Uptake Value Of Primary Tumor Research Articles

Abstract P5-01-02: Diagnostic Accuracy of 18F-FDG PET/CT plus Contrast-Enhanced MRI for Axillary Lymph Node Metastasis Involved in Invasive Ductal Carcinoma

Abstract Background: Positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) are useful imaging modalities for the preoperative nodal staging in breast cancer; however, clinical evidence demonstrating the diagnostic accuracy of the combination of PET/CT and MRI is limited. The purpose of this study is to establish a clinical prediction model based on PET/CT plus contrast-enhanced MRI for ALN metastasis, and explore the possibility of non-invasive patients’ risk stratification using the PET/CT plus MRI model preoperatively. Methods: A total of 361 women (370 axillae; mean age, 56 years ± 12 [standard deviation]) who underwent surgery for primary invasive ductal carcinoma at a single institution between April 2017 and March 2020 were evaluated. Subjects were divided into two cohorts: a derivation cohort (n = 333) and a validation cohort (n = 37). In the derivation cohort, we constructed a prediction model with logistic regression to estimate the potential explanatory variables obtained by PET/CT, MRI, and preoperative core-needle biopsy. Using a simple integer risk score, patients were divided into low-risk and high-risk groups. We assessed the predictive ability of the PET/CT plus MRI model using the area under the curve (AUC), and internal validation was achieved by risk scoring system in the validation cohort. Results: The PET/CT plus MRI model included five predictor variables: maximum standardized uptake value of primary tumor and ALN, primary tumor size, ALN cortical thickness, and histological grade. The PET/CT plus MRI model had significantly improved AUC of 0.867 (p < 0.05) as compared to those of the PET/CT model (AUC = 0.821) and MRI model (AUC = 0.815). We assigned the weighted scores to each retained variables in the PET/CT plus MRI model, and determined the optimal cut-off value of 7 (range, 0−17). In the derivation and validation cohorts, 55% and 65% of the patients were classified as low-risk by the risk scoring system, with negative predictive values of 97% and 100%, respectively. Conclusions: Our findings demonstrated a better diagnostic accuracy of the clinical prediction model utilizing both PET/CT and MRI than previous models based on either PET/CT or MRI, and the negative predictive value of 97% was not inferior to that of sentinel lymph node biopsy. Thus, the preoperative risk evaluation of axillary lymph node macrometastasis using our integrated model could be useful while considering individualized therapy for patients with invasive ductal breast cancer. Further validation should be performed for clinical applications. Citation Format: Shun Kawaguchi, Nobuko Tamura, Kiyo Tanaka, Yoko Kobayashi, Junichiro Sato, Keiichi Kinowaki, Masato Shiiba, Makiko Ishihara, Hidetaka Kawabata. Diagnostic Accuracy of 18F-FDG PET/CT plus Contrast-Enhanced MRI for Axillary Lymph Node Metastasis Involved in Invasive Ductal Carcinoma [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-01-02.

Clinical prediction model based on 18F-FDG PET/CT plus contrast-enhanced MRI for axillary lymph node macrometastasis.

PurposePositron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) are useful for detecting axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC); however, there is limited clinical evidence to demonstrate the effectiveness of the combination of PET/CT plus MRI. Further axillary surgery is not recommended against ALN micrometastasis (lesion ≤2 mm) seen in sentinel lymph nodes, especially for patients who received proper adjuvant therapy. We aimed to evaluate the efficacy of a prediction model based on PET/CT plus MRI for ALN macrometastasis (lesion >2 mm) and explore the possibility of risk stratification of patients using the preoperative PET/CT plus MRI and biopsy findings.Materials and methodsWe retrospectively investigated 361 female patients (370 axillae; mean age, 56 years ± 12 [standard deviation]) who underwent surgery for primary IDC at a single center between April 2017 and March 2020. We constructed a prediction model with logistic regression. Patients were divided into low-risk and high-risk groups using a simple integer risk score, and the false negative rate for ALN macrometastasis was calculated to assess the validity. Internal validation was also achieved using a 5-fold cross-validation.ResultsThe PET/CT plus MRI model included five predictor variables: maximum standardized uptake value of primary tumor and ALN, primary tumor size, ALN cortical thickness, and histological grade. In the derivation (296 axillae) and validation (74 axillae) cohorts, 54% and 61% of patients, respectively, were classified as low-risk, with a false-negative rate of 11%. Five-fold cross-validation yielded an accuracy of 0.875.ConclusionsOur findings demonstrate the validity of the PET/CT plus MRI prediction model for ALN macrometastases. This model may aid the preoperative identification of low-risk patients for ALN macrometastasis and provide helpful information for PET/MRI interpretation.

