Abstract P5-11-04: Anti-proliferative effect of oral metronomic vinorelbine (mVNB) in PAM50 Luminal/HER2-negative early breast cancer (SOLTI-1501 VENTANA): A randomized, three-arm, window-of-opportunity study

BACKGROUND: The anti-proliferative effect of mVNB alone or in combination with endocrine therapy in patients with hormone receptor-positive/HER2- breast cancer (BC) has been scarcely addressed.

METHODS: Postmenopausal women with untreated stage I-III BC were randomized (1:1:1) to receive 3 weeks of letrozole (LTZ) 2.5mg/day, oral mVNB 50mg 3 days/week or the combination. The 1ary objective was to evaluate, within PAM50 Luminal A/B disease, if the anti-proliferative effect of mVNB+LTZ was superior to monotherapy. An anti-proliferative effect was defined as the mean relative decrease of the PAM50 11-gene Proliferation Score in each arm. 2ary objectives included safety and the comparison of the anti-proliferative effect between arms. An unplanned analysis of stromal tumor infiltrating lymphocytes (sTILs) was performed. PAM50 analyses were performed using the nCounter®-based Breast Cancer 360TM panel. Changes in the expression of 790 genes/signatures tracking multiple biological processes from tumor cells and the microenvironment were evaluated within each arm using paired (surgery vs. baseline) univariate analyses. P-values were corrected for multiple comparisons using false discovery rate (FDR).

RESULTS: A total of 61 patients were randomized and 54 paired samples (89%) were analyzed. Main patient characteristics were mean age 67, mean tumor size 1.7 cm, stage I (55.7%) and grade 1-2 (90%). Grade 3 toxicities occurred in 3.3% of cases. Baseline samples were Luminal A (72.3%) or B (27.7%). The anti-proliferative effect of mVNB+LTZ (-73.2%) was superior to both monotherapy arms combined (-49.9%; p=0.001) and mVNB (-19.1%; p<0.001). The anti-proliferative effect of mVNB+LTZ (-73.2%) was higher compared to LTZ (-65.7%) but did not reach statistical significance (p=0.328). Across the mVNB+LTZ, LTZ and VNB arms, 413 (52.3%), 403 (51.0%) and 21 (2.6%) genes/signatures were found differentially expressed (FDR<5%) between baseline and surgery samples. Compared to mVNB+LTZ baseline samples, surgical samples showed higher expression of AP-1 transcription factor subunits FOS and JUN, inflammatory chemokines (e.g. CCL4 and IL6), stromal-related genes (e.g. CAV1 and stroma signature) and immune infiltration (e.g. CD8 T-cell signature) and lower expression of proliferation-related genes (e.g. MKI67 and UBE2C), estrogen receptor-signaling and Risk of Recurrence. Of the 413 genes found differentially expressed in surgical samples compared to baseline samples in the mVNB+LTZ arm, 108 (26.2%) were not found in the LTZ arm. Among them, high expression of LAG3, CD24, CD84 and CCR5. Under the microscope, sTILs (≥10% at week 3) were observed in 6.6% (mVNB), 15% (LTZ) and 26% (mVNB+LTZ) of the cases. In tumors with ≤10% TILs at baseline, an increase in TILs was observed following LTZ (p=0.049) and mVNB+LTZ (p=0.012).

CONCLUSIONS: mVNB is well-tolerated and presents antiproliferative activity alone and in combination with LTZ. The increase of activated CD8 T-cells or TILs observed with LTZ+mVNB opens the possibility of studying combinations with immunotherapy. Further investigation comparing these biological results with other metronomic schedules or combinations is warranted.

Citation Format: Prat A, Adamo B, Pascual T, Perez Fidalgo JA, Blanch S, Martínez N, Gomez Pardo P, Lopez Gonzalez A, Murillo Jaso L, Amillano K, Vidal M, Paré L, Canes J, Galvan P, Gonzalez Farre B, Ortega Cebrián V, Gonzalez X, Bellet Ezquerra M, Villagrasa P, Ciruelos E. Anti-proliferative effect of oral metronomic vinorelbine (mVNB) in PAM50 Luminal/HER2-negative early breast cancer (SOLTI-1501 VENTANA): A randomized, three-arm, window-of-opportunity study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-11-04.

