Analysis of angiogenesis genes from paraffin-embedded breast tumor and lymph nodes

Tamoxifen and CYP2D6: A Controversy in Pharmacogenetics

Tamoxifen reduces the rate of breast cancer recurrence by about one-half. It is converted to more active metabolites by enzymes encoded by polymorphic genes, including cytochrome P450 2D6 (CYP2D6) and transported by ATP-binding cassette transporters. Genetic polymorphisms that confer reduced CYP2D6 activity or concurrent use of CYP2D6-inhibiting drugs may reduce the clinical efficacy of tamoxifen. The issue of the clinical utility of CYP2D6 genotype testing is subject to considerable and ongoing academic and clinical controversy. In this chapter, we outline tamoxifen's clinical pharmacology and give an overview of the research to date on the association between CYP2D6 inhibition and tamoxifen effectiveness. Based on the evidence to date, the impact of drug-induced and/or gene-induced inhibition of CYP2D6 activity is likely to be null or small, or at most moderate in subjects carrying two reduced function alleles. Future research should examine the effect of polymorphisms in genes encoding enzymes in tamoxifen's complete metabolic pathway, should comprehensively evaluate other biomarkers that affect tamoxifen effectiveness, such as the transport enzymes, and focus on subgroups of patients, such as premenopausal breast cancer patients, for whom tamoxifen is the only guideline approved endocrine therapy.

Cytochrome P-450 2D6 (CYP2D6) Genotype and Breast Cancer Recurrence in Tamoxifen-Treated Patients: Evaluating the Importance of Loss of Heterozygosity

Tamoxifen therapy for estrogen receptor-positive breast cancer reduces the risk of recurrence by approximately one-half. Cytochrome P-450 2D6, encoded by the polymorphic cytochrome P-450 2D6 gene (CYP2D6), oxidizes tamoxifen to its most active metabolites. Steady-state concentrations of endoxifen (4-hydroxy-N-desmethyltamoxifen), the most potent antiestrogenic metabolite, are reduced in women whose CYP2D6 genotypes confer poor enzyme function. Thirty-one studies of the association of CYP2D6 genotype with breast cancer survival have yielded heterogeneous results. Some influential studies genotyped DNA from tumor-infiltrated tissues, and their results may have been susceptible to germline genotype misclassification from loss of heterozygosity at the CYP2D6 locus. We systematically reviewed 6 studies of concordance between genotypes obtained from paired nonneoplastic and breast tumor-infiltrated tissues, all of which showed excellent CYP2D6 genotype agreement. We applied these concordance data to a quantitative bias analysis of the subset of the 31 studies that were based on genotypes from tumor-infiltrated tissue to examine whether genotyping errors substantially biased estimates of association. The bias analysis showed negligible bias by discordant genotypes. Summary estimates of association, with or without bias adjustment, indicated no clinically important association between CYP2D6 genotype and breast cancer survival in tamoxifen-treated women.

Genotyping concordance in DNA extracted from formalin-fixed paraffin embedded (FFPE) breast tumor and whole blood for pharmacogenetic analyses

BACKGROUND

Cancer pharmacogenetic studies use archival tumor samples as a DNA source when germline DNA is unavailable. Genotyping DNA from formalin-fixed paraffin embedded tumors (FFPE-T) may be inaccurate due to FFPE storage, genetic aberrations, and/or insufficient DNA extraction. Our objective was to assess the extent and source of genotyping inaccuracy from FFPE-T DNA and demonstrate analytical validity of FFPE-T genotyping of candidate single nucleotide polymorphisms (SNPs) for pharmacogenetic analyses.

METHODS

Cancer pharmacogenetics SNPs were genotyped by Sequenom MassARRAYs in DNA harvested from matched FFPE-T, FFPE lymph node (FFPE-LN), and whole blood leukocyte samples obtained from breast cancer patients. No- and discordant-call rates were calculated for each tissue type and SNP. Analytical validity was defined as any SNP with <5% discordance between FFPE-T and blood and <10% discordance plus no-calls.

RESULTS

Matched samples from 114 patients were genotyped for 247 SNPs. No-call rate in FFPE-T was greater than FFPE-LN and blood (4.3% vs. 3.0% vs. 0.5%, p < 0.001). Discordant-call rate between FFPE-T and blood was very low, but greater than that between FFPE-LN and blood (1.1% vs. 0.3%, p < 0.001). Samples with heterozygous genotypes were more likely to be no- or discordantly-called in either tissue (p < 0.001). Analytical validity of FFPE-T genotyping was demonstrated for 218 (88%) SNPs.

