International validation of the European Organisation for Research and Treatment of Cancer QLQ-BRECON23 quality-of-life questionnaire for women undergoing breast reconstruction

Background

The aim was to carry out phase 4 international field-testing of the European Organisation for Research and Treatment of Cancer (EORTC) breast reconstruction (BRECON) module. The primary objective was finalization of its scale structure. Secondary objectives were evaluation of its reliability, validity, responsiveness, acceptability and interpretability in patients with breast cancer undergoing mastectomy and reconstruction.

Methods

The EORTC module development guidelines were followed. Patients were recruited from 28 centres in seven countries. A prospective cohort completed the QLQ-BRECON15 before mastectomy and the QLQ-BRECON24 at 4–8 months after reconstruction. The cross-sectional cohort completed the QLQ-BRECON24 at 1–5 years after reconstruction, and repeated this 2–8 weeks later (test–retest reliability). All participants completed debriefing questionnaires.

Results

A total of 438 patients were recruited, 234 in the prospective cohort and 204 in the cross-sectional cohort. A total of 414 reconstructions were immediate, with a comparable number of implants (176) and donor-site flaps (166). Control groups comprised patients who underwent two-stage implant procedures (72, 75 per cent) or delayed reconstruction (24, 25 per cent). Psychometric scale validity was supported by moderate to high item-own scale and item-total correlations (over 0·5). Questionnaire validity was confirmed by good scale-to-sample targeting, and computable scale scores exceeding 50 per cent, except nipple cosmesis (over 40 per cent). In known-group comparisons, QLQ-BRECON24 scales and items differentiated between patient groups defined by clinical criteria, such as type and timing of reconstruction, postmastectomy radiotherapy and surgical complications, with moderate effect sizes. Prospectively, sexuality and surgical side-effects scales showed significant responsiveness over time (P < 0·001). Scale reliability was supported by high Cronbach's α coefficients (over 0·7) and test–retest (intraclass correlation more than 0·8). One item (finding a well fitting bra) was excluded based on high floor/ceiling effects, poor test–retest and weak correlations in factor analysis (below 0·3), thus generating the QLQ-BRECON23 questionnaire.

Conclusion

The QLQ-BRECON23 is an internationally validated tool to be used alongside the EORTC QLQ-C30 (cancer) and QLQ-BR23 (breast cancer) questionnaires for evaluating quality of life and satisfaction after breast reconstruction.

Can we use gonadotropin plasma concentration as surrogate marker for BMI-related incomplete estrogen suppression in breast cancer patients receiving anastrozole?

BACKGROUND

BMI has been suggested to impact on estrogenic activity in patients receiving anastrozole resulting in a reduced treatment efficacy in obese women. Current evidence in this regard is controversially discussed. Since estradiol is inversely correlated with gonadotropins it can be assumed that an impact of BMI is also reflected by gonadotropin plasma concentrations. We aim at investigating the impact of BMI on the hormonal state of breast cancer (BC) patients receiving anastrozole indicated by LH, FSH and SHBG as well as estradiol.

METHODS

We determined gonadotropin-, estradiol- and anastrozole- serum concentrations from postmenopausal, early stage breast cancer patients receiving upfront anastrozole within routine after care. Gonadotropin plasma concentrations were derived from the routine laboratory examination report. A liquid chromatography tandem mass spectrometry method was used for the measurement of anastrozole serum concentrations. BMI was assessed within the routine after-care check-up.

RESULTS

The overall sample comprised 135 BC patients with a mean age of 65.3 years. BMI was significantly correlated with LH, FSH and SHBG. This association was neither influenced by age nor by anastrozole serum concentrations according to the regression model. Despite aromatase inhibition 12% of patients had detectable estrogen levels in routine quantification.

CONCLUSION

Obese women have an altered hormonal situation compared to normally weight women under the same dose of anastrozole. Our study findings are a further indicator for the relevance of BMI in regard of anastrozole metabolism and possible estrogenic activity indicated by gonadotropin plasma level.

