Individual risk calculator to predict lymph node metastases in patients with submucosal (T1b) esophageal adenocarcinoma: a multicenter cohort study.

BACKGROUND: Lymph node metastasis (LNM) is possible after endoscopic resection of early esophageal adenocarcinoma (EAC). This study aimed to develop and internally validate a prediction model that estimates the individual risk of metastases in patients with pT1b EAC. METHODS: A nationwide, retrospective, multicenter cohort study was conducted in patients with pT1b EAC treated with endoscopic resection and/or surgery between 1989 and 2016. The primary end point was presence of LNM in surgical resection specimens or detection of metastases during follow-up. All resection specimens were histologically reassessed by specialist gastrointestinal pathologists. Subdistribution hazard regression analysis was used to develop the prediction model. The discriminative ability of this model was assessed using the c-statistic. RESULTS: 248 patients with pT1b EAC were included. Metastases were seen in 78 patients, and the 5-year cumulative incidence was 30.9 % (95 % confidence interval [CI] 25.1 %-36.8 %). The risk of metastases increased with submucosal invasion depth (subdistribution hazard ratio [SHR] 1.08, 95 %CI 1.02-1.14, for every increase of 500 µm), lymphovascular invasion (SHR 2.95, 95 %CI 1.95-4.45), and for larger tumors (SHR 1.23, 95 %CI 1.10-1.37, for every increase of 10 mm). The model demonstrated good discriminative ability (c-statistic 0.81, 95 %CI 0.75-0.86). CONCLUSIONS: A third of patients with pT1b EAC experienced metastases within 5 years. The probability of developing post-resection metastases was estimated with a personalized predicted risk score incorporating tumor invasion depth, tumor size, and lymphovascular invasion. This model requires external validation before implementation into clinical practice.

Lymphovascular invasion quantification could improve risk prediction of lymph node metastases in patients with submucosal (T1b) esophageal adenocarcinoma.

AIM: To quantify lymphovascular invasion (LVI) and to assess the prognostic value in patients with pT1b esophageal adenocarcinoma. METHODS: In this nationwide, retrospective cohort study, patients were included if they were treated with surgery or endoscopic resection for pT1b esophageal adenocarcinoma. Primary endpoint was the presence of metastases, lymph node metastases, or distant metastases, in surgical resection specimens or during follow-up. A prediction model to identify risk factors for metastases was developed and internally validated. RESULTS: 248 patients were included. LVI was distributed as follows: no LVI (n = 196; 79.0%), 1 LVI focus (n = 16; 6.5%), 2-3 LVI foci (n = 21; 8.5%) and ≥4 LVI foci (n = 15; 6.0%). Seventy-eight patients had metastases. The risk of metastases was increased for tumors with 2-3 LVI foci [subdistribution hazard ratio (SHR) 3.39, 95% confidence interval (CI) 2.10-5.47] and ≥4 LVI foci (SHR 3.81, 95% CI 2.37-6.10). The prediction model demonstrated a good discriminative ability (c-statistic 0.81). CONCLUSION: The risk of metastases is higher when more LVI foci are present. Quantification of LVI could be useful for a more precise risk estimation of metastases. This model needs to be externally validated before implementation into clinical practice.

Effect of neoadjuvant chemoradiotherapy on p53 and SOX2 protein expression in esophageal adenocarcinoma.

Aim: To determine if neoadjuvant chemoradiotherapy (nCRT) affects p53 and SOX2 expression in esophageal adenocarcinoma (EAC). Materials & methods: Comparison of p53 and SOX2 expression in 100 paired pre- and post-nCRT EAC samples. Results: Aberrant p53 was largely concordant (75/83, 90%), while 13/18 (72%) pre-nCRT samples with wild-type (WT) p53 staining, showed aberrant staining in paired post-nCRT samples. Similarly, 31/45 (69%) with previous WT SOX2 showed SOX2 loss in paired post-nCRT samples, whereas aberrant SOX2 loss was concordant in 50/55 (91%) cases. The prognostic values of both markers regarding survival differ before and after nCRT. Conclusion: Aberrant expression of p53 and SOX2 staining in EAC tissue is unaffected by nCRT. Conversely, the WT-staining pattern frequently changed to aberrant expression.

Olfactomedin 4 (OLFM4) expression is associated with nodal metastases in esophageal adenocarcinoma.

