G3 Tumors Research Articles

Multicenter, retrospective, observational study of outcomes of treatment for unresectable neuroendocrine tumors G3 of gastroenteropancreatic or unknown primary origin.

660 Background: The 2017 edition of the WHO classification categorized neuroendocrine neoplasms (NEN) as neuroendocrine tumors (NET) G1, G2, G3, and neuroendocrine carcinoma (NEC). Prior to 2017, NET G3 was categorized as NEC in the WHO 2010 classification. Platinum-based chemotherapy, commonly used as first-line treatment for these tumors, shows suboptimal efficacy for NET G3. Additionally, large-scale studies and robust evidence on chemotherapy outcomes for NET G3 are lacking. We investigated chemotherapy regimens for NET G3 and evaluated their outcomes. Methods: We included 73 patients (pts) who were clinically and pathologically diagnosed with unresectable NET G3 of gastroenteropancreatic or unknown primary origin and who started chemotherapy between Jan 2011 and Dec 2019. Clinical data were collected retrospectively and analyzed for regimen selected, treatment efficacy, and prognostic factors. A central pathological review was conducted if tissue samples were available. Results: The median age of pts was 65 years (range 27-85 years), with 45 being male. Among the pts, 49 had pancreatic NETs, 10 had gastrointestinal NETs, and 14 had NETs of unknown primary origin. The median Ki-67 index was 30% (range 20-70%). Twenty-seven patients (37%) had received prior treatment, such as surgery or local therapy. A central pathological diagnosis was confirmed NET G3 in 42 out of 44 patients (95%). Primary treatment regimens were NET-based (somatostatin analogues, everolimus, sunitinib, streptozocin-based chemotherapy, and capecitabine and temozolomide [CAPTEM]) and NEC-based (platinum-based chemotherapy) in 54% and 44% of patients, respectively. NET-based regimens were selected in 36% and 78% of pts, respectively, before and after publication of the WHO 2017 classification. The overall response rate (ORR) was 16% for NEC-based regimens and 19% for NET-based regimens. However, when focusing on NET-based chemotherapy (streptozocin-based and CAPTEM), the ORR was 54%. Median progression-free survival (PFS) was 118 days (95% confidence interval [CI]: 60-337 days) for NET-based regimens and 229 days (95%CI: 133-426 days) for NEC-based regimens. Median overall survival (OS) was 841 days for NET-based regimens (95%CI: 480-989 days) and 658 days (95%CI: 455-1144 days) for NEC-based regimens. There were no significant differences in PFS or OS between the regimens. In multivariable analysis, hepatic tumor volume >25% was a negative predictor of PFS, and NSE ≥16.3 ng/mL was a negative predictor of OS. Conclusions: Since the introduction of NET G3 in the WHO classification, NET-based regimens have become the preferred treatment choice. Although there were no significant differences in PFS or OS between the regimens, the NEC-based regimens was limited. Pts with high hepatic tumor volume or elevated NSE levels had a worse prognosis.

Phase II study of mFOLFIRINOX efficacy as first and subsequent lines of advanced gastrointestinal neuroendocrine tumors G3 and neuroendocrine carcinomas therapy.

659 Background: Gastrointestinal (GI) neuroendocrine carcinomas (NEC) are rare tumors and account for 3% of all NECs. Despite the differences in genetic characteristics, treatment principles of GI NECs are extrapolated from lung NECs. The standard first-line therapy is platinum and etoposide-containing regimens, which allow to achieve a median PFS of 5-6 months. A small retrospective study demonstrated the potential effectiveness of the mFOLFIRINOX regimen with a median PFS of 5.4 months, despite that the majority of patients (pts) received this regimen as second or subsequent lines. The aim of this study is to evaluate mFOLFIRINOX +/- somatostatin analogues (SA) efficacy in GI NEC subgroup. Methods: This prospective, single center phase II study used a two-stage Simon design. The primary endpoint is disease control rate (DCR) ≥ 6 months. Statistical hypothesis: investigated therapy improves DCR compared with historical control from 50 to 70%. Secondary endpoints are progression-free survival (PFS), overall survival (OS), objective response. At the first stage, enrollment of 16 pts was planned (α=0.05, power 80%). If a disease control ≥ 6 months was achieved in at least 9 of the 16 pts, it was planned to continue enrollment up to 39 pts. Here we present results of the first stage of this study. Inclusion criteria: pts ≥18 y.o. with histologically confirmed advanced GI NEC or neuroendocrine tumor (NET) G3 ki67≥55%; ECOG 0-2. Recruitment of pts was carried from 2019 to February 2024. Results: The study included 16 pts, 12 male and 4 female. The most common sites of primary tumor are stomach (N=8, 50%) and pancreas (N=5, 31.3%). 10 (62.5%) pts had large cell carcinoma, 1 – small cell carcinoma (6.3%), 5 (31.3%) – NET G3. The median ki-67 was 70% (40-95%). 15 pts (93.7%) had IV stage, 1 (6.3%) – III. The most common site of metastases is liver – 11 (68.8%), more than half of pts have isolated metastases in liver (N=9, 56.3%). ECOG status was evaluated as 0-1 in 15 (93.7%) cases. Majority of pts (N=14, 87.5%) received mFOLFIRINOX as first line therapy. 7 pts (46.7%) had positive expression of SSTR-2A or -5 and received concurrent treatment with SA. ORR was 62.5% (N=10/16), stable disease – 37.5% (N=6/16). DCR ≥ 6 months was 93.7% (N=15). With a median follow-up of 13.2 months, median PFS was 10.8 months (95% CI 7.57-14.1). One pts had serious adverse event - myocardial infarction, no grade 5 toxicity was observed. Conclusions: Chemotherapy with mFOLFIRINOX showed promising results in GI NECs or NETs G3 ki67≥55% treatment. Primary endpoint was met, enrollment of patients in the study continues.

