Prognostic significance of venous invasion and maximum standardized uptake value of 18F-FDG PET/CT in surgically resected T1N0 esophageal squamous cell carcinoma

18F-fluorodeoxyglucose positron emission tomography/computed tomography parameters are associated with histological outcomes in superficial esophageal squamous cell carcinoma

Endoscopic submucosal dissection is a standard treatment for early esophageal squamous cell carcinoma. However, submucosal or lymphovascular invasion increases the risk of lymph node metastasis. Although 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) parameters are associated with prognosis in patients with advanced esophageal squamous cell carcinoma, the utility of FDG PET/CT in diagnosing superficial esophageal carcinoma remains unclear. This study aimed to investigate the association between FDG PET/CT parameters and histopathological findings in superficial esophageal carcinoma. Fifty-three patients with superficial esophageal cancer who underwent FDG PET/CT scans before undergoing interventions were retrospectively analyzed. The maximal standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis were significantly higher in the cases with submucosal invasion (T1b) compared with those confined to the muscularis mucosa (T1a). In contrast, classification of intrapapillary capillary loops patterns with magnifying endoscopy did not yield statistical differences between T1a and T1b. Multivariable analysis revealed that SUVmax was the only independent predictor of submucosal and lymphovascular invasion. This study demonstrated that SUVmax may be useful in predicting submucosal and lymphovascular invasion. Thus, the value of SUVmax may guide clinical decision-making in superficial esophageal squamous cell carcinoma.

Microscopic venous invasion is a predictor of prognosis in patients with esophageal squamous cell carcinoma undergoing ineffective neoadjuvant chemotherapy and surgery

BACKGROUND

Neoadjuvant chemotherapy followed by surgery is Japan's most effective treatment modality for advanced thoracic esophageal squamous cell carcinoma. However, the prognosis is not as expected. This study aimed to examine prognostic factors in patients with pathologically ineffective neoadjuvant chemotherapy followed by surgery for esophageal squamous cell carcinoma.

METHODS

We retrospectively analyzed patients who underwent neoadjuvant chemotherapy followed by curative esophagectomy for esophageal squamous cell carcinoma between December 2008 and July 2021. The patients were divided into the neoadjuvant chemotherapy effective group and the neoadjuvant chemotherapy ineffective group according to the pathological diagnosis. Clinicopathological data, prognosis, and recurrence were analyzed.

RESULTS

A total of 143 patients (121 males, 22 females; median age, 67 years) were included in this study. Of these, 34 patients were classified into the effective group and the remaining 109 patients were assigned to the ineffective group. The ineffective group had significantly worse overall survival and recurrence-free survival than the effective group (p = 0.0192 and p = 0.0070, respectively). In the ineffective group, multivariate analysis demonstrated that microscopic venous invasion was an independent prognostic factor for overall survival (hazard ratio 2.44; 95% confidence interval 1.13-5.30) and recurrence-free survival (hazard ratio 2.43; 95% confidence interval 1.24-4.73).

CONCLUSIONS

Microscopic venous invasion was associated with poor survival and cancer recurrence in the neoadjuvant chemotherapy ineffective group of patients who underwent esophagectomy for esophageal squamous cell carcinoma.

Clinical predictors of early postoperative recurrence after radical esophagectomy for thoracic esophageal cancer

PURPOSE

Esophagectomy for esophageal cancer has a high incidence rate of early postoperative recurrence and death. This study aimed to identify the clinical and pathological features in early recurrence cases and to confirm the usefulness of prediction using these factors for effective adjuvant therapy and postoperative surveillance.

METHODS

One hundred and twenty five patients who developed postoperative recurrence after undergoing radical esophagectomy for thoracic esophageal cancer were classified into two groups as follows: those with early recurrence at ≤ 6 months and those with nonearly recurrence at > 6 months after surgery. After identifying related factors of early recurrence, usefulness of these factors for prediction were examined in all patients with and without recurrence.

