Prognostic value of metabolic tumor burden in lung cancer

Prognosis of different extrathoracic metastasis patterns in patients with M1c lung adenocarcinoma receiving immunotherapy

INTRODUCTION

Lung cancer with extrathoracic metastases is classified as M1c. However, extrathoracic metastases can be further classified into different patterns. The purpose of this study was to analyze the survival differences between different patterns of extrathoracic metastases in patients with stage M1c lung adenocarcinoma after receiving immunotherapy.

MATERIALS AND METHODS

This study included 160 stage M1c lung adenocarcinoma patients and treated with immunotherapy. The enrolled patients were divided into two groups: those with multiple extrathoracic metastases alone (EM group) and those with simultaneous multiple extrathoracic and intrathoracic metastases (EIM group). Progression-free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

The median PFS and OS in the whole group were 7.7 months and 25.4 months, respectively. The patients in the EM group show better PFS (13.0 months vs. 5.0 months; hazard ratio [HR] = 0.462, 95% confidence interval [CI] 0.317-0.673, P < 0.0001) and OS (35.0 months vs. 18.9 months; HR 0.592, 95% CI 0.380-0.922, P = 0.019) compared with the EIM group. Furthermore, in patients with lung adenocarcinoma with simultaneous extrathoracic and intrathoracic metastases who received immunotherapy, immunotherapy combined with chemotherapy has better PFS and OS than immunotherapy alone. There was no difference between immunotherapy alone or combined with chemotherapy in patients with lung adenocarcinoma with extrathoracic metastasis alone.

CONCLUSION

The different patterns of extrathoracic metastasis were related to the efficacy and prognosis of immunotherapy in M1c cohort. In addition, patients with simultaneous extrathoracic and intrathoracic metastases were more recommended to choose immunotherapy in combination with chemotherapy rather than immunotherapy alone.

Metabolic active tumour volume quantified on [18F]FDG PET/CT further stratifies TNM stage IV non-small cell lung cancer patients

PURPOSE

This study aimed to assess whether the whole body metabolic active tumour volume (MTV_WB), quantified on staging [¹⁸F]FDG PET/CT, could further stratify stage IV non-small cell lung cancer (NSCLC) patients.

METHODS

A group of 160 stage IV NSCLC patients, submitted to staging [¹⁸F]FDG PET/CT between July 2010 and May 2020, were retrospectively evaluated. MTV_WB was quantified. Univariate and multivariate Cox regressions were carried out to assess correlation with overall survival (OS). C-statistic was used to test predictive power. Kaplan-Meier survival curves with Log-Rank tests were performed to compute statistical differences between strata from dichotomized variables and to calculate the estimated mean survival times (EMST). Survival rates at 1 and 5 years were calculated.

RESULTS

MTV_WB was a statistically significant predictor of OS on univariate (p < 0.0001) and multivariate analyses (p < 0.0001). The multivariate model with MTV_WB (Cindex ± SE = 0.657 ± 0.024) worked significantly better as an OS predictor than the cTNM model (Cindex ± SE = 0.544 ± 0.028) (p = 0.003). An EMST of 29.207 ± 3.627(95% CI 22.099-36.316) months and an EMST of 10.904 ± 1.171(95% CI 8.609-13.199) months (Log-Rank p < 0.0001) were determined for patients with MTV_WB < 104.3 and MTV_WB ≥ 104.3, respectively. In subsamples of stage IVA (cut-off point = 114.5) and IVB patients (cut-off point = 191.1), statistically significant differences between EMST were also reported, with p-values of 0.0001 and 0.0002, respectively. In both substages and in the entire cohort, patients with MTV_WB ≥ cut-off points had lower EMST and survival rates.

CONCLUSION

Baseline MTV_WB, measured on staging [¹⁸F]FDG PET/CT, further stratifies stage IV NSCLC patients. This parameter is an independent predictor of OS and provides valuable prognostic information over the 8th edition of cTNM staging.

Prognostic Value of Metabolic Tumor Parameters in Pretreatment 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography Scan in Advanced Non-Small Cell Lung Cancer

Objective:

This retrospective study aimed to investigate whether metabolic parameters of primary tumour i.e. maximum standardized uptake value (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) predict overall survival (OS) in patients with advanced stage non-small cell lung cancer (NSCLC).