Maximum standardized uptake value of primary tumor (SUVmax_PT) and horizontal range between two most distant PET-positive lymph nodes predict patient outcome in inoperable stage III NSCLC patients after chemoradiotherapy.

Background18F-FDG-positron emission tomography (PET)/computed tomography (CT) is a standard for initial staging in patients with locally advanced stage III non-small cell lung cancer (NSCLC). We evaluated a PET/CT staging score to characterize disease extension and patient outcome in this disease.MethodsNinety-nine consecutive patients with NSCLC stage IIIA–B (UICC 7th edition), who underwent 18F-FDG-PET/CT before the start of chemoradiotherapy (CRT) were analyzed. Maximum standardized uptake value of primary tumor (SUVmax_PT) and range between two most distant PET-positive (SUV ≥2.5) lymph nodes in two directions were analyzed for their correlation with patient outcome. The vertical distance was defined as A- and the horizontal as a B-line.ResultsAccording to the results of univariate analysis, score included the SUVmax_PT and horizontal B-line, patients were divided into three risk subgroups: low, intermediate and high-risk subgroups. Subgroups were defined as SUVmax_PT <8 and B-line <3.7 cm, SUVmax_PT >8 or B-line >3.7 cm and SUVmax_PT >8 plus B-line >3.7 cm, respectively. Twenty-eight (28%), 45 (46%) and 26 (26%) patients were assigned to the low, intermediate and high-risk subgroup, respectively. Median event-free survival (EFS) in low, intermediate and high-risk subgroups was 16 (95% CI: 7–25), 13 (95% CI: 12–15) and 10 (95% CI: 7–13) months (P=0.002, log-rank test). Median OS in the low, intermediate and high-risk subgroups was 40 (95% CI: 11–69), 23 (95% CI: 15–31) and 14 (95% CI: 13–14) months (P=0.0001, log-rank test). In the multivariate analysis, SUV, B-line and PET/CT score were significantly associated with EFS [harard ratio (HR) 2.12 (95% CI: 1.27–3.55) and intermediate risk HR 2.01 (95% CI: 1.13–3.59), P=0.003] and OS [high-risk HR 2.79 (95% CI: 1.16–4.55) and intermediate risk HR 2.30 (95% CI: 1.58–4.94), P=0.001].ConclusionsA PET/CT score was developed for inoperable stage III NSCLC patients treated with CRT and was an independent predictor of patient outcome in the single-center cohort.

Tumor volume/metabolic information can improve the prognostication of anatomy based staging system for nasopharyngeal cancer? Evaluation of the 8th edition of the AJCC/UICC staging system for nasopharyngeal cancer.