HIF1A, EPAS1, and VEGFA: angiogenesis and hypoxia-related gene expression in endometrium and endometrial epithelial tumors.

Endometrial cancer (EC) is the second most frequent gynecological malignancy and the sixth most common women's cancer worldwide. EC incidence rate is increasing rapidly. Apart from the classical, we should consider angiogenesis and hypoxia-related genes as a reason for EC manifestation and progression. We compared the patterns of HIF1A, EPAS1, and VEGFA (genes of interest - GOIs) mRNA expression in 92 cases. HIF1A and VEGFA levels were higher in EC patients than in controls. VEGFA differed significantly between controls and both tumor grades G2 and G3, and we observed a positive correlation for HIF1A and VEGFA with EC grading. VEGFA levels were significantly higher in post-menopausal compared to pre-menopausal patients. All GOIs demonstrated strong correlations in pre-menopausal cases and weak correlations in post-menopausal cases. A positive correlation was observed in pre-menopausal controls for all GOIs and in post-menopausal patients for only EPAS1 and VEGFA. HIF1A and EPAS1 positively correlated with VEGFA in post-menopausal EC cases. Multiple linear regression analyses revealed that menopause, body mass index (BMI), and HIF1A expression are significant stimulating factors for EC occurrence. HIF1A levels were higher in EC patients after BMI and comorbidity number adjustment. The gene-to-gene relation could be seen as either a diagnostic or a therapeutic target in EC. Physicians should inform patients about modifiable risk factors such as BMI. Second, more attention should be paid to diagnosing patients with comorbidities in older age and after menopause. These factors should be considered in designing angiogenesis and hypoxia-related gene-targeting therapies.

Exploring the expression of DLL3 in gastroenteropancreatic neuroendocrine neoplasms and its potential diagnostic value

Delta-like protein (DLL3) is a novel therapeutic target. DLL3 expression in gastroenteropancreatic neuroendocrine tumors (GEP-NECs) is poorly understood, complicating the distinction between well-differentiated neuroendocrine tumors G3 (NET G3) and poorly differentiated NEC. DLL3 immunohistochemistry (IHC) was performed on 248 primary GEP-NECs, correlating with clinicopathological parameters, NE markers, PD-L1, Ki67 index, and prognosis. Achaete-scute complex-like 1 (ASCL1) IHC was performed on some GEP-NECs. DLL3 IHC was conducted on 36 GEP-NETs, 29 gastric adenocarcinomas (GACs), and metastatic tumors (9 lymph node metastases and 19 distant metastases). DLL3 expression rates were 54.8% in GEP-NECs at the primary site, associated with small cell neuroendocrine carcinoma (SCNEC) (p < 0.001), chemotherapy before baseline (p = 0.015), and at least two NE markers (p = 0.048). DLL3 expression in metastatic GEP-NECs was similar to that of primary tumors. Expression rates in NET G1, NET G2, NET G3, and GACs were 0%, 0%, 15.8%, and 0%, respectively, highlighting DLL3 as a powerful tool for identifying poorly differentiated NEC. DLL3 expression was related to ASCL1 in GEP-NECs, especially in SCNEC. It was not correlated with progression-free survival (PFS) or overall survival(OS), regardless of cutoff value (1%, 50%, 75%). In conclusion, DLL3 targeted therapy may offer potential for the treatment of poorly differentiated NEC of the digestive system, although further studies are needed to validate its efficacy.

Pancreatic Well-Differentiated Neuroendocrine Tumors are Frequently Undergraded on Endoscopic Ultrasound-Guided Fine Needle Biopsy Sampling: A Single Institutional Experience.