Abstract P2-09-22: Long-term psychosocial consequences and counsellees' satisfaction after genetic counselling for hereditary breast- and ovarian cancer - A patient reported outcome study

Background: Genetic counselling and testing (GCT) for hereditary breast and ovarian cancer (BOC) has become a standard option in BOC care in Europe allowing for prognostic information on the individual risk for disease onset/ relapse as well as on treatment options comprising prophylactic surgery or surveillance programs. However, data on the psychosocial long-term consequences is limited, especially in high-risk counsellees opting against genetic testing. We aimed at investigating the long-term psychosocial consequences of GCT for hereditary BOC in all counsellees irrespective of their decision after counselling.

Patients and Methods: Counsellees for BOC with and without a previous disease who had undergone genetic counselling at Innsbruck Medical University between 2011 and 2014 were asked to participate in a cross-sectional Patient Reported Outcome (PRO) assessment (incl. Multidimensional Impact of Cancer Risk Assessment, Genetic counseling satisfaction scale, Satisfaction with Decision Scale, Breast Cancer Heredity Knowledge Scale, Hospital Anxiety and Depression Scale/ HADS, Short Form 12 Health Survey, Cancer Worry Scale/ CWS) targeting on psychological distress, cancer worry, patient knowledge and patient satisfaction with genetic counselling and decisions by means of an anonymous mail survey. Subsequent decisions for vs. against genetic testing and if eligible, for surveillance vs. prophylactic surgery were also assessed. A reference sample of BC survivors was recruited at the outpatient unit.

Results: An overall sample of 137 counselees was included in the analysis (67.9% decided to undergo genetic testing for a HCPS, 22.6% decided not to be tested, 9.5% were still uncertain about their decision). 22.6% of counsellees experienced clinically relevant levels of anxiety and 9.8% scored above the cut-off for clinically relevant depression according to the HADS. Mean CWS score was 11 (SD 3.6, 3-24). Counsellees did not differ from breast cancer survivors regarding anxiety and depression according to the HADS (depression: p<0.5). Mean patient satisfaction with decisions amounted to 25.4 (SD 5.78, min. 4 to max. 30); a mean satisfaction with counselling of 25 (5.4) was observed. Less overall satisfaction with genetic counselling (β=0.445, t=5.552, p=0.000) and lower certainty about decision for/ against genetic testing after counselling (β=-0.169, t=-2.105, p=0.037) were highly predictive for lower long-term patient satisfaction with decisions.

Conclusion: Our results indicate that genetic counselling for BOC has no overall deleterious psychosocial consequences in long-term. Levels of depression and anxiety were comparable to those of the general population, while distress levels did not differ from those of breast cancer survivors without a hereditary BOC predisposition. The overall satisfaction with counselling as well as the certainty with decisions on testing and related medical interventions are highly predictive for the long-term satisfaction with decisions. Hence, genetic counselling should focus on supporting counsellees in forming clear decisions and include identifying counsellees with increased cared needs in this regard by means of PRO assessment in follow-up.

Citation Format: Hubalek M, Sztankay M, Meraner V, Martini C, Sperner-Unterweger B, Weber I, Morscher R, Zschocke J, Egle D, Dünser M, Oberguggenberger A. Long-term psychosocial consequences and counsellees' satisfaction after genetic counselling for hereditary breast- and ovarian cancer - A patient reported outcome study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-22.

Abstract P1-11-02: Psychological morbidity in breast cancer survivors: Prevalence rates and determinants

Background: The number of breast cancer survivors (BCS) is steadily increasing due to improved treatment options, early detection and younger age at diagnosis. Thus, it is increasingly important to determine and better understand the psychological outcome following a cancer diagnosis and treatment in long-term. This might contribute to meeting the long-term health care demands of cancer survivors. We aimed at investigating levels and determinants of anxiety and depression (AD) in BCS.