RESULTS

The analysis cohort consisted of 43 and 82 patients in the early and nonearly recurrence groups, respectively. In multivariate analysis, factors associated with early recurrence were higher initial levels of tumor markers (squamous cell carcinoma [SCC] ≥ 1.5 ng/ml in tumors, except for adenocarcinoma, and carcinoembryonic antigen [CEA] ≥ 5.0 ng/ml in adenocarcinoma) and higher venous invasion (v), i.e., ≥ 2 (p = 0.040 and p = 0.004, respectively). The usefulness of these two factors for recurrence prediction was confirmed in 378 patients, including 253 patients without recurrence. Patients with at least one of the two factors had significantly higher early recurrence rates than those without any factors in pStages II and III (odds ratio [OR], 6.333; p = 0016 and OR, 4.346; p = 0.008, respectively).

CONCLUSIONS

Early recurrence of thoracic esophageal cancer (i.e., during ≤ 6 months after esophagectomy) was associated with higher initial tumor marker levels and pathological findings of v ≥ 2. The combination of these two factors is useful as a simple and critical predictor of early postoperative recurrence.

Prognostic significance of lymphovascular invasion in patients with pT1b esophageal squamous cell carcinoma

BACKGROUND

Lymphovascular invasion (LVI) is a crucial predictor of lymph node metastasis (LNM). However, few studies have investigated the LVI positivity rate and its clinical significance in pT1b esophageal squamous cell carcinoma (ESCC) using immunohistochemistry and elastin staining.

METHODS

We collected data from158 patients with pT1b ESCC who had undergone radical esophagectomy. All paraffin blocks of invasive carcinoma from each patient were subjected to HE staining, elastin staining + CK (AE1/AE3) immunohistochemistry (E&IHC), and CD31/D2-40 + CK (AE1/AE3) double immunohistochemistry (D-IHC). The LVI was classified into types, i.e., vascular invasion (VI) and lymphatic vessel invasion (LI), and its location, quantity, and clinical significance were explored.

RESULTS

The positivity rates of VI by E&IHC (E-VI), VI by CD31D-IHC (CD31-VI), and LI by D2-40 D-IHC (D2-40-LI) were significantly higher than those obtained by HE staining (P < 0.001, respectively). CD31-VI and E-VI were independent adverse prognostic factors for recurrence-free survival (RFS), and they were significantly associated with poor distant metastasis-free survival and overall survival in pT1b ESCC. Intratumoral LVI was also crucial in pT1b ESCC, and L2 (the count of D2-40-LI was 5 or more) was the strongest predictor for LNM and RFS in pT1b ESCC.

CONCLUSION

E&IHC and D-IHC can dramatically improve the detection rate of LVI in pT1b ESCC, and the classification and grading of LVI can help to improve the prediction of LNM and prognosis.

Grading criteria for venous invasion in thoracic esophageal squamous cell carcinoma

BACKGROUND

Venous invasion (VI) is an adverse prognostic indicator in esophageal squamous cell carcinoma. However, grading criteria for venous invasion in thoracic esophageal squamous cell carcinoma (ESCC) have not been established.

METHODS

We enrolled 598 thoracic ESCC patients from 2005 to 2017. We detected the presence of venous invasion using the hematoxylin and eosin (H&E)-staining method and evaluated the VI grade on the basis of the number and maximal size of the involved veins. The degree of VI was classified as either 0, V1, V2, or V3, according to the combination of V-number and V-size.

RESULTS

The 1-year, 3-year and 5-year disease-free survival rates were 79.7%, 64.7% and 61.2%, respectively. Multivariate analysis demonstrated that lymphatic invasion (HR: 1.457, 95% CI: 1.058-2.006, p = 0.021), T category (HR: 1.457, 95% CI: 1.058-2.006, p = 0.022), N category (HR: 1.535, 95% CI: 1.276-2.846, p < 0.001), stage (HR: 1.563, 95% CI: 1.235-1.976, p < 0.001) and the degree of venous invasion (HR: 1.526, 95% CI: 1.279-2.822, p < 0.001) were significant indicators of recurrence. The disease-free survival curves were distinguished especially well by the degree of venous invasion in stage III and IV patients.

CONCLUSIONS

The present study explored an objective grading criterion for VI and proved the prognostic value of the degree of venous invasion in ESCC. The classification of venous invasion into 4 groups is useful for the differentiation of prognosis in ESCC patients. The prognostic significance of the degree of VI in advanced ESCC patients for recurrence may have to be considered.

