A. S Dieudonne

Aromatase inhibitor-induced loss of grip strength is body mass index dependent: hypothesis-generating findings for its pathogenesis.

BACKGROUND Our preliminary results showed that tenosynovial changes and decrease in grip strength are associated with the aromatase inhibitor-induced musculoskeletal syndrome (AIMSS). Here, we report the final results and assess the relationship between grip strength and body mass index (BMI). PATIENTS AND METHODS We conducted a prospective study including postmenopausal early breast cancer patients receiving either an aromatase inhibitor (AI) or tamoxifen. Primary end point was change from baseline in tenosynovial abnormalities. Secondary end points were changes from baseline in morning stiffness, intra-articular fluid and grip strength and its association with BMI. RESULTS After 6 months of therapy, 74% [95% confidence interval (CI) 51% to 89%] of AI-treated patients had worsened tenosynovial abnormalities, 56% (95% CI 34% to 75%) had increased intra-articular fluid, and 22% (95% CI 9% to 45%) had increased morning stiffness. Grip strength decreased 8% for the left hand (95% CI 2% to 21%) and 11% for the right (95% CI 4% to 17%). Regression analysis suggested that grip strength decreased more for subjects with high or with low BMI. CONCLUSIONS AIMSS is characterized by tenosynovial changes, intra-articular fluid and morning stiffness. We hypothesize that the quadratic association between BMI and loss of grip strength reflects AI-induced changes on the endocrine control of the growth hormone insulin-like growth factor-I pathway.

Prospective study to assess fluid accumulation and tenosynovial changes in the aromatase inhibitor-induced musculoskeletal syndrome: 2-year follow-up data

BACKGROUND Aromatase inhibitors (AIs) frequently lead to the AI-induced musculoskeletal syndrome (AIMSS). Looking into its pathophysiology, 6 months of AI therapy thickens the tendon sheath with intra-articular fluid (IAF) retention and loss of grip strength. We here report 24-month follow-up data. PATIENTS AND METHODS A prospective cohort study of 33 postmenopausal breast cancer patients received adjuvant endocrine therapy; 27 received an AI and 6 received tamoxifen. At baseline, 6 and 24 months patients had a rheumatologic examination, including a grip strength test, and magnetic resonance imaging of both hands and wrists. The primary end point was tenosynovial changes; secondary end points were changes in morning stiffness, grip strength and IAF. RESULTS Twenty-three AI and 5 tamoxifen patients completed all investigations. Between month 6 and 24, IAF further increased in AI users (P = 0.04) but not in tamoxifen users, and grip strength further decreased in both groups. The worsened tenosynovial changes were strongly correlated with a decrease in grip strength. At 24 months, morning stiffness continued to be present in over a third of AI users. CONCLUSION AIMSS represents a substantial problem in breast cancer patients. It is associated with tenosynovial changes, IAF retention, joint stiffness and loss of grip strength that do not improve with prolonged use.

The rs1800716 variant in CYP2D6 is associated with an increased double endometrial thickness in postmenopausal women on tamoxifen

BACKGROUND Tamoxifen remains important in the treatment and prevention of estrogen receptor-positive breast cancer. In postmenopausal women, it can lead to endometrial changes such as cystic appearances, hyperplasia, polyps and endometrial cancer. Tamoxifen is metabolized by cytochrome P450 (CYP450) enzymes to the more active metabolite endoxifen. Several genetic variants in the CYP450 enzymes reduce tamoxifen metabolism, leading to reduced endoxifen levels. We hypothesize that carriers of these variants, which are established poor metabolizers of tamoxifen, do not have the typical tamoxifen-induced increase in endometrial thickness. We test the association between genetic variability in CYP450 enzymes and the increase in double endometrial thickness (DET) as measured through transvaginal ultrasound (TVU). PATIENTS AND METHODS We carried out a retrospective study on postmenopausal tamoxifen users for which germline DNA was available and at least one DET measurement was made between January 2000 and October 2011. Genotyping of 33 single nucleotide polymorphisms in CYP450 genes involved in tamoxifen metabolism was carried out using Sequenom MassARRAY. The association between these variants and TVU outcome (DET ≥5 mm) was assessed by proportional hazards regression. RESULTS Data were available for 184 women: 47 with a DET of <5 mm on all ultrasounds and 137 with a DET of ≥5 mm on at least one ultrasound. The rs1800716 variant in CYP2D6 showed a statistically significant association with DET. In particular, mutant carriers of rs1800716 had an increased chance of having a DET of ≥5 mm (P = 0.0022, false discovery rate 0.0179). None of the other variants were associated with DET. CONCLUSION Although mutant carriers of rs1800716 are characterized by reduced CYP2D6 enzyme activity and by low levels of endoxifen, we observed that mutant alleles of rs1800716 were associated with an increased chance of having a DET of ≥5 mm in postmenopausal women on tamoxifen. We conclude that the increase in endometrial thickness seen under tamoxifen cannot be used as a marker for favorable genotypes. CLINICAL TRIAL NUMBER B32220084284.