Patients and Methods: We included BCS with a non-metastatic disease in the stage of after-care. AD was determined as part of a cross-sectional, comprehensive patient reported outcome (PRO) assessment (incl. Functional Assessment of Cancer Therapy-G/+B/+ES, Eating Disorder Examination-Questionnaire, Sexual Activity Questionnaire and Body Image Scale) using the Hospital Anxiety and Depression Scale (HADS). Prevalence rates of AD and sample characteristics are presented descriptively using percentages, means and standard deviations. Predictors of anxiety and depression are identified by means of regression analysis.

Results: A final sample of 743 breast cancer survivors who were on average 2.9 years post diagnosis (range: 0.1-11.3 years) participated in the study. Mean patient age was 56.4a (SD 11.5a), 2/3 of patients were postmenopausal. 22.5% of patients reported clinically relevant levels of anxiety and 11.2% of depression. Older age (β=0.012, t=2.53, p<0.05), higher endocrine symptoms (β=-0.037, t=-8.89, p<0.01) and reduced functional well-being (β=-0.034, t=-7.73, p<0.01) were predictive for anxiety and depression in the regression model. The model explained 39.3% of the variance of anxiety and depression.

Conclusion: A distinct proportion of BCS report clinically relevant, long-term psychological morbidity. Especially older BCS, experiencing higher levels of endocrine symptoms and reduced functional well-being, seem to be at risk for psychological morbidity. A routine PRO-screening for psychological morbidity including the assessment of associated risk factors in this patient population might contribute to the identification of those women in need for psychological/ psychiatric treatment and in conjunction, improve cancer care.

Citation Format: Hubalek M, Sztankay M, Oberguggenberger A, Meraner V, Egle D, Mangweth-Matzek B, Beer B, Huber N, Sperner-Unterweger B. Psychological morbidity in breast cancer survivors: Prevalence rates and determinants. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-11-02.

Levels in neurotransmitter precursor amino acids correlate with mental health in patients with breast cancer

Breast cancer is the most common cancer among females. Approximately 30% of cancer patients develop depression or depressive adaptation disorder within 5 years post diagnosis. Low grade inflammation and subsequent changes in neurotransmitter levels could be the pathophysiological link. In the current study we investigated the association of neurotransmitter precursor amino acids with a diagnosis of depression or state anxiety in 154 subjects suffering from breast cancer (BCA(+)), depression (DPR(+)), both or neither. Sociodemographic parameters, severity of depressive symptoms, and state anxiety (ANX) were recorded. Neopterin, kynurenine/tryptophan and phenylalanine/tyrosine were analysed by HPLC or ELISA. Significantly higher serum neopterin values were found in DPR(+) patients (p = 0.034) and in ANX(+) subjects (p = 0.008), as a marker of Th1-related inflammation. The phenylalanine/tyrosine ratio (index of the catecholamine pathway) was associated with the factors "breast cancer" and "depression" and their interaction (all p < 0.001); it was highest in the DPR(+)BCA(+) group. The kynurenine/tryptophan ratio (index of the serotonin pathway) was significantly associated with the factors "breast cancer" and "state anxiety" and their interaction (p < 0.001, p = 0.026, p = 0.02, respectively); it was highest in the ANX(+)BCA(+) group. In BCA(+) patients kynurenine/tryptophan ratios correlated with severity of state anxiety (r = 0.226, p = 0.048, uncorrected) and phenylalanine/tyrosine ratios with severity of depressive symptoms (r = 0.376, p < 0.05, corrected). In conclusion, levels of neurotransmitter precursor amino acids correlate with mental health, an effect which was much more pronounced in BCA(+) patients than in BCA(-) subjects. Aside from identifying underlying pathophysiological mechanisms, these results could be the basis for future treatment studies: in BCA(+) patients with depression the use of serotonin-noradrenaline reuptake inhibitors might be recommended while in those with predominant anxiety selective serotonin reuptake inhibitors might be the treatment of choice.