CONCLUSIONS

No- and discordant-call rates were below concerning thresholds, confirming that most SNPs can be accurately genotyped from FFPE-T on our Sequenom platform. FFPE-T is a viable DNA source for prospective-retrospective pharmacogenetic analyses of clinical trial cohorts.

Prognostic and predictive role of vascular endothelial growth factor polymorphisms in breast cancer

Current evidence indicates that angiogenesis plays an important role in the pathogenesis of several malignancies, including breast cancer. The vascular endothelial growth factor (VEGF) pathway has been investigated extensively, due to its important role in angiogenesis. The major mediator of tumor angiogenesis is VEGF-A, frequently referred to as VEGF, which activates the VEGF receptor-2. The VEGF gene is located on chromosome 6 and constitutes a highly polymorphic gene. Numerous SNPs in the promoter, 5′- and 3′-untranslated regions (UTR) of VEGF gene have been recognized. This genetic variability possibly influences the production and function of VEGF. Subsequently, the VEGF SNPs may have an impact on breast cancer risk and disease outcome. Moreover, these SNPs may be of predictive value in patients receiving agents targeting the VEGF pathway. This review presents an update on the potential role of VEGF SNPs as prognostic and/or predictive markers in patients with breast cancer.

Investigation of novel circulating proteins, germ line single-nucleotide polymorphisms, and molecular tumor markers as potential efficacy biomarkers of first-line sunitinib therapy for advanced renal cell carcinoma

Purpose

Sunitinib is a first-line advanced renal cell carcinoma (RCC) standard of care. In a randomized phase II trial comparing sunitinib treatment schedules, separate exploratory biomarker analyses investigated the correlations of efficacy with selected serum, germ line single-nucleotide polymorphism (SNP), or tumor markers.

Methods

Advanced RCC patients received first-line sunitinib 50 mg/day on the approved 4-week-on-2-week-off schedule (n = 146) or 37.5 mg/day continuous dosing (n = 146). The following correlation analyses were performed: (1) response evaluation criteria in solid tumors-defined tumor response with serum soluble protein levels via two distinct multiplex (n < 1,000) platforms; (2) response and time-to-event outcomes with germ line SNPs in vascular endothelial growth factor (VEGF)-A and VEGF receptor (VEGFR)3 genes; and (3) response and time-to-event outcomes with tumor immunohistochemistry status for hypoxia-inducible factor 1-alpha (HIF-1α) and carbonic anhydrase-IX or tumor Von Hippel–Lindau (VHL) gene inactivation status.

Results

Lower baseline angiopoietin-2 (Ang-2) and higher baseline matrix metalloproteinase-2 (MMP-2) levels were identified by both platforms as statistically significantly associated with tumor response. There were no significant correlations between VEGF-A or VEGFR3 SNPs and outcomes. Progression-free survival was longer for HIF-1α percent of tumor expression groups 0–2 (HIF-1α low) versus 3–4 (HIF-1α high; p = 0.034). There were no significant correlations between outcomes and each VHL inactivation mechanism [mutation (86 % of VHL-inactive patients), methylation (14 %), and large deletion (7 %)] or mechanisms combined.

Conclusions

Serum Ang-2 and MMP-2 and tumor HIF-1α were identified as relevant baseline biomarkers of sunitinib activity in advanced RCC, warranting further research into their prognostic versus predictive value.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-014-2539-0) contains supplementary material, which is available to authorized users.

Vascular endothelial growth factor polymorphisms and clinical outcome in patients with metastatic breast cancer treated with weekly docetaxel