Materials and Methods:

SUVmax, MTV and TLG of the primary tumors were measured in staging ¹⁸F-Fluorodeoxyglucose Positron emission tomography- Computed tomography (¹⁸F-FDG PET/CT) scan of 97 NSCLC patients by gradient based tumour segmentation method. Prognostic ability was assessed for overall survival (OS) of the patients.

Result:

The median follow-up period of the study was 15.84 months (range 1.3 to 47.97 months).The estimated median OS was 11.29 months (range 1.37 to 38.63 months). Total of 40 (41.24%) patients had progressive disease and 21 (21.65%) patients died during the follow up period. Receiver Operating Characteristic (ROC) analysis showed that the area under the curve (AUC) for MTV was significant (area = 0.652 ± 0.065; 95% CI = 0.548 – 0.746; P = 0.020). Kaplan-Meier survival curves showed that the OS differences between the groups of patients who were dichotomized by the median value of MTV (38.76 ml, P = 0.0150) and TLG (301.69 ml, P = 0.0046) were significant. MTV (hazard ratio = 4.524; 95% CI = 1.244 – 16.451; P = 0.022) was found to be an independent prognostic factor for OS in multivariate analysis.

Conclusion:

MTV of the primary tumor is a potential prognostic parameter for OS in our population of advanced NSCLC patients independent of other risk factors.

Differences between TNM classification and 2-[18F]FDG PET parameters of primary tumor in NSCLC patients

Background

The aim of the study was to compare the TNM classification with 2-[¹⁸F]FDG PE T biological parameters of primary tumor in patients with NSCLC.

Materials and methods

Retrospective analysis was performed on a group of 79 newly diagnosed NSCLC patients. PET scans were acquired on Gemini TF PET/CT scanner 60–70 min after injection of 2-[¹⁸F]FDG with the mean activity of 364 ± 75 MBq, with the area being examined from the vertex to mid-thigh. The reconstructed PET images were evaluated using MIM 7.0 Software for SUV_max, MTV and TLG values.

Results

The analysis of the cancer stage according to TNM 8^th edition showed stage IA2 in 8 patients, stage IA3 — 6 patients, stage IB — 4 patients, IIA — 3 patients, 15 patients with stage IIB, stage IIIA — 17 patients, IIIB — 5, IIIC — 5, IVA in 7 patients and stage IVB in 9 patients. The lowest TLG values of primary tumor were observed in stage IA2 (11.31 ± 15.27) and the highest in stage IIIC (1003.20 ± 953.59). The lowest value of primary tumor in SUV_max and MTV were found in stage IA2 (6.8 ± 3.8 and 1.37 ± 0.42, respectively), while the highest SUV_max of primary tumor was found in stage IIA (13.4 ± 11.4) and MTV in stage IIIC (108.15 ± 127.24).

Conclusion

TNM stages are characterized by different primary tumor 2-[¹⁸F]FDG PET parameters, which might complement patient outcome.

PET-Based Volumetric Biomarkers for Risk Stratification of Non-Small Cell Lung Cancer Patients

Despite the recent advances in lung cancer biology, molecular pathology, and treatment, this malignancy remains the leading cause of cancer-related death worldwide and non-small cell lung cancer (NSCLC) is the most common form found at diagnosis. Accurate staging of the disease is a fundamental prognostic factor that correctly predicts progression-free (PFS) and overall survival (OS) of NSCLC patients. However, outcome of patients within each TNM staging group can change widely highlighting the need to identify additional prognostic biomarkers to better stratify patients on the basis of risk. 18F-FDG PET/CT plays an essential role in staging, evaluation of treatment response, and tumoral target delineation in NSCLC patients. Moreover, a number of studies showed the prognostic role of imaging parameters derived from PET images, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG). These parameters represent three-dimensional PET-based measurements providing information on both tumor volume and metabolic activity and previous studies reported their ability to predict OS and PFS of NSCLC patients. This review will primarily focus on the studies that showed the prognostic and predictive role of MTV and TLG in NSCLC patients, addressing also their potential utility in the new era of immunotherapy of NSCLC.

The prognostic value of 18F-fluorodeoxyglucose positron emission tomography/ computed tomography parameters in patients with malignant pleural mesothelioma

Background

In this study, we aimed to investigate the prognostic value of metabolic ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography parameters in malignant pleural mesothelioma patients.