Phase III development of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire module for women undergoing breast reconstruction

Background

Comprehensive outcome assessments after breast reconstruction (BRR) require surgery-specific patient-reported outcome measures. The aims of this study were to assess the relevance, acceptability and redundancy of questions/items (phase III pretesting) of a new BRR questionnaire evaluating patients' health-related quality of life before and after BRR. Phase III occurred in collaboration with the European Organization for Research and Treatment of Cancer (EORTC) following earlier development phases that identified 31 items.

Methods

The EORTC BRR subgroup applied decision-making rules to each question according to eight EORTC criteria. A total of 197 patients (from the UK, Austria, Belgium, Italy and Sweden) were recruited. Forty-seven patients completed pre- and post-BRR questionnaires prospectively, and 150 reported post-BRR questionnaires only retrospectively. Qualitative debriefing interviews were undertaken in 189 patients. Preliminary psychometric analyses were performed.

Results

Thirty-one items fulfilled ‘relevance’, with none producing ‘difficulties’. Ten items were not a priority for 10 per cent of respondents. Of these, two questions concerning muscle twitching in the affected breast and problem with donor-site swelling were deleted. Three redundant items were deleted: weakness in arm, which correlated significantly to the Quality of Life Questionnaire (QLQ) BR23 breast questionnaire, and shape and colour of the affected nipple. Descriptive statistics reduced the module to 26 items conceptualized into three provisional scales (disease treatment/surgery-related symptoms, sexuality and cosmetic outcome) within the newly completed questionnaire, EORTC QLQ-BRR26.

Conclusion

The QLQ-BRR26 is available for psychometric validation in a large-field international sample. The intended use for QLQ-BRR26 is alongside EORTC QLQ-C30 and QLQ-BR23, in women treated by mastectomy for breast cancer and undergoing all types of BRR.

Abstract P4-02-04: Impact of CYP2D6 Genotype and Side-Effects on Adherence Rates to Tamoxifen in Premenopausal Breast Cancer Patients

Background: Only few studies have investigated the issue of breast cancer patients’ adherence to tamoxifen therapy and factors influencing adherence behavior. Especially in the context of different CYP2D6 genotypes adherence to tamoxifen has not been extensively studied yet. Variations in the CYP2D6 genotype, as well as patients taking inhibitors of CYP2D6 (e.g. antidepressants) contribute to different side effects and adherence rates to adjuvant tamoxifen.

Materials and Methods: 106 premenopausal breast cancer patients who met inclusion criteria were consecutively included in the study at the outpatient unit of the Department of Gynecology, Innsbruck Medical University. Within their routine after care appointment patients completed a comprehensive PRO assessment including the FACT-B/ES, the HADS and a self-report questionnaire on adherence behavior (SMAQ). The multi-method approach comprised the Simplified Medication Adherence Questionnaire, a semi-structured interview, physicians’ ratings and blood levels for tamoxifen metabolites. Additionally, the CYP2D6 genotype was determined in all patients participating in this part of the study.

Results: 19% patients were poor metabolizer (PM), 51% intermediate metabolizer (IM), 29% extensive metabolizer (EM) and 7% ultra-rapid metabolizer (UM). Significant group differences with regard to tamoxifen and endoxifen serum concentrations were found between the metabolization groups (p=0.044). UMs had the lowest tamoxifen and highest endoxifen concentrations. Only 3.2% of the patients analyzed had no measurable tamoxifen concentrations in their serum. All non-compilant patients were from the extensive metabolizer group. However, during follow-up 25% (2/6) of patients with UM genotype, 13% (4/30) with EM genotype, 1% (1/50) with IM genotype and 0% (0/19) with the PM genotype discontinued their tamoxifen therapy due to therapy related side effects. In addition anti-depressants were more frequently prescribed in the extensive metabolizer group leading to lower levels of the active metabolite endoxifen. Conclusion: A trend towards higher hot flashes was observed in the EM and UM group. We did not find significant differences in QOL between