PurposeWe evaluated prognostic value of the 8th edition of the American Joint Committee on Cancer/International Union for Cancer Control (AJCC/UICC) staging system for nasopharyngeal cancer and investigated whether tumor volume/metabolic information refined prognostication of anatomy based staging system.Materials and MethodsOne hundred thirty-three patients with nasopharyngeal cancer who were staged with magnetic resonance imaging (MRI) and treated with intensity-modulated radiotherapy (IMRT) between 2004 and 2013 were reviewed. Multivariate analyses were performed to evaluate prognostic value of the 8th edition of the AJCC/UICC staging system and other factors including gross tumor volume and maximum standardized uptake value of primary tumor (GTV-T and SUV-T).ResultsMedian follow-up period was 63 months. In multivariate analysis for overall survival (OS), stage group (stage I-II vs. III-IVA) was the only significant prognostic factor. However, 5-year OS rates were not significantly different between stage I and II (100% vs. 96.2%), and between stage III and IVA (80.1% vs. 71.7%). Although SUV-T and GTV-T were not significant prognostic factors in multivariate analysis, those improved prognostication of stage group. The 5-year OS rates were significantly different between stage I-II, III-IV (SUV-T ≤ 16), and III-IV (SUV-T > 16) (97.2% vs. 78% vs. 53.8%), and between stage I, II-IV (GTV-T ≤ 33 mL), and II-IV (GTV-T > 33 mL) (100% vs. 87.3% vs. 66.7%).ConclusionCurrent anatomy based staging system has limitations on prognostication for nasopharyngeal cancer despite the most accurate assessment of tumor extent by MRI. Tumor volume/metabolic information seem to improve prognostication of current anatomy based staging system, and further studies are needed to confirm its clinical significance.

Value of combining serum carcinoembryonic antigen and PET/CT in predicting EGFR mutation in non-small cell lung cancer

We sought to investigate the associations between pretreatment serum Carcinoembryonic antigen (CEA) level, 18F-Fluoro-2-deoxyglucose (18F-FDG) uptake value of primary tumor and epidermal growth factor receptor (EGFR) mutation status in non-small cell lung cancer (NSCLC). We retrospectively reviewed medical records of 210 NSCLC patients who underwent EGFR mutation test and 18F-FDG positron emission tomography/computed tomography (PET/CT) scan before anti-tumor therapy. The associations between EGFR mutations and patients' characteristics, serum CEA, PET/CT imaging characteristics maximal standard uptake value (SUVmax) of the primary tumor were analyzed. Receiver-operating characteristic (ROC) curve was used to assess the predictive value of these factors. EGFR mutations were found in 70 patients (33.3%). EGFR mutations were more common in high CEA group (CEA ≥7.0 ng/mL) than in low CEA group (CEA <7.0 ng/mL) (40.4% vs. 27.6%; P=0.05). Females (P<0.001), non-smokers (P<0.001), patients with adenocarcinoma (P<0.001) and SUVmax <9.0 (P=0.001) were more likely to be EGFR mutation-positive. Multivariate analysis revealed that gender, tumor histology, pretreatment serum CEA level, and SUVmax were the most significant predictors for EGFR mutations. The ROC curve revealed that combining these four factors yielded a higher calculated AUC (0.80). Gender, histology, pretreatment serum CEA level and SUVmax are significant predictors for EGFR mutations in NSCLC. Combining these factors in predicting EGFR mutations has a moderate diagnostic accuracy, and is helpful in guiding anti-tumor treatment.

Peak of Standardized Uptake Value in Oral Cancer Predicts Survival Adjusting for Pathological Stage.

To predict survival outcomes of different patients with the same stage of disease is difficult. The possible correlation between 18F-fluorodeoxyglucose (18F-FDG) uptake parameters and survival outcomes was investigated in oral squamous cell carcinoma patients by multivariate analysis adjusted for the pathological stage according to the 8th edition of the tumor-node-metastasis (TNM) classification of the Union for International Cancer Contro. 18F-FDG-uptake parameters of 28 patients were assessed by positron emission tomography with computed tomography (PET/CT). A peak of standardized uptake value of primary tumor (p-SUVpeak) of ≥14.1 was significantly correlated with shorter overall survival by univariate and multivariate analyses adjusted for the pathological TNM stage. A p-SUVpeak of ≥14.1 was significantly associated with shorter local recurrence-free survival and disease-free survival. A higher p-SUVpeak on pretreatment 18F-FDG-PET/CT is a prognostic parameter of identifying lower survival outcomes.