The aim of the study was to evaluate the association of vascular endothelial growth factor (VEGF) genotypes with treatment efficacy in a phase II trial. This study evaluated weekly docetaxel, as first-line treatment for metastatic breast cancer. Existing data from in vitro and animal model experiments suggest that docetaxel at low doses has anti-angiogenic activity. DNA was extracted from blood samples of 86 patients participating in the trial. Genotyping was performed for selected single-nucleotide polymorphisms (SNPs; VEGF-2578, -1498, -1154, and +936). Moreover, due to the highly polymorphic nature of the studied areas, we were able to analyze additional registered SNPs. All candidate genotypes were evaluated for associations with overall survival (OS), progression-free survival (PFS) and response rate. The VEGF-1154 GG genotype was more frequent in patients not responding to treatment compared with responders (42.9% vs 0.0%, P=0.048). Moreover, the VEGF-2578 AA genotype was associated with longer PFS compared with CC (hazard ratio (HR)=0.40; 95% confidence interval (CI) 0.17-0.98; pairwise P=0.0457). Patients with the VEGF-1190 GG genotype demonstrated shorter PFS compared with those with the alternative genotypes (GA and AA) combined (HR=3.85; 95% CI: 1.20-12.50; P=0.0224). In addition, the VEGF-2551/-2534 homozygous del18bp and VEGF-2430/-2425 homozygous ins1bp genotypes were associated with worse PFS compared with no deletion and no insertion, respectively (HR=2.49; 95% CI: 1.02-6.07; pairwise P=0.0442 and HR=2.57; 95% CI: 1.05-6.27; pairwise P=0.0385, respectively). Furthermore, patients with the VEGF-1498 CC genotype exhibited longer median OS compared with those with the alternatives genotypes (CT and TT) combined (HR=0.27; 95% CI: 0.08-0.89; P=0.0311). In multivariate analysis, the VEGF-2578 AA genotype retained its significance (P=0.0220) for PFS. Our results support the association of specific VEGF genotypes with clinical outcome in patients with metastatic breast cancer treated with a potentially anti-angiogenic regimen, such as weekly docetaxel. However, current results should be validated prospectively in larger cohorts.

Clinical implications of genetic variations in the VEGF system in relation to colorectal cancer

Colorectal cancer (CRC) constitutes one of the most common malignancies in the world and, despite advances in diagnostics and treatments, patients still face a poor prognosis and a more individualized treatment approach appears necessary. The VEGF system and angiogenesis are involved in many aspects of tumor biology and the efficacy of chemotherapy, and some targeted therapeutics appear to be related to the function of these processes. There are many reasons why genetic variations are optimal biomarkers and in relation to the VEGF system may prove to be of clinical relevance. This review evaluates the literature on SNPs in relation to the risk of CRC and the possible prognostic and predictive value and argues for the role of these biomarkers in the future treatment of patients with CRC.

Vascular endothelial growth factor polymorphisms and clinical outcome in colorectal cancer patients treated with irinotecan-based chemotherapy and bevacizumab

The aim of the study was to evaluate the association of vascular endothelial growth factor (VEGF) genotypes with treatment efficacy in a randomized trial. This study compared two chemotherapy regimens (FOLFIRI versus XELIRI) combined with bevacizumab, as first-line treatment for metastatic colorectal cancer. DNA was extracted from blood samples of 173 patients participating in the trial. Genotyping was performed for selected SNPs (VEGF-1154, +936, -634, -2578 and -1498). All candidate genotypes were evaluated for associations with overall survival (OS), progression-free survival (PFS) and response rate (RR). There were no significant differences with respect to the distribution of genotypes in the treatment groups. The VEGF-1154 GG genotype was more frequent in patients not responding to treatment compared with responders (65.5 versus 39.8%, P = 0.032). Furthermore, the VEGF-1154 GG genotype was associated with inferior median OS compared with GA (hazards ratio = 1.68; 95% confidence interval: 1.10-2.57; P = 0.016) or with the alternative genotypes (GA and AA) combined (hazards ratio = 1.62; 95% confidence interval: 1.09-2.40; P = 0.017). In multivariate analysis, the VEGF-1154 GG genotype remained a significant adverse factor for OS. Our results support the potential predictive ability of VEGF genotypes in patients with metastatic colorectal cancer receiving irinotecan-based chemotherapy plus bevacizumab, in terms of RR and OS. However, current results should be validated prospectively, in larger cohorts.

Retrospective exploratory analysis of VEGF polymorphisms in the prediction of benefit from first-line FOLFIRI plus bevacizumab in metastatic colorectal cancer

BACKGROUND

Molecular predictors of bevacizumab efficacy in colorectal cancer have not been identified yet. Specific VEGF polymorphisms may affect gene transcription and therefore indirectly influence the efficacy of bevacizumab.

