The role of p53 dysfunction in colorectal cancer and its implication for therapy

Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. The carcinogenesis of CRC is based on a stepwise accumulation of mutations, leading either to an activation of oncogenes or a deactivation of suppressor genes. The loss of genetic stability triggers activation of proto-oncogenes (e.g., KRAS) and inactivation of tumor suppression genes, namely TP53 and APC, which together drive the transition from adenoma to adenocarcinoma. On the one hand, p53 mutations confer resistance to classical chemotherapy but, on the other hand, they open the door for immunotherapy, as p53-mutated tumors are rich in neoantigens. Aberrant function of the TP53 gene product, p53, also affects stromal and non-stromal cells in the tumor microenvironment. Cancer-associated fibroblasts together with other immunosuppressive cells become valuable assets for the tumor by p53-mediated tumor signaling. In this review, we address the manifold implications of p53 mutations in CRC regarding therapy, treatment response and personalized medicine

Comparative analysis of nuclear and mitochondrial DNA from tissue and liquid biopsies of colorectal cancer patients

The current standard for molecular profiling of colorectal cancer (CRC) is using resected or biopsied tissue specimens. However, they are limited regarding sampling frequency, representation of tumor heterogeneity, and sampling can expose patients to adverse side effects. The analysis of cell-free DNA (cfDNA) from blood plasma, which is part of a liquid biopsy, is minimally invasive and in principle enables detection of all tumor-specific mutations. Here, we analyzed cfDNA originating from nucleus and mitochondria and investigated their characteristics and mutation status in a cohort of 18 CRC patients and 10 healthy controls using targeted next-generation sequencing (NGS) and digital PCR. Longitudinal analyses of nuclear cfDNA level and size during chemotherapy revealed a decreasing cfDNA content and a shift from short to long fragments, indicating an appropriate therapy response, while shortened cfDNAs and increased cfDNA content corresponded with tumor recurrence. Comparative NGS analysis of nuclear tissue and plasma DNA demonstrated a good patient-level concordance and cfDNA revealed additional variants in three of the cases. Analysis of mitochondrial cfDNA surprisingly revealed a higher plasma copy number in healthy subjects than in CRC patients. These results highlight the potential clinical utility of liquid biopsies in routine diagnostics and surveillance of CRC patients as complementation to tissue biopsies or as an attractive alternative in cases where tissue biopsies are risky or the quantity/quality does not allow testing

Survival after secondary liver resection in metastatic colorectal cancer : comparing data of three prospective randomized European trials (LICC, CELIM, FIRE-3)

Metastatic colorectal cancer (mCRC) patients with liver-limited disease (LLD) have a chance of long-term survival and potential cure after hepatic metastasectomy. However, the appropriate postoperative treatment strategy is still controversial. The CELIM and FIRE-3 studies demonstrated that secondary hepatic resection significantly improved overall survival (OS). The objective of this analysis was to compare these favorable outcome data with recent results from the LICC trial investigating the antigen-specific cancer vaccine tecemotide (L-BLP25) as adjuvant therapy in mCRC patients with LLD after R0/R1 resection. Data from mCRC patients with LLD and secondary hepatic resection from each study were analyzed for efficacy outcomes based on patient characteristics, treatment and surveillance after surgery. In LICC, 40/121 (33%) patients, in CELIM 36/111 (32%) and in FIRE-3-LLD 29/133 (22%) patients were secondarily resected, respectively. Of those, 31 (77.5%) patients in LICC and all patients in CELIM were R0 resected. Median disease-free survival after resection was 8.9 months in LICC, 9.9 months in CELIM. Median OS in secondarily resected patients was 66.1 months in LICC, 53.9 months in CELIM and 56.2 months in FIRE-3-LLD. Median age was about 5 years less in LICC compared to CELIM and FIRE-3. Secondarily resected patients of LICC, CELIM and FIRE-3 showed an impressive median survival with a tendency for improved survival for patients in the LICC trial. A younger patient cohort but also more selective surgery, improved resection techniques, deep responses and a close surveillance program after surgery in the LICC trial may have had a positive impact on survival. What's new? The management of liver-limited disease (LLD) in patients with metastatic colorectal cancer (mCRC) is controversial, the optimal treatment has not been defined. Here, data from mCRC patients with LLD and secondary hepatic resection from the prospective randomized trials CELIM, FIRE-3 and LICC were compared. Secondarily resected patients from these trials showed an impressive overall survival (OS), with a tendency for improved OS in LICC. Reasons might be the deep response induced by chemotherapy and surgery combined with close surveillance after surgery. Further prospective, randomized clinical trials are strongly needed to clarify these benefits