CYP2D6 metabolizing groups. Trend level significance was found for global QOL (on a descriptive level) physical well-being and emotional well-being. Non-adherence to tamoxifen therapy is more frequent in patients with CYP2D6 EM and UM genotype. These preliminary data may explain part of the current controversy over CYP2D6 genotype predicting response to tamoxifen and suggest that patients most likely to benefit from tamoxifen are paradoxically most likely to stop their tamoxifen therapy prematurely.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-02-04.

Abstract P5-11-09: A Validated Analytical Method for Monitoring the Plasma Levels of Tamoxifen, Anastrozole and Letrozole in Patients Undergoing Endocrine Therapy

Background: Clinical data have repeatedly shown that tamoxifen as well as anastrazole and letrozole significantly increase the overall survival among breast cancer patients. However, in several cases the use of these drugs is limited by side effects, whose appearance are described to impair the adherence of a patient to endocrine treatment. Frequently, adherence is rated based on patient self-reports. One competent approach to obtain impartial information about patient adherence and its clinical relevance is based on the determination of plasma drug concentrations. The individual steady state plasma level represents an objective measure that may serve as an important comparator to check the patient-reported adherence status in clinical studies. In addition, it may also reveal useful information for the treating physician regarding concentration dependent side effects or therapeutic failure. We have developed and validated a liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the simultaneous analysis of tamoxifen, anastrazole and letrozole in human plasma. The method was applied in the PRO-BETh study to monitor 320 breast cancer patients undergoing endocrine therapy.

Material and methods: Blood plasma samples were collected from 320 patients undergoing endocrine breast cancer therapy and stored at -20° C. To prepare a sample for LC/MS/MS analysis, 1 ml plasma was treated with a solid phase extraction procedure using a cation mixed-mode polymeric sorbent phase (Strata-X-C cartridges, Phenomenex, CA). Chromatographic separation was accomplished on a reversed-phase column (200 mm x 0.5 mm, Eurosphere-C18, 5 μm, Knauer, Berlin) by using a gradient of acetone in an aqueous hexafluorobutyric acid solution. Mass spectrometric detection was performed on a quadrupole-quadrupole-linear ion trap instrument (Q Trap 3200, Applied Biosystems, Foster City, CA). Results: We have developed a fully validated method for the simultaneous quantitative analysis of tamoxifen, anastrozole and letrozole in human plasma. Validation was accomplished for a concentration range of 25-500 ng/ml for tamoxifen, 10-200 ng/ml for endoxifen, 5-200 ng/ml for anastrozol and 10-300 ng/ml for letrozole. The applicability of the method was demonstrated in the context of the PRO-BETh study, by analyzing plasma samples of 320 patients undergoing endocrine breast cancer therapy. The observed plasma levels showed a high inter-patient variability with measured values between 26-307 ng/ml (mean 125 ng/ml) regarding tamoxifen, 17-301 ng/ml (mean 107 ng/ml) regarding letrozole and 6-102 ng/ml (mean 37 ng/ml) regarding anastrozole. Eight samples did not contain a quantifiable amount of drug, indicating longer abstinence of the corresponding patients regarding endocrine therapy. Conclusions: The developed method represents a reliable and convenient tool for the quantitative analysis of tamoxifen, anastrozol and letrozole in human plasma. The method is dedicated to drug monitoring which is an important part of adherence rating. As exemplified in the context of the PRO-BETh study, the measured steady state plasma levels represent objective measures that serve as important comparators to check the patient-reported adherence status.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-11-09.