METHODS

Genomic DNA of 111 consecutive metastatic colorectal cancer patients treated with first-line FOLFIRI plus bevacizumab was obtained from blood samples. VEGF -2578 C/A, -1498 C/T, + 405 C/G, + 936 C/T polymorphisms were analyzed by means of PCR-RFLP. DNA samples from 107 patients treated with FOLFIRI alone served as historical control group. The relation of VEGF polymorphisms with PFS, evaluated through Kaplan-Meier method and log-rank test, was the primary end-point. An interaction test with a Cox model has been performed in order to demonstrate the heterogeneity of the effect of VEGF -1498 C/T polymorphism between bevacizumab-and control group.

RESULTS

In the bevacizumab-group median PFS and OS of patients carrying VEGF -1498 C/C, C/T and T/T allelic variants were, respectively, 12.8, 10.5, 7.5 months (p = 0.0046, log-rank test) and 27.3, 20.5, 18.6 months (p = 0.038, log-rank test). VEGF -1498 T/T genotype was associated with shorter PFS (HR = 2.13, [1.41-5.10], p = 0.0027). In the control group no significant association of VEGF -1498 C/T allelic variants and PFS or OS was found. Interaction between VEGF -1498 C/T variants and treatment effect suggested that the relation of VEGF -1498 T/T genotype with shorter PFS was caused by the effect of bevacizumab (p = 0.011). Other investigated polymorphisms did not affect the outcome.

CONCLUSIONS

These data suggest a possible role for VEGF -1498 C/T variants in predicting the efficacy of bevacizumab in the up-front treatment of metastatic colorectal cancer patients. A molecular tool for selecting subjects candidate to benefit from the anti-VEGF could be important for clinical practice. The retrospective and exploratory design of the present study, coupled with the non-randomized nature of the comparison between treated and untreated patients, imply that these results should be considered as hypothesis generators. A prospective validating trial is currently ongoing.

Concordance of metabolic enzyme genotypes assayed from paraffin-embedded, formalin-fixed breast tumors and normal lymphatic tissue

Objectives

Translational epidemiology studies often use archived tumor specimens to evaluate genetic hypotheses involving cancer outcomes. When the exposure of interest is a germline polymorphism, a key concern is whether the genotype assayed from tumor-derived DNA is representative of the germline. We evaluated the concordance between breast tumor-derived and normal lymph node-derived genotypes for three polymorphic tamoxifen-metabolizing enzymes.

Methods

We assayed paired DNA samples extracted from archived tumor and normal lymph node tissues from 106 breast cancer patients. We used TaqMan assays to determine the genotypes of three enzyme variants hypothesized to modify tamoxifen effectiveness, ie, CYP2D6*4, UGT2B15*2, and UGT1A8*2. We assessed genotype agreement between the two DNA sources by calculating the percent agreement and the weighted kappa statistic.

Results

We successfully obtained genotypes for CYP2D6*4, UGT2B15*2, and UGT1A8*2 in 99%, 100%, and 84% of the paired samples, respectively. Genotype concordance was perfect for the CYP2D6*4 and UGT1A8*2 variants (weighted kappa for both = 1.00; 95% confidence interval [CI] 1.00, 1.00). For UGT2B15*2, one pair out of 106 gave a discordant result that persisted over several assay repeats.

Conclusions

We observed strong agreement between DNA from breast tumors and normal lymphatic tissue in the genotyping of polymorphisms in three tamoxifen-metabolizing enzymes. Genotyping DNA extracted from tumor tissue avoids the time-consuming practice of microdissecting adjacent normal tissue when other normal tissue sources are not available. Therefore, the demonstrated reliability of tumor-derived DNA allows resources to be spent instead on increasing sample size or the number of polymorphisms examined.

NO to breast: when, why and why not?

Nitric oxide is a pleiotropic ancestral molecule, which elicits beneficial effect in many physiological settings but is also tenaciously expressed in numerous pathological conditions, particularly breast tumors. Nitric oxide is particularly harmful in adipogenic milieu of the breast, where it initiates and promotes tumorigenesis. Epidemiological studies have associated populations at a greater risk for developing breast cancer, predominantly estrogen receptor positive tumors, to express specific polymorphic forms of endothelial nitric oxide synthase, that produce sustained low levels of nitric oxide. Low sustained nitric oxide generates oxidative stress and inflammatory conditions at susceptible sites in the heterogeneous microenvironment of the breast, where it promotes cancer related events in specific cell types. Inflammatory conditions also stimulate inducible nitric oxide synthase expression, which dependent on the microenvironment, could promote or inhibit mammary tumors. In this review we re-examine the mechanisms by which nitric oxide promotes initiation and progression of breast cancer and address some of the controversies in the field.