Objectives. To determine the accuracy of grading pancreatic well-differentiated neuroendocrine tumors (PanNETs) on endoscopic ultrasound-guided fine needle biopsy (EUS-FNB). Methods. Fifty-three (53) PanNETs from 52 patients with EUS-FNB and subsequent resection were included, including 1 patient with 2 synchronous tumors biopsied separately. Grade (G) was assigned as per the 2019 World Health Organization criteria. The concordance of grade between EUS-FNB and resection was measured using kappa statistic. Clinicopathologic features were compared between specimens with concordant or discordant grading. Results. Two-thirds of patients were male, and the median age was 62 years (range 27-85). Four received neoadjuvant therapy. 89% were nonfunctional, whereas 11% were functional. Concordance of grade between EUS-FNB and resection was moderate (kappa = 0.45). Precisely 25% (13 out of 51) of G1 or G2 specimens were discordant. G2 tumors were frequently undergraded on EUS-FNB (11 out of 18; 61%), whereas G1 tumors were only rarely overgraded (2 out of 33; 6%). Two G3 tumors were concordant. There was no correlation between concordance and other clinicopathologic features, except for perineural invasion. Conclusions. The concordance of PanNET grading between EUS-FNB and resection was moderate, and G2 tumors were frequently undergraded on EUS-FNB. Knowledge of this is important to recognize and acknowledge, as this could potentially impact treatment decisions in some patients.

Clinicopathological Characteristics and Long-Term Outcomes of Cystic vs. Solid Pancreatic Neuroendocrine Tumors: A Multi-Institutional Experience with 1727 Patients.

To investigate the clinicopathological features and long-term outcomes of cystic and solid pancreatic neuroendocrine tumors (PanNETs). PanNETs uncommonly present as cystic lesions. Whether cystic PanNETs represent a distinct clinical entity compared to solid PanNETs is controversial. Clinicopathologic data of patients with resected PanNETs were collected from 4 high-volume centers between 2000-2019. Clinicopathological characteristics and outcomes of patients with cystic and solid PanNETs were compared based on a 3cm tumor size cut-off using the Chi-squared test and Mann-Whitney U test. Survival estimates were calculated with the Kaplan-Meier method and log-rank test and multivariable analysis using a Cox proportional hazard model. Of the 1727 patients undergoing pancreatectomy for PanNET, the median age was 58.1 years (IQR, 18.4), and 53.3% were male. Of these, 177 (10.3%) were cystic and 1550 (89.7%) solid. Cystic PanNETs were more prevalent in patients with hereditary syndromes, less frequently functional, and more often located in the body/tail of the pancreas. After the exclusion of patients with functional tumors, WHO G3 tumors, hereditary syndromes, neoadjuvant treatment, and metastatic stage, 145 cystic PanNETs were compared to 1059 solid PanNETs, and the median follow-up period of the cohort was 64 months. Cystic PanNETs demonstrated significantly fewer high-risk histopathological features, lymph node metastases (5.5% vs. 24.0%, P<0.001), and distant recurrence (4.1% vs. 14.4%; P<0.001). Among tumors ≤3cm, cystic PanNETs had a low rate of lymph node metastases (3.9% vs. 17.8%; P<0.001), recurrence (3.1% vs. 8.4%; P=0.041), and low propensity to recur distantly. Cystic PanNETs had favorable long-term survival regardless of tumor size. Cystic PanNETs have a more benign course than their solid counterparts and conservative management can be considered for EUS-FNA-proven cystic PanNETs ≤3cm. Parenchyma and lymph-node sparing resections are warranted in patients with cystic PanNETs>3cm. Patients with poor baseline performance status may forego cystic PanNET resection and not affect their overall survival.

Dose-Escalated SBRT for Borderline and Locally Advanced Pancreatic Cancer: Resectability Rate and Pathological Results of a Multicenter Prospective Study.

We demonstrated for the first time the safety and feasibility of escalating up to 55 Gy/11 Gy/fr/5fr in borderline (BRPC)/unresectable locally advanced pancreatic cancer (LAPC), using the standard LINAC platform. The aim of the present study is to assess for the first time the impact of this high-dose neoadjuvant stereotactic ablative radiotherapy (SABRT) protocol on tumor resectability and pathological responses. From June 2017 to December 2022, patients with BRPC/LAPC were treated with neoadjuvant chemotherapy (ChT) and SABRT-escalated doses of SIB at 45 Gy, 50 Gy, and up to 55 Gy (BED ≥ 100). Radiological evaluation was conducted with a CT scan 6-8 weeks post-treatment to determine resectability status based on established criteria (SAR/APA2014). Surgical decisions were made by the multidisciplinary tumor board of the participating institutions. Pathological assessments post-surgery used criteria from the College of American Pathologists (CAP), categorizing resection status as R0 (negative margins), R1 (microscopic tumor margins), and R2 (macroscopic tumor margins). Tumor response was evaluated with the Tumor Response Scoring (TRS) system, as G0 (no viable cancer cells), G1 (single cells or rare small groups), G2 (residual cancer with evident regression), and G3 (extensive residual cancer). Thirty-three patients (p) were included: 39.4% (13p) BRPC/60.6% (20p) LAPC. After ChT-SABRT, 45.5% (15p) were considered resectable, with 11/13 (84.6%) BRPC and 4/20 (20%) LAPC (p < 0.0001). One patient refused surgery and other patient died of COVID sepsis. Two more patients had disseminated disease at surgery. Among the 11 patients who underwent full surgery, all patients achieved either clean margins R0: 72.7% (8p) or microscopic affected margins R1: 27.3% (3p). TRS scores were G1: 27.3% (3p), G2: 54.5% (6p), and G3: 18.2% (2p). The present follow-up (FUP) was closed on 1 November 2024 (23.55 months, range: 6-71 months). The mean freedom from local progression as the first cause of disease failure was 43.30 ± 3.09 (37.23-49.38), and the median was not reached. The actuarial 1- and 2-year rates for freedom from local relapse as a first cause of disease failure were 92.3% (87.7-93.3%) and 79.7% (79.7-87.7%), respectively. Neoadjuvant ChT-SABRT in LAPC improves resectability rates and induces relevant tumor regression. These promising findings should be validated by larger sample sizes and extended follow-up.

