Beatriz Castelo

Targeting the endothelin axis in prostate carcinoma

Prostate cancer is the most common malignancy in men in Western countries. Until the last decade, the main available therapeutic options were based on hormonal therapy. For castration-refractory prostate carcinoma, from 2004, the combination of chemotherapy with docetaxel and prednisone has shown to improve survival in this subset of patients. Many agents have been tested either alone or in combination with this standard therapy, trying to find synergistic effects between drugs, and to target specific pathways that influence tumor growth, invasiveness, angiogenesis, and the development of distant metastasis. Endothelin antagonists have been recently studied, as they can get involved in many of these oncogenic pathways, and results are encouraging; nevertheless, the right setting to use them, whether to use them in monotherapy or in combination with other agents, and if they really improve the survival of our patients, are questions that remain to be addressed. In this review, we summarize the role of endothelins in tumoral biology and specifically in prostate carcinoma natural history, and the results obtained in the clinical trials involving this new therapeutic group.

Whole-Exome Sequencing Reveals Defective CYP3A4 Variants Predictive of Paclitaxel Dose-Limiting Neuropathy

Purpose: Paclitaxel, a widely used chemotherapeutic drug, can cause peripheral neuropathies leading to dose reductions and treatment suspensions and decreasing the quality of life of patients. It has been suggested that genetic variants altering paclitaxel pharmacokinetics increase neuropathy risk, but the major causes of interindividual differences in susceptibility to paclitaxel toxicity remain unexplained. We carried out a whole-exome sequencing (WES) study to identify genetic susceptibility variants associated with paclitaxel neuropathy. Experimental Design: Blood samples from 8 patients with severe paclitaxel-induced peripheral neuropathy were selected for WES. An independent cohort of 228 cancer patients with complete paclitaxel neuropathy data was used for variant screening by DHPLC and association analysis. HEK293 cells were used for heterologous expression and characterization of two novel CYP3A4 enzymes. Results: WES revealed 2 patients with rare CYP3A4 variants, a premature stop codon (CYP3A4*20 allele) and a novel missense variant (CYP3A4*25, p.P389S) causing reduced enzyme expression. Screening for CYP3A4 variants in the independent cohort revealed three additional CYP3A4*20 carriers, and two patients with missense variants exhibiting diminished enzyme activity (CYP3A4*8 and the novel CYP3A4*27 allele, p.L475V). Relative to CYP3A4 wild-type patients, those carrying CYP3A4 defective variants had more severe neuropathy (2- and 1.3-fold higher risk of neuropathy for loss-of-function and missense variants, respectively, P = 0.045) and higher probability of neuropathy-induced paclitaxel treatment modifications (7- and 3-fold higher risk for loss-of-function and missense variants, respectively, P = 5.9 × 10−5). Conclusion: This is the first description of a genetic marker associated with paclitaxel treatment modifications caused by neuropathy. CYP3A4 defective variants may provide a basis for paclitaxel treatment individualization. Clin Cancer Res; 21(2); 322–8. ©2014 AACR.

A combined strategy of SAGE and quantitative PCR provides a 13-gene signature that predicts preoperative chemoradiotherapy response and outcome in rectal cancer

Purpose: Preoperative chemoradiotherapy (CRT) is the treatment of choice for rectal cancer (RC), but half of the patients do not respond, suffer unnecessary toxicities, and surgery delays. We aimed to develop a model that could predict a clinically meaningful response to CRT by using formalin-fixed paraffin-embedded (FFPE) biopsies. Experimental Design: We first carried out an exploratory screening of candidate genes by using SAGE technology to evaluate dynamic changes in the RC transcriptome in selected refractory patients before and after CRT. Next, 53 genes (24 from SAGE and 29 from the literature) were analyzed by qPCR arrays in FFPE initial biopsies from 94 stage II/III RC patients who were preoperatively treated with CRT. Tumor response was defined by using Dworaks tumor regression grade (2–3–4 vs. 0–1). Multivariate Cox methods and stepwise algorithms were applied to generate an optimized predictor of response and outcome. Results: In the training cohort (57 patients), a 13-gene signature predicted tumor response with 86% accuracy, 87% sensitivity, and 82% specificity. In a testing cohort (37 patients), the model correctly classified 6 of 7 nonresponders, with an overall accuracy of 76%. A signature-based score identified patients with a higher risk of relapse in univariate (3-year disease-free survival 64% vs. 90%, P = 0.001) and multivariate analysis (HR = 4.35 95% CI: 1.2–15.75, P = 0.02), in which it remained the only statistically significant prognostic factor. Conclusions: A basal 13-gene signature efficiently predicted CRT response and outcome. Multicentric validation by the GEMCAD collaborative group is currently ongoing. If confirmed, the predictor could be used to improve patient selection in RC studies. Clin Cancer Res; 17(12); 4145–54. ©2011 AACR.

