The impact of KRAS mutations on VEGF-A production and tumour vascular network.

BACKGROUND: The malignant potential of tumour cells may be influenced by the molecular nature of KRAS mutations being codon 13 mutations less aggressive than codon 12 ones. Their metabolic profile is also different, with an increased anaerobic glycolytic metabolism in cells harbouring codon 12 KRAS mutations compared with cells containing codon 13 mutations. We hypothesized that this distinct metabolic behaviour could be associated with different HIF-1α expression and a distinct angiogenic profile. METHODS: Codon13 KRAS mutation (ASP13) or codon12 KRAS mutation (CYS12) NIH3T3 transfectants were analyzed in vitro and in vivo. Expression of HIF-1α, and VEGF-A was studied at RNA and protein levels. Regulation of VEGF-A promoter activity was assessed by means of luciferase assays using different plasmid constructs. Vascular network was assessed in tumors growing after subcutaneous inoculation. Non parametric statistics were used for analysis of results. RESULTS: Our results show that in normoxic conditions ASP13 transfectants exhibited less HIF-1α protein levels and activity than CYS12. In contrast, codon 13 transfectants exhibited higher VEGF-A mRNA and protein levels and enhanced VEGF-A promoter activity. These differences were due to a differential activation of Sp1/AP2 transcription elements of the VEGF-A promoter associated with increased ERKs signalling in ASP13 transfectants. Subcutaneous CYS12 tumours expressed less VEGF-A and showed a higher microvessel density (MVD) than ASP13 tumours. In contrast, prominent vessels were only observed in the latter. CONCLUSION: Subtle changes in the molecular nature of KRAS oncogene activating mutations occurring in tumour cells have a major impact on the vascular strategy devised providing with new insights on the role of KRAS mutations on angiogenesis.

Efficacy and safety of concurrent trastuzumab plus weekly paclitaxel-FEC as primary therapy for HER2-positive breast cancer in everyday clinical practice.

One of the most efficacious primary therapies in HER2-positive breast cancer was published by the M.D. Anderson group in 2005. This randomized trial evaluated the addition of trastuzumab to a taxane-anthracycline based chemotherapy. Despite largely significant differences in pathological complete response (pCR) in the trastuzumab group (65 vs. 26 %) this regimen did not become a common standard due to toxicity concerns and its premature closure with a small sample size. In order to evaluate the efficacy and safety of this regimen in an off-trial setting we conducted a prospectively monitorized series of consecutive patients with early or locally advanced Her-2 positive breast cancer following the same treatment strategy. Stage II-IIIC HER2-positive breast cancer patients, including inflammatory disease, were treated with weekly-trastuzumab for 24 weeks administered concurrently with all primary chemotherapy containing paclitaxel (80 mg/m(2)) for 12 weeks and 4 cycles of FEC-75 (fluorouracil 500 mg/m(2), epirubicine 75 mg/m(2), and cyclophosphamide 500 mg/m(2)) followed by surgery. The objectives were efficacy, in terms of pCR in both the breast and lymph nodes, and safety, with close cardiac monitoring during and after treatment. From August 2004 to February 2009, 83 patients were included. Most patients (73.5 %) had node involvement and 13.2 % had inflammatory disease. Fifty-one patients (61.4 %) achieved a pCR in breast and axilla (95 % CI 50-72 %). HR-negative tumors were associated with higher pCR rate than HR-positive tumors (77 vs. 48 %, P = 0.006). At a median follow-up of 50.2 months no patient developed symptomatic cardiac failure, and 9 patients (10.8 %) presented a transient asymptomatic decrease in left ventricular ejection fraction. Primary therapy with concurrent trastuzumab plus paclitaxel-FEC for HER2-positive breast cancer in everyday practice is highly effective and safe confirming the results observed in a randomized trial stopped prematurely.

CA-125 response patterns in patients with recurrent ovarian cancer treated with pegylated liposomal doxorubicin (PLD).