PLAP expression is linked to invasive tumor growth in urothelial carcinoma of the bladder.

Placental alkaline phosphatase (PLAP) is a protein with a poorly understood function that is normally only expressed in the placenta. In cancer, PLAP expression is a hallmark of germ cell neoplasms, but it can also occur in urothelial carcinoma. To evaluate the potential clinical significance of PLAP expression in bladder cancer, METHODS: PLAP protein was analyzed by immunohistochemistry in more than 2500 urothelial bladder carcinomas in a tissue microarray format. PLAP staining was absent in normal urothelial cells but was observed in 15.9% of urothelial carcinomas, including 282 (11.5%) with weak, 57 (2.3%) with moderate, and 51 (2.1%) with strong staining. PLAP positivity occurred in 4.1% of 413 pTa G2 low-grade, 10.2% of 176 pTa G2 high-grade, and 7.2% of 97 pTa G3 tumors (p = 0.0636). As compared to pTa tumors, the PLAP positivity rate was markedly higher in 1341 pT2-4 carcinomas (19.8%, p < 0.0001). Within pT2-4 carcinomas, PLAP staining was unrelated to pT, pN, grade, L-status, V-status, overall survival, recurrence-free survival, and cancer-specific survival (p > 0.25). However, PLAP positivity was linked to p16 positivity (p = 0.0185), GATA3 positivity (p < 0.0001), and p63 expression loss (p = 0.0456). In summary, these data show that PLAP is expressed in a significant fraction of pT2-4 urothelial carcinomas, unrelated to cancer aggressiveness but associated with specific molecular features. Once anti-PLAP cancer drugs become effective, urothelial carcinoma is a candidate tumor entity for clinical evaluation.

Temozolomide and capecitabine regimen as first-line treatment in advanced gastroenteropancreatic neuroendocrine tumors at a Latin American reference center

BACKGROUND Numerous studies have indicated that the temozolomide and capecitabine regimen (TEMCAP) exhibits a certain level of efficacy in treating advanced, well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NET). However, published data from Peru are limited. We hypothesize that this regimen could be a viable therapeutic option for advanced GEP-NET in the Peruvian population. AIM To evaluate overall survival (OS) in patients diagnosed with advanced GEP-NET treated with TEMCAP at the Instituto Nacional de Enfermedades Neoplásicas (INEN) in Lima-Perú. METHODS A retrospective review was conducted to identify patients with GEP-NEN treated with the TEMCAP regimen between 2011 and 2021 at the INEN. A total of thirty-eight patients were included in the final analysis: Thirty-five received TEMCAP as a first-line treatment, and three as a second-line treatment. The primary objective was to evaluate OS. The efficacy and safety of TEMCAP were assessed until the occurrence of unacceptable toxicity or disease progression. Survival outcomes were estimated using the Kaplan-Meier method. RESULTS The median age of the patients was 52 years (range 24-77 years), and 53.3% were female. The most common symptoms at diagnosis were abdominal pain in 31 patients (81.6%). Primary tumors included 12 in the rectum (31.6%), 11 in the pancreas (28.9%), 3 in the ileum (7.9%), 2 in the mesentery (5.3%), 2 in the small intestine (5.3%), 1 in the appendix (2.6%), 1 in the stomach (2.6%) and 6 cases of liver metastasis of unknown primary (15.8%). Five were neuroendocrine tumors (NET) G1 (13.2%), 33 were NET G2 (86.8%), five had Ki67 &lt; 3% (13.2%), and 33 had Ki67 between 3% and 20% (86.8%). TEMCAP was administered to 35 (92.1%) patients as first-line treatment. OS at 12, 36, and 60 months was estimated in 80%, 66%, and 42%, respectively, with a median OS of 49 months. CONCLUSION TEMCAP therapy is a viable first-line option regarding efficacy and tolerability in areas where standard therapy is inaccessible.