The prognostic value of separate lymphatic invasion and vascular invasion in oesophageal squamous cell carcinoma: a meta-analysis and systematic review

BACKGROUND

Lymphovascular invasion (LVI) is a factor correlated with a poor prognosis in oesophageal squamous cell carcinoma (ESCC). Lymphatic invasion (LI) and vascular invasion (VI) should be reported separately because they may indicate a difference in prognosis. The prognostic role of LI and VI in ESCC patients remains controversial. A meta-analysis was conducted to resolve this question.

METHODS

We searched the PubMed, EMBASE, Web of Science, Scopus and Cochrane Library databases for studies on the association between LI and VI and the prognosis of patients with ESCC. The PICOs (Participant, Intervention, Comparison, Outcome) strategy were selected for the systematic review and meta-analysis. The effect size (ES) was the hazard ratio (HR) or relative ratio (RR) with 95% confidence intervals (CI) for overall survival (OS) and recurrence-free survival (RFS).

RESULTS

A total of 27 studies with 5740 patients were included. We calculated the pooled results from univariate and multivariate analysis using the Cox proportional hazards method. The heterogeneity was acceptable in OS and RFS. According to the pooled results of multivariate analysis, both LI and VI were correlated with a worse OS. VI was a negative indicator for RFS, while the p value of VI was greater than 0.05. The prognostic role was weakened in subgroup analysis with studies using haematoxylin-eosin staining method.

CONCLUSIONS

Both LI and VI were indicators of a worse OS outcome. LI was a more significant indicator in predicting a worse RFS. More larger sample studies with immunohistochemical staining and good designs are required to detect the prognostic value of separate LI and VI in ESCC.

Lymphatic invasion is a prognostic factor of pathological N0 esophageal squamous cell carcinoma

Adjuvant treatment after upfront esophagectomy for esophageal squamous cell carcinoma (ESCC) is indicated only for patients with lymph node metastasis in Japan. However, the recurrence rate after curative resection is high even for node-negative patients; thus, understanding the prognostic factors for patients with node-negative ESCC, which still remains unidentified, is important. Here, we aimed to reveal the prognostic factors for the long-term outcomes of patients with node-negative ESCC. Moreover, we compared the long-term outcomes among high-risk node-negative and node-positive patients. This single-institution retrospective study included 103 patients with pT1b-3N0 ESCC who underwent upfront surgery to identify the population at a high risk of recurrence. To compare overall survival (OS) and recurrence-free survival (RFS) between high-risk node-negative and node-positive patients, 51 node-positive ESCC patients with pStage IIIA or less who had undergone upfront surgery were also included. Univariable and multivariable analyses were performed using the Cox proportional hazard regression model. OS and RFS were compared using the log-rank test. Only lymphatic invasion (Ly+) was associated with worse 3-year OS (hazard ratio, 8.63; 95% confidence interval, 2.09-35.69; P = 0.0029) and RFS (hazard ratio, 4.87; 95% confidence interval, 1.69-14.02; P = 0.0034). The node-negative and Ly+ patients showed significantly worse OS (P = 0.0242) and RFS (P = 0.0114) than the node-positive patients who underwent chemotherapy. Ly+ is the only independent prognostic factor in patients with node-negative ESCC. Patients with node-negative and Ly+ ESCC may benefit from adjuvant treatment.

Predicting tumor response and prognosis to neoadjuvant chemotherapy in esophageal squamous cell carcinoma patients using PERCIST: a multicenter study in Japan

PURPOSE

To investigate the usefulness of the positron emission tomography response criteria in solid tumors 1.0 (PERCIST1.0) for predicting tumor response to neoadjuvant chemotherapy and prognosis and determine whether PERCIST improvements are necessary for esophageal squamous cell carcinoma (ESCC) patients.

PATIENTS AND METHODS

We analyzed the cases of 177 ESCC patients and examined the association between PERCIST and their pathological responses. Associations of whole-PERCIST with progression-free survival (PFS) and overall survival (OS) were evaluated by a Kaplan-Meier analysis and Cox proportional hazards model. To investigate potential PERCIST improvements, we used the survival tree technique to understand patients' prognoses.

