The relationship between FDG uptake in PET scans and biological behavior in breast cancer

Correlation between Histopathological Prognostic Tumor Characteristics and [18F]FDG Uptake in Corresponding Metastases in Newly Diagnosed Metastatic Breast Cancer

BACKGROUND

In metastatic breast cancer (MBC), [18F]fluorodeoxyglucose positron emission tomography/computed tomography ([18F]FDG-PET/CT) can be used for staging. We evaluated the correlation between BC histopathological characteristics and [18F]FDG uptake in corresponding metastases.

PATIENTS AND METHODS

Patients with non-rapidly progressive MBC of all subtypes prospectively underwent a baseline histological metastasis biopsy and [18F]FDG-PET. Biopsies were assessed for estrogen, progesterone, and human epidermal growth factor receptor 2 (ER, PR, HER2); Ki-67; and histological subtype. [18F]FDG uptake was expressed as maximum standardized uptake value (SUVmax) and results were expressed as geometric means.

RESULTS

Of 200 patients, 188 had evaluable metastasis biopsies, and 182 of these contained tumor. HER2 positivity and Ki-67 ≥ 20% were correlated with higher [18F]FDG uptake (estimated geometric mean SUVmax 10.0 and 8.8, respectively; p = 0.0064 and p = 0.014). [18F]FDG uptake was lowest in ER-positive/HER2-negative BC and highest in HER2-positive BC (geometric mean SUVmax 6.8 and 10.0, respectively; p = 0.0058). Although [18F]FDG uptake was lower in invasive lobular carcinoma (n = 31) than invasive carcinoma NST (n = 146) (estimated geometric mean SUVmax 5.8 versus 7.8; p = 0.014), the metastasis detection rate was similar.

CONCLUSIONS

[18F]FDG-PET is a powerful tool to detect metastases, including invasive lobular carcinoma. Although BC histopathological characteristics are related to [18F]FDG uptake, [18F]FDG-PET and biopsy remain complementary in MBC staging (NCT01957332).

Imaging Molecular Targets and Metabolic Pathways in Breast Cancer for Improved Clinical Management: Current Practice and Future Perspectives

Breast cancer is the most frequently diagnosed cancer and leading cause of cancer-related deaths worldwide. Timely decision-making that enables implementation of the most appropriate therapy or therapies is essential for achieving the best clinical outcomes in breast cancer. While clinicopathologic characteristics and immunohistochemistry have traditionally been used in decision-making, these clinical and laboratory parameters may be difficult to ascertain or be equivocal due to tumor heterogeneity. Tumor heterogeneity is described as a phenomenon characterized by spatial or temporal phenotypic variations in tumor characteristics. Spatial variations occur within tumor lesions or between lesions at a single time point while temporal variations are seen as tumor lesions evolve with time. Due to limitations associated with immunohistochemistry (which requires invasive biopsies), whole-body molecular imaging tools such as standard-of-care [18F]FDG and [18F]FES PET/CT are indispensable in addressing this conundrum. Despite their proven utility, these standard-of-care imaging methods are often unable to image a myriad of other molecular pathways associated with breast cancer. This has stimulated interest in the development of novel radiopharmaceuticals targeting other molecular pathways and processes. In this review, we discuss validated and potential roles of these standard-of-care and novel molecular approaches. These approaches' relationships with patient clinicopathologic and immunohistochemical characteristics as well as their influence on patient management will be discussed in greater detail. This paper will also introduce and discuss the potential utility of novel PARP inhibitor-based radiopharmaceuticals as non-invasive biomarkers of PARP expression/upregulation.

Radiological predictive factors on preoperative multimodality imaging are related to Oncotype DX recurrence score in estrogen-positive/human epidermal growth factor receptor 2-negative invasive breast cancer: a cross-sectional study

OBJECTIVE

The Oncotype DX (ODX) estimates the 10-year risk of metastasis or recurrence of breast cancer and indicates whether chemotherapy is likely to be effective; however, the high cost of this test may limit its use for patients. The aim of this study was to evaluate the potential of preoperative imaging using mammography (MMG), ultrasonography (US), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and positron emission tomography/computed tomography (PET/CT) metabolic parameters in predicting the ODX recurrence score (ODXRS), which prognosticates estrogen receptor-positive (ER +)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer.

METHODS

This retrospective study was conducted on 51 patients with ER+/ HER2- early-stage breast cancer with preoperative images available. Surgical specimens were sent for ODX assay and the ODXRS was categorized as low (<18) or intermediate/high (≥18). MMG/US findings were classified according to BI-RADS categories. For MRI analysis, tumor growth orientation was evaluated in addition to morphological assessment in BI-RADS. For PET/CT analysis, standardized uptake value (SUV) of the tumor were measured. Patient, tumor, and image characteristics were compared between the two groups, and predictors of the low ODXRS group were determined by logistic regression analysis. Two-sided P values less than 0.05 were considered statistically significant.

RESULTS

Thirty-two (63%) and 19 (37%) patients were categorized as low and intermediate/high ODXRS, respectively. On univariate analysis, nuclear grade, tumor margin, and tumor growth orientation on MRI, and SUV_max on PET/CT were significantly associated with a low ODXRS. Multivariate analysis revealed that tumor growth orientation perpendicular to the Cooper's ligament on MRI (P = 0.031) and a low SUV_max on PET/CT (P = 0.016) were independent prognostic factors for a low ODXRS. As a predictor of low ODXRS, the receiver operating characteristic (ROC) analysis of the SUV_max showed that using 3.0 as the optimal cut-off value has a sensitivity and specificity of 94.4% and 73.0%, respectively, with an area under the curve (AUC) of 0.923.

CONCLUSIONS

The combination of perpendicular tumor growth orientation to Cooper's ligaments on MRI and a low SUV_max on PET/CT may predict a low ODXRS.

Integrated analysis reveals the participation of IL4I1, ITGB7, and FUT7 in reshaping the TNBC immune microenvironment by targeting glycolysis

BACKGROUND

The overall response rate of immunotherapy in triple-negative breast cancer (TNBC) remains unsatisfactory. Accumulating evidence indicated that glucose metabolic reprogramming could modulate immunotherapy efficacy. However, transcriptomic evidence remains insufficient.

METHODS

Genes' relationship with glucose metabolism and TNBC-specific immune was demonstrated by weighted gene co-expression network analysis (WGCNA). The glucose metabolic capability was estimated by standardised uptake value (SUV), an indicator of glucose uptake in 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET), and a reflection of cancer metabolic behaviour. PD-(L)1 expression was used to reflect the efficacy of immunotherapy. Additionally, immune infiltration, survival, and gene coexpression profiles were provided.

RESULTS

Comprehensive analysis revealing that IL4I1, ITGB7, and FUT7 hold the potential to reinforce immunotherapy by reshaping glucose metabolism in TNBC. These results were verified by functional enrichment analysis, which demonstrated their relationships with immune-related signalling pathways and extracellular microenvironment reprogramming. Their expressions have potent positive correlations with Treg and Macrophage cell infiltration and exhausted T cell markers. Meanwhile, their overexpression also lead to poor prognosis.

CONCLUSION

IL4I1, ITGB7, and FUT7 may be the hub genes that link glucose metabolism, and cancer-specific immunity. They may be potential targets for enhancing ICB treatment by reprogramming the tumour microenvironment and remodelling tumour metabolism.

Evaluation of the Histopathological Features of Early-stage Invasive Ductal Breast Carcinoma by 18Fluoride-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Objectives:

This study investigates the relationship between ¹⁸fluoride-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) parameters and histopathological features in patients with early-stage invasive ductal breast carcinoma (IDBC).

Methods:

Patients with early-stage IDBC who underwent ¹⁸F-FDG PET/CT scan for staging were included in this retrospective study. The status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2, Ki-67 proliferative index, and grades of tumors were recorded. The conventional metabolic parameters [maximum standard uptake value (SUV_max) and average standard uptake value] and volume-based parameters [metabolic tumor volume (MTV) and total lesion glycolysis] of the primary tumor were obtained from the ¹⁸F-FDG PET/CT images. The associations and correlations between the ¹⁸F-FDG PET/CT parameters and histopathological features were assessed.

Results:

One hundred forty-three patients were included. ¹⁸F-FDG PET/CT parameters, other than MTV, were significantly associated with the ER and PR status and Ki-67 index, while T-staging was significantly associated with all ¹⁸F-FDG PET/CT parameters. In the axillary lymph node (ALN) involvement, no significant difference was found in the ¹⁸F-FDG PET/CT parameters. In terms of the pathological stage, a significant difference was found in all ¹⁸F-FDG PET/CT parameters. ¹⁸F-FDG PET/CT parameters, other than MTV, were significantly higher in non-luminal breast tumors than luminal tumors and in high-grade tumors than low-grade ones. Triple-negative tumors had the highest ¹⁸F-FDG PET/CT parameter, but the difference was insignificant for MTV. The SUV_max had the strongest correlation with Ki-67 proliferative index.

Conclusion:

Tumors with aggressive histopathological features had higher ¹⁸F-FDG PET/CT parameter values. This study suggests that ¹⁸F-FDG PET/CT may provide prognostic information in patients with early-stage IDBC.

