Abstract P1-15-14: Neoadjuvant liposomal doxorubicin and carboplatin is effective and tolerable for the treatment of triple negative breast cancer

Background: The use of neoadjuvant platinum with taxane for triple negative breast cancer (TNBC) has gained increased attention for improving rates of pathologic complete response (pCR). Our prior trial combining carboplatin (CAR) with liposomal doxorubicin (DOX) for metastatic TNBC showed good response rates with minimal side effects while allowing for greater platinum dosing compared to a taxane combination. We hypothesized that the doublet of DOX+CAR is effective and tolerable in the neoadjuvant setting for TNBC and that tumor genomics may aid in determining those patients most likely to benefit.

Methods: A phase II single arm trial was conducted for patients (pts) diagnosed with stage II-III TNBC. Patients received 4 cycles of neoadjuvant carboplatin (AUC 5) and liposomal doxorubicin (30mg/m2) administered every 28 days, then underwent definitive breast surgery followed by 12 weeks of adjuvant paclitaxel 80 mg/m2 administered weekly. Primary and secondary clinical endpoints were rate of pCR and two year recurrence free survival (RFS) and overall survival (OS), respectively. Cardiac safety of the combination was assessed. Fresh residual tumor samples were obtained at time of surgery for generation of patient derived xenografts (PDX). Tumor genomic profiling was done to determine the mutational spectrum, association of this spectrum in primary tumors with achieving pCR, and identifying alternative treatment strategies for PDX evaluation for patients with resistant disease.

Results: From 2/2015 to 5/2018, 36 pts were enrolled and 32 completed treatment; 4 pts await definitive surgery; 12 (33%) are two years from diagnosis. Median age of the cohort was 53 years. There was high participation by under-represented groups: 23% African American, 20% Asian, 14% Hispanic. Most histologies were invasive ductal but included apocrine, pleomorphic lobular, and metaplastic subtypes. Of the 32 pts who completed surgery, 34% (11) achieved pCR and 64% (23) had clinical response on serial physical exam. At 2 years, there were 2 distant and 1 local recurrence. The most common toxicities during DOX+CAR were grade 1 nausea in 19 pts (53%), grade 3/4 neutropenia occurred in 10 pts (28%); these pts received GCSF support with subsequent cycles; febrile neutropenia occurred in 1 pt (3%) in this group. Grade 3 thrombocytopenia (2 pts), pruritis (1 pt), and mucositis (1 pt) were observed. Only 6 pts (17%) had grade 1 alopecia. There were no delays in treatment due to cardiotoxicity or complications from surgical healing. TP53 (93%), PI3K/PTEN (26.6%), and NOTCH (20%) were the most commonly altered pathways. Structural variants, such as amplifications, rearrangements, and frameshifts were the most frequent alterations detected. Of the 25 pts who had residual disease, PDX was attempted from 14 pts, and 10 (71%) PDX were established, including those for all 3 patients experiencing recurrence.

Conclusion: Neoadjuvant DOX+CAR demonstrated good efficacy and tolerability. Post-chemotherapy PDX is feasible and may help identify targeted approaches for patients with resistant disease. These results warrant further evaluation of this combination for early stage TNBC.

Citation Format: Chan N, Riedlinger GM, Lu S-e, Pham KT, Kirstein LJ, Eladoumikdachi FG, George MA, Potdevin LB, Kowzun MJ, Desai SA, Tang DM, Omene CO, Wong ST, Rodriguez-Rust L, Kumar S, Kearney TJ, Liu C, Ganesan S, Toppmeyer DL, Hirshfield KM. Neoadjuvant liposomal doxorubicin and carboplatin is effective and tolerable for the treatment of triple negative breast cancer [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 P1-15-14.

Modeling sequence evolution in acute HIV-1 infection

We describe a mathematical model and Monte Carlo (MC) simulation of viral evolution during acute infection. We consider both synchronous and asynchronous processes of viral infection of new target cells. The model enables an assessment of the expected sequence diversity in new HIV-1 infections originating from a single transmitted viral strain, estimation of the most recent common ancestor (MRCA) of the transmitted viral lineage, and estimation of the time to coalesce back to the MRCA. We also calculate the probability of the MRCA being the transmitted virus or an evolved variant. Excluding insertions and deletions, we assume HIV-1 evolves by base substitution without selection pressure during the earliest phase of HIV-1 infection prior to the immune response. Unlike phylogenetic methods that follow a lineage backwards to coalescence, we compare the observed data to a model of the diversification of a viral population forward in time. To illustrate the application of these methods, we provide detailed comparisons of the model and simulations results to 306 envelope sequences obtained from eight newly infected subjects at a single time point. The data from 68 patients were in good agreement with model predictions, and hence compatible with a single-strain infection evolving under no selection pressure. The diversity of the samples from the other two patients was too great to be explained by the model, suggesting multiple HIV-1-strains were transmitted. The model can also be applied to longitudinal patient data to estimate within-host viral evolutionary parameters.