RESULTS

There were significant correlations between the pathologic response and PERCIST of primary tumor (p < 0.001). The optimal cutoff value of the primary tumors' SULpeak response to classify pathologic responses was -50.0%. The diagnostic accuracy of SULpeak response was 87.3% sensitivity, 54.1% specificity, 68.9% accuracy, positive predictive value 60.5%, and negative predictive value 84.1%. Whole-PERCIST was significantly associated with PFS and OS. The survival tree results indicated that a high reduction of the whole SULpeak response was significantly correlated with the patients' prognoses. The cutoff values for the separation of prognoses were - 52.5 for PFS and - 47.1% for OS.

CONCLUSION

PERCIST1.0 can help predict tumor responses and prognoses. However, ¹⁸F-FDG-PET/CT tends to underestimate residual tumors in histopathological response evaluations. Modified PERCIST, in which the partial metabolic response is further classified by the SULpeak response (-50%), might be more appropriate than PERCIST1.0 for evaluating tumor responses and stratifying high-risk patients for recurrence and poor prognosis.

Predictive Factors for Lymph Node Metastasis in Clinical Stage I Part-Solid Lung Adenocarcinoma

BACKGROUND

Accurate clinical staging of tumors with a small solid portion is essential for developing an appropriate treatment plan. This study evaluated predictive factors for lymph node (LN) metastasis in patients with clinical stage I part-solid lung adenocarcinoma.

METHODS

Medical records of patients with clinical stage I part-solid adenocarcinoma who underwent anatomic pulmonary resection with systematic node evaluation between January 2009 and June 2018 were retrospectively reviewed. To identify predictive factors for LN metastasis, univariate and multivariable logistic regression analyses were performed.

RESULTS

Among the 593 patients in this study, the overall prevalence of LN metastasis was 3.7% (n = 22), which included 3.0% (n = 18) of patients with N1 LN metastasis and 1.5% (n = 9) of patients with N2 LN metastasis. Combined N1 and N2 nodal involvement was observed in 5 patients. Nodal metastasis was not observed in tumors with a solid portion sized 1.1 cm or smaller. The nodal metastasis rates in cT1b, cT1c, and cT2a tumors were 5.5% (13 of 237), 7.1% (6 of 84), and 13.6% (3 of 22), respectively. According to the multivariable analysis, predictive factors included the size of the solid portion (P = .015) and the high maximum standardized uptake value (SUVmax) of the primary tumor (P = .044).

CONCLUSIONS

Large solid portion and high SUVmax of the primary tumor were predictive factors of LN metastasis in patients with clinical stage I part-solid lung adenocarcinoma. Systematic LN evaluation should be performed, especially in those who have a large solid portion and high SUVmax of the primary tumor.

Predictions of Pathological Features and Recurrence Based on FDG-PET Findings of Esophageal Squamous Cell Carcinoma after Trimodal Therapy

BACKGROUND

The degree of metabolic activity in tumor cells can be determined by 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET). Associations between FDG uptake by primary tumors of locally advanced esophageal squamous cell carcinoma (ESCC) under trimodal therapy and the pathological features of such tumors have not been fully investigated.

PATIENTS AND METHODS

We evaluated relationships between the maximal standardized uptake (SUVmax) in primary tumors on preoperative PET images and pathological features as well as cancer recurrence in 143 patients with ESCC who underwent neoadjuvant chemoradiotherapy (NCRT) followed by surgery.

RESULTS

The post-SUVmax significantly differed after NCRT for ypT and ypN status, lymphatic invasion (LI), venous invasion (VI), and recurrence. Furthermore, the %ΔSUVmax (rate of decrease between before and after NCRT) for LI, VI, and recurrence significantly differed. Univariate and multivariate analyses selected post-SUVmax and %ΔSUVmax as independent preoperative predictors of recurrence-free survival [hazard ratio (HR) 1.46; 95% confidence interval (CI) 1.24-1.72 and HR 0.97; 95% CI 0.96-0.99, respectively; p < 0.001 for both]. Recurrence-free and overall survival were significantly stratified according to optimal SUVmax cutoffs for predicting recurrence (post- and %ΔSUVmax: 2.8 and 70, respectively).

CONCLUSIONS

The post- and %ΔSUVmax of primary tumors were significantly associated with the pathological features and recurrence of ESCC under trimodal therapy. Therefore, FDG-PET can preoperatively predict the degree of aggressive tumor behavior in ESCC under trimodal therapy.