Relationship between Prognostic Stage in Breast Cancer and Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

This retrospective study examined the relationship between the standardized uptake value max (SUVmax) of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and the prognostic stage of breast cancer. We examined 358 breast cancers in 334 patients who underwent ¹⁸F-FDG PET/CT for initial staging between January 2016 and December 2019. We extracted data including SUVmax of ¹⁸F-FDG PET and pathological biomarkers, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and nuclear grade. Anatomical and prognostic stages were determined per the American Joint Committee on Cancer (eighth edition). We examined whether there were statistical differences in SUVmax between each prognostic stage. The mean SUVmax values for clinical prognostic stages were as follow: stage 0, 2.2 ± 1.4; stage IA, 2.6 ± 2.1; stage IB, 4.2 ± 3.5; stage IIA, 5.2 ± 2.8; stage IIB, 7.7 ± 6.7; and stage III + IV, 7.0 ± 4.5. The SUVmax values for pathological prognostic stages were as follows: stage 0, 2.2 ± 1.4; stage IA, 2.8 ± 2.2; stage IB, 5.4 ± 3.6; stage IIA, 6.3 ± 3.1; stage IIB, 9.2 ± 7.5, and stage III + IV, 6.2 ± 5.2. There were significant differences in mean SUVmax between clinical prognostic stage 0 and ≥II (p < 0.001) and I and ≥II (p < 0.001). There were also significant differences in mean SUVmax between pathological prognostic stage 0 and ≥II (p < 0.001) and I and ≥II (p < 0.001). In conclusion, mean SUVmax increased with all stages up to prognostic stage IIB, and there were significant differences between several stages. The SUVmax of ¹⁸F-FDG PET/CT may contribute to prognostic stage stratification, particularly in early cases of breast cancers.

Relationship of the standard uptake value of 18F-FDG-PET-CT with tumor-infiltrating lymphocytes in breast tumors measuring ≥ 1 cm

Evidence suggests that tumor cells and tumor-infiltrating lymphocytes (TILs) compete for glucose in the tumor microenvironment and that tumor metabolic parameters correlate with localized immune markers in several solid tumors. We investigated the relationship of the standardized uptake value (SUV) of ¹⁸F-fluorodeoxyglucose positron emission tomography computed tomography (¹⁸F-FDG-PET-CT) with stromal TIL levels in breast cancer. We included 202 patients who underwent preoperative ¹⁸F-FDG-PET-CT and had a tumor measuring ≥ 1 cm. Maximum SUV (SUVmax) was determined using ¹⁸F-FDG-PET-CT. Multiple logistic regression was used to identify factors related to high TIL levels (≥ 40%). All tumors were treatment naïve. A significant and weak correlation existed between continuous SUVmax and continuous TIL levels (p = 0.002, R = 0.215). Tumors with high SUVmax (≥ 4) had higher mean TIL levels than those with low SUVmax (< 4). In multivariable analysis, continuous SUVmax was an independent factor associated with high TIL levels; each 1-unit increment in SUVmax corresponded to an odds ratio of 1.14 (95% confidence interval: 1.01–1.29) for high TIL levels. Our study implies that SUV is associated with TILs in breast cancer and provides clinical evidence that elevated glucose uptake by breast tumors can predict the immune system-activated tumor micromilieu.

Correlation between semiquantitative and volumetric 18F-FDG PET/computed tomography parameters and Ki-67 expression in breast cancer

OBJECTIVES

To evaluate the relationship between semiquantitative and volumetric parameters on 18F-FDG PET/computed tomography (CT), including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG), tumor to liver ratio (TLR) and tumor to mediastinum ratio (TMR) with the level of Ki-67 expression in breast cancer.

PATIENT AND METHODS

We retrospectively reviewed 105 female patients with newly diagnosed breast cancer who underwent baseline 18F-FDG PET/CT and had immunohistochemical staining to determine the level of Ki-67 expression. The following PET parameters were measured (SUVmax, SUVmean, MTV, TLG, TLR and TMR) and correlated with level of Ki-67 expression.

RESULTS

Significant moderate positive correlations were found between the PET parameters (primary SUVmax, SUVmean, TLG, TLR and TMR) and level of Ki-67 expression. The primary SUVmax had the highest correlation coefficient (r = 0.461) followed by TMR (r = 0.455) and P value of <0.001 for both. In ROC analysis, primary SUVmax had the largest area under the curve (0.806, P = 0.0001), with sensitivity of 76.5 % and specificity of 75% for prediction of high Ki-67 level. In univariate analysis, all PET parameters, patient age, tumor grade, molecular subtype, estrogen receptor and progesterone receptor status were significantly associated with Ki-67 level. In multivariate regression analysis, only tumor grade [odds ratio (OR) = 20.460, 95% confidence interval (CI): 11.360-29.559, P = <0.0001], molecular subtype (OR = -21.894, 95% CI: -37.921 to -5.866, P = 0.008), SUVmax (OR = 2.299, 95% CI: 0.703-3.895, P = 0.005) and TLR (OR = -4.908, 95% CI: -9.476 to -0.340, P = 0.035) were found to be the strongest independent predictor factors for the level of Ki-67 expression and hence proliferative activity of malignant cells in breast cancer.

CONCLUSION

The semiquantitative parameters and volumetric 18F-FDG PET/CT parameter, that is, TLG correlated well with proliferation marker Ki-67 in breast cancer. 18F-FDG PET/CT imaging can be used as a useful noninvasive diagnostic tool in imaging cellular proliferation and hence may substitute for in vitro testing of molecular markers in the diagnoses and staging of breast cancer.

Concomitant use of 18F-FDG PET-CT SUVmax is useful in the assessment of Ki67 labeling index in core-needle biopsy specimens of breast cancer

Background

Ki67 is a recognized proliferative and predictive marker in invasive breast cancer. However, results of Ki67 evaluation are affected by the method employed for sample fixation or biopsy, as well as by intratumor heterogeneity. Here, we aimed to compare the Ki67 labeling index (Ki67LI) between core-needle biopsy specimens (CNBSs) and surgically resected specimens (SRSs) of invasive breast cancer, and verify whether the discordance in Ki67LI can be reduced by analyzing the maximum standardized uptake value (SUVmax) obtained from pretreatment whole-body positron emission tomography/computed tomography (PET/CT) in combination with Ki67LI.

Methods

Tumor tissues were obtained from 118 patients with invasive breast cancer. Ki67LI was evaluated in CNBSs and SRSs by immunohistochemistry. First, we directly compared Ki67LI between CNBS and SRS, "allowing a tolerance margin of 5%." We divided the Ki67LI values into three groups (Low: 0≤ Ki67LI ≤10, Intermediate: 10< Ki67LI <30, and High: 30≤ Ki67LI) and the SUVmax into three groups (SUVmax ≤4, 4< SUVmax <8, and 8≤ SUVmax). We then verified the concordance rate between CNBS and SRS in each group in combination with the SUVmax obtained by PET/CT.

Results

The median Ki67LI was 17.8% (0.5-75.9%) and 17.0% (1.0-75.7%) in CNBS and SRS, respectively. The overall Ki67LI concordance rate between CNBS and SRS was 37.3% (44/118). The concordance was improved in the Low and High Ki67LI groups by applying SUVmax thresholds of 4 [82.6% (19/23), P=0.033 and 8 (92.3% (12/13), P=0.009], respectively.

Conclusions

Our results indicated that CNBS Ki67LI alone was not able to reflect SRS Ki67LI with sufficient accuracy. By dividing CNBS Ki67LI into three classes in combination with SUVmax, tumor proliferation could be predicted with higher accuracy in patients with invasive breast carcinoma.

Genomic Signature of the Standardized Uptake Value in 18F-Fluorodeoxyglucose Positron Emission Tomography in Breast Cancer

The standardized uptake value (SUV), an indicator of the degree of glucose uptake in ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET), has been used for predicting the clinical behavior of malignant tumors. However, its characteristics have been insufficiently explored at the genomics level. Here, we aim to identify genomic signatures reflecting prognostic SUV characteristics in breast cancer (BRC). Through integrative genomic profiling of 3710 BRC patients, including 254 patients who underwent preoperative FDG-PET, we identified an SUV signature, which showed independent clinical utility for predicting BRC prognosis (hazard ratio [HR] 1.27, 95% confidence interval [CI] = 1.12 to 1.45, p = 2.23 × 10⁻⁴). The risk subgroups classified by the signature exhibited mutually exclusive mutation patterns of TP53 and PIK3CA and showed significantly different responsiveness to immunotherapy. Experimental assays revealed that a signaling axis defined by TP53–FOXM1 and its downstream effectors in glycolysis–gluconeogenesis, including LDHA, might be important mediators in the FDG-PET process. Our molecular characterizations support an understanding of glucose metabolism and poor prognosis in BRC with a high SUV, utilizable in clinical practice to assist other diagnostic tools.

Metabolic and volume-based parameters of (18F)FDG PET/CT for primary mass and axillary lymph node metastasis in patients with invasive ductal carcinoma: a retrospective analysis in relation to molecular subtype, axillary lymph node metastasis and immunohistochemistry and inflammatory markers

OBJECTIVE

To evaluate metabolic and volume-based parameters of 18-Fluorodeoxyglucose positron emission tomography/computed tomography ((F)FDG PET/CT) for primary mass and axillary lymph node (ALN) metastasis in relation to molecular subtype, and immunohistochemistry and inflammatory markers in patients with invasive ductal carcinoma.

