Abstract P4-15-05: The presence of one or multiple foci of microinvasion is not associated with an increased risk of local recurrence in women with ductal carcinoma in situ treated with breast conserving therapy

Background: Ductal Carcinoma in Situ (DCIS) is a non-invasive breast cancer often treated with breast-conserving surgery (BCS) with or without radiotherapy (RT). It is unclear if the presence of microinvasion (MI) (invasion ≤1mm) is associated with an increased risk of LR (DCIS or invasive) or invasive LR compared to women with pure DCIS. In addition, the impact of multiple foci (>2) of MI compared to pure DCIS is also unknown; therefore, it is unclear if some women with MI require more aggressive treatment. We evaluated the impact of the presence of MI and the number of foci of MI on the risks of any LR and invasive LR in a population of women with DCIS with and without MI treated with BCS.

Methods: The cohort includes all women diagnosed with pure DCIS or DCIS with MI in Ontario from 1994-2003 treated with BCS +/- RT. All cases had systematic pathology review to confirm the presence and number of foci of MI. Treatment and outcomes were ascertained through administrative databases and validated by chart review. Cox proportional hazards model was used to evaluate the impact of MI and the number of foci of MI (1 vs >2 foci) on the development of any LR and invasive LR compared to cases with pure DCIS. The 10-yr local recurrence-free survival (LRFS) and invasive LRFS rates were calculated using the Kaplan-Meier approach with differences compared using the log-rank test.

Results: The population cohort includes 2,988 women with DCIS treated by BCS (N=2,721 pure DCIS, N= 267 DCIS with MI). Median follow-up (12 years; p=.23) and median age at diagnosis (58 years; p=.17) were similar in both groups. RT was given in 58% of cases with MI and 51% of cases with pure DCIS (p=.03). Hormonal therapy was utilized in 7.1% of women with MI and 5.3% of women with pure DCIS (p=.22). LR developed in 59 (22.1%) cases with MI and 530 (19.6%) cases of pure DCIS. Women with MI were more likely to have high nuclear grade (p<.001), and larger tumor size (p<.001) compared to those without MI. On multivariable analyses adjusted for age, the presence of 1 focus of MI(HR=.92, 95% CI: .64-1.33) or ≥2 foci of MI (HR=1.26, 95% CI: .85-1.85) was not associated with an increased risk of any LR compared to cases with pure DCIS. Factors associated with any LR were age <50 years at diagnosis, RT, multifocality and high nuclear grade. The presence of 1 focus of MI (HR=.86, 95% CI: .52-1.40) or > 2 foci of MI (HR=1.45, 95% CI: .90-2.32) was also not associated with an increased risk of invasive LR compared to cases of pure DCIS. Among women treated with BCS alone, the 10 year LRFS rates were 80%, 75% and 73% for women with pure DCIS, 1 focus, >2 foci of MI (p=.10). The invasive LRFS rates were 89%, 91% and 85% (p=.26). Among women treated with BCS+RT, the 10 year LRFS rates were 87%, 88% and 80% (p=0.32) for women with pure DCIS, 1 focus or ≥2 foci of MI. The invasive LRFS rates were 93%, 90% and 86% (p=.44). There was no interaction between the presence of MI and RT.

Conclusions: Women with DCIS with one or multiple foci of microinvasion (<1mm) treated by breast conserving therapy do not have an increased risk of LR or invasive LR compared to women with pure DCIS.

Citation Format: Lalani N, Paszat L, Sutradhar R, Gu S, Fong C, Nofech-Mozes S, Hanna W, Tuck A, Youngson B, Miller N, Done SJ, Chang MC, Sengupta S, Elavathil L, Jani PA, Bonin M, Rakovitch E. The presence of one or multiple foci of microinvasion is not associated with an increased risk of local recurrence in women with ductal carcinoma in situ treated with breast conserving therapy [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 P4-15-05.

Abstract P4-04-10: Molecular features of dormancy in ER+ breast cancers

Background:Late recurrence (emergence from dormancy) is characteristic of ER+ breast cancers. Despite adjuvant endocrine therapy, many breast cancers recur decades after their initial diagnosis and treatment. Why this occurs is poorly understood.

Methods: We studied 2 independent datasets of endocrine treated, ER+ breast cancers with up to 20 years follow-up. The 1st comprised matched samples from the primary tumor pretreatment at diagnosis and the first recurrence after or during adjuvant endocrine therapy (all FFPE). The 2nd dataset comprised pretreatment biopsies only (all snap frozen). For both datasets, high quality RNA was amplified, labelled, and subjected to transcriptome analysis using the Affymetrix technology (U133 Plus 2.0). Low quality data were identified using 'simpleaffy' and 'ffpe', and removed; all tools were from the R package unless otherwise noted. Remaining data were normalized using 'frma'. Genes differentially expressed between early (≤3 years) and late (≥ 5 years) were selected using limma. Unsupervised hierarchical clustering and PCA explored the structure of the data.