High-efficiency genotype analysis from formalin-fixed, paraffin-embedded tumor tissues

Single-nucleotide polymorphisms (SNPs) can be assayed using DNA isolated from archival formalin-fixed, paraffin-embedded (FFPE) samples, making retrospective pharmacogenetic studies possible. In this study, we describe methods that significantly increase the number of SNP determinations possible using FFPE samples. Quantifying the amount of DNA amenable to PCR (amplification-quality DNA, AQ-DNA) allows a significant reduction in the amount of sample required for Taqman-based SNP assays. Optimizing AQ-DNA input increases PCR amplification efficiency and SNP determination accuracy. DNA was extracted from 39 FFPE tumor sections and matched tumor and stromal cores, which were of the type used to generate tissue microarrays. Sections and tumor cores yielded sufficient AQ-DNA for more than 1000 SNP determinations. Seven SNPs were assessed following individual assay optimization for minimal AQ-DNA. Genotypes from tumor cores for single SNPs were 92.3-100% concordant with those obtained from sections. Using these methods, the number of SNP genotypes that can be determined from single FFPE samples is greatly increased expanding the genetic association studies possible from limited archival specimens. The use of tumor cores is of particular importance as the harvesting of tumor cores has minimal impact on the utility of the donor blocks for other purposes.

The role of vascular endothelial growth factor genetic variability in cancer

Angiogenesis is a hallmark of tumor pathogenesis. Vascular endothelial growth factor (VEGF) is a critical regulator of angiogenesis and its inhibition has become a successful approach to antitumor therapy across tumor types. The VEGF gene is highly polymorphic with multiple common single nucleotide polymorphisms (SNPs) in the promoter, 5' untranslated region and 3' untranslated region. There is evidence that these SNPs in the regulatory regions can affect VEGF expression. In vitro and in vivo data show that genetic variability affects the activity and expression of VEGF. Case-control and cohort studies suggest that genetic variability may affect risk and outcome of a variety of disease states that are tightly regulated by angiogenesis. Recently, genetic variability in VEGF has been studied as a potential predictive biomarker for bevacizumab. The VEGF-1154 AA and -2578 AA genotypes predicted an improved median overall survival, whereas the VEGF-634 CC and -1498 TT genotypes predicted protection from grade 3-4 hypertension in the pivotal trial, E2100. If validated, these finding could help direct which subgroup of patients should receive bevacizumab.

Discordant somatic and germline VEGF-A genotype in a cancer patient resistant to paclitaxel/bevacizumab with chemosensitive hepatic metastasis

Recent data reported an association between VEGF-A genotype of tumors and median overall survival as well as grade 3 or 4 hypertension when using bevacizumab in metastatic breast cancer. In the present case we report a discordant VEGF-A genotype between tumor and normal tissue in a patient with a responsive hepatic lesion of chemoresistant breast cancer treated with bevacizumab and paclitaxel. Moreover, we show that, despite the very low VEGF-A protein expression, the neoplastic lesion was well vascularized and responded to bevacizumab therapy. The discordance of VEGF-A polymorphisms in tumor and germline DNA may suggest the importance of obtaining both information in order to predict a superior overall survival or a lower risk of hypertension in patients treated with taxanes and bevacizumab.

Association of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 genetic polymorphisms with outcome in a trial of paclitaxel compared with paclitaxel plus bevacizumab in advanced breast cancer: ECOG 2100

PURPOSE

No biomarkers have been identified to predict outcome with the use of an antiangiogenesis agent for cancer. Vascular endothelial growth factor (VEGF) genetic variability has been associated with altered risk of breast cancer and variable promoter activity. Therefore, we evaluated the association of VEGF genotype with efficacy and toxicity in E2100, a phase III study comparing paclitaxel versus paclitaxel plus bevacizumab as initial chemotherapy for metastatic breast cancer.

PATIENTS AND METHODS

DNA was extracted from tumor blocks of patients from E2100. Three hundred sixty-three samples were available to evaluate associations between genotype and outcome. Genotyping was performed for selected polymorphisms in VEGF and VEGF receptor 2. Testing for associations between each polymorphism and efficacy and toxicity was performed.