Diagnostic relevance of p53 and Rb status in neuroendocrine tumors G3 from different organs: an immunohistochemical study of 465 high-grade neuroendocrine neoplasms.

The double inactivation of TP53 and RB1 is considered typical of neuroendocrine carcinomas (NECs) but is assumed to be rare in high-grade neuroendocrine tumors (NETs). The immunohistochemical determination of the p53 and Rb status has therefore been proposed as a diagnostic tool. We studied this status in a large series of high-grade neuroendocrine neoplasms, from multiple origins, in order to (a) assess the patterns observed in the different histopathological categories, (b) compare them between the various anatomic sites, and (c) evaluate their possible diagnostic relevance. Four hundred sixty-five cases from 9 organ systems (142 high-grade NETs -NET-G3-, 162 large-cell NECs -LCNEC-, 144 small-cell NECs -SCNEC-) and 60 cases of NET G1/G2 were included. The expression of both proteins was normal in 96.7% of NET G1/G2, 76.7% of NET-G3, and 5.8% of all NECs. p53 expression was abnormal in 12.7% of NET-G3 and 91.5% of NECs. Rb expression was lost in 10.6% of NET-G3 and 68.3% of NECs. Rb loss was significantly less frequent in LCNEC than in SCNEC (57.3% versus 80.6%); abnormal p53 expression was comparable in the two categories. Patterns were comparable between primary sites, except for head and neck NECs. For diagnostic purposes, taking into account, Rb status improved, but only marginally, the performances of p53 status. In conclusion, our study underlines the molecular heterogeneity of NET-G3 and LCNEC, irrespectively of the primary, and provides further insight on the diagnostic relevance of p53/Rb immunodetection in high-grade neuroendocrine neoplasms.

Intraoperative liquid biopsy as a tool for detecting R1 resection during pancreatoduodenectomy in patients with pancreatic carcinoma: the CETUPANC trial (part II).

A positive surgical margin (R1 resection) is a relevant risk factor for local recurrence in patients with pancreatic ductal adenocarcinoma of the pancreas (PDAC). An intraoperative liquid biopsy (ILB) based on tumor cell mobilization could help to detect R1 resection intraoperatively. To evaluate the potential role of the intraoperative circulating tumor cells (CTCs) and cluster mobilization on the R0/R1 detection. Sixty-three patients with resectable PDAC of the head of the pancreas were prospective enrolled under the CETUPANC trial. Open pancreaticoduodenectomy (PD) was done in all patients. Intraoperative CTCs and clusters were determined during PD. The overall rate of R1 resection was 34.9% (22/63 patients). Multivariate analysis showed that factors associated with R1 resection (AUC=0.920) were the presence of undifferentiated G3 tumor (P=0.017), microscopic vascular invasion (P=0.016), and the intraoperative increase of both free CTCs and clusters in portal vein determination from the beginning to the end of the surgery (P=0.002 and P=0.005, respectively). A specific logistic regression model, including delta end to baseline CTCs and cluster mobilization to achieve a combined cut-off to detect R1 detection was calculated (AUC=0.799). The obtained R1-index based on ILB had 84% of sensitivity and 68% of specificity to detect R1 resection. The ILB based on the intraoperative mobilization of CTCs and clusters from the beginning to the end of the PD was a predictive factor to detect R1 resection in patients with PDAC.

Is there a place for surgery in oligometastatic ductal carcinoma of the pancreatic head?

Background: New chemotherapy regimens (gemcitabine / nab-paclitaxel, FOLFIRINOX) have improved overall survival rates in ductal carcinoma, which has renewed the interest in surgical treatment for isolated liver metastases. Aim: To identify the role of surgery in ductal carcinoma of the pancreatic head with liver oligometastases. Methods: We retrospectively analyzed the data from 490 patients with morphologically verified ductal carcinoma of the pancreatic head in two specialized centers, who had undergone pancreatoduodenectomy (PD) from January 2011 to April 2024. In 21 patients, PD was performed simultaneously with liver resection (liver oligometastases were found during the surgery). Results: In the postoperative period after PD with liver resection, compared to that after PD without liver resection, intra-abdominal abscesses were more frequent (4/21 (19.0%) versus 10/469 (2.2%), p = 0.002) and relaparotomy was performed more often by 9.8% [95 confidence interval (CI, Miettinen-Nurminen score method) 0.21–30.3] (3/21 (14.3%) versus 21/469 (4.5%), p = 0.077). The postoperative death rates were comparable (1/21 (4.8%) versus 19/469 (4.1%), p = 0.8). The median overall survival of the patients after PD with liver resection was 11 (95% CI: 6–16) months, and overall 1-, 2-, and 3-year survival rates were 39.2, 16.8 and 7.2%, respectively. In the patients after PD with liver resection without any adjuvant chemotherapy (n = 5), the median overall survival was 6 (95% CI: 5–7) months, and in those with chemotherapy, 13 (95% CI: 6–16) months (p = 0.006). The overall three-year survival of the patients after PD with liver resection and adjuvant chemotherapy was 11.5%. In the patients after PD with liver resection R0, the median overall survival was 13 (95% CI: 6–32) months, with R1 resection 6 (95% CI: 6–7), and with R2 resection 6 (95% CI: 6–7) months (p = 0.021). The median overall survival of patients after PD with liver resection for G1 tumors was 17 (95% CI: 6–32) months. Conclusion: Surgery as a component of combination therapy for oligometastatic pancreatic head cancer can be considered in a certain category of patients with high tumor differentiation grade and mandatory preliminary assessment of the feasibility of R0 surgery and systemic chemotherapy.