Methods

A total of 65 patients with malignant pleural mesothelioma (34 males, 31 females; median age: 60 years; range, 39 to 84 years) who underwent whole-body ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography for staging before treatment between March 2008 and January 2018 were included. Relationships between clinicopathological factors and ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography parameters and overall survival were evaluated using a log-rank test and Cox regression analysis.

Results

The median follow-up was 13 (range, 4 to 55) months. The Kaplan-Meier analysis revealed a mean survival time of 17±2.6 months. The cumulative two- and five-year survival rates were 34.8% and 7.8%, respectively. Univariate analysis showed that ≥60 age, left hemithorax involvement, a maximum standardized uptake value of ≥9.8, c-T4 status, c-M1 status, and non-surgery were negatively associated with overall survival (p<0.05). Multivariate analysis showed that ≥60 age, left hemithorax involvement, a maximum standardized uptake value of ≥9.8, c-M1 status, and a total lesion glycolysis of ≥180.2 g were negatively associated with overall survival (p<0.05).

Conclusion

Metabolic parameters of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography have the potential to provide prognostic information for malignant pleural mesothelioma patients who are receiving surgery and/or chemotherapy.

Correlations between the metabolic profile and 18F-FDG-Positron Emission Tomography-Computed Tomography parameters reveal the complexity of the metabolic reprogramming within lung cancer patients

Several studies have demonstrated that the metabolite composition of plasma may indicate the presence of lung cancer. The metabolism of cancer is characterized by an enhanced glucose uptake and glycolysis which is exploited by ¹⁸F-FDG positron emission tomography (PET) in the work-up and management of cancer. This study aims to explore relationships between ¹H-NMR spectroscopy derived plasma metabolite concentrations and the uptake of labeled glucose (¹⁸F-FDG) in lung cancer tissue. PET parameters of interest are standard maximal uptake values (SUV_max), total body metabolic active tumor volumes (MATV_WTB) and total body total lesion glycolysis (TLG_WTB) values. Patients with high values of these parameters have higher plasma concentrations of N-acetylated glycoproteins which suggest an upregulation of the hexosamines biosynthesis. High MATV_WTB and TLG_WTB values are associated with higher concentrations of glucose, glycerol, N-acetylated glycoproteins, threonine, aspartate and valine and lower levels of sphingomyelins and phosphatidylcholines appearing at the surface of lipoproteins. These higher concentrations of glucose and non-carbohydrate glucose precursors such as amino acids and glycerol suggests involvement of the gluconeogenesis pathway. The lower plasma concentration of those phospholipids points to a higher need for membrane synthesis. Our results indicate that the metabolic reprogramming in cancer is more complex than the initially described Warburg effect.

Metabolic tumor volume predicts overall survival in patients with primary pulmonary lymphoepithelioma-like carcinoma

Pretreatment tumor metabolic burden, measured using fluorine-18 fluorodeoxyglucose positron emission tomography/computerized tomography (¹⁸F-FDG PET/CT), has been demonstrated to predict outcomes in various types of malignancies. Additionally, Epstein-Barr virus (EBV) serum titer is associated with stages of pulmonary lymphoepithelioma-like carcinoma (LELC). The present study aimed to investigate the prognostic value of the functional parameters of ¹⁸F-FDG PET/CT in pulmonary LELC and their association with serum EBV DNA. The present retrospective study analyzed data from 71 patients with pulmonary LELC; among these, 32 patients with pulmonary LELC underwent pretreatment ¹⁸F-FDG PET/CT staging between January 2008 and December 2016. EBV viral load and functional parameters of ¹⁸F-FDG PET/CT were used for survival analysis. Multivariate analysis identified tumor stage IV as a significant predictor of poor progression-free survival [hazard ratio (HR), 4.85; P=0.049], whereas elevated total metabolic tumor volume (MTV ≥72.6 ml) independently predicted worse overall survival (OS; HR, 12.59; P=0.024). Pretreatment serum EBV DNA titer was significantly positively associated with total MTV (P=0.0337) and total lesion glycolysis (TLG; P=0.0093), but could not predict outcomes. Total MTV was an independent predictor of OS, and may guide clinical management for pulmonary LELC.