Abstract P5-11-10: Gonadotropins Plasma Levels Are Significantly Influenced by Body Mass Index in Postmenopausal Breast Cancer Patients Undergoing Endocrine Therapy with Aromatase Inhibitors: Is This a Surrogate Marker for Serum Estrogen Bioactivity?

Background: Estrogens play a crucial role in breast carcinogenesis and progression. The third-generation aromatase inhibitors (AIs) have therefore become the first choice endocrine drugs for post-menopausal women with breast cancer, since they present greater efficacy when compared with tamoxifen. However, mode of action, side effects and tolerability are distinct compared to tamoxifen. In this study, we evaluated clinical side-effects, levels of gonadotropin, prolactin, progesterone and estradiol in postmenopausal women undergoing endocrine treatment with aromatase inhibitors.

Materials and Methods: 128 postmenopausal patients undergoing endocrine therapy with aromatase inhibitors were included in the study. They completed the assessment at their regular 3-month check up. For the assessment of side-effects and symptom burden we used the FACT-B/+ES and the HADS. Blood samples were collected within the routine blood collection and measurement of follicle stimulation hormone (FSH), luteinizing hormone (LH), progesterone, estradiol and prolactin plasma levels were performed by Immunoassay. Data were analyzed using Spearman rank correlation.

Results: We found a significant negative correlation of LH and FSH with body mass index (BMI) of postmenopausal breast cancer patients (LH r=- 0.281, p=0.014; FSH r=-0.250, p=0.029) receiving aromatase inhibitors. Analyses revealed a significant positive correlation for LH and FSH levels with subjectively experienced weight gain (LH r=0.499, p=0.008; FSH r=0.550, p=0.003), dyspareunia and vaginal dryness. Moreover, patients with a BMI ≥25 had significantly more gynaecological symptoms (dyspareunia p=0.008 and vaginal dryness p=0.026) than patients witha lower BMI. Progesterone was significantly associated with subjective weight gain (r=0.248, p=0.014). Prolactin significantly correlated with loss of sex drive (r=0.256, p=0.050), mood swings (r=0.239, p=0.050) and irritability (r=0.244, p=0.046).

Conclusion: Our results reveal distinct endocrine changes among postmenopausal breast cancer patients undergoing endocrine treatment with AIs. These results confirm the central role of estrogens in the evolution of adverse events to aromatase inhibitors. The main observation in this study, however, was the correlation of BMI and levels of hormone influenced by estrogenic activity. LH and FSH which are under control of various estrogen metabolites, were significantly associated with the BMI and might therefore serve as surrogate marker of estrogenic activity in serum of breast cancer patients. Direct measurement of estradiol (E2) showed no correlation with BMI indicating the influence of various other estrogen metabolites on the secretion of gonadotropins. Analysis of serum estrogen receptor bioactivity in these patients is currently underway.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-11-10.

Abstract P4-02-17: Polymerase Chain Reaction-Liquid Chromatography-Mass Spectrometry — A Convenient and Cost-Effective Strategy for CYP2D6 Genotyping

Background: Genetic polymorphisms in the drug metabolizing enzyme Cyotchrome P450 2D6 (CYP2D6) gene can significantly influence a person's ability to mediate CYP2D6 dependent metabolism. For example, a notable influence of the CYP2D6 genotype has been described regarding the conversion of tamoxifen to its pharmacologically active metabolites. Thus, the genetic determination of the CYP2D6 metabolizer status has the potential to represent a valuable therapeutic supplement in breast cancer therapy. However, the clinical relevance of the CYP2D6 genotype regarding the treatment of breast cancer with tamoxifen still remains to be elucidated. Due to the high number of relevant polymorphisms to be screened, pharmacogenetic CYP2D6 testing is considered to be time-consuming and laborious and is therefore limited to a few clinical studies only. To enable a more widespread use, we present polymerase chain reaction (PCR) - ion-pair reversed-phase high-performance liquid chromatography — electrospray ionization time of flight mass spectrometry (ICEMS) as fast, convenient and cost-effective strategy for CYP2D6 genotyping.