Diagnostic dilemma: a collision of pancreatic neuroendocrine tumor G3 and adenocarcinoma with extensive fibrosis.

An 82-year-old man presented with intermittent abdominal pain and elevated liver enzymes. Blood tests showed normal levels of tumor markers (CEA, CA19-9, NSE). Contrast-enhanced computed tomography (CE-CT) revealed a 20mm hypovascular mass in the pancreatic head. Magnetic resonance imaging indicated low intensity on both T1- and T2-weighted images and high intensity on diffusion-weighted images. Endoscopic ultrasonography visualized an irregular hypoechoic mass. Initially, it was diagnosed as pancreatic ductal adenocarcinoma (PDAC) based on imaging. Subsequent histopathological analysis via endoscopic ultrasound-guided fine-needle aspiration revealed a neuroendocrine tumor (NET). The preoperative diagnosis was changed to a pancreatic NET grade1. Consequently, a pancreaticoduodenectomy was performed. Histopathological examination of the resected specimen unveiled a mixed tumor-NET-Grade1/Grade3 and invasive PDAC. No clear transition between the NETs and PDAC was observed. The high grade of NET with significant fibrosis contributed to decreased enhancement of CE-CT. Finally, we diagnosed this case as a pancreatic collision tumor involving both NET and PDAC components, with lymph node metastases attributed to the NET components. In this case, achieving an accurate preoperative diagnosis was challenging despite utilizing both imaging and biopsy diagnostics. This unique case underscores the difficulties encountered in the preoperative assessment of mixed tumors.

Glucagon-Producing Pancreatic Neuroendocrine Tumors (Glucagonomas) are Enriched in Aggressive Neoplasms with ARX and PDX1 Co-expression, DAXX/ATRX Mutations, and ALT (Alternative Lengthening of Telomeres)

Glucagonomas are functioning pancreatic neuroendocrine tumors (PanNETs) responsible for glucagonoma syndrome. This study aims to shed light on the clinicopathological and molecular features of these neoplasms. Six patients with glucagonomas were identified. All neoplasms were investigated with immunohistochemistry for neuroendocrine markers (Synaptophysin, Chromogranin-A), ATRX, DAXX, ARX, and PDX1 transcription factors. Fluorescent in situ hybridization (FISH) for assessing alternative lengthening of telomeres (ALT), and next-generation sequencing (NGS) for molecular profiling were performed. All cases were large single masses (mean size of 8.2 cm), with necrolytic migratory erythema as the most common symptom (6/6 cases, 100%). All neoplasms were well-differentiated G1 tumors, except one case that was G2. The tumors consistently showed classic/conventional histomorphology, with solid-trabecular and nested architecture. Lymphatic and vascular invasion (6/6, 100%), perineural infiltration (4/6, 66.6%), and nodal metastasis (4/6, 66.6%) were frequently observed. Transcription factors expression showed strong ARX expression in all tumors, and PDX1 expression in 5/6 cases (83.3%), indicating co-occurring alpha- and beta-cell differentiation. NGS showed recurrent somatic MEN1 and ATRX/DAXX biallelic inactivation. Cases with ATRX or DAXX mutations also showed matched loss of ATRX or DAXX protein expression and ALT. One case harbored somatic MUTYH inactivation and showed a high tumor mutational burden (TMB, 41.0 mut/Mb). During follow-up, one patient died of the disease, and four patients developed distant metastasis. Pancreatic glucagonomas are distinct PanNETs with specific clinicopathological and molecular features, including histological aspects of biological aggressiveness, co-occurring alpha- and beta-cell differentiation, MEN1 and DAXX/ATRX mutations enrichment, and the possible presence of high-TMB as an actionable marker.

Less frequent radiological exams to avoid futile response assessments from 177-LuDOTATE therapy for patients with advanced neuroendocrine tumors.