INTRODUCTION: : In recurrent ovarian cancer, CA-125 could be the only objective response criteria. This study analyzes response patterns regarding CA-125 in responders versus nonresponders and determines whether a specific cutoff value for CA-125 could predict clinical response, compared with response evaluation criteria in solid tumors, in patients receiving pegylated liposomal doxorubicin (PLD). METHODS: : Sixty-eight patients were identified, 78% were platinum resistant. Relative changes in CA-125 values were calculated, and response was defined as higher than 50% reduction in CA-125 from baseline. Receiver operating characteristic (ROC) curves were constructed based on CA-125 value after the first cycle of PLD to evaluate the most precise cutoff point for the decision model predicting response. RESULTS: : Fifty-three patients were assessable for response: 16 patients responded and 37 did not; the median increase of CA-125 was 0.20 (-63; 312) and 52 (-29; 620), respectively. Our ROC curve generated a cutoff value with a sensitivity of 35% (positive test, the proportion of patients who will not respond) and a predictive positive value of 80%. According to the predictive positive value, 20% of the responder patients will be identified as nonresponders; P = 0.025. CONCLUSIONS: : Our ROC analysis did not demonstrate any reliable CA-125 cutoff on response. Discontinuation of the therapy before cycle 3 may exclude some patients who will benefit from PLD.

Sunitinib inhibits tumor growth and synergizes with cisplatin in orthotopic models of cisplatin-sensitive and cisplatin-resistant human testicular germ cell tumors.

PURPOSE: Germ cell tumors (GCT) of the testis are highly curable, but those patients who are refractory to cisplatin (CDDP)-based combination chemotherapy have a poor prognosis. Therefore, identifying new alternatives for treatment remains a priority. Several studies support an important role for angiogenesis in GCTs, suggesting that antiangiogenic treatment might be a good alternative. Sunitinib is an oral multitarget tyrosine kinase receptor inhibitor with antiangiogenic and antitumor activities. In the present study, we evaluated the effect of sunitinib, CDDP, or the combination of both drugs using an orthotopic model of human testicular GCT. EXPERIMENTAL DESIGN: Mice were implanted with four different testicular tumors: a yolk sac, two choriocarcinomas, and a CDDP-resistant choriocarcinoma variant induced in mice by continuous exposure to CDDP. Mice were treated with vehicle, CDDP, sunitinib, or the combination of both drugs and their effects on tumors were analyzed. RESULTS: We observed a significant inhibition in tumor growth accompanied by longer survival after sunitinib treatment. Combination therapy with CDDP significantly enhanced these effects. Sunitinib induced apoptosis, reduced tumor cell proliferation and tumor vasculature, and inhibited vascular endothelial growth factor receptor 1, 2, and 3 and platelet-derived growth factor receptor alpha phosphorylation without affecting phosphorylation of other tyrosine kinase receptors. More importantly, tumor growth inhibition induced by sunitinib was also observed in the induced CDDP-resistant choriocarcinoma model. CONCLUSIONS: Taken together, these results suggest that sunitinib might be a new alternative for treatment of CDDP-refractory patients.

Antiangiogenic effect of gemcitabine following metronomic administration in a pancreas cancer model.

Gemcitabine shows a marked antitumor effect as a result of its cytotoxic action toward proliferative cells. In this article, we aim to investigate the potential antitumor and antiangiogenic effect of gemcitabine following a metronomic schedule that involves the regular administration of cytotoxic drugs at doses lower than standard treatment. In vitro results showed that human endothelial cells are more sensitive to gemcitabine (IC(50) 3 nmol/L) than pancreatic tumor cells (IC(50) 20 nmol/L). For in vivo studies, we used an orthotopic implantation model of human pancreatic carcinoma in nude mice. Gemcitabine was administered i.p. following a low-dose schedule (1 mg/kg/d for a month) and compared with the conventional schedule (100 mg/kg days 0, 3, 6, and 9 postimplantation). Metronomic treatment effect on established tumor was equivalent to standard administration. The measure of CD31 endothelial marked area allowed us to show an in vivo antiangiogenic effect of this drug that was further enhanced by using metronomic administration. This effect correlated with an induction of thrombospondin-1, a natural inhibitor of angiogenesis. Our results allow us to hypothesize that, in addition to a direct antiproliferative or cytotoxic antiendothelial cell effect, a secondary effect involving thrombospondin-1 induction might provide an explanation for the specificity of the effects of metronomic gemcitabine treatment.