P5-05-01: Vitamin D Status in Newly Diagnosed Breast Cancer Patients Inversely Correlates with Tumor Size and Moderately Correlates with Outcome.

Aims: To study the impact of Vitamin D (VitD) status and genetic variability in key VitD regulatory genes on patient and breast tumor characteristics, and on breast cancer related outcome. Methods: We examined serum 25-hydroxyvitamin D3 (25OHD) levels in a cohort of 1800 early breast cancer patients treated in Leuven between 2003 and 2010. Serum was collected at diagnosis for all patients; germline DNA from peripheral blood was also available for the majority of them. Serum 25OHD was measured by radioimmunoassay, and single nucleotide polymorphisms (SNP9s) were assessed by Sequenom. Statistical analysis was done by multivariable regression models including age, BMI and season and by a Cox proportional hazard model for analysis of disease-specific survival and disease-free interval. Results: Lower 25OHD serum levels were significantly correlated with larger tumor size (0,4 ng/ml decrease in 25OHD per 1 cm increment in tumor size, p=0.0063) but not with lymph node invasion, estrogen receptor and HER2 status, or tumor grade. Serum 25ODH level was significantly affected by genotypes of rs10741657 and rs1993116 (25-hydroxylase; CYP2R1) and of rs222040, rs7041 and rs4588 (D-binding protein; DBP), yet its observed association with tumor size did not differ between distinct genotypes. Although not statistically significant, patients with higher 25OHD levels tended to have slightly improved survival. Also, a significant increase in relapse risk became apparent after 3 years for patients with 25OHD Conclusion: Vitamin D Level in breast cancer patients inversely correlates with tumor size and moderately correlates with outcome. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-05-01.

Cross Reactivity between the Roche Elecsys® Progesterone Assay and Exemestane.

Background:Oral aromatase inhibitors (AI) and to a lesser extend tamoxifen can promote recovery of ovarian function in postmenopausal breast cancer patients. Biochemical monitoring of ovarian function is important as folliculogenesis may lead to pregnancy, vaginal bleeding and loss of efficacy of the oral AI. Biochemical monitoring of oestradiol in exemestane users is problematic because exemestane metabolites cross react in most immunoassays for oestradiol. Following our finding of luteal phase progesterone levels in serum of some postmenopausal women with vaginal bleeding on exemestane, we assessed potential cross reactivity between exemestane and its 4-OH metabolite in the Roche Elecsys® progesterone assay. We also studied the frequency of such progesterone activity in serum from consecutive exemestane users and correlated values with FSH.Methods:Progesterone concentrations were measured with the Elecsys® assay in blanco serum, blanco serum with pure exemestane and blanco serum with the pure 17-OH-exemestane metabolite. Several concentrations of the purifided 17-OH-exemestane metabolite in DSMO solvent were then prepared using the Elecsys Diluent MultiAssay and progesterone concentration was measured in these samples using the Elecsys® assay. Cross sectional blood samples from 94 exemestane users were measured for progesterone activity with this assay and also for FSH using the Roche Modular E170® (F. Hoffmann-La Roche Ltd, Basel, Switserland).Results:Using this progesterone assay, 41% of exemestane users had luteal phase progesterone levels (>1.7 ng/mL). There is cross reactivity with exemestane but more importantly with the 17-OH metabolite (table). The level of progesterone and cross reactivity for 2 known concentrations of the 17-OH-metabolite are also shown in this table. There is a correlation between progesterone picked up by the Elecsys® assay and FSH which increased with progesterone activity.Conclusion:Progesterone levels in exemestane users measured with the Elecsys® assay from Roche were often overestimated due to cross reactivity with exemestane and its main metabolite. This progesterone assay can not be used to define menopause or distinguish postmenopausal from menstrual bleeding in exemestane users. Higher FSH levels with higher progesterone activity in this assay suggest a link between circulating exemestane/metabolites and the quantitative downregulation of postmenopausal estrogens by this AI, but serial rather than cross sectional measurements are required to confirm this.We acknowledge Pfizer for providing us with pure exemestane and 17-OH-metabolite. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5147.