PUB067 Maximum Standardized Uptake Value of Primary Tumor Predicts Lymph Node Metastasis in Non-Small Cell Lung Cancer

PUB067 Maximum Standardized Uptake Value of Primary Tumor Predicts Lymph Node Metastasis in Non-Small Cell Lung Cancer

Prognostic value of pretreatment 18F-FDG PET-CT for nasopharyngeal carcinoma patients.

Background:Nasopharyngeal carcinoma (NPC) is a special subtype of head and neck cancer (HNC). At present, there are no highly specific prognostic markers to aid in tumor grading and guide patient treatment modalities for NPC. The prognostic value of pretreatment 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-PET-CT) in NPC patients is controversial and no consensus exists as to its predictive capability.Methods:To analyze the predictive efficacy of 18F-PET-CT imaging in NPC patients, data from MEDLINE, EMBASE, the Cochrane library, CBM, CNKI, and VIP (inception to July 2016) were accessed. Results from prospective and retrospective observational studies that used 18F-FDG PET to predict disease prognosis in NPC patients were used for analysis. Two authors independently assessed study quality and extracted data. Event-free survival (EFS) was considered the primary endpoint and overall survival rate (OS) was considered the secondary endpoint.Results:Data from 14 studies and 1134 patients were included in our analysis. The hazard ratios (HRs) of maximum standardized uptake value of primary tumor (SUVmax-T), metabolic tumor volume of primary tumor (MTV-T), and total lesional glycolysis of primary tumor (TLG-T) for EFS were 1.31 (95% confidence interval [CI], 1.11–1.55, P = .001), 2.38 (95% CI 1.53–3.70, P < .001), and 1.65 (95% CI 0.76–3.59, P = .21), respectively. Among studies including TLG-T, those with a fixed SUV of 2.5 had an HR of 3.55 (95% CI, 1.42–8.84, P = .007). The HRs of SUVmax-T and MTV-T for OS were 2.19 (95% CI, 1.47–3.27, P < .001) and 2.69 (95% CI, 1.01–7.17, P = .05), respectively. Among studies including MTV-T, those with a fixed SUV of 2.5 had an HR of 4.07 (95% CI, 2.22–7.46, P < .001). Tests used for assessing predictive value of pretreatment SUVmax, MTV, and TLG of lymph nodes for EFS and OS showed that these parameters did not have significant predictive value (P>.05).Conclusion:Our results suggested that SUVmax, MTV, and TLG (with a fixed SUV of 2.5) of primary tumors before treatment initiation may be independent prognostic factors for NPC patients; however, SUVmax, MTV, and TLG of metastatic lymph nodes are not.

Volume-Based F-18 FDG PET/CT Imaging Markers Provide Supplemental Prognostic Information to Histologic Grading in Patients With High-Grade Bone or Soft Tissue Sarcoma.

The aim of the study is to assess the prognostic value of different volume-based calculations of tumor metabolic activity in the initial assessment of patients with high-grade bone sarcomas (BS) and soft tissue sarcomas (STS) using F-18 FDG PET/CT.A single-site, retrospective study from 2002 to 2012 including 92 patients with histologically verified high-grade BS (N = 37) or STS (N = 55). All patients underwent a pretreatment F-18 FDG PET/CT scan. Clinical data were registered. Measurements of the accuracy of metabolic tumor volume with a preset threshold of 40% of the maximum standardized uptake value of primary tumor (MTV40%) and total lesion glycolysis (TLG) as prognostic variables and identification of optimal discriminating cut-off values were performed through ROC curve analysis. Patients were grouped according to the cut-off values. All deaths were considered an event in survival analysis. Kaplan–Meier survival estimates and log-rank test were used to compare the degree of equality of survival distributions. Prognostic variables with related hazard ratios (HR) were assessed using Cox proportional hazards regression analysis.Forty-one of 92 patients died during follow-up (45%; 12 BS and 29 STS). Average survival for included patients was 6.5 years (95% CI 5.8–7.3 years) and probability of 5-year survival was 52%. There was a high-significant accuracy of TLG and MTV40% as prognostic variables when looking on all patients and during subgroup analysis. AUCs were higher for TLG than for MTV40%. TLG above optimal cut-off value was the only variable which was independently prognostic for survival throughout multivariate regression analysis of all included patients (P = 0.01, HR 4.78 [95% CI 1.45–15.87]) and subgroup analysis (BS: P = 0.04, HR 11.11 [95% CI 1.09–111.11]; STS: P < 0.05, HR 3.37 [95% CI 1.02–11.11]). No significant results were demonstrated for MTV40%.Volume-based F-18 FDG PET/CT imaging markers in terms of pretreatment estimation of TLG provide supplemental prognostic information to histologic grading, with significant independent properties for prediction of overall survival in patients with high-grade BS or STS.

