Comprehensive biomarker analysis of long-term response to trastuzumab in patients with HER2-positive advanced gastric or gastroesophageal adenocarcinoma

BACKGROUND

A subgroup of patients with HER2-positive metastatic gastric and gastroesophageal junction cancers shows long-term response under trastuzumab maintenance monotherapy. Obviously, HER2 status alone is not able to identify these patients. We performed this study to identify potential new prognostic biomarkers for this long-term responding patient group.

PATIENTS AND METHODS

Tumour samples of 19 patients with HER2-positive metastatic gastric and gastroesophageal junction cancer who underwent trastuzumab treatment were retrospectively collected from multiple centres. Patients were divided into long-term responding (n = 7) or short-term responding group (n = 12) according to progression-free survival (PFS≥12 months vs. PFS < 12 months). Next-generation sequencing and microarray-based gene expression analysis were performed along with HER2 and PD-L1 immunohistochemistry.

RESULTS

Long-term responding patients had significantly higher PD-L1 combined positive scores (CPS) and CPS correlated with longer progression-free survival. PD-L1 positivity (CPS ≥ 1) was further associated with an increased CD4+ memory T-cell score. The ERBB2 copy number as well as the tumour mutational burden could not discriminate between short-term and long-term responding patients. Genetic alterations and coamplifications in HER2 pathway associated genes such as EGFR, which were connected to trastuzumab resistance, were present in 10% of the patients and equally distributed between the groups.

CONCLUSION

The study highlights the clinical relevance of PD-L1 testing also in the context of trastuzumab treatment and offers a biological rational by demonstrating elevated CD4+ memory T-cells scores in the PD-L1-positive group.

Differential Effects of Somatostatin, Octreotide, and Lanreotide on Neuroendocrine Differentiation and Proliferation in Established and Primary NET Cell Lines: Possible Crosstalk with TGF-β Signaling

GEP-NETs are heterogeneous tumors originating from the pancreas (panNET) or the intestinal tract. Only a few patients with NETs are amenable to curative tumor resection, and for most patients, only palliative treatments to successfully control the disease or manage symptoms remain, such as with synthetic somatostatin (SST) analogs (SSAs), such as octreotide (OCT) or lanreotide (LAN). However, even cells expressing low levels of SST receptors (SSTRs) may exhibit significant responses to OCT, which suggests the possibility that SSAs signal through alternative mechanisms, e.g., transforming growth factor (TGF)-β. This signaling mode has been demonstrated in the established panNET line BON but not yet in other permanent (i.e., QGP) or primary (i.e., NT-3) panNET-derived cells. Here, we performed qPCR, immunoblot analyses, and cell counting assays to assess the effects of SST, OCT, LAN, and TGF-β1 on neuroendocrine marker expression and cell proliferation in NT-3, QGP, and BON cells. SST and SSAs were found to regulate a set of neuroendocrine genes in all three cell lines, with the effects of SST, mainly LAN, often differing from those of OCT. However, unlike NT-3 cells, BON cells failed to respond to OCT with growth arrest but paradoxically exhibited a growth-stimulatory effect after treatment with LAN. As previously shown for BON, NT-3 cells responded to TGF-β1 treatment with induction of expression of SST and SSTR2/5. Of note, the ability of NT-3 cells to respond to TGF-β1 with upregulation of the established TGF-β target gene SERPINE1 depended on cellular adherence to a collagen-coated matrix. Moreover, when applied to NT-3 cells for an extended period, i.e., 14 days, TGF-β1 induced growth suppression as shown earlier for BON cells. Finally, next-generation sequencing-based identification of microRNAs (miRNAs) in BON and NT-3 revealed that SST and OCT impact positively or negatively on the regulation of specific miRNAs. Our results suggest that primary panNET cells, such as NT-3, respond similarly as BON cells to SST, SSA, and TGF-β treatment and thus provide circumstantial evidence that crosstalk of SST and TGF-β signaling is not confined to BON cells but is a general feature of panNETs.

