Association between semiquantitative PET parameters and molecular subtypes of breast invasive ductal carcinoma.

BACKGROUND: Molecular subtypes of breast cancer have been proposed since 2012. The correlation between various baseline [18F]fluorodeoxyglucose ([18F]FDG) uptake parameters, including total lesion glycolysis (TLG), and molecular subtypes of primary breast cancer lesions in patients with invasive ductal cancer will be investigated. METHODS: Staging [18F]FDG PET/CT for breast invasive ductal carcinoma were retrospectively evaluated. Breast lesions were examined for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and proliferation index (Ki-67). Breast tumors were classified into five molecular subtypes: Luminal A, Luminal B-HER2(-), Luminal B-HER2(+), HER2(+) and Basal or Triple Negative cancers. The correlations between tumor characteristics and PET semiquantitative data of primary breast lesion (SUVmean, SUVmax, Mean tumor volume (MTV), TLG) were assessed. Specific Breast Uptake Ratio (SBUR) is used as a new quantification method of breast uptake to correct for physiological background activity. RESULTS: Fifty-eight patients were included. TLG was significantly higher in triple negative group when compared with luminal A (P<0.01). Significantly higher uptake was found in triple negative lesions when compared with luminal B-HER2(-) and luminal B-HER2(+) categories using SUVmax, SUVmean and TLG (all P<0.05). Conversely, no statistically significant difference for [18F]FDG uptake was observed between all other molecular subtypes. No value of SBUR in terms of correlation with histopathological parameters was demonstrated. CONCLUSIONS: TLG was superior to SUVmax and SUVmean in differentiating between triple negative breast cancer lesions and all other molecular subtypes. SBUR was not different statistically between various molecular subtypes.

Diagnostic and prognostic impact of fluorine-18-fluorodeoxyglucose PET/CT in preoperative and postoperative setting of breast cancer patients.

PURPOSE: The aim of this study was to assess the diagnostic and prognostic value of fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT in patients with breast cancer (BC) in the preoperative and the postoperative setting. PATIENTS AND METHODS: Between 2011 and 2015, we prospectively enrolled 275 patients (mean age: 53 years) with BC (stage I-III; triple-negative or HER2-positive cancer). One-hundred and forty-nine (54.2%) patients underwent F-FDG PET/CT before neoadjuvant therapy and 126 (45.8%) after surgery and before any additional adjuvant therapy. The patients were followed for a median period of 44 (2-57) months. The different effects of PET/CT on the presetting and postsetting phase form a therapeutic and prognostic point of view were assessed by χ, by Kaplan-Meier, and Cox-regression analyses. RESULTS: In the preoperative setting, PET/CT provided additional diagnostic information in 42/149 (28%) patients. In particular, 17/70 (24%) patients at stage III were converted into stage IV and 4/68 (6%) at stage II were upstaged to IV. In the postoperative setting, PET/CT upstaged the disease in both stage IIIC and stage IV in 14/126 (11%) cases. At the end of follow-up, 28/271 (10%) patients died from BC and 40 (15%) had a recurrence of disease. On Kaplan-Meier analysis, patients with a positive PET/CT other than the primary tumor site showed both a worse overall survival and a worse disease-free survival compared with their counterpart (76 vs. 92%; P=0.063 and 65 vs. 100%; P<0.001). Conversely, in the postoperative setting, no differences in overall survival and disease-free survival were found between patients with positive and negative PET/CT findings (both P>0.05). On multivariate Cox-regression analysis, a positive PET/CT was a significant predictive factor of a poor prognosis in the preoperative setting. The significance was lost in the postoperative setting. CONCLUSION: In the preoperative setting, PET/CT can provide additional diagnostic and prognostic information. Conversely, in the postoperative setting, PET/CT adds diagnostic information, but does not provide any adjunctive prognostic assessment.

Staging of locally advanced breast cancer and the prediction of response to neoadjuvant chemotherapy: complementary role of scintimammography and 18F-FDG PET/CT.

