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.

Consumer acceptability of beef from two sexes supplemented with essential oil mix

Essential oils are natural extracts from plants which can be included in cattle diets as an alternative to additives, such as ionophores, to improve the shelf life of meat. The aim of this study was to evaluate the sensory acceptability of meat from 57 crossbred (1/2 Angus–1/2 Nellore) animals of different sexes [heifers n = 30, and young bulls n = 27], finished in feedlot with isoenergetic and isonitrogenous diets, which differed in the level of supplementation (0.0, 3.5 or 7.0 g/animal/day) with a commercial mix of essential oils (Mixoil®) from seven plants: oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange. The Longissimus thoracis muscle, aged for 24 h, was evaluated by 120 consumers who scored tenderness acceptability, flavour acceptability and overall acceptability using a hedonic 9-point scale. The inclusion of essential oils affected tenderness acceptability and flavour acceptability (P ≤ 0.01), with a tendency (P < 0.10) for overall acceptability. Meat from heifers was more appreciated by consumers than that from young bulls in all attributes (P ≤ 0.001), however, different groups of consumers had different preferences. The inclusion of a mix of essential oils in beef diets was well accepted by consumers, and could improve the acceptability of meat from young bulls, when is added at a concentration of 3.5 g/animal/day during the last 4 months of fattening.

Experience in the treatment of osseous hydatidosis

Osseous hydatidosis is a very uncommon disease which often recurs after treatment. There is no well-established effective method of management. Radical excision may produce serious mutilation and often fails to control the disease. We have used oral mebendazole as adjuvant treatment in four patients. Two also underwent radical excision, one had received limited excision elsewhere and the other did not have operative treatment. The patients who underwent radical excision and the other who did not have an operation became and remain free of symptoms and are serologically negative.A combination of excision and treatment with mebendazole may have a role in the management of this complex disease.

Abstract P6-12-09: Pan-HER, an antibody mixture with antitumor activity against drug-resistant HER2-overexpressing breast cancers with high ERBB ligand expression

Background: Amplification/overexpression of ERBB receptors and/or ligands has been associated with resistance to anti-HER2 therapies. Pan-HER is a mixture of six antibodies targeting each of the ERBB receptors, EGFR, HER2 and HER3, with synergistic pairs of antibodies. Each pair of antibodies simultaneously blocks ligand binding and/or induces target degradation, thus preventing compensatory mechanisms to anti-ERBB therapies. We examined the antitumor activity of Pan-HER against drug-sensitive and -resistant HER2+ breast cancer cells and xenografts.

Results: Pan-HER exhibited potent growth inhibitory activity against a panel of HER2+ breast cancer cells (BT474, MDA-453, MDA-361, SUM190, HCC1954, UACC893 and SKBR3). Growth inhibition was associated with internalization and degradation of EGFR, HER2 and HER3. Pan-HER was superior to the combination of trastuzumab/pertuzumab (TP) against HER2+/PIK3CA mutant MDA-361, HCC1954, UACC893 and MDA-453 cells. We next compared the effect of Pan-HER against BT474, HCC1954 and MDA-361 xenografts established in nude mice to that of trastuzumab/lapatinib (TL), TP and T-DM1. All treatments were effective across the panel of xenografts. In mice with MDA-361 tumors, Pan-HER and TP were superior to TL. Immunoblot analysis showed significant downregulation of EGFR, HER2 and HER3 only in tumors treated with Pan-HER. After a complete response, treatment was discontinued. Among mice with BT474 xenografts treated with TP, TL and T-DM1, 25-50% of mice exhibited a tumor recurrence within 50 weeks of follow-up, while no recurrences were registered in mice treated with Pan-HER. Tumors recurring after TP and T-DM1 expressed significantly higher HER3 and P-HER3 protein levels and NRG1 mRNA levels. HCC1954 xenografts recurring after T-DM1 also overexpressed NRG1 mRNA compared to tumors before therapy.

We next examined the effect of Pan-HER against trastuzumab-resistant HR6 (BT474) cells (Ritter et al. CCR 2007) and HCC1954 and UACC893 cells with acquired resistance to T-DM1 (TDR; IC50 &gt;5-, &gt;6- and 600-fold in HR6, UACC893-TDR and HCC1954-TDR cells, respectively, vs. parental cells). All T-DM1-resistant cells expressed significantly higher HER3 and P-HER3 protein levels and NRG1 mRNA and protein levels. Treatment with the HER3 neutralizing antibody LJM716 resensitized HR6 and HCC1954-TDR cells to T-DM1, suggesting a causal association between the NRG1-HER3 axis and drug resistance. Mice with HR6 tumors were treated with Pan-HER, TL, TP and T-DM1. Only Pan-HER arrested HR6 tumor growth and downregulated EGFR, HER2, HER3, P-HER3 and P-AKT. Finally, HCC1954-TDR tumors rapidly grew in vivo despite treatment with T-DM1. Administration of Pan-HER to mice bearing HCC1954-TDR xenografts growing in the presence of T-DM1, induced rapid tumor regressions.