Surgically Resected Esophageal Squamous Cell Carcinoma: Patient Survival and Clinicopathological Prognostic Factors

We aimed to report patients' survival after surgical resection of eSCC and to ascertain the clinical, imaging, and pathological factors related to patient prognosis. This retrospective study included 435 patients with eSCC of <stage T2 (median follow-up period, 49.3 months). A total of 103 (23.7%) patients died, and 89 (20.5%) experienced recurrence during follow-up. The maximum standardized uptake value (SUV_max) on positron emission tomography (PET)/computed tomography (CT) of the primary tumor was significantly correlated with tumor length, nodal metastasis, and pathologic T stage in a positive linear fashion. In the multivariate analysis, higher SUV_max on PET/CT was a negative prognostic factor for both disease-free survival (DFS) and overall survival (OS). Contrarily, the presence of nodal metastasis was a prognostic factor only for DFS, and pathologic T stage only for OS. By applying SUVmax cut-off, both DFS and OS were significantly different among three groups when divided by cut-off values (A: SUVmax ≤ 3.05, B: SUVmax 3.06 - 5.64, C: SUVmax ≥ 5.65). In patients with a surgically resectable eSCC, measuring the SUV_max of the primary tumor during PET/CT can help predict patient survival. Additionally, PET/CT renders triage criterion for endoscopic submucosal dissection (ESD; T1a cancer and SUVmax, ≤3.05).

Prediction of lymph node metastasis by PET/CT metabolic parameters in patients with esophageal squamous cell carcinoma

OBJECTIVE

The aim of this study was to investigate the capability of F-FDG PET/computed tomography (CT)-related metabolic parameters to predict lymph node metastasis (LNM) and occult lymph node metastasis (OLNM) in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Totally 84 patients undergoing curative esophagectomy with lymph node dissection were enrolled in this study. Metabolic tumor volume (MTV) was measured using threshold-based methods with a threshold of 40% maximum standardized uptake value (SUVmax). The derivative of the volume (V)-threshold (T) function (volume difference/threshold difference) was defined as the heterogeneity factor (HF). In addition, SUVmax, SUVmean, total lesion glycolysis (TLG), maximum tumor-to-blood SUV ratio (SURmax), SURmean and several clinicopathologic parameters were analyzed to identify risk factors of LNM and OLNM.

RESULTS

SUVmax, SUVmean, MTV, TLG, SURmax, SURmean and HF were significantly different between LNM (+) and LNM (-). The optimal cut-off values of those parameters were 12.5, 8.34, 15.01, 117.185, 7.885, 4.855 and 0.300, respectively. Logistic regression analysis showed that MTV (OR = 1.127, P = 0.04) and SURmax (OR = 1.446, P = 0.004) were independent predictors of LNM, with sensitivity and specificity were 51.2%, 83.7% vs. 53.7%, 79.1%. In univariate and multivariate analysis, MTV was the sole parameter associated with OLMN (P = 0.024).

CONCLUSION

MTV and SURmax were statistically significant predictors of LNM in patients with ESCC, while MTV was a predictor of OLNM. High SURmax and MTV may indicate that the treatment planning should be tailored, which may improve patient prognosis.

Prognostic impact of lymphovascular invasion in lymph node-negative superficial esophageal squamous cell carcinoma

The relationship between lymphovascular invasion (LVI) and prognosis in patients with superficial esophageal squamous cell carcinoma (SESCC) is unclear. The aim of this study is to evaluate prognostic factors in patients with lymph node-negative SESCC. A total of 195 patients with pathologically confirmed T1a-MM, T1b, and lymph node-negative SESCC were retrospectively reviewed in this study. Overall, the disease-free survival (DFS) rate was poorer in the lymphatic invasion-positive group than in the lymphatic invasion-negative group (p = 0.002) and a multivariate analysis suggested that lymphatic invasion was the only independent prognostic factor of DFS in patients with lymph node-negative SESCC (HR = 4.075, p = 0.005). Distant organ recurrence occurred in one patient (1/52, 1.9%) in the T1b-SM2 group and in six patients (6/61, 9.7%) in the T1b-SM3 group; all of these patients had LVI. LVI-positive patients had a poorer DFS than invasion-negative patients in the T1b-SM2 and SM3 groups (p = 0.026), and a multivariate analysis suggested that LVI was the only independent prognostic factor of DFS in patients with lymph node-negative SM2 and SM3 SESCC (HR = 5.165, p = 0.031). Lymph node-positive patients had a significantly poorer DFS rate than lymph node negative and LVI positive patients among the SM2 and SM3 SESCC patients (p = 0.018). The present results suggested that LVI was an independent prognostic factor in patients with SM2 and SM3 lymph node-negative SESCC; however their prognosis was not worse than that of patients with lymph node-positive SM2 and SM3 SESCC, for whom adjuvant therapy is indicated as a standard treatment.