RESULTS

The VEGF-2578 AA genotype was associated with a superior median overall survival (OS) in the combination arm when compared with the alternate genotypes combined (hazard ratio = 0.58; 95% CI, 0.36 to 0.93; P = .023). The VEGF-1154 A allele also demonstrated a superior median OS with an additive effect of each active allele in the combination arm but not the control arm (hazard ratio = 0.62; 95% CI, 0.46 to 0.83; P = .001). Two additional genotypes, VEGF-634 CC and VEGF-1498 TT, were associated with significantly less grade 3 or 4 hypertension in the combination arm when compared with the alternate genotypes combined (P = .005 and P = .022, respectively).

CONCLUSION

Our data support an association between VEGF genotype and median OS as well as grade 3 or 4 hypertension when using bevacizumab in metastatic breast cancer.

Association of polymorphisms of angiogenesis genes with breast cancer

BACKGROUND

Few studies have systematically explored a pathway approach: to test the association of multiple polymorphisms from multiple genes important to angiogenesis simultaneously with risk of breast cancer. We report our preliminary data evaluating the association of polymorphisms from seven genes known to influence angiogenesis with the likelihood of having breast cancer.

METHODS

We recruited 715 controls and 520 subjects with breast cancer. Subjects provided a blood specimen and completed a questionnaire that included common breast cancer risk factors and breast cancer status. We evaluated candidate polymorphisms in the following genes: Hypoxia Inducible Factor-1 alpha (HIF1alpha), Vascular Endothelial Growth Factor (VEGF), VEGF Receptor 1 (VEGFR-1), VEGFR-2, endothelial Nitric Oxide Synthase (eNOS), Neuropilin-1 (NRP-1) and Neuropilin-2 (NRP-2). Testing for associations between each polymorphism and the presence or absence of breast cancer was performed.

RESULTS

VEGF-2578 AA and -1498 CC genotypes were more common in cancer cases than controls (P = 0.06 and P = 0.04, respectively). These two genotypes remained significant predictors of breast cancer status after adjusting for non-genetic risk factors estimated by the Gail model (P = 0.03 and P = 0.03, respectively). When comparing women with invasive versus pre-invasive breast cancer, the eNOS-786 TT and eNOS 894 GG genotypes were associated with a greater likelihood of invasive disease and the eNOS 894 GG genotype was associated with a greater likelihood of having metastatic disease.

CONCLUSION

There is an association of the VEGF-2578A and -1498C alleles with increased breast cancer risk. This association remains significant when adjusted for Gail score-related risk factors.

Enhanced surgery-induced angiogenesis among premenopausal women might partially explain excess breast cancer mortality of blacks compared to whites: an hypothesis

There is excess breast cancer mortality for African-Americans (AA) compared to European-Americans (EA) of 1.5-2.2 fold that first appeared in 1970s and has been worsening since. This disparity may not be explained solely by reduced access to medical care. We proposed that surgery to remove a primary tumor induces angiogenesis of distant dormant micrometastases in 20% of premenopausal node-positive patients. This hypothesis helps explain the reduced benefit of mammography for women aged 40-49. Interestingly, for AA the average age at diagnosis is 46 while for EA it is 57. The resultant increased proportion of AA premenopausal breast cancer suggests a possible explanation for the AA/EA excess mortality. Early detection, which began in the 1970s, is more effective in postmenopausal women than in premenopausal women. Since AA breast cancer is mostly premenopausal and EA breast cancer is mostly postmenopausal, it might be anticipated that starting in the 1970s because of surgery-induced early mortality, outcome would be superior for EA compared to AA.

Vascular endothelial growth factor pharmacogenetics: a new perspective for anti-angiogenic therapy

The pharmacogenetic approach to anti-angiogenic therapy should be considered a possible strategy for many pathological conditions with high incidence in Western countries, including solid tumors, age-related macular degeneration or endometriosis. While pharmacogenetic studies are building stronger foundations for the systematic investigations of phenotype–genotype relationships in many research and clinical fields of medicine, pharmacogenetic data regarding anti-angiogenic drugs are still lacking. Here we review preclinical and clinical genetic studies on angiogenic determinants such as vascular endothelial growth factor and vascular endothelial growth factor receptor-2. We suggest that pharmacogenetic profiling of patients who are candidates for the currently available anti-angiogenic agents targeting vascular endothelial growth factor and vascular endothelial growth factor receptor-2 may aid the selection of patients on the basis of their likelihood of responding to the drugs or suffering from toxicity.