Prognosis of EGFR-mutant advanced lung adenocarcinoma patients with different intrathoracic metastatic patterns

Introduction: Lung cancer diagnosed solely with the presence of intrathoracic metastases is classified as M1a. However, intrathoracic metastases can be further divided into different patterns. The objective of our study was to analyze the differences in survival between the different metastatic patterns of intrathoracic metastases in lung adenocarcinoma patients who have epidermal growth factor receptor (EGFR) mutations. Materials and Methods: Patients who were diagnosed only with intrathoracic metastasis between March 2011 and October 2016 and had EGFR-mutations were selected for this study. Prognosis was determined based on metastatic patterns by univariate and multivariate analysis. Results: A total of 137 patients (60 patients who only had pleural metastasis [Group A], 44 patients who only had contralateral lung metastasis [Group B] and 33 patients who had both pleural and contralateral lung metastasis with or without pericardial effusion [Group C]) were selected for this in the study. The median OS (overall survival) time was 38.1 (95%confidence interval [CI]: 27.8-48.4), 35.7(95%CI: 23.4-48.0), and 29.7(95%CI: 22.8-36.6) months for Group A, Group B, and Group C, respectively (p=0.037). Multivariate analysis demonstrated that Group A and Group B had higher OS compared to Group C (hazard ratio [HR]=0.524, 95%CI: 0.307-0.894, p=0.018; HR=0.473, 95%CI: 0.241-0.931, p=0.030, respectively) among lung adenocarcinoma patients with EGFR mutations. With regard to patients with pleural or contralateral metastasis only, OS benefit (p=0.579) was not significant between the two groups. Subgroup analysis demonstrated that OS benefit in Group A was significant in patients with N0-1 disease and 21L858R mutations but not in EGFR exon 19 deletions, N2-3 stage or T3-4 stage patients. Conclusion: The prognosis of EGFR-mutant lung adenocarcinoma patients diagnosed only with intrathoracic metastasis was different, indicating that M1a staging should be refined.

Diagnostic and Prognostic Role of 18-FDG PET/CT in the Management of Resectable Biliary Tract Cancer

OBJECTIVES

Role of 18-FDG PET/CT had been well established in other more prevalent malignancies such as colorectal and lung cancer; however, this is not as well defined in cholangiocarcinoma. Literature focusing on the prognostic values of preoperative PET/CT for resectable cholangiocarcinoma is scarce.

METHOD

This is a retrospective cohort of 66 consecutive patients who had received curative resection for cholangiocarcinoma from 2010 to 2015. All patients had preoperative 18-FDG PET/CT performed. Accuracy of metastatic lymph node detection of PET/CT and the prognostic value of maximum standard uptake value (SUV-max) was explored.

RESULTS

There were 38 male and 28 female recruited, and the median age was 66. Intrahepatic cholangiocarcinoma (ICC) constituted the majority (59.1%) of the cases, followed by hilar cholangiocarcinoma (22.8%), gallbladder cancer (13.6%) and common bile duct cancer (4.5%). The 3-year disease-free survival (DFS) and overall survival (OS) of the whole population were 27.1 and 39.2%, respectively. The median follow-up duration was 27 months. The accuracy of PET/CT in metastatic lymph node detection was 72.7% (P = 0.005, 95% CI 0.583-0.871) and 81.8% (P = 0.011, 95% CI 0.635-0.990) in whole population and ICC subgroup analysis, respectively. SUV-max was shown by multivariate analysis to be an independent factor for DFS (P = 0.007 OR 1.16, 95% CI 1.04-1.29) and OS (P = 0.012 OR 1.145, 95% CI 1.030-1.273) after resection. SUV-max of 8 was shown to be a discriminant cut-off for poor oncological outcomes in patients with early cholangiocarcinoma (TNM stage I or II) after curative resection (3-year DFS: 21.2 vs. 63.2%, P = 0.004, and 3-year OS: 29 vs. 74% P = 0.048, respectively).

CONCLUSION

PET/CT is a reliable imaging modality for metastatic lymph node detection in cholangiocarcinoma. Tumour SUV-max is an independent factor for oncological outcomes in patients with resectable disease. For patients who have TNM stage I or II cholangiocarcinoma, tumour SUV-max over 8 is associated with significantly inferior disease-free and overall survival even after curative resection.