Angiogenesis as a therapeutic target in urothelial carcinoma.

In the last few years, angiogenesis has confirmed its critical role in the development of malignant neoplasms. Antiangiogenic drugs, mainly bevacizumab, sorafenib, or sunitinib, are currently approved in a wide number of tumor types, such as breast, colorectal, liver, or kidney cancer, and have changed dramatically the evolution of our patients. Unfortunately, in urothelial carcinoma, which is a very common neoplasm, antiangiogenic agents are still in a very preliminary phase of clinical research. In this study, we focus on the biological basis of angiogenesis in urothelial tumors, its influence in the prognosis of these malignancies, and the available evidence about the use of antiangiogenic drugs in urothelial carcinoma.

Clinical role of Sm-153 EDTMP in the treatment of painful bone metastatic disease

Purpose: Sm-153 EDTMP is an effective treatment of painful bone metastases from different neoplasms. However, there are few studies describing clinical experience with this therapeutic modality. The aim of this clinical study was to evaluate the efficacy of Sm-153 EDTMP in a group of patients with skeletal metastases and poor pain control with conventional therapies. Materials and Methods: Sixty-four patients with painful bone metastases treated with Sm-153 EDTMP were retrospectively evaluated. Nine patients were treated twice. The most common primaries were breast in 28 cases (44%) and prostate in 27 (41%). Treatment efficacy was assessed by a visual analog scale, analgesic consumption, and performance status before and after treatment. Response was graded as complete, moderate, or minor. Toxicity evaluation included analytic parameters (blood counts, renal function) and clinical follow up. Results: Efficacy and toxicity were evaluated separately for each dose (total doses: 73), and complete follow up was only possible in 62 of 73 administrations. The response rate was 85% (21% complete, 40% moderate, and 24% minor). Onset of improvement took place a median of 7 days after Sm-153 EDTMP administration, and pain relief persisted for a mean of 3 months. No relevant toxicity was found in the early phase. Myelotoxicity appeared in 29% of the administrations and was mild in most cases (there was one case of grade 4 leukopenia). Conclusions: Sm-153 EDTMP is a good therapeutic option for patients with painful bone metastases. It is an effective treatment of pain relief without major secondary effects.

Merkel cell carcinoma: An algorithm for multidisciplinary management and decision-making

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine tumor of the skin. Therapeutic approach is often unclear, and considerable controversy exists regarding MCC pathogenesis and optimal management. Due to its rising incidence and poor prognosis, it is imperative to establish the optimal therapy for both the tumor and the lymph node basin, and for treatment to include sentinel node biopsy. Sentinel node biopsy is currently the most consistent predictor of survival for MCC patients, although there are conflicting views and a lack of awareness regarding node management. Tumor and node management involve different specialists, and their respective decisions and interventions are interrelated. No effective systemic treatment has been made available to date, and therefore patients continue to experience distant failure, often without local failure. This review aims to improve multidisciplinary decision-making by presenting scientific evidence of the contributions of each team member implicated in MCC management. Following this review of previously published research, the authors conclude that multidisciplinary team management is beneficial for care, and propose a multidisciplinary decision algorithm for managing this tumor.

Continuation of bevacizumab and addition of hormone therapy following weekly paclitaxel therapy in HER2-negative metastatic breast cancer.

Background Bevacizumab plus taxane chemotherapy improves progression-free survival (PFS) versus taxane monotherapy in the first-line treatment of HER2-negative metastatic breast cancer (MBC) and appears promising in the second-line setting. This retrospective analysis evaluated the efficacy and safety of this combination in a real-world setting. Patients and methods Eligible patients received bevacizumab (10 mg/kg days 1 and 15, every 28 days) plus paclitaxel (80 mg/m2 days 1, 8, and 15, every 28 days) as first-line therapy for MBC, or as subsequent lines, including bevacizumab continuation therapy, at La Paz University Hospital between August 2007 and October 2012. End points included objective response rate (ORR), PFS, overall survival (OS), and safety. Results Seventy-eight patients were included. Median PFS was 12.8 months for patients receiving first-line treatment and 9.3 months for subsequent lines. Forty-five patients (57.7%) continued bevacizumab after stopping paclitaxel, and had significantly longer PFS and OS than those who did not (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.248–0.653, P<0.001; HR 0.39, 95% CI 0.218–0.710, P=0.002; respectively). In the continuation phase, estrogen receptor-positive patients had longer PFS and OS when receiving hormone therapy plus bevacizumab versus patients receiving only bevacizumab (HR 0.50, 95% CI 0.24–1.04, P=0.06; HR 0.43, 95% CI 0.16–1.16, P=0.09; respectively). Thirty-five patients (44.9%) reported grade 3–4 adverse events. Conclusion Bevacizumab plus paclitaxel was effective in HER2-negative MBC. Continuation of bevacizumab and addition of hormone therapy following paclitaxel therapy could be beneficial.