Conclusions: These data suggest that multitarget therapeutic interventions, such as Pan-HER, which simultaneously remove and/or block all ERBB receptors and ligands, are a feasible and effective approach against HER2-overexpressing cancers both sensitive and resistant to anti-HER2 therapies.

Citation Format: Schwarz LJ, Hutchinson KE, Estrada MV, Sanders ME, Dugger TC, Formisano L, Guerrero AL, Red-Brewer M, Young CD, Lantto J, Pedersen MW, Kragh M, Horak ID, Arteaga CL. Pan-HER, an antibody mixture with antitumor activity against drug-resistant HER2-overexpressing breast cancers with high ERBB ligand expression [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-09.

How dietary cottonseed hull affects the performance of young bulls finished in a high-concentrate system

This study aimed to evaluate the effects of diets composed of cottonseed hull on feed intake, in vitro digestibility, animal performance, carcass characteristics and ingestive behaviour of young bulls (1/2 Simmental × 1/2 Nellore) fed in a high-concentrate system. Thirty crossbred young bulls (319 ± 12.5 kg of bodyweight, and 11 ± 0.8 months old) were assigned to a complete randomised experimental design of three diets (CH21: cottonseed hull 210 g/kg on a DM, basis; CH27: cottonseed hull 270 g/kg on a DM basis; CH33: cottonseed hull 330 g/kg on a DM basis) with 10 animals per group. The animals were kept in a feedlot for 162 days. The cottonseed hull diets had effects on DM intake and neutral detergent fibre intake. The CH21 diet reduced the DM and detergent fibre intakes (kg/day and kg/100 kg bodyweight) and increased the in vitro digestibility of DM. However, the in vitro digestibility of neutral detergent fibre was greater with the CH27 diet. The cottonseed hull diets did not have effects on animal performance or the carcass characteristics of young bulls. However, the CH33 diet reduced the feed efficiency of the animals. A cottonseed hull level up to 270 g/kg of dietary DM may be utilised as a non-forage fibre in high-concentrate diets for young bulls in feedlots.

Real-life data in 115 chronic migraine patients treated with Onabotulinumtoxin A during more than one year

Background

OnabotulinumtoxinA (OnabotA) is effective in Chronic Migraine (CM) during first year of treatment and longer. In real clinical setting, CM patients with acute Medication Overuse (MO) or concurrently receiving oral preventatives are treated with OnabotA. We aim to assess evolution of CM patients beyond first year on OnabotA.

Methods

Data were retrospectively collected in three headache units. We analyzed cases who had received at least five sessions of OnabotA according to PREEMPT protocol. We continued OnabotA therapy when a reduction of number of headache days of at least 30% was achieved.

Results

We included 115 patients (98 females, 17 males) who completed 7.6 ± 2.3 (5–13) OnabotA procedures. Previously they had not responded to topiramate and, at least, one other preventative. Age at inclusion was 45.3 ± 12 (14–74) years, and latency between CM onset and OnabotA therapy was 43.1 ± 38.2 (6–166) months. At first OnabotA session 92 patients (80%) fulfilled MO criteria and 107 (93%) received a concurrent oral preventative. In 42 cases (36.5%) OnabotA dose was increased over 155 units. After first year in 57 out of 92 patients (61.9%) MO was discontinued. Among those receiving preventatives, in 52 out of 107 they were retired (48.6%). In 22 cases (19.1%) OnabotA administration was delayed to the fourth or fifth month and in 12 (10.4%) it was temporally stopped. Finally, in 18 patients (15.7%) OnabotA was discontinued due to lack of efficacy beyond first year of treatment.

Conclusion

Our results suggest that discontinuation of acute medication overuse and oral preventive therapies are achievable objectives in long-term using of OnabotA in CM patients.

Factors influencing aversive learning in the oriental fruit fly, Bactrocera dorsalis

Parameters such as the intensity of conditioned and unconditioned stimuli, the inter-trial interval, and starvation time can influence learning. In this study, the parameters that govern aversive learning in the oriental fruit fly, Bactrocera dorsalis, a serious pest of fruits and vegetables, were examined. Male flies were trained to associate the attractive odorant methyl eugenol, a male lure, with a food punishment, sodium chloride solution, and the conditioned suppression of the proboscis-extension response was investigated. We found that high methyl eugenol concentrations support a stronger association. With increasing concentrations of sodium chloride solution, a steady decrease of proboscis-extension response during six training trials was observed. A high level of learning was achieved with an inter-trial interval of 1-10 min. However, extending the inter-trial interval to 15 min led to reduced learning. No effect of physiological status (starvation time) on learning performance was detected, nor was any non-associative learning effect induced by the repeat presentation of odor or punishment alone. The memory formed after six training trials could be retained for at least 3 h. Our results indicate that aversive learning by oriental fruit flies can be affected by odor, punishment concentration and inter-trial interval.