Abstract 4018: Long-term response to Trastuzumab in patients with advanced gastric or gastroesophageal adenocarcinoma - A retrospective study

Since 2010, Trastuzumab combined with chemotherapy is the standard treatment for patients with HER2 (ERBB2) positive advanced or metastatic gastric and gastroesophageal junction cancer (GGEJ). While few patients show long-term response to the treatment, most suffer from rapid disease progression. Several studies revealed that genomic alterations, gene expression changes and altered HER2 signaling activity contribute to impaired therapy response. However, the underlying mechanism remains unclear. The aim of this research project is to analyze differences between patients with long and short progression-free survival by utilizing combined genetic, histologic, clinical and gene expression data. We collected a retrospective German patient cohort (n=20) including patients with HER2 positive advanced GGEJ who received Trastuzumab combined with chemotherapy. Using archival samples that were obtained prior to Trastuzumab treatment, we created a dataset including clinical information, histologic assessment, immunostaining, target amplicon sequencing (TAS; 409 gene panel) and human transcriptome data using the Affymetrix platform. To analyze the TAS sequencing data, we generated an automated analysis pipeline, which detects single nucleotide variants (SNV) and copy number alterations (CNA). Information about genomic alteration will be correlated with pathway and gene set enrichment analysis (GSEA) from the Affymetrix data. Furthermore, the data will be supported by investigating the functional status of HER2 in patient samples via electron microscopy. The results of this study could give insights on how genetic and transcriptomic alterations are connected to long-term Trastuzumab therapy response in HER2 positive GGEJ patients. This could potentially support therapy decision in personalized medicine.

Citation Format: Isabel Porth, Philip Weidner, Sylvie Lorenzen, Wilko Weichert, Thorsten Oliver Götze, Sven Perner, Kim Luley, Daniela Hirsch, Ralf-Dieter Hofheinz, Diana B. Peckys, Zahra Mostajeran, Niels de Jonge, Timo Gaiser. Long-term response to Trastuzumab in patients with advanced gastric or gastroesophageal adenocarcinoma - A retrospective study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4018.

Tailored Systemic Therapy for Colorectal Cancer Liver Metastases

Liver metastases are the most common site of metastatic spread in colorectal cancer. Current treatment approaches involve effective systemic therapies in combination with surgical and/or interventional strategies. Multimodal strategies greatly improved clinical outcomes of patients with metastatic colorectal cancer over the last decades. Identification of predictive and prognostic biomarkers helped to comprehensively refine individual targeted treatment approaches and resulted in median overall survival rates of 30 months or longer. Current guidelines, thus, recommend treatment selection according to patients' performance status, tumor localization and stage as well as the tumor's molecular and genetic status. Here, we outline the latest developments in molecular decision-making for patients with upfront resectable, potentially or initially unresectable and non/never-resectable colorectal cancer liver metastases.

Resection of Non-Functional Pancreatic Neuroendocrine Neoplasms-A Single-Center Retrospective Outcome Analysis

Surgery remains the only curative treatment of pancreatic neuroendocrine neoplasms (pNEN). Here, we report the outcome after surgery for non-functional pNEN at a European Neuroendocrine Tumor Society (ENETS) center in Germany between 2000 and 2019; cases were analyzed for surgical (Clavien–Dindo classification; CDc) and oncological outcomes. Forty-nine patients (tumor grading G1 n = 25, G2 n = 22, G3 n = 2), with a median age of 56 years, were included. Severe complications (CDc ≥ grade 3b) occurred in 11 patients (22.4%) and type B/C pancreatic fistulas (POPFs) occurred in 5 patients (10.2%); in-hospital mortality was 2% (n = 1). Six of seven patients with tumor recurrence (14.3%) had G2 tumors in the pancreatic body/tail. The median survival was 5.7 years (68 months; [1–228 months]). Neither the occurrence (p = 0.683) nor the severity of complications had an influence on the relapse behavior (p = 0.086). This also applied for a POPF (≥B, p = 0.609). G2 pNEN patients (n = 22) with and without tumor recurrence had similar median tumor sizes (4 cm and 3.9 cm, respectively). Five of the six relapsed G2 patients (83.3%) had tumor-positive lymph nodes (N+); all G2 pNEN patients with recurrence had initially been treated with distal pancreatic resection. Pancreatic resections for pNEN are safe but associated with relevant postoperative morbidity. Future studies are needed to evaluate suitable resection strategies for G2 pNEN.

Perioperative chemotherapy with fluorouracil plus leucovorin, oxaliplatin, and docetaxel versus fluorouracil or capecitabine plus cisplatin and epirubicin for locally advanced, resectable gastric or gastro-oesophageal junction adenocarcinoma (FLOT4): a randomised, phase 2/3 trial

BACKGROUND

Docetaxel-based chemotherapy is effective in metastatic gastric and gastro-oesophageal junction adenocarcinoma. This study reports on the safety and efficacy of the docetaxel-based triplet FLOT (fluorouracil plus leucovorin, oxaliplatin and docetaxel) as a perioperative therapy for patients with locally advanced, resectable tumours.

