Retrospective analysis of pathological response in colorectal cancer liver metastases following treatment with bevacizumab.

AIMS: Pathological response has been shown to be a predictor for survival after preoperative chemotherapy and surgical resection of colorectal cancer liver metastases. This retrospective analysis evaluated the effect on pathological response of adding bevacizumab to standard neoadjuvant chemotherapy in patients with metastatic colorectal cancer (mCRC) and liver metastases. METHODS: Patient records from two Spanish centres were retrospectively examined for this analysis. Patients were included if they had stage IV mCRC with liver metastases, were unresectable or marginally resectable tumour before chemotherapy, and had oxaliplatin- or irinotecan-based chemotherapy, with or without bevacizumab, before resection. Tumour response was evaluated using response evaluation criteria in solid tumours (RECIST). Pathological response was assessed by pathologists blinded to treatment. RESULTS: Ninety-five patients were included. Good pathological responses (PR0/PR1) were observed in 37 patients (39 %). The RECIST response rate was 51 %. Only 42 % of patients with a good pathological response had a complete or partial response according to RECIST, while 57 % of those with a poor pathological response had a complete or partial response according to RECIST. RECIST response rates were similar with and without bevacizumab, although 49 % of bevacizumab-treated patients had a good pathological response versus 27 % of those receiving chemotherapy alone (χ (2) P = 0.0302). CONCLUSION: Pathological response may be a better indicator of treatment efficacy than RECIST for patients with mCRC receiving bevacizumab in the neoadjuvant setting. Adding bevacizumab to chemotherapy has the potential to increase pathological response rates. Well-designed prospective clinical studies are required to establish the efficacy and tolerability of this approach.

Multicenter phase II study of oxaliplatin and sorafenib in advanced gastric adenocarcinoma after failure of cisplatin and fluoropyrimidine treatment. A GEMCAD study.

BACKGROUND: Cisplatin and fluoropyrimidine (CF) are standard first- line treatment in advanced gastric cancer, but no second-line treatment has yet been established. We present a phase II study in which we evaluated the efficacy and toxicity of the combination of Sorafenib (S), and Oxaliplatin as second-line therapy. METHODS: Patients with progressive gastric adenocarcinoma after CF- first-line, ECOG 0-2, and measurable disease were included. The primary objective was PFS. Treatment doses were Oxaliplatin 130 mg/m²/3 weeks and Sorafenib 800 mg/bid/d. RESULTS: We included 40 patients. CR was 2.5% and SD was 47.2%. Grade 3-4 toxic effects were neutropenia (9.8%), thrombocytopenia (7.3%), neurotoxicity (4.9%) and diarrhea (4.9%). Median PFS was 3 months (95%CI: 2.3-4.1) and median OS was 6.5 months (95% CI: 5.2-9.6). Time to progression (TTP) to first line therapy was a prognosis factor. Median OS was 9.7 months when time-to-progression during first-line chemotherapy was >6 months and 5.6 m when it was <6 months (p = 0.04). CONCLUSIONS: Time-to-progression under a CF-based first-line therapy determines subgroups of GC patients with different prognosis. The combination of Oxaliplatin-Sorafenib in advanced GC patients previously treated with CF appears safe, but our results do not support the implementation of a phase III trial.

Preoperative treatment with bevacizumab in combination with chemotherapy in patients with unresectable metastatic colorectal carcinoma.

PURPOSE: This prospective observational study assessed the efficacy of bevacizumab in combination with chemotherapy as preoperative treatment to downsize tumours for radical resection in patients with unresectable metastatic colorectal cancer (mCRC). PATIENTS/METHODS: Patients with mCRC initially unresectable according to predefined criteria were included. Preoperative treatment consisted of bevacizumab (5 mg/kg) combined with oxaliplatin- or irinotecan-based chemotherapy, which was followed by surgery in patients showing clinical benefit. Resection rate was the primary endpoint. Response rate (RR) and clinical benefit of preoperative chemotherapy, and overall survival (OS) were secondary endpoints. RESULTS: A total of 120 eligible patients were included and received preoperative treatment. Chemotherapy was irinotecan-based in 73 (61 %) patients, oxaliplatin-based in 25 (21 %) and 22 (18 %) patients received more than one line. A RR of 30 % and a clinical benefit rate of 73 % were observed with preoperative chemotherapy. Metastatic resection was possible in 61 (51 %) patients. Median OS was 33 months (95 % CI 31-NA months) for patients undergoing surgery, and 15 months (95 % CI 11-25 months) in non-operated patients. Thirty-five patients experienced 59 postoperative complications (morbidity rate 57 %). CONCLUSION: Preoperative bevacizumab-based chemotherapy offers a high surgical rescue rate in patients with initially unresectable mCRC.

Cross-suppression of EGFR ligands amphiregulin and epiregulin and de-repression of FGFR3 signalling contribute to cetuximab resistance in wild-type KRAS tumour cells.

BACKGROUND: In addition to the mutational status of KRAS, the epidermal growth factor receptor (EGFR) ligands amphiregulin (AREG) and epiregulin (EREG) might function as bona fide biomarkers of cetuximab (Ctx) sensitivity for most EGFR-driven carcinomas. METHODS: Lentivirus-delivered small hairpin RNAs were employed to specifically reduce AREG or EREG gene expression in wild-type KRAS A431 squamous cell carcinoma cells. Colony-forming assays were used to monitor the impact of AREG and EREG knockdown on Ctx efficacy. Amphiregulin and EREG protein expression levels were assessed by quantitative ELISA in parental A431 cells and in pooled populations of A431 cells adapted to grow in the presence of Ctx. A phosphoproteomic platform was used to measure the relative level of phosphorylation of 42 distinct receptor tyrosine kinases before and after the acquisition of resistance to Ctx. RESULTS: Stable gene silencing of either ligand was found to notably reduce the expression of the other ligand. Parental A431 cells with normal expression levels of AREG/EREG exhibited significantly increased growth inhibition in response to Ctx, compared with derivatives that are engineered to produce minimal AREG/EREG. The parental A431 cells acutely treated with Ctx exhibited reduced basal expression levels of AREG/EREG. Pooled populations of Ctx-resistant A431 cells expressed significantly lower levels of AREG/EREG and were insensitive to the downregulatory effects of Ctx. Phosphoproteomic screen identified a remarkable hyperactivation of FGFR3 in Ctx-resistant A431 cells, which gained sensitivity to the cytotoxic and apoptotic effects of the FGFR3 TK inhibitor PD173074. The A431 parental cells acutely treated with Ctx rapidly activated FGFR3 and their concomitant exposure to Ctx and PD173074 resulted in synergistic apoptosis. CONCLUSION: Cross-suppression of AREG/EREG expression may explain the tight co-expression of AREG and EREG, as well as their tendency to be more highly expressed than other EGFR ligands to determine Ctx efficacy. The positive selection for Ctx-resistant tumour cells exhibiting AREG/EREG cross-suppression may have an important role in the emergence of Ctx resistance. As de-repression of FGFR3 activity rapidly replaces the loss of EGFR-ligand signalling in terms of cell proliferation and survival, combinations of Ctx and FGFR3-targeted drugs may be a valuable strategy to enhance the efficacy of single Ctx while preventing or delaying acquired resistance to Ctx.