Semi-Quantitative Calculations of Primary Tumor Metabolic Activity Using F-18 FDG PET/CT as a Predictor of Survival in 92 Patients With High-Grade Bone or Soft Tissue Sarcoma.

To assess the prognostic value of primary tumor metabolic activity in patients with high-grade bone sarcomas (BS) or soft tissue sarcomas (STS) using F-18 FDG PET/CT.A single-site, retrospective study including 92 patients with high-grade BS or STS. Pretreatment F-18 FDG PET/CT scan was performed. Clinical data were registered. Accuracy of maximum standardized uptake value of primary tumor (SUVmax) and tumor-to-background (T/B) uptake ratio as prognostic variables and identification of cut-off values to group patients were determined. Kaplan–Meier survival estimates and log-rank test were used to compare survival distributions. Prognostic variables were assessed using Cox proportional hazards regression analysis.Forty-one of 92 patients died during follow-up (45%). Average survival was 6.5 years (95% CI 5.8–7.3 years) and probability of 5-year survival was 52%. Accuracy of SUVmax and T/B uptake ratio as prognostic variables in all patients and during subgroup analysis of patients with STS was significant. No significant results for AUCs were registered in patients with BS. Surgery was independently prognostic for survival throughout multivariate regression analysis of all patients (P = 0.001, HR 3.84) and subgroup analysis (BS: P = 0.02, HR 11.62; STS: P = 0.005, HR 4.13). SUVmax was significant as prognostic variable in all patients (P = 0.02, HR 3.66) and in patients with STS (P = 0.007, HR 3.75). No significant results were demonstrated for T/B uptake ratio.Estimation of primary tumor metabolic activity with pretherapeutic SUVmax using F-18 FDG PET/CT demonstrates independent properties beyond histologic grading for prediction of survival in patients with high-grade STS, but not with high-grade BS.

Circulating Tumor Cells in Diagnosing Lung Cancer: Clinical and Morphologic Analysis

The purpose of this study was to evaluate the value of circulating non-hematologic cells to differentiate benign from malignant lung lesions and their comparison with clinico-histologic features of corresponding primary lesions. Circulating cells were isolated by size method from peripheral blood of 77 patients with malignant (n= 60) and benign (n= 17) lung lesions. They were morphologically classified as cells with malignant feature; cells with uncertain malignant feature; and cells with benign feature; then statistically correlated with clinico-cytopathologic characteristics of corresponding lung lesion. Malignant circulating cells were detected in 54of 60 (90%) malignant patients, and in 1 of 17 (5%) benign patients; benign circulating cells in 1 of 60 (1%) malignant patients and in 15 of 17 (88%) benign patients; and circulating cells with uncertain malignant aspect in 5of 60 (8%) malignant patients and 1 of 17 (5%) benign patients. For a malignant circulating cells count greater than 25, sensitivity and specificity were 89% and 100%, respectively. The count was significantly correlated with stage, size, and standard uptake value of primary tumor. In 39 of 54 (72%) cases, the malignant circulating cells allowed a specific histologic diagnosis of the corresponding primary tumor after immunohistochemical analysis. Malignant circulating cells may be a valid marker in the diagnostic workup of lung lesions. However, our resuts should be corroborated by larger future studies especially for patients having small nodules.