METHODS

In this controlled, open-label, phase 2/3 trial, we randomly assigned 716 patients with histologically-confirmed advanced clinical stage cT2 or higher or nodal positive stage (cN+), or both, resectable tumours, with no evidence of distant metastases, via central interactive web-based-response system, to receive either three pre-operative and three postoperative 3-week cycles of 50 mg/m² epirubicin and 60 mg/m² cisplatin on day 1 plus either 200 mg/m² fluorouracil as continuous intravenous infusion or 1250 mg/m² capecitabine orally on days 1 to 21 (ECF/ECX; control group) or four preoperative and four postoperative 2-week cycles of 50 mg/m² docetaxel, 85 mg/m² oxaliplatin, 200 mg/m² leucovorin and 2600 mg/m² fluorouracil as 24-h infusion on day 1 (FLOT; experimental group). The primary outcome of the trial was overall survival (superiority) analysed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01216644.

FINDINGS

Between Aug 8, 2010, and Feb 10, 2015, 716 patients were randomly assigned to treatment in 38 German hospitals or with practice-based oncologists. 360 patients were assigned to ECF/ECX and 356 patients to FLOT. Overall survival was increased in the FLOT group compared with the ECF/ECX group (hazard ratio [HR] 0·77; 95% confidence interval [CI; 0.63 to 0·94]; median overall survival, 50 months [38·33 to not reached] vs 35 months [27·35 to 46·26]). The number of patients with related serious adverse events (including those occurring during hospital stay for surgery) was similar in the two groups (96 [27%] in the ECF/ECX group vs 97 [27%] in the FLOT group), as was the number of toxic deaths (two [<1%] in both groups). Hospitalisation for toxicity occurred in 94 patients (26%) in the ECF/ECX group and 89 patients (25%) in the FLOT group.

INTERPRETATION

In locally advanced, resectable gastric or gastro-oesophageal junction adenocarcinoma, perioperative FLOT improved overall survival compared with perioperative ECF/ECX.

FUNDING

The German Cancer Aid (Deutsche Krebshilfe), Sanofi-Aventis, Chugai, and Stiftung Leben mit Krebs Foundation.

[Prevention and treatment of cachexia : Exercise and nutritional therapy]

BACKGROUND

Cachexia is a multifactorial and complex syndrome characterized by progressive functional impairment and ongoing loss in quality of life, which lead to a deterioration of the prognosis for affected patients. The prevalence of cachexia can be very high and is up to 80 % in patients with malignant tumors.

OBJECTIVE

The aim of the study was to assess the relevance of exercise and nutrition in the prevention and therapy of cachexia.

METHODS

An evaluation of the current literature on exercise and nutritional therapy in patients with cachexia or with advanced stage diseases where a high prevalence of cachexia is probable, was carried out.

RESULTS

There is a lack of scientific evidence for the benefits of exercise in cachexia. A major problem of relevant studies was that cachexia was frequently not defined according to valid criteria; however, data indicate a benefit of exercise training in patients with advanced diseases associated with a high prevalence of cachexia. A solely nutritional intervention and dietary counselling seem to be of minimal benefit. The administration of omega 3 fatty acids is controversially discussed.

CONCLUSION

Although there is a lack of data on the effects of exercise and nutritional therapy in cachexia, there is evidence for the benefits. The present data indicate the necessity for the use of a multimodal treatment including exercise, nutritional and pharmacological therapy in cachexia. There is a great necessity for prospective studies.

The association of objective response and overall survival in patients with inoperable or metastatic gastric and esophagogastric junction (EGJ) cancer: A pooled analysis of individual patient data from first-line clinical trials