Subcutaneous epinephrine in the prehospital setting

OBJECTIVES

To outline current practice regarding the prehospital use of subcutaneous epinephrine, and systematically review the existing literature to determine the level of support for its use in the elderly. Many health care personnel are reluctant to administer subcutaneous epinephrine for potentially life-threatening conditions such as asthma and anaphylaxis in older patients. This sytematic review examined the following focused question: "For older patients not known to have coronary artery disease, does administration of subcutaneous epinephrine carry a significant enough risk of cardiovascular side effects to mandate age as a relative contraindication to self-administration or emergency medical services administration in the prehospital setting?"

METHODS

The MEDLINE and Health Star databases were searched to identify studies evaluating the use of subcutaneous epinephrine in the treatment of asthma and anaphylaxis. Bibliographies from included studies, known reviews, and textbooks were examined to identify additional studies. The strength of evidence presented in each study was assessed in accordance with the classification system proposed by the American Heart Association's Emergency Cardiovascular Care Committee.

RESULTS

The review of the literature revealed only three case reports (level VII evidence) that record adverse reactions of epinephrine when used for anaphylaxis and allergy, while several level III and V studies found no adverse effects when used for asthma. No controlled trials documenting adverse effects were found.

CONCLUSIONS

The authors did not find significant evidence to contraindicate the use of subcutaneous epinephrine in older patients who are not known to have coronary artery disease, who present with either asthma or allergic reactions.

Case design to emphasize population health concepts in problem-based learning

BACKGROUND

Medical training traditionally focuses on disease diagnosis and management. The need to incorporate preventive medicine, economics, and health promotion is increasingly apparent. Because problem-based learning (PBL) encourages multidisciplinary thinking, it is ideal for linking traditional medical education and population-oriented training. Although use of PBL has grown in medical education, cases typically focus upon patho-physiology, diagnosis, and therapy of individuals. Even when cases are intended to integrate multidisciplinary topics such as behavioral sciences or prevention, the biological aspects are emphasized.

PURPOSE

To describe approaches to case design that emphasize population perspectives of health.

DESCRIPTION

Specific examples drawn from actual cases we have used illustrate how five basic components of a case--namely, title, context, intrigue, indicators of problem resolution, and tight structure--facilitate discussion of, and enhance concern for, population issues.

CONCLUSION

The literature indicates that health professional students tend to favor biological over population content in clinical cases. We illustrate how population content can be represented in specifically designed cases.

Ovarian aging and hormone replacement therapy. Hormonal levels, symptoms, and attitudes of African-American and white women

OBJECTIVES

To characterize reproductive hormone levels, symptoms, and attitudes related to menopause among healthy, menstruating white and African-American women aged 44 to 49 years.

DESIGN

Pilot study; cross-sectional survey.

SETTING

Community-based convenience sample of women in the Philadelphia metropolitan area.

PARTICIPANTS

Thirty-three African-American and 35 white women.

MEASUREMENTS

The survey instrument collected demographic data, medical and reproductive history, health practices and behaviors. It included previously validated function, depression, and quality-of-life instruments, and a Menopause Attitude Scale that included two factors, attitudes toward the menopause and attitudes toward medical therapy. Anthropometric measurements were taken at enrollment, and reproductive hormones and daily symptom logs were followed over two menstrual cycles.

MAIN RESULTS

The two groups were comparable in mean age (African-American 46.2 years, white 46.9 years). Serum levels of estradiol, follicle-stimulating hormone, dihydroepiandrosterone-sulfate, and progesterone were comparable. Symptoms were similar in type and frequency. However, the African-American women had significantly more positive attitudes toward menopause, were more likely to rely on family for information about menopause, and were less likely to have been recommended hormone replacement therapy by their physicians. A majority of women in each group expressed satisfaction with the care they had received.

CONCLUSIONS

Perimenopausal African-American and white women have different expectations of menopause and the role of medical care in menopause. This bears directly on women's acceptance of hormone replacement therapy. Conclusions are limited by the small sample size and convenience nature of the study population: further work with larger samples is needed to confirm these apparent differences.

Transthyretin: a choroid plexus-specific transport protein in human brain. The 1986 S. Weir Mitchell award

Plasma transthyretin (TTR, formerly called prealbumin) is a 55-kd protein that participates in the plasma transport of both thyroxine and retinol (vitamin A). TTR concentrations are disproportionately high in human ventricular CSF, suggesting that TTR is either selectively transported across or synthesized de novo within the blood-CSF barrier. To address this question, we adopted a molecular genetic approach; after isolating a cDNA clone encoding human TTR, we previously demonstrated specific TTR messenger RNA (mRNA) synthesis in rat choroid plexus. We have now extended these investigations to the human brain. Northern analysis of postmortem brain homogenates revealed abundant TTR mRNA in choroid plexus, but not in cerebellum or cerebral cortex. Choroid plexus mRNA was readily translated into TTR preprotein in an in vitro translation system. An immunocytochemical survey of human postmortem brain sections revealed the presence of TTR protein specifically and uniquely in the cytoplasm of choroid plexus epithelial cells; these results were corroborated at the mRNA level by an extensive survey of whole rat-brain sections by in situ hybridization. Therefore, within the mammalian CNS, TTR is the first known protein synthesized solely by the choroid plexus, suggesting a special role for TTR in the brain or CSF. Whether this function differs from its established plasma transport functions is presently unknown.