a randomized, placebo-controlled phase II AIO trial with serum biomarker program

Background As a multi-targeted anti-angiogenic receptor tyrosine kinase (RTK) inhibitor sunitinib (SUN) has been established for renal cancer and gastrointestinal stromal tumors. In advanced refractory esophagogastric cancer patients, monotherapy with SUN was associated with good tolerability but limited tumor response. Methods This double-blind, placebo-controlled, multicenter, phase II clinical trial was conducted to evaluate the efficacy, safety and tolerability of SUN as an adjunct to second and third-line FOLFIRI (NCT01020630). Patients were randomized to receive 6-week cycles including FOLFIRI plus sodium folinate (Na-FOLFIRI) once every two weeks and SUN or placebo (PL) continuously for four weeks followed by a 2-week rest period. The primary study endpoint was progression-free survival (PFS). Preplanned serum analyses of VEGF-A, VEGF-D, VEGFR2 and SDF-1α were performed retrospectively. Results Overall, 91 patients were randomized, 45 in each group (one patient withdrew). The main grade ≥3 AEs were neutropenia and leucopenia, observed in 56 %/20 % and 27 %/16 % for FOLFIRI + SUN/FOLFIRI + PL, respectively. Median PFS was similar, 3.5 vs. 3.3 months (hazard ratio (HR) 1.11, 95 % CI 0.70–1.74, P = 0.66) for FOLFIRI + SUN vs. FOLFIRI + PL, respectively. For FOLFIRI + SUN, a trend towards longer median overall survival (OS) compared with placebo was observed (10.4 vs. 8.9 months, HR 0.82, 95 % CI 0.50–1.34, one-sided P = 0.21). In subgroup serum analyses, significant changes in VEGF-A (P = 0.017), VEGFR2 (P = 0.012) and VEGF-D (P < 0.001) serum levels were observed. Conclusions Although sunitinib combined with FOLFIRI did not improve PFS and response in chemotherapy-resistant gastric cancer, a trend towards better OS was observed. Further biomarker-driven studies with other anti- angiogenic RTK inhibitors are warranted. Trial registration This study was registered prospectively in the NCT Clinical Trials Registry (ClinicalTrials.gov) under NCT01020630 on November 23, 2009 after approval by the leading ethics committee of the Medical Association of Rhineland- Palatinate, Mainz, in coordination with the participating ethics committees (see Additional file 2) on September 16, 2009

Radiochemotherapy with or without cetuximab for unresectable esophageal cancer: final results of a randomized phase 2 trial (LEOPARD-2)

Abstract Purpose To investigate the efficacy and toxicity of cetuximab when added to radiochemotherapy for unresectable esophageal cancer. Methods This randomized phase 2 trial (clinicaltrials.gov, identifier NCT01787006) compared radiochemotherapy plus cetuximab (arm A) to radiochemotherapy (arm B) for unresectable esophageal cancer. Primary objective was 2‑year overall survival (OS). Arm A was considered insufficiently active if 2‑year OS was ≤40% (null hypothesis = H0), and promising if the lower limit of the 95% confidence interval was >45%. If that lower limit was >40%, H0 was rejected. Secondary objectives included progression-free survival (PFS), locoregional control (LC), metastases-free survival (MFS), response, and toxicity. The study was terminated early after 74 patients; 68 patients were evaluable. Results Two-year OS was 71% in arm A (95% CI: 55–87%) vs. 53% in arm B (95% CI: 36–71%); H0 was rejected. Median OS was 49.1 vs. 24.1 months (p = 0.147). Hazard ratio (HR) for death was 0.60 (95% CI: 0.30–1.21). At 2 years, PFS was 56% vs. 44%, LC 84% vs. 72%, and MFS 74% vs. 54%. HRs were 0.51 (0.25–1.04) for progression, 0.43 (0.13–1.40) for locoregional failure, and 0.43 (0.17–1.05) for distant metastasis. Overall response was 81% vs. 69% (p = 0.262). Twenty-six and 27 patients, respectively, experienced at least one toxicity grade ≥3 (p = 0.573). A significant difference was found for grade ≥3 allergic reactions (12.5% vs. 0%, p = 0.044). Conclusion Given the limitations of this trial, radiochemotherapy plus cetuximab was feasible. There was a trend towards improved PFS and MFS. Larger studies are required to better define the role of cetuximab for unresectable esophageal cancer

