Lasting response by vertical inhibition with cetuximab and trametinib in KRAS-mutated colorectal cancer patient-derived xenografts.

Although approximately half of all metastatic colorectal cancers (mCRCs) harbour mutations in KRAS or NRAS, hardly any progress has been made regarding targeted treatment for this group over the last few years. Here, we investigated the efficacy of vertical inhibition of the RAS-pathway by targeting epidermal growth factor receptor (EGFR) and mitogen-activated protein kinase kinase (MEK) in patient-derived xenograft (PDX) tumours with primary KRAS mutation. In total, 19 different PDX models comprising 127 tumours were tested. Responses were evaluated according to baseline tumour volume changes and graded as partial response (PR; ≤ - 30%), stable disease (SD; between -30% and +20%) or progressive disease (PD; ≥ + 20%). Vertical inhibition with trametinib and cetuximab induced SD or PR in 74% of analysed models, compared to 24% by monotherapy with trametinib. In cases of PR by vertical inhibition (47%), responses were lasting (as long as day 137), with a low incidence of secondary resistance (SR). Molecular analyses revealed that primary and SR was driven by transcriptional reprogramming activating the RAS pathway in a substantial fraction of tumours. Together, these preclinical data strongly support the translation of this combination therapy into clinical trials for CRC patients.

SUVmax Above 20 in 18F-FDG PET/CT at Initial Diagnostic Workup Associates with Favorable Survival in Patients with Cancer of Unknown Primary.

Cancer of unknown primary (CUP) is a heterogeneous entity with a limited prognosis. Novel prognostic markers are needed for patient stratification in prospective clinical trials exploring innovative therapies. Methods: In CUP patients treated at the West German Cancer Center Essen, the prognostic value of 18F-FDG PET/CT at the initial diagnostic workup was analyzed by comparing overall survival (OS) in patients who underwent 18F-FDG PET/CT with those who did not. Results: Of 154 patients with a CUP diagnosis, 76 underwent 18F-FDG PET/CT at the initial diagnostic workup. The median overall survival (OS) of the full analysis set was 20.0 mo. Within the PET/CT subgroup, an SUVmax above 20 was associated with significantly superior OS (median OS, not reached vs. 32.0 mo; hazard ratio, 0.261; 95% CI, 0.095-0.713; P = 0.009). Conclusion: Our retrospective work shows that an SUVmax above 20 on 18F-FDG PET/CT at the initial diagnostic workup is a favorable prognostic factor in patients with CUP. This finding deserves further prospective studies for validation.

Clinical Outcome and Treatment Sequences of Patients with Advanced Pancreatic Cancer Treated with Contemporary Chemotherapy Protocols.

INTRODUCTION: Systemic therapy is firmly established in patients with advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). Clinical efficacy is still modest and options are limited. Combination therapy protocols such as FOLFIRINOX and gemcitabine/nab-paclitaxel (Gem/NP) define standard-of-care. Patients may receive a sequence of both regimens as first- and second-line palliative treatment. However, there is no guidance regarding a preferred order. METHODS: This is a retrospective analysis of clinical characteristics, treatment trajectories, and outcomes of patients with advanced PDAC treated at the West German Cancer Center Essen from 2014 to 2020 to inform treatment decisions with respect to predictive factors, impact of chemotherapy regimen sequence, and maintenance treatment. RESULTS: We identified 170 patients with available follow-up. Of those, 160 (94.1%) patients received palliative CTX for primary metastatic, locally advanced, or recurrent PDAC. Median progression-free survival (PFS) upon first palliative chemotherapy was 4.1 (3.1-5.9) months. First-line FOLFIRINOX was associated with superior PFS (median 6.3 months) and OS (9.7 months, HR 0.7, p = 0.03) as compared to Gem/NP or other regimens (PFS 3.0, OS 6.9 months). However, OS benefit of first-line FOLFIRINOX was lost in patients who received at least two treatment lines (median OS 12.1 vs. 13.1 months, p = 0.43). A landmark analysis of patients with clinical benefit (defined as CR/PR/SD for at least 20 weeks) upon first-line therapy revealed improved OS (HR 0.53, p = 0.02) for patients receiving continued deescalated maintenance therapy. Second-line regimens resulted in similar PFS (overall log-rank p = 0.92, median PFS upon second-line therapy 2.3 [1.8-2.9], per-regimen median between 1.8 and 3.9 months). A previously established systemic inflammation score proved to be strongly prognostic and allowed identification of a patient subgroup with dismal prognosis (OS 2.9 vs. 11.4 months, HR 5.23, p < 0.001), independent of other prognostic factors and with no relevant interaction with the choice of first-line regimen. CONCLUSION: In this real-world population of PDAC patients treated with contemporary combination chemotherapies, a positive impact of first-line FOLFIRINOX was only observed when no second or further line treatment was administered. Intensity-reduced maintenance therapy may lead to superior survival.

MCL1 as putative target in pancreatoblastoma.