To date no informative biomarkers exist to accurately predict presence of lymph node metastases (LNM) in esophageal adenocarcinoma (EAC). We studied the discriminative value of Olfactomedin 4 (OLFM4), an intestinal stem cell marker, in EAC. Patients who had undergone esophagectomy as single treatment modality for both advanced (pT2-4) and early (pT1b) adenocarcinoma of the esophagus or gastro-esophageal junction were selected for this study from an institutional database (Erasmus MC University Medical Center, Rotterdam, The Netherlands). Surgical resection specimens of 196 advanced and 44 early EAC were examined. OLFM4 expression was studied by immunohistochemistry and categorized as low (<30%) or high (> = 30%) expression. Low OLFM4 was associated with poor differentiation grade in both advanced (60% vs. 34.8%, p = 0.001) and early EAC (39.1% vs. 9.5%, p = 0.023). LNM were present in 161 (82.1%) of advanced and 9 (20.5%) of early EAC respectively. Low OLFM4 was independently associated with the presence of LNM in advanced EAC in multivariable analysis (OR 2.7; 95% CI, 1.16-6.41; p = 0.022), but not in early EAC (OR 2.1; 95% CI, 0.46-9.84; p = 0.338). However, the difference in association with LNM between advanced (OR 2.7; 95% CI, 1.18-6.34; p = 0.019) and early (OR 2.3; 95% CI, 0.47-11.13; p = 0.302) EAC was non-significant (p = 0.844), suggesting that the lack of significance in early EAC is due to the small number of patients in this group. OLFM4 was not of significance for the disease free and overall survival. Overall, low expression of intestinal stem cell marker OLFM4 was associated with the presence of LNM. Our study suggests that OLFM4 could be an informative marker with the potential to improve preoperative assessment in patients with EAC. Further studies are needed to confirm the value of OLFM4 as a biomarker for LNM.

Pattern of p53 protein expression is predictive for survival in chemoradiotherapy-naive esophageal adenocarcinoma.

INTRODUCTION: TP53 mutations are considered to be the driving factor in the initiation of esophageal adenocarcinoma (EAC). However, the impact of this gene and its encoded protein as a prognostic marker has not been definitely established yet. METHODS: In total, 204 chemoradiotherapy (CRT)-naive patients with EAC were included for p53 protein expression evaluation by immunohistochemistry (IHC) on the resection specimens, categorized as overexpression, heterogeneous or loss of expression, and correlated with disease free survival (DFS) and overall survival (OS) using multivariable Cox regression analysis. In a subset representing all three IHC subgroups mutational status of selected candidate genes (n=33) and high throughput methylation profiling (n=16) was assessed. RESULTS: Compared to heterogeneous p53 expression, loss and overexpression were both independently predictive for adverse DFS and OS. TP53 mutational status significantly correlated with the IHC categories (p=0.035). Most of the EAC with loss- or overexpression harbored TP53 mutations (18/20, representing nonsense and missense mutations respectively). In contrast, 6/13 EAC with heterogeneous expression were TP53 wild type, of which two demonstrated MDM4 or MDM2 amplification. Combined genomic hypomethylation and high frequency of intra-chromosomal breaks was found in a selection of EAC without p53 overexpression. CONCLUSION: P53 expression pattern is prognostic for DFS and OS in this historical cohort of CRT-naive EAC. P53 IHC is an informative readout for TP53 mutational status in EAC with either loss- or overexpression, but not in case of a heterogeneous p53 pattern. Different EAC pathogenesis might exist, related to p53 and other candidate gene status, DNA hypomethylation and intrachromosomal breaks.

Organization of cerebral projections to identified cerebellar zones in the posterior cerebellum of the rat.

The cerebrocerebellar connection makes use of two of the largest fiber tracts in the mammalian brain, i.e., the cerebral and medial cerebellar peduncles. Neuroanatomical approaches aimed to elucidate the organization of this important connection have been hindered by its multisynaptic nature, the complex organization of its components, and the dependency of conventional tracers on precisely placed injections. To overcome these problems, we used rabies virus (RV) as a retrograde transneuronal tracer. RV was injected simultaneously with cholera toxin ß subunit (CTb) into selected areas of the cerebellar cortex of 18 male Wistar rats. A survival time of 48-50 h resulted in first- and second-order labeling of RV in combination with first-order labeling of CTb. The distribution of CTb-labeled neurons in the inferior olive established the zonal identity of the injection site. In this way, it was possible to examine the cortical distribution of neurons from which disynaptic cerebrocerebellar projections to specific cerebellar loci originate. The results show that this distribution covaries with the identity of the injected cerebellar lobule. More subtle changes were present when different zones of the same lobule were injected. The C1 zone of lobule VIII receives a more prominent projection from the somatosensory cortex compared with the C2/D zones. The laterally positioned D zones receive information from more rostral regions of the cerebral cortex. The vermis of lobule VII receives a prominent input from the retrosplenial and orbitofrontal cortices. Different injection sites also result in differences in laterality of the connections.