The Role of p53 Dysfunction in Colorectal Cancer and Its Implication for Therapy

Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. The carcinogenesis of CRC is based on a stepwise accumulation of mutations, leading either to an activation of oncogenes or a deactivation of suppressor genes. The loss of genetic stability triggers activation of proto-oncogenes (e.g., KRAS) and inactivation of tumor suppression genes, namely TP53 and APC, which together drive the transition from adenoma to adenocarcinoma. On the one hand, p53 mutations confer resistance to classical chemotherapy but, on the other hand, they open the door for immunotherapy, as p53-mutated tumors are rich in neoantigens. Aberrant function of the TP53 gene product, p53, also affects stromal and non-stromal cells in the tumor microenvironment. Cancer-associated fibroblasts together with other immunosuppressive cells become valuable assets for the tumor by p53-mediated tumor signaling. In this review, we address the manifold implications of p53 mutations in CRC regarding therapy, treatment response and personalized medicine

Safety and efficacy of afatinib as add-on to standard therapy of gemcitabine/cisplatin in chemotherapy-naive patients with advanced biliary tract cancer: an open-label, phase I trial with an extensive biomarker program

Abstract Background To date, the cornerstone of treatment in patients with advanced or metastatic cholangiocarcinoma (CCA) is systemic chemotherapy based on a combination of gemcitabine and a platinum derivative. Other therapeutic approaches including targeted agents and tyrosine kinase inhibitors (TKI) have demonstrated disappointing results, highlighting the complexity of CCA. Recently, drugs aiming at the inhibition of HER-receptors have shown first therapeutic benefit in patients with late stage disease. The aim of this phase I study was to test the dose level toxicities (DLTs), safety and efficacy of afatinib, a highly specific panErbB family receptor TKI, in chemotherapy naive patients with advanced CCA in conjunction with an extensive biomarker program. Methods Afatinib was administered continuously p. o. as add-on in patients with advanced CCA who received conventional chemotherapy with gemcitabine/cisplatin. A classical 3 + 3 phase I study was employed, while the maximum tolerated dose (MTD) of oral afatinib was determined in a 2 step dose escalation. Safety, overall survival (OS) and progression free survival (PFS) were evaluated for all patients. Finally, a translational biomarker analysis was conducted for the EGFR and VEGF signalling cascades. Results Overall, 9 patients were enrolled. Further recruitment was discontinued due to lack of efficacy results of the tested drug in other indications. 30 mg afatinib could be safely administered as add-on to 80% of standard dose gemcitabine/cisplatin. The mOS and mPFS were 7.7 and 6.0 months, respectively. Diarrhoea and haematological disorders were the most common observed AEs. Almost all patients overexpressed EGFR on their tumour tissues, whereas none of them expressed mutations in Exons 18, 19 and 21. Non-responders showed a higher variation of VEGF-C, −D, leptin and sEGFR in their sera. Conclusions Afatinib failed to show survival benefits in combination with gemcitabine/cisplatin in patients with advanced CCA. Mutational analysis of EGFR and pathways associated with VEGF-C, −D and leptin might show promising results in future studies. Clinical trials registration NCT01679405 August, 2012

Lapatinib with ECF/X in the first-line treatment of metastatic gastric cancer according to HER2neu and EGFR status: a randomized placebo-controlled phase II study (EORTC 40071)

PURPOSE: HER2-targeted therapy with trastuzumab and (CF/X) prolonged overall survival (OS) in metastatic HER2neu+ gastric carcinoma (GC). Lapatinib inhibits both EGFR and HER2neu. We investigated the efficacy and safety of lapatinib with epirubicin (E) + CF/X in GC according to HER2neu and EGFR status. METHODS: Tumors from chemotherapy-naïve patients were screened centrally by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). Patients with EGFR and/or HER2neu expression or amplification were allocated to three strata based on EGFR/HER2neu status and were randomized to lapatinib (arm A) or placebo (arm B), with 6 cycles of ECF or ECX (investigator-selected). The primary endpoint was progression-free survival (PFS) in stratum 3. RESULTS: 29 of 72 screened patients were randomized to strata 1 (HER2neu+: by FISH and IHC, n = 6), 2 (HER2neu-: by FISH/+ by IHC, n = 5) and 3 (HER2neu-/EGFR+, n = 18), of which 28 patients were eligible (14 per arm). Enrollment was curtailed after announcement of the negative LOGiC trial results. Median PFS was 8.0 versus 5.9 months (HR = 0.86, 95% CI 0.37-1.99) in the per protocol population, and 8.0 versus 6.3 months (HR = 0.85, 95% CI 0.30-2.46) for stratum 3, in the lapatinib versus placebo arm respectively. Median OS was 13.8 versus 10.1 months, respectively (HR = 0.90, 95% CI 0.35-2.27). There were no safety concerns. CONCLUSIONS: Central EGFR and HER2neu stratification by IHC and FISH can be used for further pan-HER strategies. Lapatinib with ECF/X was well tolerated, but did not show clear activity in patients with metastatic GC.status: publishe