Pretreatment 18F-FDG PET standardized uptake value of primary tumor and neck lymph nodes as a predictor of distant metastasis for patients with nasopharyngeal carcinoma

To evaluate the prognostic value of maximum standardized uptake value (SUVmax) measured in [(18)F]-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) for patients with non-disseminated nasopharyngeal carcinoma (NPC). From January 2002 to July 2008, 371 NPC patients who underwent (18)F-FDG-PET before radical intensity-modulated radiotherapy (IMRT) were recruited. The SUVmax was recorded for the primary tumor (SUVmax-T) and neck lymph nodes (SUVmax-N). The median follow-up was 64months. The optimal cutoff value was 9.3 for SUVmax-T and 7.4 for SUVmax-N. Patients with a lower SUVmax-T or SUVmax-N had a significantly better 5-year distant metastasis-free survival (DMFS), but showed no significant difference in local control or regional control. Patients were divided into four groups by SUVmax, as follows: (a) both lower SUVmax-T and SUVmax-N, (b) higher SUVmax-T only, (c) higher SUVmax-N only, and d) both higher SUVmax-T and SUVmax-N. There were significant differences between these four groups in 5-year DMFS: (a) 95.5%, (b) 90.0%, (c) 83.3%, and (d) 79.9%, respectively (p=0.004). When looking at the stage of disease, the 5-year DMFSs in group a, b, c, d were 96.9%, 94.6%, 97.4%, and 84.3%, respectively in stage I-III patients (p=0.037) and were 91.6%, 82.9%, 68.5%, and 76.7% in stage IVA-B patients (p=0.145). Using multivariate analysis, the SUVmax grouping, gender, and stage were independent factors for DMFS. The SUVmax of the primary tumor and neck lymph nodes were independent prognostic factors for DMFS in NPC patients treated with IMRT.

The Prognostic Significance of Maximum Standardized Uptake Value of Primary Tumor in Surgically Treated Non–Small-Cell Lung Cancer Patients: Analysis of 413 Cases

BackgroundIntegrated PET/CT is widely used in the preoperative staging and prognostic assessment of non–small-cell lung cancer (NSCLC) patients. The aims of this study were to evaluate the prognostic significance of SUVmax of primary tumor in patients undergoing surgical treatment and, in order to minimize technical interferences, to verify whether SUVmax standardized by SUVmax liver or SUVmax blood pool provided additional prognostic information. Patients and MethodsA retrospective study of 413 consecutive NSCLC patients undergoing potentially curative surgical resection after PET/CT obtained in the same PET center over a 6-year period. The SUVmax was calculated drawing region of interest around the primitive tumor, the liver, and the aortic arch in PET images. The same procedure was performed for 2 adjacent planes and the average of these measures was considered. ResultsNine patients were considered 30-day postoperative deaths and were excluded from the analysis. At the end of the study, 312 (77.2%) of the 404 patients were alive (median follow-up, 26 months) and 92 had died (median survival, 17 months). At multivariate analysis tumor-node-metastasis stage, primary tumor grading and primary tumor SUVmax (T-SUVmax) were found to be independent prognostic factors, while T-SUVmax/SUVmax blood pool ratio, and T-SUVmax/SUVmax liver ratio were not. ConclusionsT-SUVmax is an independent predictor for survival in NSCLC patients undergoing surgery and might be helpful in guiding adjuvant treatment strategies. SUVmax of primary tumor normalized by SUV blood pool or SUV liver does not provide additional prognostic information.

