A serological scoring system to predict lymph node metastasis in patients with hepatocellular carcinoma

BACKGROUND

Lymph node metastasis (LNM)has widely been recognized as a poor prognostic indicator for hepatocellular carcinoma (HCC) patients. Preoperative prediction of LNM is important for clinicians to decide on treatment. This study was designed to develop a simple and convenient system to predict LNM.

METHODS

Consecutive HCC patients who were suspected to have LNM were divided into a training, an internal validation and an external validation cohort. The receiver operating characteristic (ROC) analysis was used to determine the threshold value of the preoperative serological variables. A nomogram visualization system model was then established.

RESULT

Of the 287 patients, there were 31 patients who had LNM (10.8%), and 21 of 203 patients (10.3%) were in the training cohort and 10 of 84 patients (11.9%) in the internal validation cohort. Sixteen of 176 patients (9.1%) in the external validation cohort had LNM. The serological indices including neutrophil/lymphocyte rate, age, platelet, prothrombin time, and total protein, were included in the nomogram. The areas of the ROC curve were 0.846, 0.679 and 0.738 in predicting LNM in the training cohort, the internal validation cohort and the external validation cohort, respectively.

CONCLUSION

The scoring system constructed using the preoperative serological variables predicted LNM in HCC patients.

Predictors of unexpected nodal upstaging in patients with cT1-3N0 non-small cell lung cancer (NSCLC) submitted to thoracoscopic lobectomy

Background

In the last decades, the use of video-assisted thoracoscopic surgery (VATS) lobectomy for the treatment of early stage non-small cell lung cancer is continuously growing. This is mainly due to the development of more advanced surgical devices, to the rising incidence of peripheral lung tumors and is also favored by the increased reliability of preoperative staging techniques. Despite this progress, postoperative unexpected nodal upstaging is still a relevant issue. Aim of this study is to identify possible predictors of unexpected nodal upstaging in patients affected by cT1-3N0 NSCLC submitted to VATS lobectomy.

Methods

A total of 231 cases of cT1-3N0 patients submitted to thoracoscopic lobectomy at our centre between June 2012 and October 2016 were retrospectively reviewed. All data regarding clinical staging by means of computed tomography (CT) and positron-emission tomography (PET)/CT were collected and reviewed. The subsequent pathological staging has been analyzed, with special regards to the possible type of nodal involvement, and the number of pathological nodal stations.

Results

Most of the patients included in this study were in a clinical stage cT1aN0, cT1bN0 (stage IA) and cT2aN0 (stage IB), 86 (37.2%) patients, 73 (31.6%) patients and 62 (26.8%) patients, respectively. Postoperative histopathological analysis showed that the most frequent tumor histotype was adenocarcinoma (192 patients, 83.1%). Thirty-eight (16.5%) patients had a nodal upstaging; among these, 17 (7.4%) patients had N2 disease (8 patients with isolated mediastinal nodal involvement, 9 patients with N1 + N2 disease) and 21 (9.1%) patients had an isolated hilar nodal involvement (N1). At bivariate analysis, the clinical T (cT)-parameter (P=0.023), the histotype (P=0.029) and the pathological T (pT)-parameter (P=0.003) were identified as statistically significant predictors of nodal upstaging. Concerning the type of nodal upstaging, the pT was found to be statistically significant (P=0.042). At bivariate analysis for the number of involved nodal stations, a statistical significance was highlighted for the parameters cT (P=0.030) and pT (P=0.027). With linear logistic regression, histology as well as pT reached statistical significance (P=0.0275 and P=0.0382, respectively). No correlation was found between nodal upstaging and the intensity of FDG uptake in the primary lung tumor or with the timing between PET and surgery.

Conclusions

There is a strong correlation between the clinical staging of the parameter T evaluated with CT and the possible unexpected nodal upstaging. The same correlation with nodal upstaging is found for pT. At equal clinical stage, in patients affected by adenocarcinoma of the lung the relative risk of having a postoperative unexpected nodal upstaging is almost 7 times higher than in patients with squamous cell carcinoma.

The diagnostic ability of 18F-FDG PET/CT for mediastinal lymph node staging using 18F-FDG uptake and volumetric CT histogram analysis in non-small cell lung cancer

OBJECTIVES

To evaluate the clinical implications of lymph node (LN) density on ¹⁸F-FDG PET/CT for mediastinal LN characterization in non-small cell lung cancer (NSCLC).

METHODS

One hundred and fifty-two patients with 271 mediastinal LNs who underwent PET/CT and endobronchial ultrasound-guided transbronchial needle aspiration for staging were enrolled. Maximum standardized uptake value (SUVmax), short axis diameter, LN-to-primary cancer ratio of SUVmax, and median Hounsfield unit (HU) based on CT histogram were correlated to histopathology.