177-LuDOTATE is an effective but expensive treatment for neuroendocrine tumors (NETs). Reducing treatment-related costs, such as the number of images, could improve access to 177-LuDOTATE. We evaluated early radiological tumor progression and prognostic factors in patients with NETs treated with 177-LuDOTATE. We retrospectively included all patients with NETs who received at least one cycle of 177-LuDOTATE. The primary endpoint was the rate of early radiological progression between cycles 2 and 3 (in 10-16 weeks). Secondary endpoints were progression-free survival (PFS) and overall survival (OS) according to prognostic factors (tumor grade, primary site, functioning syndrome, 177-LuDOTATE treatment line) in Cox proportional hazards models. The median number of 177-LuDOTATE cycles was 3 (range 1-6) among 59 patients included. Ten (17%) patients had early progression. Among 14 patients who received ≤2 cycles of 177-LuDOTATE, ten (72%) stopped treatment due to disease progression, with five patients having a G2 (ki67: 5-25%) and 4, a G3 (ki67: 25-90%) NET. In the Cox multivariable analysis, higher grade (G2 or G3 vs G1) were significantly associated with inferior PFS and OS. The median PFS of G1, G2 and G3 NET patients were: 34.1, 11.7 and 6.1 months (P = 0.015), respectively. It is feasible to perform imaging tests after 177-LuDOTATE completion for patients with indolent NETs with the intent to avoid futile assessments. For patients with more aggressive diseases, such as G3 NETs and G2 tumors with high tumor burden, we advise to perform more frequent images during 177-LuDOTATE therapy.

433. UNRAVELLING THE MOLECULAR MECHANISMS BEHIND TUMOUR DIFFERENTIATION IN ESOPHAGEAL ADENOCARCINOMA

Abstract Background Esophageal adenocarcinoma tumors are divided into three grades based on the tumour’s histological differentiation: well, moderate and poor. Poorly differentiated tumours have a worse survival rate than moderate and well tumours. Understanding the molecular programs of this differentiation may lead to the identification of novel therapeutic interventions specific to tumour differentiation. We have utilized laser-capture microdissection to enrich tumour cells followed by gene expression profiling (RNA-seq) to identify gene expression programs and whole genome sequencing for differentiating specific mutations and copy number changes. Collectively, these results will enable us to unravel the molecular drivers of tumour differentiation. Methods Laser capture microdissection was applied to N=127 RNA-seq samples from N=74 patients and N=103 from N=81 patients from a mix of primary tumour biopsies, resections, and metastatic biopsies. Most samples have a matching RNA-seq and WGS sample. We used a standard pipeline to analyze the WGS data and produce somatic mutation, structural variant, and copy number calls. The gene expression data was segregated into two sets a test set consisting of N=74 samples and a test set of N=53 samples. Non-negative matrix factorization was used to identify eleven gene expression programs. Results Our testing RNA-seq cohort consisted of N=74 samples from N=74 patients with N=4 G1, N=26 G2, N=35 G3, and N=9 missing differentiation data. Our initial goal was to unravel the gene expression programs that correlate with tumour differentiation. Our non-negative matrix factorization analysis yielded 11 gene signatures, N=3 programs enriched in glandular gene expression, N=3 enriched in EMT pathways, N=2 with fibroblasts, and N=3 associated with immune / inflammation genes (not shown) (Figure 1). Moreover, the glandular signatures were associated with G1/G2 and the EMT and fibroblast signatures with G3. Moreover, the glandular 2 signature was associated with HER2 amplifications. Conclusion In this work we have begun to unravel the gene expression and genomic changes associated with tumour differentiation. We have found signatures enriched for both G1/G2 and G3 tumours and from these signatures we have observed gene expression heterogeneity within the different tumour differentiation categories. Moreover, the G3 tumours are enriched in fibroblasts despite our laser-capture microdissection. We are currently working on a classification model to predict tumor differentiation from these gene expression programs and are looking to further integrate our whole genome data to find additional genomic drivers.

Lateral pelvic lymph nodes dissection of rectal neuroendocrine neoplasms: A prospective case-series and literature review

BackgroundRectal neuroendocrine neoplasms are relatively rare. Patients with rectal neuroendocrine neoplasms undergoing radical surgery have a higher rate of lymph node metastases. Robust evidence on the status of lateral pelvic lymph node metastases and the role of lateral pelvic lymph node dissection in those patients is lacking. This case-series study aimed to explore and address these issues. MethodsThis single-center, prospective case series consecutively enrolled patients with biopsy-proven rectal neuroendocrine neoplasms in a tertiary referral hospital between June 2022 and January 2024. All eligible patients underwent laparoscopic total mesorectal excision surgery and bilateral lateral pelvic lymph node dissection under general anesthesia. The clinicopathologic features, surgical outcomes, and postoperative complications were presented. The last follow-up was conducted in March 2024. ResultsA total of 11 patients with rectal neuroendocrine neoplasms—3 female and 8 male—were enrolled. The average age was 60.0 years (range, 53.5–65.5 years), and the median tumor size was 2.0 cm (range, 1.6–2.5 cm). Tumors invaded the muscularis propria in 7 patients. There were 3 cases of neuroendocrine tumor G1, 6 cases of neuroendocrine tumor G2, and 2 cases of neuroendocrine carcinoma. Among these patients, 11 (100.0%) had lymph node metastases, and 6 (54.5%) had lateral pelvic lymph node metastases. In addition, in 2 patients, only lateral pelvic lymph node metastases were observed, without involvement of the mesenteric lymph nodes. Five patients had tumors located on the left wall of the rectum, and only left-sided lateral pelvic lymph node metastases were observed. The other patient had both sides of lateral pelvic lymph node metastases due to circumferential growth of the tumor around the rectum. Anal preservation was achieved in all patients. The median operating time was 235.0 minutes (range, 210.5–335.5 minutes), and the median estimated blood loss was 50.0 mL (range, 45.0–75.0 mL). Two patients experienced postoperative dysuria and recovered spontaneously within 2–4 months after surgery. ConclusionOn the basis of a prospective case series, we demonstrate, for the first time, the lateral pelvic lymph node metastasis status in patients with rectal neuroendocrine neoplasms requiring radical total mesorectal excision surgery. Simultaneous bilateral lateral pelvic lymph node dissection may be a feasible and beneficial procedure for preventing local recurrence in these patients due to the lack of definitive neoadjuvant or adjuvant therapy options.