68Ga-DOTANOC PET/CT in Patients With Carcinoma of Unknown Primary of Neuroendocrine Origin

To evaluate the role of ⁶⁸Ga-DOTANOC (⁶⁸Gallium-labeled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI³-octreotide) PET/CT for localization of the primary tumor in patients with carcinoma of unknown primary of neuroendocrine origin. Twenty patients (median age, 55 years; male 10) with histopathologically proven metastatic neuroendocrine tumor and no localization of primary tumor on conventional imaging were included in the study. PET/CT was done after injection of 132-222 MBq (4-6 mCi) of ⁶⁸Ga-DOTANOC. Images were evaluated by 2 experienced nuclear medicine physicians both qualitatively as well as quantitatively (maximum standardized uptake value). Histopathology (when available) and/or follow-up imaging with biochemical markers were taken as reference standard. ⁶⁸Ga-DOTANOC PET/CT localized the primary tumor in 12/20 (60%) patients. Midgut was the most common site of primary tumor (n = 9); duodenum (4), ileum (4), and colon (1). In 1 patient each the primary was localized to the pancreas, stomach, and lung. In these 12 patients, significant correlation was found between maximum standardized uptake value of primary tumor and metastasis (ρ = 0.615; P = 0.041). Even in patients in whom no primary tumor was localized, additional sites of metastatic disease were observed when compared with conventional imaging, mostly in lymph nodes and bones. There was a change in management in 3/20 patients (15%), who underwent surgery. In the remaining 17 patients, demonstration of somatostatin receptor expression by PET/CT made them suitable candidate for peptide receptor radionuclide therapy. ⁶⁸Ga-DOTANOC PET/CT seems to be a promising modality for detecting primary tumor in patients with carcinoma of unknown primary of neuroendocrine origin.

Abstract 4178: Circulating cell-free DNA in plasma of never smokers with advanced lung adenocarcinoma receiving gefitinib or standard chemotherapy as a first-line therapy

Abstract Background: Circulating cell-free DNA (CFDNA) has been investigated as a potential screening or prognostic marker in a variety of cancers, including lung cancers. This study aimed to investigate prospectively its clinical significance in never smokers with advanced lung adenocarcinoma (ALAC) undergoing chemotherapy. Methods: We analyzed blood samples of 134 patients among 309 never smokers with ALAC who were enrolled to a prospective randomized phase III study comparing gefitinib with gemcitabine plus cisplatin (GP) as first-line therapy from April 2005 to November 2007 (the First-SIGNAL). An amount of plasma CFDNA was measured by real-time quantitative polymerase chain reaction targeting human β-actin genomic sequence. Results: Median baseline CFDNA value was 122.3 ng/ml (range, 11.5 to 2487.9 ng/ml). Patients with &amp;gt; 2 of metastatic sites had higher plasma CFDNA compared those with ≤ 2 metastatic sites (P = 0.015). Baseline plasma CFDNA was positively associated with peak standardized uptake value of primary tumor on 18F-FDG PET (coefficient = 0.316; P = 0.056). In GP arm, high CFDNA group showed higher response rate (RR) than low CFDNA group (60.7% vs. 37.8%; P = 0.047). However, in gefitinib arm, no difference was observed in RR between the two groups (47.2% vs. 58.1%; P = 0.376). The risk of death was elevated with increasing baseline plasma CFDNA [hazard ratio (HR) = 1.23; 95% CI, 1.01-1.50; P = 0.045)]. The low tertile group of baseline CFDNA showed longer overall survival (OS) than the high tertile group [HR of low vs. high groups = 0.52 (95% CI, 0.31-0.87); median OS, 28.6 vs. 16.0 months; P = 0.041]. Conclusion: High plasma CFDNA at diagnosis predicts an aggressive behavior and poor survival outcomes in these patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4178. doi:10.1158/1538-7445.AM2011-4178

The Prognostic Implications for 18F-FDG PET Standardized Uptake Value of Primary Tumor and Neck Lymph Nodes in Patients with Nasopharyngeal Carcinoma

To evaluate the prognostic value of maximum standardized uptake value (SUVmax) measured on 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) in patients with non-disseminated nasopharyngeal carcinoma (NPC).