METHODS

A total of 129 patients (mean±SD age: 49.2±13.0 years) with invasive ductal breast cancer who had (F)FDG PET/CT imaging prior to chemotherapy or surgery were included in this single-center retrospective study. Data on patient age, molecular subtype, ALN metastasis status, inflammatory markers, immunohistochemistry markers and (F)FDG PET/CT imaging parameters for primary mass and ALN were recorded.

RESULTS

ALN metastasis was evident in 52.7% of patients and associated with significantly higher median diameter (P=0.027), MTV (P<0.001) and TLG (P<0.001). NLR was positively correlated with all primary mass (p ranged from 0.041 to 0.001) and ALN (P ranged from 0.026 to <0.001) PET parameters. PET parameters did not change with respect to molecular subtype or immunohistochemistry markers. Primary mass and ALN metastasis PET parameters showed significant positive correlations for TLG (r=0.274, P=0.001) and SUVmax (r=0.358, P<0.001).

CONCLUSION

In conclusion, our findings in a retrospective cohort of invasive ductal breast cancer patients revealed primary mass PET parameters to significantly differ with respect to ALN metastasis status and NLR levels, but not according to molecular subtype or immunohistochemistry markers. Accordingly, our findings highlight the value of acquisition of preoperative PET/CT imaging and role of both metabolic and volume-based parameters in predicting aggressiveness of the tumor as correlated with presence of ALN metastasis and high NLR.

A preliminary study to propose a diagnostic algorithm for PET/CT-detected incidental breast lesions: application of BI-RADS lexicon for US in combination with SUVmax

OBJECTIVES

To develop a diagnostic algorithm for positron emission tomography (PET)-detected incidental breast lesions using both breast imaging reporting and data system (BI-RADS) and maximum standardized uptake value (SUVmax) criteria.

METHODS

Fifty-six PET-detected incidental breast lesions from 51 patients, which were subsequently investigated by breast ultrasound within 1 month of the PET study, constituted the study cohort and they were finally verified by tissue diagnosis or a 2-year follow-up. Based on the maximum specificity with sensitivity > 60.0% and maximum sensitivity with specificity > 60.0%, two SUVmax cutoff values were calculated at 2 and 3.7. BI-RADS ≥ 4 was considered as highly suspicious for malignancy. The diagnostic accuracies were estimated for SUVmax levels above or below the cutoff points combined with the BI-RADS suspicion level.

RESULTS

Overall, 46 benign and 10 malignant lesions were studied. The diagnostic characteristics of SUVmax ≥ 2, SUVmax ≥ 3.7, and BI-RADS ≥ 4 were 80.0%, 60.0%, and 80.0% for sensitivity, 73.9%, 95.7%, and 92.7% for specificity, and 75.0%, 89.3%, and 90.2% for accuracy, respectively. When the SUVmax threshold was set at 2, combined with BI-RADS suspicion level, the sensitivity, specificity, and accuracy were 100.0%, 69.6%, and 75.0%, respectively. The results for SUVmax threshold set at 3.7 combined with BI-RADS were 90.0%, 91.3%, and 91.1% for the sensitivity, specificity, and accuracy, respectively. A diagnostic algorithm was accordingly generated.

CONCLUSION

The need for biopsy should be justified in low BI-RADS lesions presenting with high SUVmax at 3.7 or higher. The biopsy of patients with high B-IRADS and low SUVmax could be preserved.

KEY POINTS

• A diagnostic algorithm was developed for PET-detected incidental breast lesions using both BI-RADS and SUVmax criteria. • Diagnostic performance was calculated separately and conjunctively for SUVmax ≥ 2, SUVmax ≥ 3.7, and BI-RADS ≥ 4. • The need for biopsy can be justified in BI-RADS < 4 lesions with SUVmax ≥ 3.7. Lesions with BI-RADS < 4 and indeterminate SUVmax (2 < SUVmax < 3.7) benefit from a short-interval follow-up. BI-RADS < 4 lesions with SUVmax < 2 may confidently be scheduled for routine screening.

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 SUVmax 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 SUVmax 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

SUVmax 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.

Impact of physiological hormonal fluctuations on 18F-fluorodeoxyglucose uptake in breast cancer

PURPOSE

Premenopausal physiologic steroid levels change cyclically, in contrast to steady state low levels seen in postmenopausal patients. The purpose of this study was to evaluate whether ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake in breast cancer is influenced by physiological hormonal fluctuations.

METHODS

A total of 160 primary invasive breast cancers from 155 females (54 premenopausal, 101 postmenopausal) who underwent ¹⁸F-FDG positron emission tomography/computed tomography before therapy were retrospectively analyzed. The maximal standardized uptake values (SUVmax) of tumors were compared with menstrual phases and menopausal status according to the following subgroups: 'luminal A-like,' 'luminal B-like,' and 'non-luminal.' Additionally, the effect of estradiol (E2) on ¹⁸F-FDG uptake in breast cancer cells was evaluated in vitro.

RESULTS

Among premenopausal patients, SUVmax during the periovulatory-luteal phase was significantly higher than that during the follicular phase in luminal A-like tumors (n = 25, p = 0.004), while it did not differ between the follicular phase and the periovulatory-luteal phase in luminal B-like (n = 24) and non-luminal tumors (n = 7). Multiple regression analysis showed menstrual phase, tumor size, and Ki-67 index are independent predictors for SUVmax in premenopausal luminal A-like tumors. There were no significant differences in SUVmax between pre- and postmenopausal patients in any of the subgroups. In in vitro studies, uptake in estrogen receptor-positive cells was significantly augmented when E2 concentration was increased from 0.01 to ≥ 1 nM.

CONCLUSIONS

Our data suggest that ¹⁸F-FDG uptake may be impacted by physiological hormonal fluctuations during menstrual cycle in luminal A-like cancers, and that E2 could be partly responsible for these events.

Carbon nanospheres mediated nuclear delivery of SMAR1 protein (DNA binding domain) controls breast tumor in mice model

Aim: To investigate anticancer activity of the DNA binding domain of SMAR1 (His 5) in vitro and in vivo. Materials & methods: His 5 was conjugated to hydrothermally synthesized carbon nanospheres (CNs). Anticancer activity of CNs-His 5 was evaluated in vitro and in vivo. Results: CNs- His 5 significantly reduced cyclin D1 levels in MDA-MB-231 cells. Tumor bearing Balb/c mice injected with CNs-His 5 showed approximately 62% tumor regression and significantly reduced 18FDG uptake. Caspases assay and IHC staining confirmed tumor growth inhibition, which could be attributed to apoptotic, antiproliferative and antiangiogenic activities of His 5. Conclusion: DNA binding domain of the SMAR1 protein (His 5) has potent anticancer activity and its CNs mediated delivery could control breast tumor in mice model.

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.

Considering the Relationship between Quantitative Parameters and Prognostic Factors in Breast Cancer: Can Mean Standardized Uptake Value be an Alternative to Maximum Standardized Uptake Value?

It was aimed to investigate the correlation between maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and retention index (RI), which represents the quantitative evaluation of the uptake of ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) used in positron emission tomography (PET) and clinicopathologic as well as biologic prognostic factors. Forty-one women with breast cancer who were histopathologically diagnosed were included in this study. Neoadjuvant chemotherapy was applied to all patients before PET/computed tomography (CT). After FDG injection, PET/CT screening was applied within the 1^st h (PET-1) and in the 2^nd h (PET-2). SUVmax, SUVmean, SUVmax RI, and SUVmean RI of every image were calculated qualitatively and semiquantitatively. The correlation between quantitative and semiquantitative PET parameters and biologic as well as clinicopathologic prognosis factors was evaluated. Statistically, significant positive correlation was found between lymph nodes (LNs), which were evaluated by clinical picture, clinical stage as well as histopathologically and quantitative PET parameters (SUVmax1, SUVmax2,, RImax, SUVmean1, SUVmean2, RImean) (P < 0.05). While statistically significant correlation with RImax was detected only by LN (histopathological), correlations with RImean were detected by clinical picture, clinical stage, metabolic stage, and LN (histopathological). Statistically, significant correlation was found between RImax and estrogen receptor in patients who were histopathologically diagnosed with invasive ductal carcinoma (n = 34) (P < 0.05). We detected correlations between biologic and clinicopathologic prognostic factors and SUVmax as well as SUVmean values in breast carcinoma. SUVmean values may provide important knowledge when the correlation between prognostic factors and PET parameters is investigated even if they are not used routinely.