[Impact on budget of new drugs for colorectal cancer treatment]. / Impacto presupuestario de los nuevos fármacos para el tratamiento del cáncer colorrectal.

BACKGROUND AND OBJECTIVE: To assess the impact on the medicines budget of the introduction of new treatments in colorectal cancer, as monoclonal antibodies cetuximab and bevacizumab and oxaliplatin in the adjuvant setting, for the Catalan health public system in 2006. METHOD: In advanced stages of the disease, the medicines budget impact of the introduction of cetuximab and bevacizumab in relation to the standard treatment (FOLFIRI and FOLFOX regimes) was evaluated. In adjuvant treatment stage II-III, the medicines budget impact of the utilization of FOLFOX regime compared to the combination of fluorouracil and folinic acid was evaluated. RESULTS: The medicines budget impact of the new therapies is evaluated at 27.9 million euros and 18.3 million euros in advanced stages of the disease and the adjuvant setting, respectively. In the adjuvant setting, the impact assessed depends on the number of new cases estimated. CONCLUSIONS: The impact on the health budget in Catalonia will be of great magnitude, and it could be higher considering these drugs are just only an example. Health policy should take this impact into account when future costs of health care are assessed in the public sector.

Impacto presupuestario de los nuevos fármacos para el tratamiento del cáncer colorrectal / Impact on budget of new drugs for colorectal cancer treatment

Fundamento y objetivo: Evaluar el impacto presupuestario de los nuevos fármacos para el tratamiento del cáncer colorrectal, como son los anticuerpos monoclonales cetuximab y bevacizumab y el oxaliplatino en adyuvancia, para el sistema público catalán en el año 2006. Método: En estadios avanzados se evaluó el impacto en el presupuesto para fármacos de la incorporación de cetuximab y bevacizumab con respecto al tratamiento considerado estándar (FOLFIRI ­irinotecán, fluorouracilo y ácido folínico­ y FOLFOX ­oxaliplatino, fluorouracilo y ácido folínico­). En el tratamiento adyuvante por estadios II-III se evaluó el impacto presupuestario de la utilización del esquema FOLFOX con respecto a la combinación de fluorouracilo con ácido folínico. Resultados: En estadios avanzados la introducción de los nuevos tratamientos supone un coste incremental de 27,9 millones de euros. En adyuvancia, la introducción del FOLFOX supone un coste incremental de 18,3 millones de euros, que dependerá notablemente del número de pacientes diagnosticados. Conclusiones: El impacto sobre el presupuesto sanitario público en Cataluña será de gran magnitud, más aún si se tiene en cuenta que los fármacos considerados son sólo un ejemplo

Background and objective: To assess the impact on the medicines budget of the introduction of new treatments in colorectal cancer, as monoclonal antibodies cetuximab and bevacizumab and oxaliplatin in the adjuvant setting, for the Catalan health public system in 2006. Method: In advanced stages of the disease, the medicines budget impact of the introduction of cetuximab and bevacizumab in relation to the standard treatment (FOLFIRI and FOLFOX regimes) was evaluated. In adjuvant treatment stage II-III, the medicines budget impact of the utilization of FOLFOX regime compared to the combination of fluorouracil and folinic acid was evaluated. Results: The medicines budget impact of the new therapies is evaluated at 27.9 million euros and 18.3 million euros in advanced stages of the disease and the adjuvant setting, respectively. In the adjuvant setting, the impact assessed depends on the number of new cases estimated. Conclusions: The impact on the health budget in Catalonia will be of great magnitude, and it could be higher considering these drugs are just only an example. Health policy should take this impact into account when future costs of health care are assessed in the public sector

Tumor thymidylate synthase 1494del6 genotype as a prognostic factor in colorectal cancer patients receiving fluorouracil-based adjuvant treatment.