Abstract P2-09-27: Integrated analysis of PTEN protein expression and PI3KCA mutations as predictors for pathological complete response in HER2-positive breast cancer

Introduction: Anti-HER2 treatment has also influenced the response to neoadjuvant chemotherapy in HER2-positive breast cancer (BC) by increasing the pathologic complete response (pCR) rate. The activation of HER2 signaling causes the downstream activation of the PI3K/AKT/mTOR pathway that plays a crucial role in developing resistance to trastuzumab (T). Therefore, candidate biomarkers with a potential role in the prediction of a pCR and prognosis after anti-HER2 treatment could be selected from this pathway.

Material and Methods: We retrospectively evaluated PTEN protein expression and PI3KCA mutations in core biopsies from HER2-positive patients treated at our institution with neoadjuvant therapy based on anthracyclines, paclitaxel and T. Protein expression was assessed by immunohistochemistry and used as dichotomic variable, PTEN loss was considered if Hscore ≤ 40. The association of PTEN status, PI3KCA mutation and PI3K activation (defined as either PTEN loss and/or presence of PI3KCA) with pathological complete response (ypT0/isN0) and progression-free survival (PFS) was evaluated.

Results: In our database 86 patients with HER2-positive clinical stage II-III BC were identified. Median follow-up was 75.85 months. PTEN was available from 84 (97.7%) and PI3KCA genotype from 67 patients (77.9%). Median age was 47.34, stage III 58.8% and 50% were hormonal receptor (HR) positive. Low PTEN was described in 29.8% tumors and was statistically associated with Grade1-2 and HR positive tumors. PI3KCA mutations (exon 9 and 20) were observed in 23.9% tumors. PI3K activation was detected in 37.5% tumors. Overall, the pCR rate was 53.5%. In low PTEN tumors pCR was 12% and in PTEN-high tumors, it was 72.1% (p<.0001). pCR rate was statistically different between PIK3CA mutant and wild-type tumors (6.3% vs. 51.9%; p<.0001). PI3K activation was statistically associated with lower pCR rate (12.5 vs. 72.9%; p<.0001). In multivariable analysis adjusted for baseline parameters, HR expression (OR 4.170; 95% CI 0.975-17.829;p=0.054) and PI3K activation (OR 45.87; 95% CI8.059-261.101; p<.0001) independently predicted pCR. In univariable analysis clinical, stage III, non-pCR and PI3K activation were correlated with worse PFS. PI3K activation was statistically associated with lower PFS at 5 years (OR 3.813;CI 95%1.369-10.347; p=0.009) in the multivariable analysis.

Conclusions: The study showed the potential role of PIK3CA Genotype and PTEN expression in predicting pCR and prognosis after anthracycline–taxane-based chemotherapy and anti-HER2 treatment.

Citation Format: Gavila J, Gozalbo F, Climent MA, Guerrero AL, Sandiego S, Blanch S, Algarra MA, Soriano V, Guillem V, Ruiz A, Lopez Guerrero JA. Integrated analysis of PTEN protein expression and PI3KCA mutations as predictors for pathological complete response in HER2-positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-27.

Effect of dexfenfluramine on energy expenditure in obese patients on a very-low-calorie-diet

AIM

To investigate the effect of dexfenfluramine (dF) on Energy Expenditure (EE).

DESIGN

20 obese females were studied in a double-blind design. Pre-diet and at 14 and 28 days of VLCD and dF treatment (30 mg/d) or placebo, Resting Metabolic Rate (RMR), 3 h-Thermic Effect of Food (3 h-TEF) and body composition were determined. EE and body composition were measured by indirect calorimetry and bioelectrical impedance, respectively.

RESULTS

No differences between groups were observed in relation to weight loss, body composition changes or RMR. At 3 h postprandial, the EE was still elevated in both groups. No changes on TEF were observed in the placebo group during VLCD. In contrast, TEF decreased in dF group during VLCD (P < 0.05). No significant differences in TEF at the end of the study were observed between groups.

CONCLUSION

These results suggest that dF modifies 3 h-TEF but not RMR in obese patients during VLCD administration.

Changes in body composition and resting energy expenditure after rapid weight loss: is there an energy-metabolism adaptation in obese patients?