Tumor size and proliferative marker geminin rather than Ki67 expression levels significantly associated with maximum uptake of 18F-deoxyglucose levels on positron emission tomography for breast cancers

It has been well established that maximum standardized uptake value (SUVmax) for ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) is clinically useful for evaluating treatment efficacy as well as predicting prognosis of breast cancer patients. Although SUVmax reflects increased glucose uptake and metabolism possibly induced by activation of growth factor signaling or TP53 dysfunction, tumor characteristics of SUVmax-high breast cancers remain to be elucidated. For the present study, we used immunohistochemical staining to investigate expressions of phospho-ribosomal protein S6 (pS6, downstream molecule of phosphatidyl inositol 3-kinase/Akt/mammalian target of the rapamycin/S6K pathway) and phosphor-p44/42 mitogen-activated protein kinase (pMAPK). Expression levels of TP53 and proliferative marker geminin as well as Ki67 were also examined by means of immunostaining in 163 invasive breast cancers. Cutoff values were set at 10% for pS6, 20% for pMAPK and TP53, and 4% for geminin. The SUVmax levels were significantly higher in the pS6-positive (p = 0.0173), TP53-positive (p = 0.0207) and geminin-high cancers (p<0.0001), but there was no significant association between pMAPK expression levels and SUVmax levels. Multivariable analysis showed that a high geminin level (odds ratio: 6.497, 95% confidence interval: 2.427–19.202, p = 0.0001) and large tumor size (6.438, 2.224–20.946, p = 0.0005) were significantly and independently associated with SUVmax-high. Univariable but not multivariable analysis indicated that Ki67-high significantly correlated with SUVmax-high. Twenty of 23 (87.0%) breast cancers with tumor size >2cm and geminin-high showed SUVmax-high, while only 6 of 49 (12.2%) breast cancers ≤2cm in size and with low geminin levels were SUVmax-high. In conclusion, we could determine that breast cancers with a large tumor and a geminin-high rather than Ki67-high proliferative marker were significantly associated with high levels of SUVmax. These findings may signify that SUVmax reflects tumor characteristics with high proliferative activity but not activation of mTOR/S6K and MAPK pathways or increased glucose metabolism due to dysfunction of TP53.

Strong association of epidermal growth factor receptor status with breast cancer FDG uptake

PURPOSE

Imaging tumor FDG uptake could complement breast cancer biomarkers of risk and treatment response. Although breast cancer FDG uptake is reputedly influenced by major biomarker states, the role of epidermal growth factor receptor (EGFR) expression remains largely unexplored.

METHODS

This is a retrospective study that included 499 patients with primary breast cancer at initial presentation. Tumor FDG uptake was measured on pretreatment PET/CT as maximum standardized uptake value (SUVmax), and biomarkers were assessed by immunohistochemistry of tumor tissue. Regression analysis was performed for predictors of high tumor FDG uptake (SUVmax ≥ 8.6).

RESULTS

SUVmax was higher in ER- (36.5%; 11.2 ± 6.0 vs. 8.3 ± 5.3), PR- (42.3%; 10.9 ± 6.0 vs. 8.2 ± 5.2), and triple-negative tumors (19.8%; 12.0 ± 6.9 vs. 8.7 ± 5.2; all p < 0.0001). EGFR expression (28.5%) was more frequent in ER-, PR-, triple-negative, cytokeratin 5/6 (CK5/6) + and mutant P53 (mP53) + tumors (all p < 0.0001). EGFR+ was associated with higher SUVmax among all tumors (11.9 ± 6.0 vs. 8.3 ± 5.3), ER- tumors (p < 0.0001), PR- and + tumors (p < 0.0001 and 0.027), hormone receptor- and + tumors (p < 0.0001 and 0.004), human epidermal growth factor receptor 2 (HER2)- and + tumors (p < 0.0001 and 0.006), non-triple negative tumors (p < 0.0001), CK5/6- and + tumors (p = 0.021 and <0.0001), and mP53- and + tumors (p < 0.0001 and 0.008). Tumors had high FDG uptake in 73.2% of EGFR+ and 40.6% of EGFR- tumors. On regression analysis, significant multivariate predictors of high tumor FDG uptake were large size, EGFR+ and CK5/6+ for the entire subjects, and EGFR+ and CK5/6+ for ER- and hormone receptor negative subgroups. High FDG uptake was able to sub-stratify EGFR+ tumors that were more likely to be ER- and CK5/6+, and EGFR- tumors more likely to be mP53 +.

CONCLUSIONS

Primary breast tumor FDG uptake is strongly influenced by EGFR status beyond that by other major biomarkers including hormone receptor and HER2 status, and EGFR expression is a strong independent predictor of high breast tumor FDG uptake.

Comparison of standardized uptake value of 18F-FDG-PET-CT with 21-gene recurrence score in estrogen receptor-positive, HER2-negative breast cancer

BACKGROUND

We investigated the relationship between 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET-CT) standardized uptake value (SUV) and 21-gene recurrence score (RS) in estrogen receptor (ER)-positive/HER2-negative breast cancer.

MATERIALS AND METHODS

One hundred sixty-seven patients were identified among those who underwent preoperative 18F-FDG-PET-CT and had RS. Maximum SUV was obtained from 18F-FDG-PET-CT; the cut-off point was 4.

RESULTS

The continuous RS and SUV correlated positively (Pearson's R = 0.555; P < 0.001). An inverse correlation was found between progesterone receptor (PR) expression by reverse transcriptase-polymerase chain reaction, and SUV (Pearson's R = -0.408; P < 0.001). Good agreement between dichotomized RS (<26 vs. ≥26) and SUV (<4 vs. ≥4) was observed in 137 of 167 patients (82.0%; 95% confidence interval [CI], 76.2-87.9). Among patients with low SUV, 114 of 115 (99.1% [95% CI, 97.4-100.0]) had tumors with lower RS (<26). Although 23 of 52 women (44.2% [95% CI, 30.7-57.7]) with high SUV had higher RS (≥26), all 13 women with high RS (≥31) had high-SUV tumors. Most cases with disagreements between SUV and RS (n = 30) were classified as high SUV/lower RS (n = 29). The discordant group had higher grade or elevated Ki67 expression (≥20%) compared with the low SUV/lower RS group (n = 109), but higher PR expression compared with the high SUV/higher RS group (n = 23). Multiple logistic regression analysis showed that high SUV were associated with higher RS (≥26).

CONCLUSIONS

SUV, as a biologic parameter represented using a continuous variable, was found to associate with RS in ER-positive, HER2-negative breast cancer. Further studies may reveal the biology underlying the discordance between the markers.

Molecular imaging using PET and SPECT for identification of breast cancer subtypes

Breast cancer is a major disease with high morbidity and mortality in women. As a highly heterogeneous tumor, it contains different molecular subtypes: luminal A, luminal B, human epidermal growth factor 2-positive, and triple-negative subtypes. As each subtype has unique features, it may not be universal to the optimal treatment and expected response for individual patients. Therefore, it is critical to identify different breast cancer subtypes. Targeting subcellular levels, molecular imaging, especially PET and single photon emission computed tomography, has become a promising means to identify breast cancer subtypes and monitor treatment. Different biological processes between various subtypes, including changes correlated with receptor expression, cell proliferation, or glucose metabolism, have the potential for imaging with PET and single photon emission computed tomography radiopharmaceuticals. Receptor imaging, with radiopharmaceuticals targeting estrogen receptor, progesterone receptor, or human epidermal growth factor 2, is available to distinguish receptor-positive tumors from receptor-negative ones. Cell proliferation imaging with fluorine-18 fluorothymidine PET aids identification of luminal A and B subtypes on the basis of the correlation with the immunohistochemical biomarker Ki-67. Glucose metabolism imaging with fluorine-18 fluorodeoxyglucose PET may have potential to discriminate triple-negative subtypes from others. With increasing numbers of novel radiopharmaceuticals, noninvasive molecular imaging will be applied widely for the identification of different subtypes and provide more in-vivo information on individualized management of breast cancer patients.

A virtual clinical trial comparing static versus dynamic PET imaging in measuring response to breast cancer therapy

We developed a method to evaluate variations in the PET imaging process in order to characterize the relative ability of static and dynamic metrics to measure breast cancer response to therapy in a clinical trial setting. We performed a virtual clinical trial by generating 540 independent and identically distributed PET imaging study realizations for each of 22 original dynamic fluorodeoxyglucose (¹⁸F-FDG) breast cancer patient studies pre- and post-therapy. Each noise realization accounted for known sources of uncertainty in the imaging process, such as biological variability and SUV uptake time. Four definitions of SUV were analyzed, which were SUVmax, SUVmean, SUVpeak, and SUV50%. We performed a ROC analysis on the resulting SUV and kinetic parameter uncertainty distributions to assess the impact of the variability on the measurement capabilities of each metric. The kinetic macro parameter, K _i , showed more variability than SUV (mean CV K _i   =  17%, SUV  =  13%), but K _i pre- and post-therapy distributions also showed increased separation compared to the SUV pre- and post-therapy distributions (mean normalized difference K _i   =  0.54, SUV  =  0.27). For the patients who did not show perfect separation between the pre- and post-therapy parameter uncertainty distributions (ROC AUC  <  1), dynamic imaging outperformed SUV in distinguishing metabolic change in response to therapy, ranging from 12 to 14 of 16 patients over all SUV definitions and uptake time scenarios (p  <  0.05). For the patient cohort in this study, which is comprised of non-high-grade ER+  tumors, K _i outperformed SUV in an ROC analysis of the parameter uncertainty distributions pre- and post-therapy. This methodology can be applied to different scenarios with the ability to inform the design of clinical trials using PET imaging.

Correlation of Molecular Subtypes of Invasive Ductal Carcinoma of Breast with Glucose Metabolism in FDG PET/CT: Based on the Recommendations of the St. Gallen Consensus Meeting 2013

PURPOSE

This study aimed to investigate the relationship between the SUVmax of primary breast cancer lesions and the molecular subtypes based on the recommendations of the St. Gallen consensus meeting 2013.

METHODS

Clinical records of patients who underwent F-18 FDG PET/CT for initial staging of invasive ductal carcinoma (IDC) of the breast were reviewed. A total of 183 patients were included. SUVmax was correlated with the molecular subtypes defined by the St. Gallen Consensus Meeting 2013, i.e., luminal A-like (LA), luminal B-like HER2 negative (LBHER2-), luminal B-like HER2 positive (LBHER2+), HER2 positive (HER2+), and triple negative (TN), and with the clinicohistopathologic characteristics.