Abstract P3-07-46: CYPTAM-BRUT 3: Endometrial thickness cannot be used as a marker for tamoxifen metabolization in postmenopausal breast cancer patients

Background: Tamoxifen is commonly used for the treatment of all stages of estrogen receptor (ER) positive breast cancer (BC), the largest group of BC. In postmenopausal women, known endometrial side-effects are cystic appearance, hyperplasia, polyps and endometrial cancer. Tamoxifen is converted through several CYP450 enzymes into the active metabolite endoxifen. Patients with particular single nucleotide polymorphisms (SNPs) in those CYP450 enzymes (e.g. CYP2D6) have lower endoxifen concentrations and therefore could experience less benefit from tamoxifen. However, the clinical significance stays controversial in the literature as results remain contradictory. Our primary hypothesis is that women with lower endoxifen levels do not have the typical tamoxifen-induced increase in endometrial thickness. The aim of this study is to test the association between endoxifen concentration and the increase in double endometrial thickness (DET). Patients and methods: CYPTAM-BRUT 3 is a prospective, multicentric study including postmenopausal women with an ER positive BC receiving tamoxifen in the adjuvant setting. Primary objective is the association between serum endoxifen levels and change in DET between baseline and follow-up after 3 - 6 months. Secondary objectives are investigating the relation between serum endoxifen levels and other endometrial changes (i.e. the presence of cysts/polyps), menopausal symptoms assessed with a questionnaire and serum levels of follicle-stimulating hormone (FSH) and sex hormone-binding globulin (SHBG). Other objectives are the association between the 9CYP2D6 tamoxifen activity score9, based on SNPs and co-medication, and DET, other endometrial changes, FSH and SHBG. The CYPTAM-BRUT 3 study is a sub-study of the CYPTAM study in Leiden, The Netherlands, with survival as primary outcome. Results: 144 women were included in 19 hospitals. There was no significant association found between endoxifen and change in DET (p=0.888), as for the association between endoxifen and the development of cysts or polyps (p=0.208). For the questionnaire items no correlation was found (p≥0.051). Changes of FSH and SHBG were in the range of what would be expected during tamoxifen treatment in the general population and there was no association with endoxifen (p=0.726 and p=0.181). In addition, no association was found between the CYP2D6 TAS score and DET (p=0.613), other endometrial changes (p=0.196), FSH (p=0.976) and SHBG (p=0.900). Conclusion: Our study is one of the first studies that prospectively investigated the relation between tamoxifen metabolization, in correlation with endometrial thickness and SNPs. We can conclude that the typical increase in endometrial thickness seen in a significant proportion of postmenopausal women under tamoxifen cannot be used to predict that those women have a high endoxifen concentration or that women without an increased endometrial thickness have a significantly lower endoxifen concentration. The same conclusions can be made for the other tamoxifen-induced changes as cysts and polyps, menopausal symptoms, FSH and SHBG. It may also apply to tamoxifen efficacy but further prospective studies looking at survival are needed to answer that question. Citation Format: Poppe A, Dieudonne A-S, Lintermans A, Laenen A, Blomme C, Lambrechts D, Wildiers H, Christiaens M-R, Timmerman D, Van Calster B, Vereecke C, Vandeputte G, Fontaine C, Decloedt J, Berteloot P, Depypere H, Joerger M, Dezentje V, Neven P. CYPTAM-BRUT 3: Endometrial thickness cannot be used as a marker for tamoxifen metabolization in postmenopausal breast cancer patients. [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 P3-07-46.

P2-17-09: A Prospective Assessment of Loss of Grip Strength by Baseline BMI in Breast Cancer Patients Receiving Adjuvant Aromatase Inhibitors or Tamoxifen.