Material and Methods: After DNA extraction from saliva swabs, the CYP2D6 gene was amplified by a long range PCR. Subsequently, polymorphism-specific short amplicons were generated in a multiplexed PCR. The amplicons were directly analysed by ICEMS. The information necessary to determine the allelic state of a PCR-amplified polymorphic locus were obtained from the measured molecular masses. Gene duplications or deletions were analysed by a long range PCR protocol and subsequent agarose gel detection.

Results: The developed CYP2D6 genotyping approach enables the reliable determination of the most frequent CYP2D6 alleles in Europe (*1, *2, *3, *4, *6, *7, *8, *9, *10, *11, *12, *17, *41) including whole gene duplications and deletions (*5). The assay involves the following steps: (1) collecting biological material in form of non-invasive saliva swabs; (2) DNA extraction; (3) long range PCR for a specific CYP2D6 amplification; (3) multiplexed PCR for the generation of polymorphism-specific short amplicons; (4) direct analysis of the reaction mixture with ICEMS; (4) determination of the allelic state with the measured molecular masses; (5) analysis of gene duplications or deletions by a long range PCR protocol and subsequent agarose gel detection. Genotyping of a single sample costs about 5-10 USD and can be accomplished within 2-3 days. Parallelization increases the sample throughput and reduces costs. For proof of principle, we have applied the developed method in the context of the PRO-BETh study to determine the CYP2D6 status of 106 breast cancer patients treated with tamoxifen. According to the classification of Gaedik A. et al [1], 19% of the typed breast cancer patients turned out to be “Poor Metabolizers", 51% were “Intermediate Metabolizers", 29% were “Extensive Metabolizers” and 7% turned out to be “Ultrarapid Metabolizers”.

Conclusion: PCR-ICEMS represents a cost-effective and convenient tool for pharmacogenetic testing, which enables the determination of the CYP2D6 status using DNA obtained from a non-invasive saliva swab as template.

[1] Gaedigk A. et al, J. Clin Pharmacol Ther. 2007 Jun;81(6):817-20.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-02-17.

Abstract P5-11-04: Phenotype-Genotype Correlations in Breast Cancer Patients Treated with Tamoxifen

Background: Personalized medicine strategies are especially relevant for drugs which show a high inter-individual variability regarding their pharmacokinetic and -dynamic properties. Considerable inter-patient variations have been described regarding the plasma concentrations of tamoxifen and its metabolites. Due to the observation that tamoxifen metabolites can show a high pharmacological activity, tamoxifen metabolism has received considerable attention. The metabolism of tamoxifen is complex resulting in a huge number of different products. Important metabolic transformation reactions include demethylation catalyzed by Cytochrome P450 3A4 and hydroxylation mainly catalyzed by Cytochrome P450 2D6 (CYP2D6). The impact of the CYP2D6 activity, which can be predicted from genetic information, on plasma levels and the related pharmacological effects has controversially been discussed. To get a better understanding of the inter-individual differences of the plasma levels of tamoxifen and some of its metabolites we have used liquid chromatography-tandem mass spectrometry (LC/MS/MS) to screen the plasma samples of 106 breast cancer patients. This method enabled the quantification of tamoxifen as well as a relative quantification of demethyltamoxifen and hydroxylated tamoxifen metabolites. To study the impact of enzyme activity on plasma levels, CYP2D6 genotypes were determined as well.

Material and methods: For metabolic profiling 1 ml plasma was treated with a solid phase extraction procedure. Chromatographic separation was accomplished on a reversed-phase column. Analytes were detected by mass spectrometry. For genotyping, the CYP2D6 gene was amplified by a long range PCR followed by a multiplexed PCR to generate specific short amplicons. The amplicons were directly analysed by LC/MS. The information necessary to determine the allelic state were obtained from the measured molecular masses.