RESULTS

The molecular subtype was LA in 38 patients, LBHER2- in 72, LBHER2+ in 21, HER2+ in 30, and TN in 22. The mean SUVmax in the LA, LBHER2-, LBHER2+, HER2+, and TN groups were 4.5 ± 2.3, 7.2 ± 4.9, 7.2 ± 4.3, 10.2 ± 5.5, and 8.8 ± 7.1, respectively. Although SUVmax differed significantly among these subtypes (p < 0.001), the values showed a wide overlap. Optimal cut-off SUVmax to differentiate LA from LBHER2-, LBHER2+, HER2+ and TN were 5.9, 5.8, 7.5, and 10.2 respectively, with area under curve (AUC) of 0.648, 0.709, 0.833, and 0.697 respectively. The cut-off value of 5.9 yielded the highest accuracy for differentiation between the LA and non-LA subtypes, with sensitivity, specificity, and AUC of 79.4 %, 57.9 %, and 0.704 respectively.

CONCLUSION

The SUVmax showed a significant correlation with the molecular subtype. Although SUVmax measurements could be used along with immunohistochemical analysis for differentiating between molecular subtypes, its application to individual patients may be limited due to the wide overlaps in SUVmax.

Role of Pre-therapeutic (18)F-FDG PET/CT in Guiding the Treatment Strategy and Predicting Prognosis in Patients with Esophageal Carcinoma

OBJECTIVES

The present study aimed to evaluate the role of pre-therapeutic (18)fluorine-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) and maximum standardized uptake value (SUVmax) in guiding the treatment strategy and predicting the prognosis of esophageal carcinoma, using the survival data of the patients.

METHODS

The present retrospective, cohort study was performed on 40 consecutive patients with esophageal carcinoma (confirmed by endoscopic biopsy), who underwent pre-operative (18)F-FDG PET-CT staging between January 2009 and June 2014. All the patients underwent contrast-enhanced CT and non-contrasted (18)F-FDG PET-CT evaluations. The patients were followed-up over 12 months to assess the changes in therapeutic strategies. Survival analysis was done considering the primary tumor SUVmax, using the Kaplan-Meier product-limit method.

RESULTS

In a total of 40 patients, (18)F-FDG PET-CT scan led to changes in disease stage in 26 (65.0%) cases, with upstaging and downstaging reported in 10 (25.0%) and 16 (40.0%) patients, respectively. The management strategy changed from palliative to curative in 10 out of 24 patients and from curative to palliative in 7 out of 16 cases. Based on the (18)F-FDG PET-CT scan alone, the median survival of patients in the palliative group was 4.0 (95% CI 3.0-5.0) months, whereas the median survival in the curative group has not been reached, based on the 12-month follow-up. Selection of treatment strategy on the basis of (18)F-FDG PET/CT alone was significantly associated with the survival outcomes at nine months (P=0.03) and marginally significant at 12 months (P=0.03). On the basis of SUVmax, the relation between survival and SUVmax was not statistically significant.

CONCLUSION

(18)F-FDG PET/CT scan had a significant impact on stage stratification and subsequently, selection of a stage-specific treatment approach and the overall survival outcome in patients with esophageal carcinoma. However, pre-treatment SUVmax failed to stablish its usefulness in the assessment of patient prognosis and survival outcome.

Ductal carcinoma in situ and ductal carcinoma in situ with microinvasion: correlation of FDG uptake with histological and biological prognostic factors

BACKGROUND

Several studies investigated the correlation between the intensity of fluorodeoxyglucose (FDG) uptake and some histological and biological characteristics in breast cancer. Ductal carcinoma in situ (DCIS) is generally thought to be a precursor lesion of invasive breast cancer. The aim of this study was to assess the correlation between FDG uptake values on positron emission tomography/computed tomography (PET/CT) with histological and biological prognostic factors in DCIS and ductal carcinoma in situ with microinvasion (DCIS-Mi).

MATERIALS AND METHODS

PET/CT images for initial staging of confirmed DCIS and DCIS-Mi patients, taken between July 2004 and December 2009, were reviewed retrospectively. Maximum standardized uptake values (SUVmax) and tumor background count density ratio on PET/CT were compared with tumor characteristics. Histological and biological prognostic factors included tumor size, nuclear grade, Van Nuys Prognostic Index, estrogen receptor, progesterone receptor, HER2, and Ki-67 index.

RESULTS

In total, 87 lesions from 83 patients (all females; mean age 51 ± 9 years) were studied. The Van Nuys Prognostic Index group was 1 in 25 lesions, 2 in 36, and 3 in 26. On statistical analysis, significant differences in SUVmax and tumor background count density ratio were seen between the Van Nuys Prognostic Index groups and according to tumor size and HER2. The correlation between SUVmax and Ki-67 was significant. However, the correlation between tumor background count density ratio and Ki-67 was not statistically significant.

CONCLUSION

In DCIS and DCIS-Mi cases, significant correlations were found between increased FDG uptake and several histological and biological factors for poor prognosis (tumor size, Van Nuys Prognostic Index, and HER2).

Association between partial-volume corrected SUVmax and Oncotype DX recurrence score in early-stage, ER-positive/HER2-negative invasive breast cancer

PURPOSE

Oncotype DX, a 21-gene expression assay, provides a recurrence score (RS) which predicts prognosis and the benefit from adjuvant chemotherapy in patients with early-stage, estrogen receptor-positive (ER-positive), and human epidermal growth factor receptor 2-negative (HER2-negative) invasive breast cancer. However, Oncotype DX tests are expensive and not readily available in all institutions. The purpose of this study was to investigate whether metabolic parameters on (18)F-FDG PET/CT are associated with the Oncotype DX RS and whether (18)F-FDG PET/CT can be used to predict the Oncotype DX RS.

METHODS

The study group comprised 38 women with stage I/II, ER-positive/HER2-negative invasive breast cancer who underwent pretreatment (18)F-FDG PET/CT and Oncotype DX testing. On PET/CT, maximum (SUVmax) and average standardized uptake values, metabolic tumor volume, and total lesion glycolysis were measured. Partial volume-corrected SUVmax (PVC-SUVmax) determined using the recovery coefficient method was also evaluated. Oncotype DX RS (0 - 100) was categorized as low (<18), intermediate (18 - 30), or high (≥31). The associations between metabolic parameters and RS were analyzed. Multivariate logistic regression was used to identify significant independent predictors of low versus intermediate-to-high RS.

RESULTS

Of the 38 patients, 22 (58 %) had a low RS, 13 (34 %) had an intermediate RS, and 3 (8 %) had a high RS. In the analysis with 38 index tumors, PVC-SUVmax was higher in tumors in patients with intermediate-to-high RS than in those with low RS (5.68 vs. 4.06; P = 0.067, marginally significant). High PVC-SUVmax (≥4.96) was significantly associated with intermediate-to-high RS (odds ratio, OR, 10.556; P = 0.004) in univariate analysis. In multivariate analysis with clinicopathologic factors, PVC-SUVmax ≥4.96 (OR 8.459; P = 0.013) was a significant independent predictor of intermediate-to-high RS.

CONCLUSIONS

High PVC-SUVmax on (18)F-FDG PET/CT was significantly associated with an intermediate-to-high Oncotype DX RS. PVC metabolic parameters on (18)F-FDG PET/CT can be used to predict the Oncotype DX RS in patients with early-stage, ER-positive/HER2-negative breast cancer.

Exploring Tumor Biology with Fluorodeoxyglucose-Positron Emission Tomography Imaging in Breast Carcinoma

This article reviews the promising application of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging in exploring tumor biology of breast carcinoma based upon the authors' experience and also reviews current literature on this topic. The interest in this novel aspect of breast PET imaging has gained momentum in recent years as more is understood about the molecular subtypes and heterogeneous behavior of breast cancer. With the development of newer targeted therapies, oncologists are realizing the need for a means of accurate prediction and assessment of treatment response early in the course of therapy. Hence the studies on FDG-PET imaging in exploring the tumor biology of breast carcinoma have focused on: tumor histologic subtypes, hormonal receptor expression, disease burden at diagnosis, tumor proliferation index, and other molecular parameters. The correlation of various PET tracer parameters (eg, 15O-water PET-derived blood flow measurements and 18F-FDG-PET derived glucose metabolism rate parameters) is also of considerable interest. To summarize, the utility of FDG-PET/CT imaging on this aspect of breast carcinoma imaging holds considerable promise in disease characterization, and it can be foreseen that it will soon aid in guiding and adapting newer therapeutic regimens.

The Relationship Between Estrogen Receptor, Progesterone Receptor and Human Epidermal Growth Factor Receptor 2 Expression of Breast Cancer and the Retention Index in Dual Phase (18)F-FDG PET/CT

PURPOSE

This study investigates the correlation of retention index (RI) using the dual phase FDG PET/CT scan with the breast cancer biomarkers.

METHODS

A total of 55 patients with breast cancer underwent dual phase FDG PET/CT scans (60 and 120 min after FDG injection) before treatment. SUVmax and SUVmean of the primary breast tumors were measured, then the percent change of SUVmax and SUVmean between the two scans were calculated, and denoted as RImax and RImean, respectively. After the surgical resection of the breast tumor, the status of biomarkers (ER, PR, and HER-2) was evaluated in the postsurgical specimen.