Metabolic tumor burden quantified on [18F]FDG PET/CT improves TNM staging of lung cancer patients

PURPOSE

The purpose of our study was to test a new staging algorithm, combining clinical TNM staging (cTNM) with whole-body metabolic active tumor volume (MATV-WB), with the goal of improving prognostic ability and stratification power.

METHODS

Initial staging [¹⁸F]FDG PET/CT of 278 non-small cell lung cancer (NSCLC) patients, performed between January/2011 and April/2016, 74(26.6%) women, 204(73.4%) men; aged 34-88 years (mean ± SD:66 ± 10), was retrospectively evaluated, and MATV-WB was quantified. Each patient's follow-up time was recorded: 0.7-83.6 months (mean ± SD:25.1 ± 20.3).

RESULTS

MATV-WB was an independent and statistically-significant predictor of overall survival (p < 0.001). The overall survival predictive ability of MATV-WB (C index: mean ± SD = 0.7071 ± 0.0009) was not worse than cTNM (C index: mean ± SD = 0.7031 ± 0.007) (Z = -0.143, p = 0.773). Estimated mean survival times of 56.3 ± 3.0 (95%CI:50.40-62.23) and 21.7 ± 2.2 months (95%CI:17.34-25.98) (Log-Rank = 77.48, p < 0.001), one-year survival rate of 86.8% and of 52.8%, and five-year survival rate of 53.6% and no survivors, were determined, respectively, for patients with MATV-WB < 49.5 and MATV-WB ≥ 49.5. Patients with MATV-WB ≥ 49.5 had a mortality risk 2.9-5.8 times higher than those with MATV-WB < 49.5 (HR = 4.12, p < 0.001). MATV-WB cutoff points were also determined for each cTNM stage: 23.7(I), 49.5(II), 52(III), 48.8(IV) (p = 0.029, p = 0.227, p = 0.025 and p = 0.001, respectively). At stages I, III and IV there was a statistically-significant difference in the estimated mean overall survival time between groups of patients defined by the cutoff points (p = 0.007, p = 0.004 and p < 0.001, respectively). At stage II (p = 0.365), there was a clinically-significant difference of about 12 months between the groups. In all cTNM stages, patients with MATV-WB ≥ cutoff points had lower survival rates. Combined clinical TNM-PET staging (cTNM-P) was then tested: Stage I < 23.7; Stage I ≥ 23.7; Stage II < 49.5; Stage II ≥ 49.5; Stage III < 52; Stage III ≥ 52; Stage IV < 48.8; Stage IV ≥ 48.8. cTNM-P staging presented a superior overall survival predictive ability (C index = 0.730) compared with conventional cTNM staging (C index = 0.699) (Z = -4.49, p < 0.001).

CONCLUSION

cTNM-P staging has superior prognostic value compared with conventional cTNM staging, and allows better stratification of NSCLC patients.

Clinically determined type of 18F-fluoro-2-deoxyglucose uptake as an alternative prognostic marker in resectable pancreatic cancer

PURPOSE

To investigate the association between clinical PET (positron emission tomography) type and oncologic outcome in resectable pancreatic cancer.

METHODS

Between January 2008 and October 2012, patients who underwent potentially curative resection for resectable pancreatic ductal adenocarcinoma without neoadjuvant treatment were retrospectively investigated. Clinical PET type was defined as follows: pancreatic cancer with similar 18FDG uptake to renal calyx was determined as kidney-type (K-type), and relatively lower 18FDG uptake than that of renal calyx was regarded as Non-K type.

RESULTS

A total of 53 patients were enrolled. After agreement-based reclassification, agreement based K-type (aK-type) was noted in 34 patients (64.2%), and agreement based Non-K type (aNon K-type) was found in 19 patients (35.8%). There was a significant difference between aK-type and aNon K-type pancreatic cancer (tumor size (P = 0.030), adjusted CA 19-9 (P = 0.007), maximum standard uptake value (SUVmax,P<0.001), metabolic tumor volume (MTV2.5, P<0.001), total lesion glycolysis (TLG, P<0.001)). K-type pancreatic cancer (n = 31) showed a significantly shorter disease-free time compared with Non-K type (n = 16) (10.8 vs. 24.1 months, P = 0.013). It was also noted that aK-type showed inferior disease-free survival to that of aNon-K type pancreatic cancer (11.9 vs. 28.6 months, P = 0.012).