The aim of this study was to assess changes in resting energy expenditure (REE) related to changes in fat free mass (FFM) in nine morbid obese (BMI 43 +/- 5.1 kg/m2) hospitalised females on VLCD. REE was measured by 30 min indirect calorimetry before and after 28 days of hospitalisation. Changes in FFM were assessed by bioelectrical impedance analysis (BIA), hydrostatic weighing (HW) and nitrogen balance (N). REE decreased 11.5% from 7.8 +/- 1.0 to 6.9 +/- 0.8 MJ/d. Total weight loss was 8.4 +/- 1.9 kg or 7.4% with an estimated FFM loss of 3.4 +/- 1.8 (BIA), 2.9 +/- 1.9 (HW) and 1.8 +/- 1.0 (N). As the fall in REE was larger than the loss of FFM, it is concluded that morbid obese patients develop an energy saving adaptation during rapid weight loss.

[Estimation of energy expenditure in patients with morbid obesity]

BACKGROUND

The equations available for the prediction of basal energy expenditure (BEE) may not be applicable in morbid obese individuals since the contribution of the fat free mass (FFM) over the BEE is not constant. The aim of this study was to obtain new equations for the prediction of BEE which are specific for patients with morbid obesity.

METHODS

In 26 women with morbid obesity age, weight, body composition by bioelectric impedance and BEE by open circuit indirect calorimetry were determined. The BEE observed was compared with that estimated from the previously described equations. The multiple regression method was used to obtain the BEE prediction equations.

RESULTS

Upon comparison of the BEE observed with the BEE estimated by the described equations a significant relation was found between both parameters. The differences were also significant except when the Harris-Benedict equation was used. Multiple regression analysis demonstrated that when the variables of body composition were included, the FFM explained 75% of the variation in BEE and on forcing the entrance of fatty mass, the explanation increased to 79%. When only the anthropometric variables were included, weight explained 69% of the variation.

CONCLUSIONS

In morbid obesity, most of the equations described for estimating basal energy expenditure are not applicable. New equations are reported for the prediction of energy expenditure.

Plasminogen activator inhibitor activity and other fibrinolytic variables in patients with coronary artery disease

Several fibrinolytic variables, including plasminogen activator inhibitor activity, were studied before and after exercise in 67 normolipidaemic patients with coronary artery disease and in 25 hyperlipidaemic patients with coronary artery disease. Before exercise plasminogen activator inhibitor activity was higher in the patient groups than in a group of 10 healthy volunteers. For those who were normolipidaemic plasminogen activator inhibitor activity was greater in patients with angina pectoris who had had a myocardial infarction. The concentration of antigenic tissue-type plasminogen activator was similar in all the patients with coronary artery disease and higher than in the control group. After the exercise test fibrinolytic capacity was lower in the patients with angina pectoris and a previous history of myocardial infarction. After exercise both the released immunological tissue-type plasminogen activator and fibrinolytic capacity were lower in the hyperlipidaemic patients than in the normolipidaemic patients. The concentration of plasminogen activator inhibitor was also higher in the hyperlipidaemic patients. Patients with hyperlipidaemia IV had the highest plasminogen activator inhibitor activity. The increase in plasminogen activator inhibitor activity found in the patients was partially inhibited by antiserum against plasminogen activator inhibitor-1 in vitro. The formation of a complex of about 115,000 daltons between plasminogen activator inhibitor and purified tissue-type plasminogen activator was detected by a zymographic fibrin technique. These findings show that in patients with coronary artery disease fibrinolytic activity is impaired by an increase in plasminogen activator inhibitor. Impaired fibrinolysis may be related to the clinical evolution of coronary artery disease in these patients.

Early load-limiting versus symptom-limited exercise testing: prognostic value in 200 myocardial infarction patients

The prognostic value of early load-limited and symptom-limited exercise testing has been compared in 200 men younger than 65 years of age, after myocardial infarction. 164 patients performed both tests and in 79 of the 200 cases who performed the early test the result was positive (40%); the percentage of positive tests was higher with the symptom-limited test (53.6%). The prognostic value of both tests was high. During the follow-up the mortality rate was higher in patients with positive results, but the early test enables the identification of patients in a higher risk group before hospital discharge.