The prognostic role of angiolymphatic invasion in N0 esophageal carcinoma: a meta-analysis and systematic review

Background

Angiolymphatic invasion (ALI) plays an important role in lymph node metastasis. The presence of an ALI predicts a high risk for lymph node metastasis and a poor prognosis in patients with lymph node negative esophageal carcinoma. The independent prognostic value of ALI in node-negative patients remains controversial. A meta-analysis was conducted to investigate the relationship between ALI and prognosis in cases of lymph node negative esophageal carcinoma.

Methods

We searched the PubMed, EMBASE, Web of Science, and Cochrane Library databases for studies on the relationship between ALI and the prognosis of patients with esophageal carcinoma. Studies with N0 patients' survival data related to ALI were included. The effect size (ES) was the hazard ratio (HR) with 95% confidence intervals (CI) for cancer-specific survival (CSS), overall survival (OS) and recurrence-free survival (RFS).

Results

A total of 9 studies with 2,154 patients were included after applying the inclusion and exclusion criteria. The pooled HR showed that patients with ALI have a poor cancer specific survival (HR =2.54; 95% CI, 1.84-3.51; P<0.001), a poor overall survival (HR =2.84; 95% CI, 2.17-3.72; P<0.001) and a short disease free survival (HR =2.84; 95% CI: 1.85-4.37; P<0.001).

Conclusions

ALI could be used as an indicator for identifying high-risk patients with lymph node-negative esophageal carcinoma and can be used as an indicator for sub-stages in further stage classification.

Exploratory radiomic features from integrated 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging are associated with contemporaneous metastases in oesophageal/gastroesophageal cancer

PURPOSE

The purpose of this study was to determine if 18F-fluorodeoxyglucose positron emission tomography/magnetic resonance imaging (18F-FDG PET/MRI) features are associated with contemporaneous metastases in patients with oesophageal/gastroesophageal cancer.

METHODS

Following IRB approval and informed consent, patients underwent a staging PET/MRI following 18F-FDG injection (326 ± 28 MBq) and 156 ± 23 min uptake time. First-order histogram and second-order grey level co-occurrence matrix features were computed for PET standardized uptake value (SUV) and MRI T1-W, T2-W, diffusion weighted (DWI) and apparent diffusion coefficient (ADC) images for the whole tumour volume. K-means clustering assessed the correlation of feature-pairs with metastases. Multivariate analysis of variance (MANOVA) was performed to assess the statistical separability of the groups identified by feature-pairs. Sensitivity (SN), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC) were calculated for these features and compared with SUVmax, ADCmean and maximum diameter alone for predicting contemporaneous metastases.

RESULTS

Twenty patients (18 males, 2 female; median 67 years, range 52-86) comprised the final study cohort; ten patients had metastases. Lower second-order SUV entropy combined with higher second-order ADC entropy were the best feature-pair for discriminating metastatic patients, MANOVA p value <0.001 (SN = 80%, SP = 80%, PPV = 80%, NPV = 80%, ACC = 80%). SUVmax (SN = 30%, SP = 80%, PPV = 60%, NPV = 53%, ACC = 55%), ADCmean (SN = 20%, SP = 70%, PPV = 40%, NPV = 47%, ACC = 45%) and tumour maximum diameter (SN = 10%, SP = 90%, PPV = 50%, NPV = 50%, ACC = 50%) had poorer sensitivity and accuracy.

CONCLUSION

High ADC entropy combined with low SUV entropy is associated with a higher prevalence of metastases and a promising initial signature for future study.