CONCLUSIONS

Clinical PET type is a reliable clinical marker to estimate aggressive tumor biology and can be utilized in predicting tumor recurrence and necessity for postoperative chemotherapy.

Metabolic tumor volume predicts overall survival and local control in patients with stage III non-small cell lung cancer treated in ACRIN 6668/RTOG 0235

PURPOSE

To determine whether higher pre-treatment metabolic tumor volume (tMTV-pre) is associated with worse overall survival (OS) in patients with inoperable NSCLC treated with definitive chemoradiation (CRT).

METHODS

This is a secondary analysis of the American College of Radiology Imaging Network (ACRIN) 6668/Radiation Therapy Oncology Group 0235 trial. Pre-treatment PET scans were performed on ACRIN-qualified scanners. Computer-aided MTV measurement was performed using RT_Image. Kaplan-Meier curves and Cox proportional hazards regression models were used to assess the association between tMTV and OS.

RESULTS

Of the 250 patients enrolled on the study, 230 were evaluable for tMTV-pre. Patients with MTV-pre >32 mL (median value) vs. ≤32 mL had worse median OS (14.8 vs. 29.7 months, p < 0.001). As a continuous variable, higher tMTV-pre (per 10-mL increase) remained associated with worse OS (HR = 1.03, p < 0.001) after controlling for other variables. A significant interaction between radiation dose and tMTV-pre occurred for OS (p = 0.002), demonstrating that the negative prognostic impact of tMTV-pre decreased as radiotherapy dose increased. Among patients with tMTV-pre ≤32 mL, there was no difference in survival according to radiotherapy dose delivered (p = 0.694). However, median OS was inferior in patients with tMTV-pre >32 mL who received ≤60 Gy compared with those who received 61-69 Gy or ≥70 Gy (p = 0.001).

CONCLUSIONS

Higher tMTV-pre is associated with significantly worse OS in inoperable stage III NSCLC treated with definitive CRT. Our findings suggest that for patients with large tMTV-pre, achieving a therapeutic radiation dose may help maximize OS. Prospective studies are needed to confirm this finding.

Microscopic Invasions, Prognoses, and Recurrence Patterns of Stage I Adenocarcinomas Manifesting as Part-Solid Ground-Glass Nodules: Comparison With Adenocarcinomas Appearing as Solid Nodules After Matching Their Solid Parts' Size

The purpose of the present study was to compare the frequency of microscopic invasions, disease-free-survival (DFS), and the frequency and pattern of disease recurrence between stage I pulmonary adenocarcinomas appearing as solid nodules and those appearing as part-solid ground-glass nodules (GGNs) after matching their solid parts' size (D(solid)) and patients' age. Among 501 patients who underwent curative surgery for stage I pulmonary adenocarcinomas between 2003 and 2011, 172 patients (86 with solid nodules [M: F = 36: 50; mean age, 62.8 years] and 86 with part-solid GGNs [M:F = 30:56; mean age, 63.0 years]) matched for D(solid) and patients' age were included. DFS, frequency of microscopic invasions, recurrence, and recurrence pattern were compared between the two groups. No significant difference was observed in the frequency of microscopic invasions between the two groups (visceral pleural invasion, 30.23% vs. 29.07%, P = 0.867; lymphatic invasion, 5.81% vs. 3.49%, P = 0.720; vascular invasion, 1.16% vs. 0%, P = 1.000; solid nodules vs. part-slid GGNs, respectively) and DFS (estimated 5-year DFS, 83.6% vs. 81.9%, P = 0.744; solid nodules vs. part-slid GGNs, respectively). As for recurrence and recurrence pattern, there were no significant differences between the solid nodule group (14/86), and part-solid GGN group (12/86) (P = 0.670). Lung parenchymal nodules were the most frequent pattern of disease recurrence in both groups, followed by pleural seeding. In conclusion, after matching D(solid) and patients' age, there was no significant difference in the frequency of microscopic invasions, DFS, and the frequency and pattern of recurrence between stage I pulmonary adenocarcinomas appearing as solid nodules and part-solid GGNs.