Results: We determined the CYP2D6 genotype of 106 breast cancer patients treated with tamoxifen. We found 19% “Poor Metabolizers", 51% “Intermediate Metabolizers", 29% “Extensive Metabolizers” and 7% “Ultrarapid Metabolizers”. The observed plasma concentrations of tamoxifen and its metabolites showed a high inter-patient variability For instance, plasma concentrations between 26-307 ng/ml (mean 125 ng/ml) were observed for tamoxifen. We did not find a significant impact of the CYP2D6 status on tamoxifen plasma levels. However, the demethyltamoxifen/tamoxifen as well as the hydroxytamoxifen/tamoxifen ratios appear to be influenced by the CYP2D6 status: the higher the metabolic activity, the higher the hydroxytamoxifen content and the lower the demethyltamoxifen content.

Conclusions: We have developed analytical tools, which allow the determination of the content of tamoxifen and its major metabolites in human plasma and the genotyping of the CYP2D6 gene. Phenotypic and genotypic data of 106 patients were acquired. Correlation of the data revealed that the genotype had no significant impact on tamoxifen plasma levels. Nevertheless, patients with a predicted higher CYP2D6 activity showed lower demethyltamoxifen/tamoxifen ratios as well as higher hydroxytamoxifen/tamoxifen ratios.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-11-04.

Abstract PD08-02: The Impact of Patient Reported Outcomes (PRO) on the Evaluation of Therapy Related Side-Effects and the Improvement of Adherence to Endocrine Treatment in Breast Cancer Patients

Background: Long term treatment regimen with significant side effects may diminish a patient's quality of life (QOL) and consequently undermine adherence. Endocrine treatment for breast cancer causes various side effects, which can lead to early discontinuation of this effective therapy. Current knowledge on patients’ quality of life (QOL) impairments caused by endocrine therapy originates from clinicians’ impressions and expert ratings. This runs the risk of underestimating the effects of endocrine therapy on patients’ quality of life. Patient reported outcome (PRO) may provide higher accuracy and may therefore essentially contribute to medication evaluation and clinical decision making. In this study, we report on the patient reported outcome (PRO) related to endocrine therapy in early breast cancer.

Methods: Pre-and postmenopausal breast cancer outpatients treated with aromatase inhibitors (AIS) or tamoxifen were approached at their routine control appointment with the treating physician. We conducted a comprehensive PRO assessment comprising the following scales: FACT-B/+ES and HADS (high scores indicate high symptoms). In a short, semi-structured interview data on patients’ general medication intake behavior were collected focusing on the intake of complementary and alternative medicine (CAM)

Results: We analyzed PRO data of 240 patients undergoing endocrine treatment. 66.6% received AI therapy, 71.9% were postmenopausal. We found high levels of symptom burden in this study group: 55.9% had moderate to severe bone pain, 47.8% menopausal symptoms and 49.1% loss of sex drive. Postmenopausal women in the AI group had significantly more symptoms on the endocrine subscale (mean 24.25 vs. 16.42, p=0.045), significantly more anxiety (mean 8.8 vs. 5.11, p=0.036) and depression (mean 8.75 vs. 3.86, p=0.011). In the tamoxifen group premenopausal patients scored significantly higher on all scales. Moreover, patients who used complementary substances had a significant lower physical well-being (22.70 vs. 24.39, p=0.007) and more endocrine symptoms (22.63 vs. 16.30, p=0.004).

Conclusion:The results of our study show a significantly higher assessment of physical side-effects and psychosocial burden on part of the patients than implied by clinicians’ reports and expert ratings. PRO data may therefore provide a more accurate measure for symptom burden and contribute to individualized clinical decision making. It is an important tool to detect and effectively treat therapy related side effect to ultimately preserve adherence to endocrine treatment. According to our findings, it appears mandatory to incorporate PRO data in individualized clinical decision making to arrive at a more accurate assessment of symptom burden.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD08-02.