was 10.94 ± 5.25 (range: 2-32.8). There was a positive correlation between SUVmax and Ki-67 (Spearman's rho = 0.29, P = 0.003) and tumour size (Spearman's rho = 0.27, P = 0.006), whereas this relationship was not observed in the nodal status, histological grade, p53 status and 'basal-like' phenotypes. In a multivariate regression analysis, Ki-67 (P < 0.001) and tumour size (P = 0.009) were significantly associated with SUVmax in TNBCs.

CONCLUSIONS

Increased (18)F-FDG uptake on PET/CT was correlated with a high Ki-67 proliferation index and larger tumour size in TNBC. These results suggest a potential role of (18)F-FDG PET/CT in identifying TNBC with more aggressive behaviour.

KEY POINTS

• A wide range of FDG uptake reflected heterogeneity of cancer metabolism. • FDG uptake was correlated with the Ki-67 proliferation index in TNBC. • FDG uptake was correlated with tumour size in TNBC. • FDG uptake was not correlated with 'basal-like' phenotype.

Lectin RCA-I specifically binds to metastasis-associated cell surface glycans in triple-negative breast cancer

Introduction

Triple-negative breast cancer (TNBC) patients often face a high risk of early relapse characterized by extensive metastasis. Previous works have shown that aberrant cell surface glycosylation is associated with cancer metastasis, suggesting that altered glycosylations might serve as diagnostic signatures of metastatic potential. To address this question, we took TNBC as an example and analyzed six TNBC cell lines, derived from a common progenitor, that differ in metastatic potential.

Methods

We used a microarray with 91 lectins to screen for altered lectin bindings to the six TNBC cell lines. Candidate lectins were then verified by lectin-based flow cytometry and immunofluorescent staining assays using both TNBC/non-TNBC cancer cells. Patient-derived tissue microarrays were then employed to analyze whether the staining of Ricinus communis agglutinin I (RCA-I), correlated with TNBC severity. We also carried out real-time cell motility assays in the presence of RCA-I. Finally, liquid chromatography-mass spectrometry/tandem spectrometry (LC-MS/MS) was employed to identify the membrane glycoproteins recognized by RCA-I.

Results

Using the lectin microarray, we found that the bindings of RCA-I to TNBC cells are proportional to their metastatic capacity. Tissue microarray experiments showed that the intensity of RCA-I staining is positively correlated with the TNM grades. The real-time cell motility assays clearly demonstrated RCA-I inhibition of adhesion, migration, and invasion of TNBC cells of high metastatic capacity. Additionally, a membrane glycoprotein, POTE ankyrin domain family member F (POTEF), with different galactosylation extents in high/low metastatic TNBC cells was identified by LC-MS/MS as a binder of RCA-I.

Conclusions

We discovered RCA-I, which bound to TNBC cells to a degree that is proportional to their metastatic capacities, and found that this binding inhibits the cell invasion, migration, and adhesion, and identified a membrane protein, POTEF, which may play a key role in mediating these effects. These results thus indicate that RCA-I-specific cell surface glycoproteins may play a critical role in TNBC metastasis and that the extent of RCA-I cell binding could be used in diagnosis to predict the likelihood of developing metastases in TNBC patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0544-9) contains supplementary material, which is available to authorized users.

Utility of (18)F FDG-PET/CT for predicting prognosis of luminal-type breast cancer

Postoperative prognosis is better for hormonal receptor-positive breast cancer than for other phenotypes; however, there are no definitive predictive factors for relapse or survival. This study aimed to evaluate the maximum standardized uptake value (SUVmax) on (18)F-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (FDG-PET/CT) and clinicopathological characteristics as possible predictors of postoperative relapse-free survival (RFS) and overall survival (OS) in hormonal receptor-positive breast cancer patients. We evaluated 262 patients with Stage I-III breast cancer diagnosed as luminal type (luminal A, 166; luminal B, 96 patients) who underwent preoperative FDG-PET/CT between January 2006 and December 2011 at two institutions. The relationships among SUVmax and clinicopathological factors (age, clinical T/N stage, nuclear grade, lymph node metastasis and vascular invasion) were evaluated. A phantom study was performed to correct differences in PET/CT analysis between two institutions. The patients were divided according to the SUVmax cutoff on receiver operating characteristic (ROC) analysis for OS (≤6.0 group vs. >6.0 group, AUC = 0.742). Clinical T-factor and nuclear grade were significantly correlated with SUVmax (p < 0.0001 and p = 0.0092, respectively). In the uni- and multivariate analyses using the Cox model for relapse, SUVmax was significant (p = 0.013 and p = 0.055, respectively) among characteristics. RFS curves showed that prognosis was significantly better for the SUVmax ≤ 6.0 group than for the SUVmax > 6.0 group (p = 0.004). Similarly, SUVmax was significant for OS (p = 0.007 and p = 0.008). OS was significantly different between the SUVmax ≤ 6.0 and >6.0 groups (p < 0.001). SUVmax was useful for predicting outcomes in patients with luminal-type breast cancer.