RESULTS

RImean was significantly higher in ER (-) (median, 16.2; IQR, 10.8-21.0) or HER-2 (+) (median, 16.1; IQR, 10.7-21.6) tumors than in ER (+) tumors (median, 9.9; IQR, 5.5-15.3) or HER-2 (-) tumors (median, 10.5; IQR, 5.5-16.1). However, there were no significant differences of SUVmax or RImax according to the ER or HER-2 status. There were no significant differences of any PET parameters between PR (+) and PR (-) tumors. Based off ROC curve analyses, RImean predicted the ER (+) tumors (AUC, 0.699; p = 0.006), and HER-2 (+) tumors (AUC, 0.674; p = 0.022), but not the PR (+) tumors. However, neither SUVmax nor RImax predicted ER (+), PR (+), or HER-2 (+) tumors.

CONCLUSIONS

Retention index of SUVmean can reflect the ER and HER-2 status of breast cancers. Higher retention index of SUVmean might associate with lower ER expression and higher HER-2 expression.

Standardized uptake value of ¹⁸F-fluorodeoxyglucose positron emission tomography for prediction of tumor recurrence in breast cancer beyond tumor burden

Introduction

¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) can reveal the metabolic activity of malignant tumors. Recent advances gained from molecular studies suggest that tumor biology can be a good predictor of prognosis in breast cancer. We compared the ability of maximum standardized uptake values (SUV_max) derived by FDG-PET with tumor burden in predicting tumor recurrence for patients with breast cancer.

Methods

496 patients with breast cancer who underwent preoperative FDG-PET between April 2004 and May 2009 were retrospectively identified. SUV_max was obtained by FDG-PET, and the cutoff point was defined using a time-dependent receiver operating characteristic curve for recurrence-free survival (RFS). The primary endpoint was RFS.

Results

In multivariate analysis for RFS, SUV_max carried independent prognostic significance (hazard ratio, 2.39; 95% confidence interval, 1.20 to 4.76; P = 0.012). When the patients were classified into four groups according to the combined factors of tumor size (≤2 cm versus >2 cm) and SUV_max (<4 versus ≥4), RFS differed significantly (P < 0.001). Similarly, SUV_max had prognostic value in combination with nodal status (negative versus positive) or stage (I versus II and III) (P < 0.001 and P = 0.001, respectively). In hormone receptor–positive disease, SUV_max remained a significant prognostic factor for RFS based on multivariate analysis.

Conclusions

Our results highlight the prognostic value of FDG-PET in prediction of tumor relapse for patients with breast cancer. Particularly in patients with hormone receptor–positive disease, the tumor metabolic information provided by FDG-PET is more significantly correlated with prognosis than tumor burden.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-014-0502-y) contains supplementary material, which is available to authorized users.

Glycolytic activity in breast cancer using 18F-FDG PET/CT as prognostic predictor: A molecular phenotype approach

AIM

To explore the relationship between basal (18)F-FDG uptake in breast tumors and survival in patients with breast cancer (BC) using a molecular phenotype approach.

MATERIAL AND METHODS

This prospective and multicentre study included 193 women diagnosed with BC. All patients underwent an (18)F-FDG PET/CT prior to treatment. Maximum standardized uptake value (SUVmax) in tumor (T), lymph nodes (N), and the N/T index was obtained in all the cases. Metabolic stage was established. As regards biological prognostic parameters, tumors were classified into molecular sub-types and risk categories. Overall survival (OS) and disease free survival (DFS) were obtained. An analysis was performed on the relationship between semi-quantitative metabolic parameters with molecular phenotypes and risk categories. The effect of molecular sub-type and risk categories in prognosis was analyzed using Kaplan-Meier and univariate and multivariate tests.

RESULTS

Statistical differences were found in both SUVT and SUVN, according to the molecular sub-types and risk classifications, with higher semi-quantitative values in more biologically aggressive tumors. No statistical differences were observed with respect to the N/T index. Kaplan-Meier analysis revealed that risk categories were significantly related to DFS and OS. In the multivariate analysis, metabolic stage and risk phenotype showed a significant association with DFS.

CONCLUSION

High-risk phenotype category showed a worst prognosis with respect to the other categories with higher SUVmax in primary tumor and lymph nodes.

Nodular fasciitis mimicking soft tissue metastasis on 18F-FDG PET/CT during surveillance

Nodular fasciitis (NF) is a common benign soft tissue tumor. However, F-FDG PET/CT findings of NF are limited. Two cases of NF are described that mimic soft tissue metastasis on F-FDG PET/CT during surveillance. F-FDG PET/CT is well documented in the surveillance of malignancy and increasing worldwide. There are growing chances of encountering FDG-avid nonmalignant soft tissue lesion. Nodular fasciitis could be considered as possible diagnosis on F-FDG PET/CT if a solitary well- circumscribed ovoid hypermetabolic soft tissue lesion is located in a muscle, intermuscular space, or adjacent tendon, especially in patients with a clinically low probability of tumor recurrence or metastasis.

Correlation of the value of 18F-FDG uptake, described by SUVmax, SUVavg, metabolic tumour volume and total lesion glycolysis, to clinicopathological prognostic factors and biological subtypes in breast cancer

OBJECTIVE

The aim of this study was to observe the relationships between different metabolic parameters and clinicopathological features (CPFs) or immunohistochemically defined biological subtypes (IHC-BS) in breast cancer.

MATERIALS AND METHODS

Eighty-two women (83 lesions, tumour size>15 mm) underwent PET/computed tomography imaging after a core biopsy. Maximum and average standardized uptake values (SUVmax, SUVavg), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) in the primary tumour were calculated and compared with CPFs and IHC-BS. Tumours with oestrogen receptor (ER) positivity were separately investigated in relation to their progesterone receptor (PR) status.

RESULTS

Significant correlation was found between all metabolic parameters and high nuclear grade or ER status or IHC-BS. All parameters were higher in PR(-) and triple-negative cases than in PR(+) and non-triple-negative tumours, and the correlation was significant for most of the metabolic parameters (except for SUVavg in the case of PR status and MTV in the case of triple negativity). Significant correlation was found only for SUVmax regarding the human epidermal growth factor receptor 2 (HER2) status. There was moderate correlation between the Ki67 expression and the SUVmax or SUVavg. All metabolic parameters were higher in ER(+)/PR(-)/HER2(-) lesions compared with ER(+)/PR(+)/HER2(-) cancers. However, ER(+)/PR(-)/HER2(+) tumours had lower SUVmax and SUVavg compared with ER(+)/PR(+)/HER2(+) lesions.

CONCLUSION

Our study confirms that the fluorine-18 fluorodeoxyglucose uptake in primary tumour is associated with distinct CPFs or IHC-BS in breast cancer. SUVmax may reflect tumour metabolism more reliably compared with SUVavg, MTV or total lesion glycolysis. Our preliminary results suggest different biological properties in ER(+) tumours with different PR statuses.

Correlation between the Uptake of 18F-Fluorodeoxyglucose (18F-FDG) and the Expression of Proliferation-Associated Antigen Ki-67 in Cancer Patients: A Meta-Analysis

Objective

To study the correlation between ¹⁸F-FDG uptake and cell proliferation in cancer patients by meta-analysis of published articles.

Methods

We searched PubMed (MEDLINE included), EMBASE, and Cochrane Database of Systematic Review, and selected research articles on the relationship between ¹⁸F-FDG uptake and Ki-67 expression (published between August 1, 1994-August 1, 2014), according to the literature inclusion and exclusion criteria. The publishing language was limited to English. The quality of included articles was evaluated according to the Quality Assessment of Diagnosis Accuracy Studies-2 (QUADAS-2). The correlation coefficient (r) was extracted from the included articles and processed by Fisher's r-to-z transformation. The combined correlation coefficient (r) and the 95% confidence interval (CI) were calculated with STATA 11.0 software under a random-effects model. Begg's test was used to analyze the existence of publication bias and draw funnel plot, and the sources of heterogeneity were explored by sensitivity and subgroup analyses.

Results

According to the inclusion and exclusion criteria, 79 articles were finally included, including 81 studies involving a total of 3242 patients. All the studies had a combined r of 0.44 (95% CI, 0.41-0.46), but with a significant heterogeneity (I² = 80.9%, P<0.01). Subgroup analysis for different tumor types indicated that most subgroups showed a reduced heterogeneity. Malignant melanoma (n = 1) had the minimum correlation coefficient (-0.22) between ¹⁸F-FDG uptake and Ki-67 expression, while the thymic epithelial tumors (TETs; n = 2) showed the maximum correlation coefficient of 0.81. The analytical results confirmed that correlation between ¹⁸F-FDG uptake and Ki-67 expression was extremely significant in TETs, significant in gastrointestinal stromal tumors (GISTs), moderate in patients with lung, breast, bone and soft tissue, pancreatic, oral, thoracic, and uterine and ovarian cancers, average in brain, esophageal and colorectal cancers, and poor in head and neck, thyroid, gastric and malignant melanoma tumors. Subgroup analysis indicated that positron emission tomography (PET) or PET/CT imaging technology or Ki-67 and standardized uptake value (SUV) measurement technology did not significantly affect the results of r values, and Begg's test showed no significant publication bias.