Phase II study of neoadjuvant treatment of rectal cancer with oxaliplatin, raltitrexed and radiotherapy

3746 Background and objective: Preoperative chemoradiation can improve the outcome of surgery in rectal cancer. The aim of this phase II study was to evaluate the efficacy and toxicity of a preoperative radiochemotherapy combination including oxaliplatin, raltitrexed and radiotherapy in locoregionally advanced rectal cancer. METHODS Between January 2002 and July 2003, 43 consecutive patients (22 women, 21 men; median age 61 years, range 34-74) with stage II and III rectal adenocarcinomas have been enrolled. All patients underwent endorectal ultrasonography (uT2N1= 2, uT3N0= 14, uT3N1= 23, uT4N0= 1, uT4N1= 3), and CT scan for staging purposes. Radiotherapy was delivered with a three-field technique to a dose of 50Gy over 5 weeks with a concomitant boost approach. Chemotherapy was initiated concurrently with RT and consisted of three courses of raltitrexed 3 mg/m2 followed by oxaliplatin 130 mg/m2 every 21 days. Surgery was planned six to eight weeks after RT. Three additional cycles of chemotherapy were given after surgery. RESULTS 33 patients can be evaluated for response and 43 for toxicity. 25 patients were downstaged (76%), there were 6 pathological complete responses (18%) and sphincter sparing surgery was accomplished in 22 patients (67%). Grade 3 diarrea developed in two patients, and grade 4 in one patient (7%). Grade 3 neutropenia was observed in three patients (7%), including one febrile neutropenia. Other adverse events were mild, including grade 2 hepatotoxicity (transaminases) in 5 patients (11%). CONCLUSION The regimen is feasible, has a low toxicity profile and can be administered in a three weeks basis. This treatment achieves significant tumor downstaging with a remarkable rate of conservative surgeries and complete pathological responses. No significant financial relationships to disclose.

Targeted sequencing reveals low-frequency variants in EPHA genes as markers of paclitaxel-induced peripheral neuropathy.

Purpose: Neuropathy is the dose-limiting toxicity of paclitaxel and a major cause for decreased quality of life. Genetic factors have been shown to contribute to paclitaxel neuropathy susceptibility; however, the major causes for interindividual differences remain unexplained. In this study, we identified genetic markers associated with paclitaxel-induced neuropathy through massive sequencing of candidate genes. Experimental Design: We sequenced the coding region of 4 EPHA genes, 5 genes involved in paclitaxel pharmacokinetics, and 30 Charcot–Marie–Tooth genes, in 228 cancer patients with no/low neuropathy or high-grade neuropathy during paclitaxel treatment. An independent validation series included 202 paclitaxel-treated patients. Variation-/gene-based analyses were used to compare variant frequencies among neuropathy groups, and Cox regression models were used to analyze neuropathy along treatment. Results: Gene-based analysis identified EPHA6 as the gene most significantly associated with paclitaxel-induced neuropathy. Low-frequency nonsynonymous variants in EPHA6 were present exclusively in patients with high neuropathy, and all affected the ligand-binding domain of the protein. Accumulated dose analysis in the discovery series showed a significantly higher neuropathy risk for EPHA5/6/8 low-frequency nonsynonymous variant carriers [HR, 14.60; 95% confidence interval (CI), 2.33–91.62; P = 0.0042], and an independent cohort confirmed an increased neuropathy risk (HR, 2.07; 95% CI, 1.14–3.77; P = 0.017). Combining the series gave an estimated 2.5-fold higher risk of neuropathy (95% CI, 1.46–4.31; P = 9.1 × 10−4). Conclusions: This first study sequencing EPHA genes revealed that low-frequency variants in EPHA6, EPHA5, and EPHA8 contribute to the susceptibility to paclitaxel-induced neuropathy. Furthermore, EPHAs neuronal injury repair function suggests that these genes might constitute important neuropathy markers for many neurotoxic drugs. Clin Cancer Res; 23(5); 1227–35. ©2016 AACR.

Prolonged response to aflibercept in ovarian cancer relapse: a case report.

VEGF-targeted therapies have shown activity in ovarian cancer, and one of them, bevacizumab, has been recently approved in this disease. Aflibercept is an antiangiogenic soluble fusion protein that inhibits VEGF-mediated signaling. In ovarian cancer, phase II trials with aflibercept have shown a significant benefit in the control of malignant ascites but with a lower response rate than expected. We report the case of a patient with relapsed ovarian cancer treated with aflibercept in fourth line, who experienced a prolonged response during more than two years with good tolerance. The duration of response to aflibercept was longer than that of the three previous lines of therapy (including the initial carboplatin-paclitaxel regimen) and ascites did not reappear. Further clinical research with this drug in ovarian cancer to identify patients who benefit most is warranted.