4095

Background: The aim of the study is to determine whether the achievement of an objective response to first-line chemotherapy is prognostic of patient’s outcome in gastric/EGJ adenocarcinoma. Methods: Individual patient (pts) data from prospective first-line trials conducted by a single study group were used. Patients received platin/5-FU based chemotherapy with or without docetaxel. Responses were evaluated according to WHO criteria in all trials. Response data, patients’ characteristics (age, sex, entity, histological type, primary location, ECOG PS, and type and number of metastatic sites), type of chemotherapy, and overall survival data were analyzed. Results: 612 pts were included. Median age was 66 yrs; 31.5% had ECOG status 0, 58.3% ECOG 1, and 9.8% ECOG 2 & 3. Gastric primaries were found in 44.4% and EGJ in 35.8% of pts (19.7% were overlapping/not evaluable). According to Lauren classification, 36.8% had intestinal, 32.4% diffuse, and 8.5% mixed types (22.4% were not classifiable). 64.5% had positive non-regional lymph nodes (LN) involvement, 14.1% LN involvement without other metastases, 33.3% had peritoneal carcinomatosis, 44.0% liver and 16.7% lung metastases. Response rates were complete (CR) in 3.1%, partial (PR) in 36.4%, stable disease (SD) in 34.5%, and progressive disease (PD) in 15.0% pts (10.9% were not evaluable). Overall response rate (OR; CR + PR) was 39.5%. Median overall survival times in pts with CR vs PR vs SD vs PD were 37.9 vs 14.7 vs 10.9 vs 5.2 months, respectively; p=1.26 x 10-33). OR (CR or PR) also strongly predicted OS (16.7 vs 8.1 months in pts with vs no OR, p=1.08 x 10-17). OR remained the strongest predictor of OS in the multivariate analysis (p=6.55 x 10-7) including all baseline criteria mentioned above followed by ECOG PS (p=0.048) and the presence of non-regional LN as the only site of metastasis (p=0.034). Conclusions: The achievement of an objective response is the strongest predictor of survival in pts with gastric and EGJ cancer and could serve as a surrogate marker if validated.

Interim safety analysis of a phase III trial with 5-FU, oxaliplatin, and docetaxel (FLOT) versus epirubicin, cisplatin, and 5-FU (ECF) in patients with locally advanced, resectable gastric/oesophagogastric junction (OGJ) cancer: The AIO-sto-0210 FLOT4 study

4079

Background: Perioperative ECF is a standard treatment for localized gastric/OGJ adenocarcinoma. However, 5-year survival rate remains below 40%. The FLOT regimen is an effective combination with pathologic response rates in the 15% range. This phase III study compares both regimens in resectable stages. Methods: Pts are stratified by different baseline criteria and randomized to either 3 + 3 perioperative cycles of ECF (epirubicin 50 mg/m2, d1; cisplatin 60 mg/m², d1; 5-FU 200 mg/m², d1-d21, qd21) or 4 + 4 cycles of perioperative FLOT (docetaxel 50mg/m2, d1; 5-FU 2600 mg/m², d1; leucovorin 200 mg/m², d1; oxaliplatin 85 mg/m², d1, qd14). 5-FU can be replaced by capecitabine in the ECF-arm (ECX). Central pathology is performed. This is a preplanned safety analysis after 300 patients. Results: The ongoing studyhas enrolled 380 of planned 590 pts, so far. 305 pts were included in this analysis. Median age is 62 yrs; 78% of pts are male. The primaries were gastric in 44.9%, OGJ in 50.4% and not evaluable/documented in 4.7% of pts. 281 pts were eligible for safety analyses. Median no. of preoperative cycles was 3 and 4 with ECF/ECX and FLOT, respectively, 35.9% vs. 44.6% of pts (ECF/ECX vs. FLOT) started postoperative chemotherapy (ct) and 22.5% vs 33.1% received all planned cycles. Grade 3/4 neutropenia was observed in 28.0% of ECF/ECX and 45.3% of FLOT pts (p=.0026). Thromboembolic events occurred in 14.1% vs. 5.8% in pts with ECF/ECX vs. FLOT (p=.027). Serious adverse events occurred in 52.1% vs. 47.5% of pts with ECF/ECX vs. FLOT (p=.48). Preoperative delay/interruptions of ct were observed in 71.1% vs. 56.8% of pts with ECF/ECX vs. FLOT (p=.013). Dose modifications of preoperative ct were performed in 27.5% vs. 20.1% of treatment cycles with ECF/ECX vs. FLOT, respectively. 197 pts have undergone surgery so far. Severe surgical morbidity was similar in both arms (ECF/ECX, 19.8%; FLOT, 16.8%). Surgical mortality was observed in 4 and 2 pts with ECF/ECX and FLOT. Toxic deaths were observed in 1 pt each. Conclusions: Perioperative FLOT is feasible and safe. Clinical trial information: NCT01216644.

Impact of pathologic complete response on disease-free survival in patients with esophagogastric adenocarcinoma receiving preoperative docetaxel-based chemotherapy

BACKGROUND

The aim of this study was to evaluate the impact of pathologic complete response (pCR) on outcome in patients with gastric or esophagogastric junction (EGJ) adenocarcinoma after neoadjuvant docetaxel/platin/fluoropyrimidine-based chemotherapy.