Conclusion

In cancer patients, ¹⁸F-FDG uptake showed a moderate positive correlation with tumor cell proliferation. Different tumor types exhibited varied degree of correlation, and the correlation was significant in TETs and GSTs. However, our results need further validation by clinical trials with a large sample of different tumor types.

Response evaluation after primary systemic therapy of Her2 positive breast cancer – an observational cross-sectional study

Aim

To evaluate (I) trastuzumab-containing primary systemic therapy (PST) in human epidermal growth factor receptor 2 (Her2) overexpressing breast carcinomas; (II) compare the patients who achieved and those who did not achieve pathological complete remission (pCR), and (III) analyze the accuracy of different clinical-imaging modalities in tumor response monitoring.

Methods

188 patients who received PST between 2008 and 2014 were reviewed and 43 Her2 overexpressing breast cancer patients (28 Luminal B/Her2-positive and 15 Her2-positive) were enrolled. 26 patients received mostly taxane-based PST without trastuzumab (Group 1) and 17 patients received trastuzumab-containing PST (Group 2). We compared the concordance between pCR and complete remission (CR) defined by breast-ultrasound, CR defined by standard 18F-fluoro-deoxy-glucose positron emission tomography and computerized tomography (FDG-PET/CT) criteria (Method 1) and CR defined by a novel, breast cancer specific FDG-PET/CT criteria (Method 2). Sensitivity (sens), specificity (spec), and positive (PPV) and negative predictive values (NPV) were calculated.

Results

10 patients (38.5%) in Group 1 and 8 (47%) in Group 2 achieved pCR. pCR was significantly more frequent in Her2-positive than in Luminal B/Her2-positive tumors in both Group 1 (P = 0.043) and Group 2 (P = 0.029). PET/CT evaluated by the breast cancer specific criteria (PET/CT Method 2) differentiated pCR from non-pCR more accurately in both groups (Group 1: sens = 77.8%, spec = 100%, PPV = 100%, NPV = 71.4%; Group 2: sens = 87.5%, spec = 62.5%, PPV = 70%, NPV = 83.3%) than standard PET/CT criteria (Method 1) (Group 1: sens = 22.2% spec = 100% PPV = 100% NPV = 41.7%; in Group 2: sens = 37.5%, spec = 87.5%, PPV = 75% NPV = 58.3%) or breast ultrasound (Group 1, sens = 83.3% spec = 25% PPV = 62.5% NPV = 50%; Group 2, sens = 100% spec = 12.5% PPV = 41.6% NPV = 100%).

Conclusion

The benefit of targeted treatment with trastuzumab-containing PST in Her2 overexpressing breast cancer was defined in terms of pCR rate. Luminal B/Her2-positive subtype needs further subdivision to identify patients who would benefit from PST. Combined evaluation of tumor response by our novel, breast cancer specific FDG-PET/CT criteria accurately differentiated pCR from non-pCR patients.

Tumour and lymph node uptakes on dual-phased 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography correlate with prognostic parameters in breast cancer

OBJECTIVES

To examine correlations between the uptake of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) by primary tumours and axillary lymph nodes, and clinical and biological tumour prognostic parameters, in patients with newly diagnosed breast cancer.

METHODS

Newly diagnosed breast cancer patients who had received a dual-phased FDG positron emission tomography/computed tomography scan for pretreatment staging were enrolled retrospectively. Maximal standardized uptake values at 1 h (SUV1), 2 h (SUV2), and retention indices (RI) of the tumours and ipsilateral axillary lymph nodes were measured. SUV and RI were compared with clinical and biological prognostic parameters.

RESULTS

A total of 32 patients participated in the study. Tumour FDG uptake correlated with histological grade and tumour size. FDG uptake in axillary lymph nodes correlated positively with lymph node status, metastasis status and clinical stage. RI values for the tumour and lymph nodes were significantly positively correlated with human epidermal growth factor receptor-2 positivity.

CONCLUSIONS

FDG uptake in tumours and lymph nodes showed correlations with some clinical and biological parameters, and may serve as a predictive marker of tumour biological behaviour in breast cancer.

Journal Club: Diagnostic value of (18)F-FDG PET/CT and MRI in predicting the clinicopathologic subtypes of invasive breast cancer

OBJECTIVE

The purpose of this study was to assess the diagnostic value of (18)F-FDG PET/CT and MRI in predicting the clinicopathologic subtypes of breast cancer.

MATERIALS AND METHODS

The cases of 89 patients with mass-type invasive breast cancer who underwent FDG PET/CT and MRI before therapy were retrospectively analyzed. Eight imaging variables-maximum standardized uptake value (SUVmax), apparent diffusion coefficient, size, shape, margin, intratumoral enhancement, dynamic kinetics, and high intratumoral signal intensity on T2-weighted images-were compared with results for the pathologic markers Ki-67 antibody, estrogen receptor (ER), progesterone receptor (PR), and ERBB2 (formerly HER2 or HER2/neu). The diagnostic performance of the imaging variables for sub-typing was evaluated, and the predictors of the subtypes were elucidated.

RESULTS

Higher SUVmax was significantly associated with a high Ki-67 index (p < 0.0001), ER-negative status (p = 0.0001), and PR-negative status (p = 0.047). Significant correlation was also found between size and ER status (p = 0.002) and between shape and PR status (p = 0.044). The AUC exceeded 0.7 only in identification of the luminal A sub-type by application of cutoff values for SUVmax (AUC, 0.751). When smaller tumors were excluded, AUC increased (AUC, 0.803 for tumors > 16 mm). Multivariate analysis showed that SUVmax was the sole independent predictor of luminal A subtype (odds ratio per SD, 0.291; p < 0.0001). SUVmax was significantly lower for luminal A (4.4 ± 2.2) than non-luminal A (8.1 ± 4.4; p < 0.0001) tumors. A cutoff value of 5.4 yielded 79% sensitivity and 68% specificity for prediction that a tumor was the luminal A subtype.

CONCLUSION

FDG PET/CT findings may contribute to differentiation of the luminal A and non-luminal A subtypes of invasive breast cancer.

[18F]-fluorodeoxyglucose positron emission tomography can contribute to discriminate patients with poor prognosis in hormone receptor-positive breast cancer

BACKGROUND

Patients with hormone receptor-positive breast cancer typically show favorable survival. However, identifying individuals at high risk of recurrence among these patients is a crucial issue. We tested the hypothesis that [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) scans can help predict prognosis in patients with hormone receptor-positive breast cancer.

METHODS

Between April 2004 and December 2008, 305 patients with hormone receptor-positive breast cancer who underwent FGD-PET were enrolled. Patients with luminal B subtype were identified by positivity for human epidermal growth factor receptor-2 (HER2) or high Ki67 (≥14%) according to criteria recently recommended by the St. Gallen panelists. The cut-off value of SUVmax was defined using the time-dependent receiver operator characteristic curve for recurrence-free survival (RFS).

RESULTS

At a median follow up of 6.23 years, continuous SUVmax was a significant prognostic factor with a hazard ratio (HR) of 1.21 (p = 0.021). The cut-off value of SUVmax was defined as 4. Patients with luminal B subtype (n = 82) or high SUVmax (n = 107) showed a reduced RFS (p = 0.031 and 0.002, respectively). In multivariate analysis for RFS, SUVmax carried independent prognostic significance (p = 0.012) whereas classification with immunohistochemical markers did not (p = 0.274). The Harell c-index was 0.729. High SUVmax was significantly associated with larger tumor size, positive nodes, HER2 positivity, high Ki67 (≥14%), high tumor grade, and luminal B subtype.

CONCLUSIONS

Among patients with hormone receptor-positive breast cancer, FDG-PET can help discriminate patients at high risk of tumor relapse.

Clinical correlations with (18)FDG PET scan patterns in solid pseudopapillary tumors of the pancreas: still a surgical enigma?

BACKGROUND

There are limited numbers of PET studies of solid pseudopapillary tumors (SPT) of the pancreas.

MATERIALS AND METHODS

We reviewed the medical records of 37 patients who underwent resection of pancreatic SPT and had been preoperatively evaluated by (18)F-FDG PET or PET/CT scan. Immunohistochemical analysis of glucose transporter-1 (GLUT-1) and hexokinase II (HK-II) was performed.

RESULTS

SPT could be categorized into five types according to the morphologic characteristics observed in PET images. Type I (hot FDG uptake in the entire tumor portion) was the most frequent (13, 34.2%), followed by type IV (focal uptake, 12, 31.6%), II (focal defect, 8, 21.1%), III (multiple and geographic uptake, 3, 7.9%), and V (total defective type, 1, 2.6%). The SUVmax in the solid portion of the SPT was 5.3 ± 4.1. The clinical pattern of FDG uptake in SPT was not associated with histopathologic features suggesting malignant potential. The SUVmax of SPT followed a pattern according to pattern of FDG uptake (R(2) = 0.203, p = 0.055), and was significantly associated with adjusted tumor volume (p = 0.001). GLUT-1 was not expressed in SPT, and only eight patients (12.3%) showed mild to moderate expression of HK-II, which was associated with the clinical pattern of SPT in PET images (p < 0.05).

CONCLUSION

SPT of the pancreas could be categorized according to the morphologic patterns observed in PET images. The clinical significance of FDG uptake, glucose metabolism, and clinical usefulness of PET scan in SPT need to be further investigated, and thus this tumor remains a surgical enigma.