BACKGROUND: The primary endpoint of the study was to established the role of sestamibi scintimammography and PET/CT findings in locally advanced breast cancer (LABC) before neoadjuvant systemic therapy (NST) in different histological subtypes. The secondary endpoint was to determine the role of FDG PET/CT as multi-drug resistance marker. METHODS: From January 2012, we prospectively enrolled 51 consecutive women (median age: 49 years; range: 27-76 yrs) with a biopsy-proven LABC. All patients underwent both sestamibi scintimammography and FDG PET/CT within one week before to start NST. Both examinations were qualitatively and semiquantitatively analysed. For scintimammography we calculated the tumor to background ratio (T/B) and the most intense uptake of the tumor to background ratio (I/B) according the following formula: T/B=[cntsT-cntsB]/ [cntsB] and I/B [cntsI-cntsB]/[cntsB]. Furthermore, the percentage washout index (WO) for T and I were obtained, according to: WOT,I= [cntsT,I]early image-[cntsT,I]delayed image/[cntsT,I]early image. Maximum and average (avg) standardized uptake value (SUV) was computed by PET/CT, using a region of interest. Patients who had an evidence of systemic metastases or a second active cancer at imaging scans, were excluded. At the end of pre-operative therapy, the response to therapy was assessed by the analysis of surgical specimen and then correlated with both scintimammographic and PET/CT data. RESULTS: Based on the inclusion criteria, the final analysis was performed in 49 patients. Scintimammography and PET/CT showed a sensitivity of 100% for the evaluation of primary cancer, while PET/CT showed a slightly higher detection rate for axillary lymph node than scintimammography. According to the biological pattern, SUVmax and SUVavg resulted significantly different among histological subtypes, whereas scintimammographic data did not. At the end of neo-adjuvant therapy, pathological complete response was obtained in 12 (24.4%) patients, while 37 had a partial or no response to NST (identified as no-responders). On the basis of histopathological response to NST, median WOI resulted significantly lower in responders than non-responders (30.5% vs. 44%; P=0.027). Conversely, SUVmax and SUVavg were significantly higher in responders than non-responders (all P<0.05). In this latter subset of patients, high WOTs were associated with low SUVs. On the contrary, in responder group, high SUVs were reported particularly for high WOT values. CONCLUSIONS: Scintimammography with sestamibi did not accurately determine the responsiveness to therapy. FDG PET/CT is more accurate in the prediction of response to therapy, particularly in the aggressive LABC subtype. Moreover, semiquantitative data by FDG PET seems to be linked with the chemosensitivity to NST.

18F-fluorodeoxyglucose PET/computed tomography and risk stratification after neoadjuvant treatment in esophageal cancer patients.

OBJECTIVES: The aim of the study was to evaluate the prognostic value of F-fluorodeoxyglucose PET/computed tomography (CT) after neoadjuvant therapy (NAT) in locally advanced esophageal cancer (EC) patients. MATERIALS AND METHODS: We recruited 79 EC patients from a sample of 210 who underwent F-fluorodeoxyglucose PET/CT after NAT and who did not have evidence or suspicion of distant metastases. All patients were followed up for a median period of 18 months (range: 2-53 months) from nuclear imaging. PET/CT findings were correlated with surgical management and long-term prognosis. The χ-test was used for categorical variables and the Student t-test for continuous data. Survival curves were computed using the Kaplan-Meier method. A P value less than 0.05 was considered statistically significant. RESULTS: Twenty patients (25.3%) had negative PET/CT and 59 (74.7%) had positive PET/CT results after NAT. Of the 20 patients with negative PET/CT results, eight underwent radical-intent surgery and 12 did not, whereas of the 59 patients with positive PET/CT 44 were scheduled for surgery and 15 were not (P<0.05). On follow-up, 38 patients were seen to be disease free, whereas 23 had relapsed and 15 had died. The overall survival was different between patients with negative PET/CT and those with positive PET/CT scans (98 vs. 40%; P=0.019). Event-free survival was higher in patients with negative PET/CT than in those with positive PET/CT after NAT (78 vs. 0%; P=0.003). Considering patients with positive PET/CT, in the nonsurgical group only three patients were alive without evidence of disease, whereas in the surgical group 19 patients were disease free (20 vs. 46%; P<0.001). CONCLUSION: PET/CT is able to stratify the recurrence risk of EC patients. After a median follow-up period of 18 months, 91% of patients with negative PET/CT scans who did not undergo surgery were seen to be disease free. A positive PET/CT after NAT should be followed by surgery for improving event-free survival.

Positron emission tomography/computed tomography and esophageal cancer in the clinical practice: How does it affect the prognosis?

AIMS: The aim of this study was to assess the diagnostic value of positron emission tomography/computed tomography (PET/CT) in staging of esophageal cancer and to evaluate the prognostic role of metabolic parameters before and after neo-adjuvant treatment. SETTINGS AND DESIGN: Mono-institutional retrospective study. MATERIALS AND METHODS: We retrospectively evaluated 29 patients who underwent PET/CT at initial staging and after neo-adjuvant therapy. Metabolic parameters were calculated: mean, average, maximum standardized uptake value (SUVmax), and total lesion glycolysis (TLG). Diagnostic advantages of PET/CT over conventional imaging (CI) were determined. The relationships between baseline and after-therapy SUVmax and TLG, change in SUV and TLG (reported as ∆) for the primary tumor and prognosis were assessed. STATISTICAL ANALYSIS USED: Non-parametric statistic (e.g. Wilcoxon test and chi-square test). RESULTS: Twenty-nine patients were eligible for the initial staging. Thirteen patients were incorrectly staged based on CI; PET/CT was able to identify distant lymph nodes in seven patients (59%) and distant metastases in four (31%). The median SUVmax before and after neoadjuvant therapy was 10.38 and 3.53 (P = 0.0005), respectively. Only few semi-quantitative parameters obtained by PET/CT after neoadjuvant therapy seemed to have a prognostic value. TLG and ∆TLG were significantly different between disease-free and died patients (0.49 versus 15.51 and 100% versus 94%, respectively; all P = <0.05). CONCLUSIONS: PET/CT is confirmed as being able to detect distant metastases and to avoid unnecessary surgery. Although not routinely reported, post-neoadjuvant TLG and ∆TLG might be considered as useful prognostic parameters and should be further evaluated prospectively.