PURPOSE: The purpose of this study was to analyze the value of germline and tumor thymidylate synthase (TS) genotyping as a prognostic marker in a series of colorectal cancer patients receiving adjuvant fluorouracil (FU) -based treatment. PATIENTS AND METHODS: One hundred twenty-nine colorectal cancer patients homogeneously treated with FU plus levamisole or leucovorin in the adjuvant setting were included. TS enhancer region, 3R G > C single nucleotide polymorphism (SNP), and TS 1494del6 polymorphisms were assessed in both fresh-frozen normal mucosa and tumor. Mutational analyses of TS and allelic imbalances were studied in all primary tumors and in 18 additional metachronic metastases. TS protein immunostaining was assessed in an expanded series of 214 tumors. Multivariate Cox models were adjusted for stage, differentiation, and location. RESULTS: Tumor genotyping (frequency of allelic loss, 26%) showed that the 3R/3R genotype was associated with a better outcome (hazard ratio [HR] = 0.38; 95% CI, 0.16 to 0.93; P = .020 for the recessive model). 3R G > C SNP genotyping did not add prognostic information. Tumor TS 1494del6 allele (frequency of allelic loss, 36%) was protective (for each allele with the deletion, based on an additive model, HR = 0.42; 95% CI, 0.22 to 0.82; P = .0034). Both polymorphisms were in strong linkage disequilibrium (D' = 0.71, P < .001), and the 3R/-6 base pair (bp) haplotype showed a significant overall survival benefit compared with the most prevalent haplotype 2R/+6bp (HR = 0.42; 95% CI, 0.20 to 0.85; P = .017). No TS point mutation was detected in primary tumors or metastases. TS protein immunostaining was not associated with survival or any of the genotypes analyzed. CONCLUSION: Tumor TS 1494del6 genotype may be a prognostic factor in FU-based adjuvant treatment of colorectal cancer patients.

Founder mutation in familial adenomatous polyposis (FAP) in the Balearic Islands.

The incidence of familial adenomatous polyposis (FAP) is approximately 7.4 per 100,000 inhabitants. APC gene mutations have been found in 60-70% of all FAP families, codons 1309 (20%) and 1061 (8%) being known hot-spots. We searched for mutations in the APC gene in a population-based registry of FAP from the Spanish Balearic Islands. Fifty-one members of 12 FAP families registered in the Balearic Islands Cancer Registry were studied; three of them were de novo cases. Mutations in the APC gene were analyzed by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and sequencing. Haplotype was established by combining intra- and extragenic markers. Mutations in the APC gene were detected in 10 out of 12 (83%) families analyzed. Six families shared the same mutation, a 5-bp deletion at codon 1061 (c.3221_3225delACAAA). Five of the families containing this mutation shared the same haplotype and originated in the same geographic area. The codon 1061 mutation in the APC gene is the most common one in the Balearic Islands. Although this codon is a hot-spot, the haplotype analysis of these families is consistent for the presence of a founder effect of the 5-bp deletion at codon 1061 in FAP families in the Spanish Balearic Islands.

Common genetic evolutionary pathways in familial adenomatous polyposis tumors.

Cancer cells progress through the accumulation of genetic alterations. Familial adenomatous polyposis (FAP) tumors provide an excellent model to unravel the molecular steps underlying malignant transformation. Global genomic damage was assessed in 56 adenomas and 3 carcinomas from six FAP patients and compared with that of sporadic adenomas and carcinomas. Evolutive trees were traced after application of maximum likelihood clustering and split decomposition methods to the analysis of comprehensive genetic profiles generated by diverse molecular approaches: arbitrarily primed PCR, comparative genomic hybridization, and flow cytometry. Overall, genomic damage as assessed by arbitrarily primed PCR was lower in familial adenomas than in sporadic adenomas and carcinomas. Comparative genomic hybridization data also show a low number of alterations in the majority of FAP adenomas. Tumors of the same patient were likely to share specific genetic alterations and may be grouped into one or two clusters. Putative common pathways were also identified, which included tumors of up to three different patients. According to our data, FAP tumors accumulate specific genetic alterations and in a preferred order that is characteristic of each individual. Moreover, the particular genetic background and environmental conditions of a FAP patient restrain the molecular evolution portrait of synchronous tumors.