Using (18)F-FLT PET to distinguish between malignant and benign breast lesions with suspicious findings in mammography and breast ultrasound

PURPOSE

To investigate the diagnostic performance of 3'-deoxy-3'-[(18)F]fluorothymidine ((18)F-FLT) PET in women with suspicious breast findings on conventional imaging (mammography and breast ultrasound).

METHODS

Twenty-eight women with suspicious findings on conventional imaging were enrolled. A whole-body PET/CT in the supine position (first PET) was performed 60 min after intravenous injection of 0.07 mCi/kg (18)F-FLT, followed by a regional PET of the breast in the prone position (second PET). For each lesion, the SUVmax of the first PET (SUV1) and second PET (SUV2) were measured. For the receiver operating characteristic (ROC) analysis of the diagnostic parameters, of the cutoff points with sensitivities >90 %, we chose the one with highest specificity as the optimal cutoff point to obtain the corresponding sensitivity and specificity.

RESULTS

A total of 34 breast lesions (21 benign, 13 malignant) were analyzed. The SUV1 and SUV2 of the malignant lesions (median values 4.6 vs. 4.4, respectively) were higher than those of the benign lesions that had medians of 1.2 and 1.0, respectively (P = 0.0001). The area under the ROC curve (AUC) of SUV1 (0.905) showed no significant difference from that of SUV2 (0.912) (P = 0.77). The sensitivity and specificity using SUV1 = 1.24 as cutoff were 92.3 and 52.4 %, and those using SUV2 = 1.5 as cutoff were 92.3 and 66.7 %, respectively.

CONCLUSION

(18)F-FLT PET showed acceptable diagnostic performance for suspicious breast findings on conventional imaging, and SUV2 showed higher specificity than SUV1.

Imaging features of HER2 overexpression in breast cancer: a systematic review and meta-analysis

Breast cancer imaging phenotype is diverse and may relate to molecular alterations driving cancer behavior. We systematically reviewed and meta-analyzed relations between breast cancer imaging features and human epidermal growth factor receptor type 2 (HER2) overexpression as a marker of breast cancer aggressiveness. MEDLINE and EMBASE were searched for mammography, breast ultrasound, magnetic resonance imaging (MRI), and/or [(18)F]fluorodeoxyglucose positron emission tomography studies through February 2013. Of 68 imaging features that could be pooled (85 articles, 23,255 cancers; random-effects meta-analysis), 11 significantly related to HER2 overexpression. Results based on five or more studies and robustness in subgroup analyses were as follows: the presence of microcalcifications on mammography [pooled odds ratio (pOR), 3.14; 95% confidence interval (CI), 2.46-4.00] or ultrasound (mass-associated pOR, 2.95; 95% CI, 2.34-3.71), branching or fine linear microcalcifications (pOR, 2.11; 95% CI, 1.07-4.14) or extremely dense breasts on mammography (pOR, 1.37; 95% CI, 1.07-1.76), and washout (pOR, 1.57; 95% CI, 1.11-2.21) or fast initial kinetics (pOR, 2.60; 95% CI, 1.43-4.73) on MRI all increased the chance of HER2 overexpression. Maximum [(18)F]fluorodeoxyglucose standardized uptake value (SUVmax) was higher upon HER2 overexpression (pooled mean difference, +0.76; 95% CI, 0.10-1.42). These results show that several imaging features relate to HER2 overexpression, lending credibility to the hypothesis that imaging phenotype reflects cancer behavior. This implies prognostic relevance, which is especially relevant as imaging is readily available during diagnostic work-up.

Different biological and prognostic breast cancer populations identified by FDG-PET in sentinel node-positive patients: results and clinical implications after eight-years follow-up

BACKGROUND

Sentinel node (SN) biopsy is the standard method to evaluate axillary node involvement in breast cancer (BC). Positron emission tomography with 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (FDG-PET) provides a non-invasive tool to evaluate regional nodes in BC in a metabolic-dependent, biomolecular-related way. In 1999, we initiated a prospective non-randomized study to compare these two methods and to test the hypothesis that FDG-PET results reflect biomolecular characteristics of the primary tumor, thereby yielding valuable prognostic information.

PATIENTS AND METHODS

A total of 145 cT1N0 BC patients, aged 24-70 years, underwent FDG-PET and lymphoscintigraphy before surgery. SN biopsy was followed in all cases by complete axillary dissection. Pathologic evaluation in tissue sections for involvement of the SN and other non-SN nodes served as the basis of the comparison between FDG-PET imaging and SN biopsy.

RESULTS

FDG-PET and SN biopsy sensitivity was 72.6% and 88.7%, respectively, and negative predictive values were 80.5% and 92.2%, respectively. A subgroup of more aggressive tumors (ER-GIII, Her2+) was found mainly in the FDG-PET true-positive (FDG-PET+) patients, whereas LuminalA, Mib1 low-rate BCs were significantly undetected (p = 0.009) in FDG-PET false-negative (FDG-PET-) patients. Kaplan-Meier survival estimates after a median follow-up of more than 8 years showed significantly worse overall survival for FDG-PET+ patients in node-positive (N+) patients (p = 0.035) as compared to N+/FDG-PET- patients, which overlapped with survival curves of N- and FDG-PET+ or - patients.

CONCLUSIONS

Our findings suggest that FDG-PET results reflect intrinsic biologic features of primary BC tumors and have prognostic value with respect to nodal metastases. FDG-PET false negative cases appear to identify less aggressive indolent metastases. The possibility to identify a subgroup of N+ BC patients with an outcome comparable with N- BC patients could reduce the surgical and adjuvant therapeutic intervention.

Breast cancer detection using high-resolution breast PET compared to whole-body PET or PET/CT

PURPOSE

To compare the performance characteristics of positron emission mammography (PEM) with those of whole-body PET (WBPET) and PET/CT in women with newly diagnosed breast cancer.

METHODS

A total of 178 women consented to PEM for presurgical planning in an IRB-approved protocol and also underwent either WBPET (n = 69) or PET/CT (n = 109) imaging, as per usual care at three centers. Tumor detection sensitivity, positive predictive values, and (18)F-fluorodeoxyglucose (FDG) uptake were compared between the modalities. The effects of tumor size, type, and grade on detection were examined. The chi-squared or Fisher's exact tests were used to compare distributions between groups, and McNemar's test was used to compare distributions for paired data within subject groups, i.e. PEM versus WBPET or PEM versus PET/CT.

RESULTS

The mean age of the women was 59 ± 12 years (median 60 years, range 26-89 years), with a mean invasive index tumor size of 1.6 ± 0.8 cm (median 1.5 cm, range 0.5-4.0 cm). PEM detected more index tumors (61/66, 92%) than WBPET (37/66, 56%; p < 0.001) or PET/CT (95/109, 87% vs. 104/109, 95% for PEM; p < 0.029). Sensitivity for the detection of additional ipsilateral malignancies was also greater with PEM (7/15, 47%) than with WBPET (1/15, 6.7%; p = 0.014) or PET/CT (3/23, 13% vs. 13/23, 57% for PEM; p = 0.003). Index tumor detection decreased with decreasing invasive tumor size for both WBPET (p = 0.002) and PET/CT (p < 0.001); PEM was not significantly affected (p = 0.20). FDG uptake, quantified in terms of maximum PEM uptake value, was lowest in ductal carcinoma in situ (median 1.5, range 0.7-3.0) and invasive lobular carcinoma (median 1.5, range 0.7-3.4), and highest in grade III invasive ductal carcinoma (median 3.1, range 1.4-12.9).

CONCLUSION

PEM was more sensitive than either WBPET or PET/CT in showing index and additional ipsilateral breast tumors and remained highly sensitive for tumors smaller than 1 cm.

The Prognostic Value of (18)F-FDG PET/CT for Early Recurrence in Operable Breast Cancer: Comparison with TNM Stage

PURPOSE

We evaluated whether the maximum standardized uptake values (SUVmax) of primary tumor from the initial staging by (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) of patients with breast cancer could identify patients at risk for early recurrence within 2 years, particularly in comparison to the American Joint Committee on Cancer (AJCC) stage.

METHODS

We reviewed the staging (18)F-FDG PET/CT images of patients with primary breast cancer and their medical records. The SUVmax of the primary tumor was measured. The presence or absence of FDG uptake in the axillary lymph node (ALN) was also assessed. The patient's pathologic primary tumor stage (pT), pathologic regional lymph node stage (pN), stage grouping, age, estrogen receptor (ER) and progesterone receptor (PR) status, and neoadjuvant chemotherapy history were evaluated with the FDG uptake parameters for recurrence within 2 years following the end of first-line therapy.

RESULTS

Recurrence within 2 years was present in 9.1 % (n = 40) out of the 441 patients assessed. The FDG uptake in ALN, pT, pN, stage grouping and neoadjuvant chemotherapy history were prognostic for early recurrence, while primary tumor SUVmax, age, and ER or PR status were not significant on logistic regression. On multivariate analysis, only the stage grouping (odds ratio 2.79; 95 % CI 1.73, 4.48; p < 0.0001) and neoadjuvant chemotherapy history (odds ratio 2.70; 95 % CI 1.22, 5.98; p = 0.0141) could identify patients at increased risk for recurrence within 2 years.

CONCLUSIONS

Primary tumor FDG uptake measured by SUVmax, and visual assessment of FDG uptake in the ALN in the initial staging PET/CT of patients with breast cancer may not have additional prognostic value compared with the AJCC stage grouping for early recurrence.