Molecular aspects of BRAF and HER2 in prognosis of periampullary carcinoma

BackgroundBiological behaviour of Periampullary cancers (PACS) differs from pancreatic head cancer, and analysis of molecular alteration is needed. BRAF and HER2 are keys members of the RAS/RAF and EGFR pathway, playing roles in prognostic markers and therapeutic targets. MethodsA study on 89 PACS patients, undergoing Whipple Pancreaticoduodenectomy, PCR-RFLP, and qPCR methods used for SNP and mRNA expression studies. Clinicopathological and survival data collected. Molecular changes were correlated with Clinicopathological parameters. Survival outcomes were assessed by Kaplan Meir Log rank test. ResultsThe study revealed that homozygous mutant BRAF V600E was significantly higher in PAC compared to a healthy control (p = 0.0012). Whereas the genotype frequency of HER2 I1655V was similar among PAC and healthy control. The A > G change in HER2 was associated with tumor arising from duodenum (p = 0.004) and showed poor survival outcome (p = 0.001). Upregulation of BRAF and HER2 was found in 43 % of patients with synergistic effect, the median overall survival (OS) being 50.5 ± 13 months. The increased expression of HER2 was higher in early stage (p = 0.04) PAC. The gene expression did not impact the OS, whereas female gender, G3 tumors, T3-T4 depth of tumour, advanced stage, LN metastasis, LVI and PNI were poor predictors of OS. ConclusionsBRAF V600E SNP was associated with disease susceptibility, and had increased mRNA expression while HER2 I1655V SNP was associated with poor survival outcome in PAC. The increased expression of BRAF and HER2 in early tumors and their co-expression in PAC exhibit cross talk between RAS/RAF and EGFR pathway in PAC.

NGS mutational status on first diagnostic tissue, liquid biopsy and mastectomy in G2-G3 breast cancer.

Breast cancer is one of the more frequently diagnosed cancers leading to death in women, and, like other tumor types, it is heterogeneous in its immunophenotype. It harbors mutations that modify tumor aggressiveness, therapy responses, residual disease, drug resistance, and relapse rates in advanced stages. This study aims to assess the mutational status of G2 and G3 tumors using next-generation sequencing (NGS) on initial tissue biopsies, liquid biopsies, and mastectomy specimens. The histopathological (HP) diagnosis for the 32 selected cases was established via Hematoxylin-Eosin (HE) staining by two observers. For the immunohistochemical (IHC) testing of estrogen receptor (ER), progesterone receptor (PGR) and human epidermal growth factor receptor 2 (HER2), we used the Ventana BenchMark Ultra. Ki67 testing was conducted using Bond-III from Leica. For cases with a score of 2+, gene amplification was assessed by silver-enhanced in situ hybridization (ISH) (SISH; Inform HER2 Dual ISH) on Ventana BenchMark Ultra. NGS analysis was initially performed on biopsies and plasma, and later on mastectomy specimens. After automated deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) extraction, concentrations were measured using the Invitrogen Qubit system. Libraries were created using Oncomine systems, and sequencing and analysis were done with the Ion Torrent system. Most tumors were graded as G3 (19 cases), with Luminal A being the predominant molecular subtype, and a significant number displayed HER2∕HER2-low characteristics (24 out of 32 cases). The NGS assessment showed that phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations were the most frequent across all sample types. A significant limitation was the high number of invalid plasma tests due to pre-analytical handling errors or transport issues. Nonetheless, plasma testing (liquid biopsy) proved useful for monitoring tumor evolution and assessing residual disease.

Predictive factors for adnexal involvement in endometrial cancer FIGO stage IIIA

ObjectiveUnderstanding ovarian involvement incidence and risk factors in women with endometrial cancer may inform the decision of ovary preservation.MethodsOur retrospective study included all consecutive fully surgically staged patients with endometrial...