A similar molecular analysis was done on the 2nd dataset. A classification scheme that robustly separated early from late recurrences was validated in an independent public dataset of comparable patients, array platform, and frozen tissues. We also explored features in pretreatment samples that predetermined response duration.

Results: Genes that separated pretreatment specimens by recurrence time did not separate posttreatment specimens. Specimens did not cluster in patient pairs or by site of recurrence.

8245 genes were differentially expressed between early and late recurrences in the FFPE samples, while 2400 genes were significantly different in the same comparison in the frozen samples. Initial pathway analysis was done on each dataset independently using IPA (Ingenuity® Systems, www.ingenuity.com). 70 canonical pathways were identified in common between the two datasets (pretreatment). We then looked for genes regulated in both datasets (ignores FFPE and frozen tissue as source). There were 279 genes in common that differentially regulated in the same direction (upregulated; downregulated). IPA analysis of these genes identified 49 canonical pathways. We also explored the differentially expressed gene sets using 'GSEA' (www.software.broadinstitute.org/gsea/index.jsp). Pathways consistently associated with early vs. late recurrence include integrin signaling, the unfolded protein response, endoplasmic reticulum stress, actin-based motility, and estrogen biosynthesis.

Conclusion: Analysis of pretreatment tumors can predict early recurrences from those that will remain dormant and recur much later. Recurrent tumors exhibit a remodeled molecular landscape that likely reflects the effects of treatments and/or a recreation of a niche with potentially common features at the site of recurrence. Changes in molecular signaling associated with duration of recurrence are consistent with our experimental model studies in vitro implicating UPR signaling as a major integrator of response to endocrine therapy and duration of survival. Additional data sets are being arrayed and more detailed molecular signaling studies are in progress.

Citation Format: Clarke R, Dixon MJ, Jin L, Turnbull A, Hu R, Zwart A, Wang Y, Xuan J, Sengupta S, Renshaw L, Sims A, Liu MC. Molecular features of dormancy in ER+ breast cancers [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 P4-04-10.

Abstract P2-12-02: Is breast-conserving therapy effective in women with large ductal carcinoma in situ (DCIS) lesions? A population-based analysis

Background: Most women diagnosed with DCIS will be treated by breast-conserving surgery (BCS) with or without radiotherapy (RT). Data on outcomes following breast-conserving therapy are predominantly based on women with small (<25mm) lesions. The paucity of data on outcomes of women with larger (>40mm) DCIS lesions leads to uncertainty of the appropriateness of breast-conserving therapy for women with larger lesions. Specifically, it is unclear if women with large tumors experience higher risks of local recurrence (LR) and invasive LR after BCS+/-RT that would preclude recommendations of breast-conserving therapy. We report the outcomes and evaluate the impact of large tumor size (>40mm) on recurrence risk in a population of women with pure DCIS treated by BCS alone or with RT.

Methods: The cohort includes all women diagnosed with DCIS in Ontario from 1994-2003 treated with BCS +/- RT; 82% had pathology review. Treatment and outcomes were ascertained through administrative databases and validated by chart review. Cox proportional hazards model was used to evaluate the impact of tumor size (≤10mm,11-25mm, 26-39mm, ≥40mm) on the development of any LR (DCIS or invasive) and invasive LR. The 10 and 15-year LR-free survival (LRFS) and invasive LRFS rates were calculated using the Kaplan-Meier method with differences compared using the log-rank test.

Results: The cohort includes 3262 women with DCIS treated by BCS (N=1635 had RT). Median age at diagnosis was 59 years (IQR 50-68 years). Median follow-up was 13 years (IQR 8-15 years). Distribution of tumor size: 707 (22%) ≤10mm, 524 (16%) 11-25mm, 107 (3%) 26-39mm, 84 (3%) ≥40mm, unable to determine in 1840 (56%). Women with lesions ≥ 40mm were more likely to be ≤50 years of age at diagnosis (p=.02), have high nuclear grade (p<.001), multifocality (p<.001), and positive margins (p<.001) compared to women with smaller lesions. On multivariable analyses adjusted for age and year of diagnosis, tumor size ≥40mm was significantly associated with an increased risk of LR compared to size ≤10mm (HR=2.5, 95%CI:1.64-3.81). Other factors associated with LR were age <50 years (p<.001), omission of RT (p<.001), high nuclear grade (p=.002), and multifocality (p=.0008). Tumor size ≥40mm was not significantly associated with an increased risk of invasive LR (HR=1.68, 95%CI:.94-3.04). Women with tumour size ≥40mm treated with BCS alone had lower 10 and 15 year LRFS (53% and 41%) and invasive LRFS rates (78% and 75%) compared to women with smaller lesions. However, women with larger lesions treated with RT had significantly higher LRFS and invasive LRFS rates