RESULTS

Of 271 nodes, 162 (59.8 %) were malignant. SUVmax, short axis diameter, and LPR of malignant LNs were higher than those of benign nodes. Among malignant LNs, 71.0 % had median HU between 25 and 45, while 78.9 % of benign LNs had values <25 HU or >45 HU. Using a cutoff value of 4.0, SUVmax showed the highest diagnostic ability for detecting malignant LNs with a specificity of 94.5 %, but showing a sensitivity of 70.4 %. Using additional density criteria (median HU 25-45) in LNs with 2.0< SUVmax ≤4.0, the sensitivity increased to 88.3 % with the specificity of 82.6 %.

CONCLUSIONS

LN density is useful for the characterization of LNs with mild ¹⁸F-FDG uptake. The risk of mediastinal LN metastasis in NSCLC patients could be further stratified using both ¹⁸F-FDG uptake and LN density.

KEY POINTS

• SUVmax showed the highest diagnostic ability for detecting malignant LNs. • LN density was useful in characterization of LNs with mild FDG uptake. • SUVmax and LN density together could stratify the risk of LN metastasis.

PET-CT for assessing mediastinal lymph node involvement in patients with suspected resectable non-small cell lung cancer

BACKGROUND

A major determinant of treatment offered to patients with non-small cell lung cancer (NSCLC) is their intrathoracic (mediastinal) nodal status. If the disease has not spread to the ipsilateral mediastinal nodes, subcarinal (N2) nodes, or both, and the patient is otherwise considered fit for surgery, resection is often the treatment of choice. Planning the optimal treatment is therefore critically dependent on accurate staging of the disease. PET-CT (positron emission tomography-computed tomography) is a non-invasive staging method of the mediastinum, which is increasingly available and used by lung cancer multidisciplinary teams. Although the non-invasive nature of PET-CT constitutes one of its major advantages, PET-CT may be suboptimal in detecting malignancy in normal-sized lymph nodes and in ruling out malignancy in patients with coexisting inflammatory or infectious diseases.

OBJECTIVES

To determine the diagnostic accuracy of integrated PET-CT for mediastinal staging of patients with suspected or confirmed NSCLC that is potentially suitable for treatment with curative intent.

SEARCH METHODS

We searched the following databases up to 30 April 2013: The Cochrane Library, MEDLINE via OvidSP (from 1946), Embase via OvidSP (from 1974), PreMEDLINE via OvidSP, OpenGrey, ProQuest Dissertations & Theses, and the trials register www.clinicaltrials.gov. There were no language or publication status restrictions on the search. We also contacted researchers in the field, checked reference lists, and conducted citation searches (with an end-date of 9 July 2013) of relevant studies.

SELECTION CRITERIA

Prospective or retrospective cross-sectional studies that assessed the diagnostic accuracy of integrated PET-CT for diagnosing N2 disease in patients with suspected resectable NSCLC. The studies must have used pathology as the reference standard and reported participants as the unit of analysis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data pertaining to the study characteristics and the number of true and false positives and true and false negatives for the index test, and they independently assessed the quality of the included studies using QUADAS-2. We calculated sensitivity and specificity with 95% confidence intervals (CI) for each study and performed two main analyses based on the criteria for test positivity employed: Activity > background or SUVmax ≥ 2.5 (SUVmax = maximum standardised uptake value), where we fitted a summary receiver operating characteristic (ROC) curve using a hierarchical summary ROC (HSROC) model for each subset of studies. We identified the average operating point on the SROC curve and computed the average sensitivities and specificities. We checked for heterogeneity and examined the robustness of the meta-analyses through sensitivity analyses.