A new PET/CT volumetric prognostic index for non-small cell lung cancer

OBJECTIVES

Whole-body metabolic tumor volume (MTVWB) has been shown of prognostic value for non-small cell lung cancer (NSCLC) beyond that of TNM stage, age, gender, performance status, and treatment selection. The current TNM staging system does not incorporate tumor volumetric information. We propose a new PET/CT volumetric prognostic (PVP) index that combines the prognostic value of MTVWB and TNM stage.

MATERIALS AND METHODS

Based on 328 consecutive NSCLC patients with a baseline PET/CT scan before treatment, from which MTVWB was measured semi-automatically, we estimated hazard ratios (HRs) for ln(MTVWB) and TNM stage from a Cox proportional hazard regression model that consisted of only ln(MTVWB) and TNM stage as prognostic variables of overall survival. We used the regression coefficients, which gave rise to the HRs, as weights to formulate the PET/CT volumetric prognostic (PVP) index. We also compared the prognostic value of the PVP index against that of TNM stage alone and ln(MTVWB) alone with univariate and multivariate survival analyses and C-statistics.

RESULTS

Univariate analysis C-statistic for the PVP index (C=0.71) was statistically significantly greater than those for TNM stage alone (C=0.67, p<0.01) and for ln(MTVWB) alone (C=0.69, p=0.033). Multivariate analyses showed that the PVP index yielded significantly greater discriminatory power (C=0.74) than similar models based on either TNM stage (C=0.72, p<0.01) or ln(MTVWB) (C=0.73, p<0.01). Lower values of the PVP index were associated with significantly better overall survival (adjusted HR=2.70, 95%CI [2.16, 3.37]).

CONCLUSION

The PVP index provides a practical means for clinicians to combine the prognostic value of MTVWB and TNM stage and offers significantly better prognostic accuracy for overall survival of NSCLC patients than the current TNM staging system or metabolic tumor burden alone.

Efficacy of third-line pemetrexed monotherapy versus pemetrexed combination with bevacizumab in patients with advanced EGFR mutation-positive lung adenocarcinoma

OBJECTIVE

The purposes of this study were to observe the effects of different treatment strategies, including third-line pemetrexed alone versus its combination with bevacizumab, in patients with advanced epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma, and to analyze the effects of the different medication orders of first- and second-line drugs on third-line efficacy.

PATIENTS AND METHODS

One hundred and sixteen cases of patients with EGFR-positive lung adenocarcinoma who had received third-line pemetrexed alone or in combination with bevacizumab between March 2010 and March 2014 at Guangzhou Institute of Respiratory Diseases, the First Affiliated Hospital of Guangzhou Medical University were analyzed retrospectively. Additionally, all the patients were treated with first-line gemcitabine and cisplatin (GP) chemotherapy and second-line EGFR tyrosine kinase inhibitor (TKI) or with first-line EGFR-TKI and second-line GP chemotherapy.

RESULTS

The median survival of 61 cases with third-line pemetrexed monotherapy was 36.22 months, the median survival time of 55 cases with third-line pemetrexed plus bevacizumab was 38.76 months, and there was a significant difference in survival time between the two groups (P=0.04). Subgroup analysis revealed that among the 55 cases with third-line bevacizumab plus pemetrexed treatment, the median survival of 29 patients with first-line GP and second-line EGFR-TKI was 42.80 months, while the median survival of 26 patients with first-line EGFR-TKI and second-line GP was only 34.46 months; additionally, there was a significant difference in the survival time between the two subgroups (P=0.001). Among 61 cases with third-line pemetrexed treatment, the median survival of 34 patients with first-line GP and second-line EGFR-TKI was 38.72 months, while the median survival of 27 patients with first-line EGFR-TKI and second-line GP was only 32.94 months; the survival time of the two subgroups was significantly different (P=0.001).

CONCLUSIONS

Regardless of the order of the first- and second-line chemotherapy and TKI therapy, the pemetrexed plus bevacizumab regimen was superior to the pemetrexed monotherapy as the third-line therapy in patients with advanced EGFR-positive lung adenocarcinoma. However, this strategy is worth further investigation in prospective studies.

Positron Emission Tomography (PET) in Oncology

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