Pharmacogenetic variants and response to neoadjuvant single-agent doxorubicin or docetaxel: a study in locally advanced breast cancer patients participating in the NCT00123929 phase 2 randomized trial.

OBJECTIVES: Taxanes and anthracyclines are widely used in the treatment of breast cancer, although the benefit is limited to a proportion of patients and predictive biomarkers for clinical outcome remain elusive. PATIENTS AND METHODS: We carried out a pharmacogenetic study in 181 patients with locally advanced breast cancer enrolled in a phase 2 randomized clinical trial (NCT00123929), where patients were randomly assigned to receive neoadjuvant single-agent docetaxel 100 mg/m(2) (n=84) or doxorubicin 75 mg/m(2) (n=97). We studied the association of 226 single nucleotide polymorphisms (SNPs) in 15 key drug biotransformation genes with neoadjuvant pathological tumor response residual cancer burden index to docetaxel and to doxorubicin. RESULTS: We identified a significant association for rs162561, an intronic SNP located in the cytochrome P450 family 1 subfamily B member 1 (CYP1B1) gene, with tumor response in patients treated with single-agent docetaxel (dominant model: ß=1.02, 95% confidence interval=0.49-1.55; P=1.77×10(-4)), and for rs717620, an SNP located in the promoter of the ATP-binding cassette subfamily C member 2 (ABCC2) gene, in patients treated with neoadjuvant doxorubicin (recessive model: ß=1.67; 95% confidence interval=0.26-3.11; P=0.02). CONCLUSION: We identified two polymorphisms in CYP1B1 and ABCC2 associated with tumor pathological response following docetaxel or doxorubicin neoadjuvant monotherapy, respectively. Although further validation is required, these variants could be potential predictive genetic markers for treatment outcome in breast cancer patients.

Standard versus continuous administration of capecitabine in metastatic breast cancer (GEICAM/2009-05): a randomized, noninferiority phase II trial with a pharmacogenetic analysis.

BACKGROUND: The approved capecitabine regimen as monotherapy in metastatic breast cancer (MBC) is 1,250 mg/m(2) twice daily for 2 weeks on and 1 week off (Cint). Dose modifications are often required because of severe hand-foot syndrome (HFS). We tested a continuous regimen with a lower daily dose but a similar cumulative dose in an attempt to reduce the severity of adverse events (AEs) while maintaining efficacy. METHODS: We randomized 195 patients with HER-2/neu-negative MBC to capecitabine 800 mg/m(2) twice daily throughout the 21-day cycle (Ccont) or to Cint to assess noninferiority in the percentage of patients free of progression at 1 year. Secondary endpoints included efficacy and safety. Associations between polymorphisms in capecitabine metabolism-related genes and drug response were assessed. RESULTS: The percentage of patients free of progression at 1 year was 27.3% with Cint versus 25.3% with Ccont (difference of -2.0%; 95% confidence interval: -15.5% to 11.5%, exceeding the 15% deemed noninferior). Differences regarding other efficacy variables were also not found. Grade 3-4 HFS was the most frequent AE (41.1% in Cint vs. 42.3% in Ccont). Grade 3-4 neutropenia, thrombocytopenia, diarrhea, and stomatitis were more frequent with Cint. A 5' untranslated region polymorphism in the carboxylesterase 2 gene was associated with HFS. One polymorphism in cytidine deaminase and two in thymidine phosphorylase were associated with survival. CONCLUSION: Our study was unable to show noninferiority with the continuous capecitabine regimen (Ccont) compared with the approved intermittent regimen (Cint). Further investigation is required to improve HFS. Polymorphisms in several genes might contribute to interindividual differences in response to capecitabine.

Regulatory CDH4 Genetic Variants Associate With Risk to Develop Capecitabine-Induced Hand-Foot Syndrome.

Capecitabine-induced hand-foot syndrome (CiHFS) is a common dermatological adverse reaction affecting around 30% of patients with capecitabine-treated cancer, and the main cause of dose reductions and chemotherapy delays. To identify novel genetic factors associated with CiHFS in patients with cancer, we carried out an extreme-phenotype genomewide association study in 166 patients with breast and colorectal capecitabine-treated cancer with replication in a second cohort of 85 patients. We discovered and replicated a cluster of four highly correlated single-nucleotide polymorphisms associated with susceptibility to CiHFS at 20q13.33 locus (top hit = rs6129058, hazard ratio = 2.40, 95% confidence interval = 1.78-3.20; P = 1.2 × 10-8 ). Using circular chromosome conformation capture sequencing, we identified a chromatin contact between the locus containing the risk alleles and the promoter of CDH4, located 90 kilobases away. The risk haplotype was associated with decreased levels of CDH4 mRNA and the protein it encodes, R-cadherin (RCAD), which mainly localizes in the granular layer of the epidermis. In human keratinocytes, CDH4 downregulation resulted in reduced expression of involucrin, a protein of the cornified envelope, an essential structure for skin barrier function. Immunohistochemical analyses revealed that skin from patients with severe CiHFS exhibited low levels of RCAD and involucrin before capecitabine treatment. Our results uncover a novel mechanism underlying individual genetic susceptibility to CiHFS with implications for clinically relevant risk prediction.

Vascular endothelial growth factor stimulates organ-specific host matrix metalloproteinase-9 expression and ovarian cancer invasion.

Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP) regulate each other, contributing to tumor progression. We have previously reported that MMP9 induces the release of tumor VEGF, promoting ascites formation in human ovarian carcinoma xenografts. The aim of this study was to investigate whether tumor-derived VEGF regulated the expression of gelatinase by the stroma, influencing the invasive properties of ovarian tumors. Tumor variants derived from 1A9 human ovarian carcinoma, stably expressing VEGF(121) in the sense (1A9-VS-1) and antisense orientations (1A9-VAS-3), were used. In vivo, zymographic analysis of tumors from 1A9-VS-1 implanted in the peritoneal cavity of nude mice showed higher levels of gelatinases, particularly murine MMP9, indicating that VEGF stimulates host expression of the matrix-degrading enzyme. Murine MMP9 expression was also high in the ovaries of mice bearing 1A9-VS-1 tumors. The effect on host MMP9 activity was organ-specific. The levels of host pro-MMP9 in ovaries correlated with the plasma levels of tumor VEGF and with the selective invasion of the ovaries. Induction of host MMP9 expression in tumors and ovaries was independent of the site of tumor growth as it was seen in mice carrying both intraperitoneal and subcutaneous tumors. The anti-VEGF antibody bevacizumab (Avastin) inhibited MMP9 expression and tumor invasion in the ovaries of mice bearing 1A9-VS-1 tumors. These findings point to a complex cross-talk between VEGF and MMPs in the progression of ovarian tumor and suggest the possibility of using VEGF inhibitors to affect MMP-dependent tumor invasion.

Effect of ABCB1 and ABCC3 polymorphisms on osteosarcoma survival after chemotherapy: a pharmacogenetic study.

BACKGROUND: Standard treatment for osteosarcoma patients consists of a combination of cisplatin, adriamycin, and methotrexate before surgical resection of the primary tumour, followed by postoperative chemotherapy including vincristine and cyclophosphamide. Unfortunately, many patients still relapse or suffer adverse events. We examined whether common germline polymorphisms in chemotherapeutic transporter and metabolic pathway genes of the drugs used in standard osteosarcoma treatment may predict treatment response. METHODOLOGY/PRINCIPAL FINDINGS: In this study we screened 102 osteosarcoma patients for 346 Single Nucleotide Polymorphisms (SNPs) and 2 Copy Number Variants (CNVs) in 24 genes involved in the metabolism or transport of cisplatin, adriamycin, methotrexate, vincristine, and cyclophosphamide. We studied the association of the genotypes with tumour response and overall survival. We found that four SNPs in two ATP-binding cassette genes were significantly associated with overall survival: rs4148416 in ABCC3 (per-allele HR = 8.14, 95%CI = 2.73-20.2, p-value = 5.1×10⁻5), and three SNPs in ABCB1, rs4148737 (per-allele HR = 3.66, 95%CI = 1.85-6.11, p-value = 6.9×10⁻5), rs1128503 and rs10276036 (r²â€Š= 1, per-allele HR = 0.24, 95%CI = 0.11-0.47 p-value = 7.9×10⁻5). Associations with these SNPs remained statistically significant after correction for multiple testing (all corrected p-values [permutation test] ≤ 0.03). CONCLUSIONS: Our findings suggest that these polymorphisms may affect osteosarcoma treatment efficacy. If these associations are independently validated, these variants could be used as genetic predictors of clinical outcome in the treatment of osteosarcoma, helping in the design of individualized therapy.

A polymorphism in the cytidine deaminase promoter predicts severe capecitabine-induced hand-foot syndrome.

PURPOSE: Hand-foot syndrome (HFS) is one of the most relevant dose-limiting adverse effects of capecitabine, an oral prodrug of 5-fluorouracil used in the standard treatment of breast and colorectal cancer. We investigated the association between grade 3 HFS and genetic variations in genes involved in capecitabine metabolism. EXPERIMENTAL DESIGN: We genotyped a total of 13 polymorphisms in the carboxylesterase 2 (CES2) gene, the cytidine deaminase (CDD) gene, the thymidine phosphorylase (TP) gene, the thymidylate synthase (TS) gene, and the dihydropyrimidine dehydrogenase (DPD) gene in 130 patients treated with capecitabine. We correlated these polymorphisms with susceptibility to HFS. RESULTS: We found an association of HFS appearance with rs532545 located in the promoter region of CDD (OR = 2.02, 95% CI = 1.02-3.99, P = 0.039). Because we found no association between the rs532545 genotype and CDD mRNA expression in Epstein-Barr virus lymphoblastoid cells, we explored additional genetic variations across the CDD promoter. We found an insertion, rs3215400, in linkage disequilibrium with rs532545 (D' = 0.92), which was more clearly associated with HFS (OR = 0.51, 95% CI = 0.27-0.95, P = 0.028) in patients and with total CDD gene expression (P = 0.004) in lymphoblastoid cells. In silico analysis suggested that this insertion might create a binding site for the transcriptional regulator E2F. Using a SNaPshot assay in lymphoblastoid cells, we observed a 5.7-fold increased allele-specific mRNA expression from the deleted allele. CONCLUSIONS: The deleted allele of rs3215400 shows an increased allele-specific expression and is significantly associated with an increased risk of capecitabine-induced HFS.

Exome sequencing identifies MAX mutations as a cause of hereditary pheochromocytoma.

Hereditary pheochromocytoma (PCC) is often caused by germline mutations in one of nine susceptibility genes described to date, but there are familial cases without mutations in these known genes. We sequenced the exomes of three unrelated individuals with hereditary PCC (cases) and identified mutations in MAX, the MYC associated factor X gene. Absence of MAX protein in the tumors and loss of heterozygosity caused by uniparental disomy supported the involvement of MAX alterations in the disease. A follow-up study of a selected series of 59 cases with PCC identified five additional MAX mutations and suggested an association with malignant outcome and preferential paternal transmission of MAX mutations. The involvement of the MYC-MAX-MXD1 network in the development and progression of neural crest cell tumors is further supported by the lack of functional MAX in rat PCC (PC12) cells and by the amplification of MYCN in neuroblastoma and suggests that loss of MAX function is correlated with metastatic potential.