The PINC trial (NCT01023477) examined the dosage efficacy of oral chloroquine (CQ), an autophagy inhibitor, as a neoadjuvant therapy to reduce the volume, cause regression and decrease the recurrence of breast ductal carcinoma in situ (DCIS), for any grade or ER/PR/Her2 status. Study Objectives: Establish the safety of preventive doses of chloroquine in patients receiving external beam radiation. Elucidate functional molecular and cellular impacts of in vivo autophagy pathway treatment for DCIS. Study the impact of autophagy inhibitors on the MRI characteristics of DCIS lesions. Study the molecular cytogenetic profile of DCIS lesions before and after therapy. This trial implemented a general strategy to accelerate the pace of community-based translational research. Technology for providing immediate feedback on the therapeutic efficacy at the molecular level can be broadly extended to other trials. Methodology: 12 patients diagnosed with DCIS (any grade or ER/PR/Her2 status) were enrolled and randomly assigned to receive CQ at 250mg/week (n=5) or 500mg/week (n=7) for 4 weeks, followed by standard of care surgical therapy. MRI was performed before/after CQ treatment. DCIS spheroid forming cells were isolated and propagated from fresh human DCIS lesions. DCIS cells were characterized by organ culture, xenograft transplantation, molecular cytogenetics, and 59 cell signaling kinases were quantified by Reverse Phase Protein Microarrays. Results: 12 patients completed 4 weeks of CQ treatment prior to surgical excision of their DCIS lesion, with 1 yr follow-up information. CQ treatment reduced PCNA proliferation index in DCIS lesions compared to untreated controls (p=0.001) and inhibited autophagic flux (LC3B positive puncta by IHC). CQ reduced the number of mammospheres in organoid culture without altering copy number variation. Xenograft transplants in NOD/SCID mouse mammary fat pads failed to generate tumors (n=4). 7/12 patients exhibited a reduction in lesion diameter by MRI, 3/12 patients exhibited no measurable change, and 2/12 had a slight increase. Calcium export channel protein (PMCA2) co-localized with 3+ HER2 positive DCIS lesions. Tumor infiltrating macrophages migrated into DCIS ducts following CQ therapy compared to controls (p=0.006). Conclusion: Oral chloroquine, as anti-autophagy therapy, generates a measurable reduction in proliferation of DCIS lesions and enhances immune cell migration into the duct. Citation Format: Virginia A. Espina, Lance Liotta, Svetlana Rassulova, Holly Gallimore, Thalia Grant-Wisdom, Geetha Menezes, Hassan Nayer, Kirsten Edmiston. PINC trial: Preventing invasive breast neoplasia with chloroquine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT140. doi:10.1158/1538-7445.AM2017-CT140

Background Childhood acute lymphoblastic leukemia (ALL) has a very high cure rate, however, long-term survivors are at increased risk of chronic medical illnesses that are likely in part microbiome mediated. Previous studies comparing microbiota of pediatric ALL survivors to healthy siblings showed altered composition in survivors. Longitudinal microbiome changes through treatment leading to these alterations are unknown. Methods Children with ALL were enrolled and stool samples were collected at diagnosis and at the end of induction, consolidation, interim maintenance I, delayed intensification, interim maintenance II, as well as approximately 3 months and 6 months into maintenance. Stool samples from healthy siblings were used as controls. Clinical data were collected. DNA was extracted from stool samples and 16S rRNA was sequenced for analysis of hypervariable region V4. Differences in alpha and beta diversities and relative abundance of taxa were calculated between phases and with sibling controls. Results 35 ALL patients age 3 months-19 years were included. The diagnoses were 14 standard risk pre-B ALL, 14 high risk pre-B ALL, 6 T-ALL, and 1 relapsed pre-B ALL. Stool samples were sequenced from 19 healthy siblings. Statistically significant differences in alpha diversity (Shannon) were found between healthy siblings and ALL patients during the more intense chemotherapy phases before low dose maintenance (Figure 1A). Beta diversity (Bray-Curtis), was significantly different between microbiota of ALL patients at diagnosis and their siblings, as well as between ALL patients at diagnosis and at each of the subsequent treatment phases (Figure 1B). Longitudinal comparison using multivariate analysis showed that leukemia risk group (high risk vs standard risk) and antibiotic treatment were significant factors in beta diversity changes. The relative abundance of microbes showed that with treatment, ALL patients exhibit a significant decrease in the phylum Verrucomicrobiota, driven by the genus Akkermansia, which is beneficial to health and is associated with protection against obesity and other chronic inflammatory diseases (Figure 2). Proteobacteria and Fusobacteria, which include proinflammatory species, were increased. Conclusion Pediatric ALL patients have decreased diversity of gut microbes at diagnosis and during treatment. The types of gut microbes harbored in ALL patients are already different than their siblings at diagnosis and continue to change during treatment, but may begin to recover in low dose maintenance therapy. Taxa considered to be beneficial are depleted, while more pathogenic microbes become prominent. Microbiota changes are likely influenced by intensity of chemotherapy and antibiotic exposure. Continued longitudinal follow up is needed to determine whether these changes correlate with adverse long term health outcomes. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Background Clostridioides difficile infection (CDI) is frequent in pediatric patients with acute lymphoblastic leukemia (ALL). Studies have shown upwards of 20% positivity rate in CDI testing among pediatric oncology patients, and up to several percent in pediatric ALL patients in the first 180 days of diagnosis. Antibiotic usage has been variably linked to CDI positivity in these populations. As CDI testing is usually done in symptomatic patients, the question of C. difficile carriage versus CDI has not been addressed. We and others have shown that microbiome is altered in pediatric ALL patients and survivors. We conducted a longitudinal stool microbiome study in pediatric ALL patients and tested the hypothesis that alteration of the microbiome during ALL treatment promotes C. difficile carriage. Methods Children with ALL were prospectively recruited on a rolling basis and stool samples were collected at diagnosis (Dx) and at the end of induction (EOI), consolidation (EOC), interim maintenance I (IMI), delayed intensification (DI), interim maintenance II (IMII), as well as approximately 3 months and 6 months into maintenance (M3, M6). Stool samples from healthy siblings were used as controls. TaqMan-based quantitative-PCR (qPCR) was performed on DNA extracted from stool samples to detect C. diff 16S rRNA, tcdA, (Toxin A) and tcdB (Toxin B) genes . Samples positive or either tcdA or tcdB, or both, were designated positive for toxigenic C. difficile. 16S rRNA hypervariable region V4 was sequenced and analyzed for microbiome diversity and relative abundance of microbiota. Results 32 ALL patients age 3 months-19 years were included. The diagnoses were 12 standard risk and 14 high risk pre-B ALL, 5 T-ALL, and 1 relapsed pre-B ALL. Stool samples were collected from 18 healthy siblings. The numbers of samples tested at each treatment phase were: 29 Dx, 24 EOI, 23 EOC, 25 IMI, 21 DI, 6 IMII, 14 M3, 7 M6. No patient had symptoms suggestive of CDI, and no patient was clinically tested or treated for CDI. Total number of stool samples tested was 149, of which 43 (29%) were positive for toxigenic C. difficile (Figure 1). At diagnosis, 2/29 (7%) patients were positive, compared to 2/18 (11%) in healthy siblings. At EOI, positivity rate increased to 17%, then up to 40% - 52% at EOC, IMI, and DI. C. difficile positivity were lower around 30% at M3 and M6, although few patients reached maintenance to contribute samples for analysis. Twenty-five patients (78%) were positive at some phase. Longitudinal analysis of individual patients showed that C. difficile positivity was intermittent through treatment phases; only 3 patients remained persistently positive. Seven patients (22%) were never positive. Multivariate analysis showed that EOC, IMI, and DI treatment phases were significant risk factors for C. difficile carriage. Neither the number of antibiotics nor the number of antibiotic courses administered was significant. Leukemia risk stratification (high risk versus standard risk) also did not correlate with C. difficile positivity. Microbiome analysis showed statistically significant differences in relative abundance of certain taxa between C. diff positive and negative samples at the class, order, and family levels (Figure 2). Examples include depletion of the class Verrucomicrobiae, which contains protective Akkermansia, and depletion of the common taxa Bifidobacteriaceae and Ruminococcaceae. Conclusion Longitudinal PCR testing of toxigenic C. difficile in pediatric ALL patients demonstrated increased C. difficile prevalence further into treatment phases. C. difficile carriage correlated significantly with depletion of several bacterial taxa, as microbiome diversity decreased overall with successive treatment phases. Our data lend support to the hypothesis that altered microbiome in ALL treatment allows permissibility for C. difficile carriage. In addition, no C. difficile positive patient had symptoms of CDI, therefore, caution must be taken in clinical testing, as there is a high asymptomatic carriage rate. Further longitudinal testing during maintenance and off-therapy is needed to see if C. difficile carriage rate returns to baseline and correlates with recovery of gut microbiome. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.