Pancreatoblastoma (PB) is a rare tumor of the pancreas. In case of metastases, the treatment options are sparse and targeted approaches are not developed. We here evaluate MCL1 amplification as a putative target in PB.Thirteen samples from adult (10/13) and pediatric patients (3/13) were collected. Three of these samples had been previously subjected to whole-exome sequencing (2 cases) or whole-genome sequencing (1 case) within a precision oncology program (NCT/DKTK MASTER), and this analysis had shown copy number gains of MCL1 gene. We established a fluorescence in situ hybridization (FISH) test to assess the copy number alterations of MCL1 gene in 13 formalin-fixed paraffin-embedded PBs, including the 3 cases assessed by genome sequencing. FISH analysis showed the amplification of MCL1 in 2 cases (both were adult PB), one of which was a case with the highest copy number gain at genomic analysis. In both cases, the average gene copy number per cell was ≥ 5.7 and the MCL1/1p12 ratio was ≥ 2.4. Our data support MCL1 as a putative target in PB. Patients with MCL1-amplified PB might benefit from MCL1 inhibition. Sequencing data is useful to screen for amplification; however, the established FISH for MCL1 can help to determine the level and cellular heterogeneity of MCL1 amplification more accurately.

Efficacy of Immune Checkpoint Inhibitors Alone or in Combination With Chemotherapy in NSCLC Harboring ERBB2 Mutations.

INTRODUCTION: In contrast to other driver mutations, no targeted therapies have yet been approved in ERBB2-mutated NSCLC (HER2mu NSCLC). Nevertheless, several compounds have revealed promising early efficacy data, which need to be evaluated in the context of current standard approaches. Although data on the efficacy of immune checkpoint inhibitors (ICIs) in second or subsequent lines of treatment remain limited and conflicting, there are virtually no data on patient outcome under ICI/platinum-doublet combinations in the first-line setting. METHODS: We retrospectively evaluated outcomes of patients with HER2mu NSCLC treated with ICI alone or in combination with chemotherapy within the German National Network Genomic Medicine Lung Cancer consortium by means of overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: ICI either in combination with chemotherapy or as monotherapy was applied as first-line treatment in 27 patients, whereas 34 received single-agent ICI in second or subsequent lines. Patient characteristics were in line with previously published data. In treatment-naive patients receiving ICI in combination with chemotherapy, the ORR, median PFS, and OS rate at 1 year were 52%, 6 months, and 88%, respectively. In second or subsequent lines, ICI monotherapy was associated with an ORR of 16%, a median PFS of 4 months, and a median OS of 10 months. CONCLUSIONS: ICIs are effective as monotherapy and in combination with platinum-doublet chemotherapy. Therefore, ICI-based treatments may be found as the current standard of care and benchmark for targeted therapies in HER2mu NSCLC.

[Multimodal treatment of periampullary carcinoma]. / Multimodale Therapie ampullärer Karzinome.

Ampullary carcinoma is a rare malignant neoplasm and arises in the region of Vater's ampulla. The differentiation from pancreatic and distal cholangiocarcinoma can be difficult. The prognosis is more favorable than for pancreatic ductal adenocarcinoma but recurrences are frequent. An exact diagnostic clarification and differentiation from pancreatic carcinoma is therefore essential. Although the resection of periampullary carcinoma is established, prospectively controlled studies on the role of multimodal treatment are rare. Adjuvant chemotherapy is oriented to the protocols for pancreatic carcinoma and could be of benefit in lymph node metastases, advanced T stage and low differentiation of tumors. Intestinal and pancreatobiliary subtypes can be differentiated histologically, which is relevant for systemic treatment strategies. Patients with pancreatobiliary differentiated tumors in particular could benefit from gemcitabine-based treatment but insufficient evidence exists for chemoradiotherapy. The role of neoadjuvant and perioperative treatment strategies is currently unclear. Molecular characterization can help to identify familial risk constellations and targeted treatment strategies for this rare tumor entity.

ERK phosphorylation as a marker of RAS activity and its prognostic value in non-small cell lung cancer.

BACKGROUND: Deregulated signal transduction pathways play a key role in development, progression and therapeutic resistance of non-small cell lung cancers (NSCLC). The purpose of this study is to assess the downstream markers of two well-characterized pathways and to correlate them with clinical outcome. DESIGN: 670 patients with metastatic NSCLC were prospectively enrolled in a comprehensive biomarker profiling program at a single center from 2012 to 2016. Phosphorylation of extracellular signal-regulated kinase (p-ERK), and protein kinase B (p-AKT) was assessed by standardized immunohistochemistry. Product of scores for quantity and quality of staining were calculated (immunoreactive score, 0-9). Somatic mutations of Kirsten rat sarcoma viral oncogene homolog [KRAS], epithelial growth factor receptor [EGFR], v-Raf murine sarcoma viral oncogene homolog B [BRAF] and phosphatidylinositol 3-kinase [PIK3CA]) were detected by Sanger (2012-03/2015) and amplicon NGS (04/2015-02/2016). Patients enrolled during the first year (2012) were used as discovery cohort. Patients enrolled from 2013 to 02/2016 were used as validation cohort. Clinical data were retrieved from the electronic medical records and were analyzed retrospectively. RESULTS: Using a discovery cohort, we identified an immunoreactive score of p-ERK ≥3 to be prognostically relevant. The validation cohort confirmed that higher levels of p-ERK correlated with worse overall survival (OS) and higher proportion of RAS mutations. Multivariate analysis including established risk factors such EGFR, ALK or ROS mutations and metastatic disease showed a trend of a detrimental effect of high p-ERK on OS (HR 1.23, CI 0.94-1.59, p = 0.131 for p-ERK immunoreactive score ≥3) and time to treatment failure after first-line therapy in the validation cohort. Phosphorylated AKT did not correlate with clinical outcome. CONCLUSION: While serving as a prognosticator in univariate analysis, highly phosphorylated ERK does not convey a significant prognostic effect for OS in the presence of other prognostic factors. Phosphorylated ERK indicates a higher activity of RAS in advanced NSCLC.