Background The 3 rd generation aromatase inhibitors (AIs) induce or enhance musculoskeletal problems. Underlying mechanisms are probably multiple, but remain unknown. We have previously reported that loss of grip strength together with tenosynovial abnormalities are more important in AI- than in tamoxifen-users (Morales et al, JCO 2008) and that musculoskeletal changes in AI-users are more pronounced in women with extremes in baseline BMI (Lintermans et al, Ann Oncol 2011) We here report preliminary results from a larger population and plan to validate findings in patients from University of Michigan. Patients and methods In this prospective observational study, postmenopausal early breast cancer patients scheduled to start adjuvant hormonal therapy with any of the third generation AIs or tamoxifen were recruited. After providing informed consent, a functional assessment test of grip strength was performed with a modified sphygmomanometer. Re-evaluation was done after 3, 6 and 12 months of therapy. BMI and waist to hip ratio (WHR) were assessed and a rheumatological questionnaire was completed at each visit. Results Ninety-four (79 AI; 15 tamoxifen) of the planned 200 patients were included in this preliminary study. 18% of AI-users discontinued their treatment due to musculoskeletal symptoms compared with none of the tamoxifen-users. 62% of patients on AI and 35% of tamoxifen patients complained of new or worsened joint pain. Table 1 shows the proportion of patients that attribute their complaints to their endocrine therapy. Grip strength significantly decreased over time (p=0.03), with patients under AI treatment having a larger loss of grip strength than patients under tamoxifen treatment (p=0.04). We confirm our previously reported results on the shape of the curve “BMI AI-induced loss of grip strength”. Years past menopause and age showed a significant effect on grip strength (p Conclusion Our preliminary results confirm that a majority of patients treated with an AI experience musculoskeletal problems, which are considered due to the therapy by most patients. Grip strength decreased over time, with a significantly larger loss of grip strength in the AI-users compared with the tamoxifen-users. AI-induced loss of grip strength and baseline BMI showed an inverted U-shaped association, although differences between quartiles were small. Further results should be awaited as this is only a preliminary analysis. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-17-09.

P1-08-20: Parity Interferes with the Effect of Age at Diagnosis on the Frequency Breast Cancers Are Triple-Negative.

Background Epidemiologic studies show an age related decrease in the frequency that breast cancers are triple negative (TN) (estrogen receptor, progesterone receptor and HER-2 negative). Parity increases the risk of TN breast cancer as a previous full-term pregnancy mainly protects against ER+ breast cancer. It is unknown whether this protective affect appears at all ages of breast cancer diagnosis. We study the frequency of triple negative breast cancers by parity and age at breast cancer diagnosis. Methods We performed a retrospective case-case analysis including 1583 consecutive female patients with primary diagnosis of invasive breast cancer, Results We confirmed a decrease of TN breast cancer with age (p 40 years at breast cancer diagnosis. Discussion : Although several other factors may affect the frequency breast cancers are TN, age at breast cancer diagnosis interacts with the effect of a previous pregnancy on the frequency breast cancers are TN. Breast cancers in young women ( Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-20.

Abstract P4-08-09: The Prognostic Importance of “Detection Mode” and “Palpability” in Primary Operable Grade 2 Breast Cancers

Background: Histologic grade 2 breast cancer may benefit most from molecular classification for prognosis. We studied the prognostic value of ‘detection mode’ and ‘palpability’ together with other prognostic variables in a consecutive series of grade 2 lesions. Patients and methods: We used follow-up data from new diagnosed and primary operable grade 2 breast cancers from UH Leuven (January 2000 - May 2005). Endocrine, chemo-and radiotherapy were given when indicated. The first appearing breast cancer related event (BCRE) was calculated as local (local, regional or contra-lateral) or metastatic (metastatic if both appeared together). These prognostic variables were assessed: age at diagnosis (per decade increase), tumor size (per cm increase), screening (yes/no), palpability (yes/no), lobular type (yes/no), chemotherapy (yes/no), endocrine therapy (yes/no), lymph node status (0, 1, 2-4, >4), combined expression of IHC-measured ER (pos = any expression), PgR (pos if any expression) and HER-2 (positive = IHC2/3+ and FISH pos), architectural, nuclear and mitotic score. Univariable and multivariable proportional hazards Cox regression using the Firth9s penalization method to reduce bias in the parameter estimates were used. Results: Of the 1013 patients in the dataset, 14 had missing values (1.4%). With a median follow-up of 80 months, we observed 116 BCRE (11.6%); 43 local and 73 metastatic. In univariable analysis, screen detected cancers showed better (HR 0.63, 95% CI 0.42-0.93) and palpable cancers worse prognosis (HR 1.96, 95% CI 1.13-3.71) than non-screen detected and non-palpable cases respectively. The beneficial univariable effect of screening weakened in the multivariable analysis (HR 0.83, 95% CI 0.52-1.31) as 582/602 (97%) of non-screen detected cancers were palpable vs 227/397 (57%) for screen-detected cancers. If palpable was omitted from the multivariable model the HR of screening decreased to 0.68 (95% CI 0.44-1.03) thereby approximating its univariable result. Conclusion: Overall, palpability is more strongly related to prognosis, but detection method also has an effect even though we do not have enough events to show this with a convincing level of reliability. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-09.