PATIENTS AND METHODS

Patients received at least one cycle of chemotherapy for potentially operable disease. Pretreatment clinicopathologic factors and pCR were investigated. Disease-free survival (DFS), overall survival (OS) and tumor-related death were correlated with pCR.

RESULTS

One hundred twenty patients were included in this analysis. Eighteen patients (15%) achieved a pCR. Tumor localization in the EGJ was identified as the only significant predictor of pCR (P = 0.019). Median follow-up was 41.1 months. Median DFS and OS for all patients were 24.1 and 48.6 months, respectively. Median DFS for patients with a pCR was not reached versus 22.1 months non-pCR patients (hazard ratio, HR 0.38; 3-year DFS: 71.8% and 37.7%, respectively, P = 0.018). While OS was not significantly different, the risk for tumor-related death was significantly lower for pCR patients compared with non-pCR patients (3-year cumulative incidences of 6.4% and 45.4%, respectively, P = 0.009).

CONCLUSION

A pCR following preoperative docetaxel/platin/fluoropyrimidine indicates favorable outcome in patients with gastric or EGJ adenocarcinoma. Tumor location in the EGJ is associated with a higher pCR rate.

The feasibility of triple-drug chemotherapy combination in older adult patients with oesophagogastric cancer: a randomised trial of the Arbeitsgemeinschaft Internistische Onkologie (FLOT65+)

BACKGROUND

We evaluated the feasibility and tolerability of triple- versus double-drug chemotherapy in elderly patients with oesophagogastric cancer.

METHODS

Patients aged 65 years or older with locally advanced or metastatic oesophagogastric cancer were stratified and randomised to infusional 5-FU, leucovorin and oxaliplatin without (FLO) or with docetaxel 50 mg/m(2) (FLOT) every 2 weeks. The study is registered at ClinicalTrials.gov, identifier NCT00737373.

FINDINGS

One hundred and forty three (FLO, 71; FLOT, 72) patients with a median age of 70 years were enrolled. The triple combination was associated with more treatment-related National Cancer Institute Common Toxicity Criteria (NCI-CTC) grade 3/4 adverse events (FLOT, 81.9%; FLO, 38.6%; P<.001) and more patients experiencing a ≥10-points deterioration of European Organization for Research and Treatment of Cancer Quality of Life (EORTC QoL) global health status scores (FLOT, 47.5%; FLO 20.5%; p=.011). The triple combination was associated with more alopecia (P<.001), neutropenia (P<.001), leukopenia (P<.001), diarrhoea (P=.006) and nausea (P=.029).). No differences were observed in treatment duration and discontinuation due to toxicity, cumulative doses or toxic deaths between arms. The triple combination improved response rates and progression-free survival in the locally advanced subgroup and in the subgroup of patients aged between 65 and 70 years but not in the metastatic group or in patients aged 70 years and older.

INTERPRETATION

The triple-drug chemotherapy was feasible in elderly patients with oesophagogastric cancer. However, toxicity was significantly increased and QoL deteriorated in a relevant proportion of patients.

FUNDING

The study was partially funded by Sanofi-Aventis.

Pathological complete remission in patients with oesophagogastric cancer receiving preoperative 5-fluorouracil, oxaliplatin and docetaxel

The aim of this study was to determine the pathological complete remission (pCR) rate, and its relationship to clinical outcome, in patients with adenocarcinoma of the stomach or oesophagogastric junction receiving preoperative 5-fluorouracil, leucovorin, oxaliplatin and docetaxel (FLOT) every 2 weeks. Data from these patients who received at least one cycle of preoperative FLOT followed by surgery were prospectively collected in three German centres. Outcome analyses were conducted and tumour samples were evaluated for pathological remission by a central pathologist. A total of 46 patients were included in this analysis. All patients had clinical T3- and/or N+-stages and 11 (23.9%) had distant metastases (M1). After a median of 4 (range 2-8) preoperative cycles, 8 of 46 patients (17.4%) achieved a pCR. The pCR rate was highest in tumours of intestinal type histology (30.8%) and in those located in the oesophagogastric junction (30.4%) and lowest in patients with diffuse/mixed type tumours (0%) or tumours located in the stomach (4.3%; p < 0.05 for both comparisons). Patients with pCR had 100% probability of overall and disease-free survival (DFS) during the observation period, which was significantly higher (p = 0.037 and p = 0.009, respectively) than the survival probability in patients without pCR. In conclusion, treatment intensification using FLOT was associated with significant pCR rates in patients with oesophagogastric cancer. The distribution of pCR appeared to be significantly different according to histological type and location of the tumours.