MAIN RESULTS

We included 45 studies, and based on the criteria for PET-CT positivity, we categorised the included studies into three groups: Activity > background (18 studies, N = 2823, prevalence of N2 and N3 nodes = 679/2328), SUVmax ≥ 2.5 (12 studies, N = 1656, prevalence of N2 and N3 nodes = 465/1656), and Other/mixed (15 studies, N = 1616, prevalence of N2 to N3 nodes = 400/1616). None of the studies reported (any) adverse events. Under-reporting generally hampered the quality assessment of the studies, and in 30/45 studies, the applicability of the study populations was of high or unclear concern.The summary sensitivity and specificity estimates for the 'Activity > background PET-CT positivity criterion were 77.4% (95% CI 65.3 to 86.1) and 90.1% (95% CI 85.3 to 93.5), respectively, but the accuracy estimates of these studies in ROC space showed a wide prediction region. This indicated high between-study heterogeneity and a relatively large 95% confidence region around the summary value of sensitivity and specificity, denoting a lack of precision. Sensitivity analyses suggested that the overall estimate of sensitivity was especially susceptible to selection bias; reference standard bias; clear definition of test positivity; and to a lesser extent, index test bias and commercial funding bias, with lower combined estimates of sensitivity observed for all the low 'Risk of bias' studies compared with the full analysis.The summary sensitivity and specificity estimates for the SUVmax ≥ 2.5 PET-CT positivity criterion were 81.3% (95% CI 70.2 to 88.9) and 79.4% (95% CI 70 to 86.5), respectively.In this group, the accuracy estimates of these studies in ROC space also showed a very wide prediction region. This indicated very high between-study heterogeneity, and there was a relatively large 95% confidence region around the summary value of sensitivity and specificity, denoting a clear lack of precision. Sensitivity analyses suggested that both overall accuracy estimates were marginally sensitive to flow and timing bias and commercial funding bias, which both lead to slightly lower estimates of sensitivity and specificity.Heterogeneity analyses showed that the accuracy estimates were significantly influenced by country of study origin, percentage of participants with adenocarcinoma, (¹⁸F)-2-fluoro-deoxy-D-glucose (FDG) dose, type of PET-CT scanner, and study size, but not by study design, consecutive recruitment, attenuation correction, year of publication, or tuberculosis incidence rate per 100,000 population.

AUTHORS' CONCLUSIONS

This review has shown that accuracy of PET-CT is insufficient to allow management based on PET-CT alone. The findings therefore support National Institute for Health and Care (formally 'clinical') Excellence (NICE) guidance on this topic, where PET-CT is used to guide clinicians in the next step: either a biopsy or where negative and nodes are small, directly to surgery. The apparent difference between the two main makes of PET-CT scanner is important and may influence the treatment decision in some circumstances. The differences in PET-CT accuracy estimates between scanner makes, NSCLC subtypes, FDG dose, and country of study origin, along with the general variability of results, suggest that all large centres should actively monitor their accuracy. This is so that they can make reliable decisions based on their own results and identify the populations in which PET-CT is of most use or potentially little value.

Diagnostic value of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for the detection of metastases in non-small-cell lung cancer patients

In the recent years, fluorine 18 fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET)/computed tomography (CT) has emerged as a new modality for staging non-small-cell lung cancer (NSCLC) patients. The aim of this meta-analysis was to assess the diagnostic value of (18)F-FDG PET/CT in detecting metastatic lesions in NSCLC patients. Meta-analysis methods were used to pool sensitivity, specificity, positive and negative likehood ratios, diagnostic odd ratios and to construct a summary receiver-operating characteristic curve. Data from included studies were pooled to compare the diagnostic accuracy between PET/CT and PET or CT alone in nodal staging. Totally, 56 studies involving 8,699 patients met the inclusion criteria. The pooled sensitivities and specificities of (18)F-FDG PET/CT were 0.72 [95% confidence interval (CI): 0.65-0.78] and 0.91 (95% CI: 0.86-0.94) in determining mediastinal nodal staging; 0.71 (95% CI: 0.60-0.80) and 0.83 (95% CI: 0.77-0.88) in intrathoracic staging; 0.78 (95% CI: 0.64-0.87) and 0.90 (95% CI: 0.84-0.94) in intrathoracic staging on a per-node basis. For detecting extrathoracic metastases, the pooled sensitivities and specificities of (18)F-FDG PET/CT were 0.77 (95% CI: 0.47-0.93) and 0.95 (95% CI: 0.92-0.97) for all extrathoracic metastases; 0.91 (95% CI: 0.80-0.97) and 0.98 (95% CI: 0.94-0.99) for bone metastases. (18)F-FDG PET/CT is beneficial in detecting lymph node metastases and extrathoracic metastases although PET/CT showed low sensitivity in detecting brain metastases. (18)F-FDG PET/CT confers significantly higher sensitivity and specificity than contrast-enhanced CT (both p < 0.01) and higher sensitivity than (18)F-FDG PET in staging NSCLC (p < 0.05).

Non-invasive molecular imaging of prostate cancer lymph node metastasis

Imaging in medicine has been classically based on the anatomical description of organs. In the past 15 years, new imaging techniques based on gene expression that characterize a pathological process have been developed. Molecular imaging is the use of such molecules to image cell-specific characteristics. Here, we review recent advances in molecular imaging, taking as our prime example lymph node (LN) metastasis in prostate cancer. We describe the new techniques and compare their accuracy in detecting LN metastasis in prostate cancer. We also present new molecular strategies for improving tumor detection using adenoviruses, molecular promoters and amplification systems. Finally, we present the concept of 'in vivo pathology', which envisages using molecular imaging to accurately localize metastatic lesions based on the molecular signature of the disease.