Role of positron emission tomography for the monitoring of response to therapy in breast cancer

This review considers the potential utility of positron emission tomography (PET) tracers in the setting of response monitoring in breast cancer, with a special emphasis on glucose metabolic changes assessed with (18)F-fluorodeoxyglucose (FDG). In the neoadjuvant setting of breast cancer, the metabolic response can predict the final complete pathologic response after the first cycles of chemotherapy. Because tumor metabolic behavior highly depends on cancer subtype, studies are ongoing to define the optimal metabolic criteria of tumor response in each subtype. The recent multicentric randomized AVATAXHER trial has suggested, in the human epidermal growth factor 2-positive subtype, a clinical benefit of early tailoring the neoadjuvant treatment in women with poor metabolic response after the first course of treatment. In the bone-dominant metastatic setting, there is increasing clinical evidence that FDG-PET/computed tomography (CT) is the most accurate imaging modality for assessment of the tumor response to treatment when both metabolic information and morphologic information are considered. Nevertheless, there is a need to define standardized metabolic criteria of response, including the heterogeneity of response among metastases, and to evaluate the costs and health outcome of FDG-PET/CT compared with conventional imaging. New non-FDG radiotracers highlighting specific molecular hallmarks of breast cancer cells have recently emerged in preclinical and clinical studies. These biomarkers can take into account the heterogeneity of tumor biology in metastatic lesions. They may provide valuable clinical information for physicians to select and monitor the effectiveness of novel therapeutics targeting the same molecular pathways of breast tumor.

Role of FDG-PET/CT in prediction of underestimation of invasive breast cancer in cases of ductal carcinoma in situ diagnosed at needle biopsy

BACKGROUND

The aim of this study was to evaluate the significance of FDG-PET/CT for predicting the underestimation of invasive breast cancer in cases of DCIS at needle biopsy.

PATIENTS AND METHODS

Of 83 consecutive cases with diagnoses of DCIS at primary needle biopsy who underwent curative surgery between 2010 and 2013, the association between the SUVmax on FDG-PET/CT before excision and the underestimation of invasive breast cancer was examined.

RESULTS

There were 29 (34.9%) cases diagnosed to have invasive breast cancer at excision. Receiver operating characteristics curve analysis showed the cutoff value of the SUVmax to predict underestimation of invasive breast cancer was 1.6. The rates of underestimation were 61.5% for patients with a tumor of SUVmax > 1.6 and 11.4% for patients with a tumor of SUVmax ≤ 1.6 (P < .001). A high value of SUVmax was significantly associated with symptomatic presentation (P < .001), palpability (P < .001), mass formation (P = .013), high Breast Imaging Reporting and Data System category (P = .011), and core needle biopsy (P = .007). In multivariate analysis, high SUVmax was only a significant predictive factor of underestimation of invasive breast cancer (hazard ratio, 11.7; 95% confidence interval, 3.70-37.0; P < .001).

CONCLUSION

SUVmax on FDG-PET/CT is useful for predicting the underestimation of invasive breast cancer in cases of DCIS at needle biopsy.

Role of maximum standardized uptake value in fluorodeoxyglucose positron emission tomography/computed tomography predicts malignancy grade and prognosis of operable breast cancer: a multi-institute study

The malignant biological behavior of breast cancer remains obscure on diagnostic images, although understanding the grade of such malignancy is important for selecting appropriate treatment. Therefore, malignancy grades in operable breast cancer were evaluated using positron emission tomography/computed tomography (PET/CT) in a multicenter setting. We prospectively examined the features and prognosis of 344 patients (mean age ± SD: 58.0 ± 12.5 years) with clinical stages I–III breast cancer, who underwent surgical intervention without induction therapy between January 2006 and December 2011. Maximum standardized uptake values (maxSUV) obtained from whole-body fluorodeoxyglucose-PET/CT immediately before surgery were assessed to predict the malignant aggressiveness of tumors including the recurrence-free survival of the patients. Variations in maxSUV among institutions, which are limitations of PET assessments in multicenter studies, were adjusted using a phantom study. The median follow up period was 52 months. The patients were divided into groups according to cut-off maxSUV (≤3.0 vs. >3.0) values established from receiver operating characteristic analysis of recurrence (area under the curve = 0.713). A higher maxSUV was significantly associated with a higher T-factor (p < 0.0001), N-factor (p = 0.0049), nuclear grade (p < 0.0001), negative for estrogen (p = 0.0309), and progesterone receptors (p = 0.0063), positive for human epidermal growth factor receptor 2 (p = 0.0012), lymph node metastasis (p = 0.0128), and vascular invasion (p = 0.0110). Multivariate analysis using Cox proportional hazard regression model revealed high maxSUV and negative estrogen receptor status as significantly prognostic factors (p = 0.033 and p = 0.004, respectively). This study demonstrated that maxSUV on PET/CT as well as estrogen receptor status is useful to predict malignancy grades and the prognosis of patients with breast cancer.