Outcomes by tumour size for women with DCIS treated with BCS with or without RT  ≤10mm N=70711-25mm N=52426-39mm N=107≥40mm N=84p-valueBCS AloneLRFS (%)      10 yr85797053<0.001 15 yr81746741  Invasive LRFS (%)      10 yr928786780.03 15 yr89838375 BCS + RTLRFS (%)      10 yr928874850.01 15 yr86847079  Invasive LRFS (%)      10 yr959492910.27 15 yr90918789 

. There was a significant interaction between tumor size ≥40mm and RT (p=.02).

Conclusions: Women with DCIS lesions ≥40mm treated by BCS alone experience significantly higher risks of LR and invasive LR compared to smaller lesions but this risk can be mitigated with the addition of RT.

Citation Format: Lalani N, Paszat L, Nofech-Mozes S, Sutradhar R, Gu S, Hanna W, Fong C, Miller N, Youngson B, Done SJ, Tuck A, Chang MC, Sengupta S, Jani PA, Bonin M, Rakovitch E. Is breast-conserving therapy effective in women with large ductal carcinoma in situ (DCIS) lesions? A population-based analysis [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 P2-12-02.

Patients' preferences for adjuvant sorafenib after resection of renal cell carcinoma in the SORCE trial: what makes it worthwhile?

Background

We sought to determine the survival benefits that patients judged sufficient to warrant adjuvant therapy with sorafenib for 1 year, or for 3 years after resection of renal cell carcinoma in the SORCE trial.

Methods

SORCE participants from all sites in Australia and New Zealand, and selected sites in the UK, completed a validated preferences questionnaire at months 0, 3, 15, and 42 to elicit the minimum survival benefits they judged sufficient to warrant adjuvant sorafenib for 1 year (versus observation), or for 3 years (versus 1 year). The questionnaires used reference survival times of 5 and 15 years; and reference survival rates at 5 years of 65% and 85%.

Results

The 233 participants had a median age of 57 years (range 29-78) and 71% were male. For 1 year of sorafenib versus no adjuvant therapy, the median benefits in survival times judged sufficient to warrant treatment were an extra 9 months beyond 5 years and an extra 1 year beyond 15 years; the median benefit in survival rates were an extra 4% beyond 65% and an extra 3% beyond 85% at 5 years. For 3 years of sorafenib versus 1 year of sorafenib, the median benefit in survival time judged sufficient to warrant extended treatment was an extra 1 year beyond both 5 and 15 years. Participants randomly allocated to treatment with sorafenib judged larger benefits necessary than those allocated to placebo. Participants' preferences were not associated with their baseline characteristics or the interval from randomisation.

Conclusion

Most participants judged an extra year of survival necessary to warrant 1 year of adjuvant sorafenib worthwhile, and an additional year of survival to warrant extending the duration of sorafenib from 1 to 3 years. Patients' preferences are important in shared decision making.

SORCE trial clinical trials number

NCT00492258.

Screening for vision-threatening diabetic retinopathy in South India: comparing portable non-mydriatic and standard fundus cameras and clinical exam

PurposeTo evaluate the sensitivity and specificity of a portable non-mydriatic fundus camera to diagnose vision-threatening diabetic retinopathy (VTDR).Patients and methodsA prospective, single-site, comparative instrument validation study was undertaken at the Aravind Eye Care System. Overall, 155 subjects with and without diabetes were recruited. Images from 275 eyes were obtained with the (1) non-mydriatic Smartscope, (2) mydriatic Smartscope, and (3) mydriatic table-top camera of the macular, nasal, and superotemporal fields. A retina specialist performed a dilated fundus examination (DFE), (reference standard). Two masked retina specialists graded the images. Sensitivity and specificity to detect VTDR with the undilated Smartscope was calculated compared to DFE.ResultsGraders 1 and 2 had a sensitivity of 93% (95% confidence interval (CI): 87-97%) and 88% (95% CI: 81-93%) and a specificity of 84% (95% CI: 77-89%) and 90% (95% CI: 84-94%), respectively, in diagnosing VTDR with the undilated Smartscope compared to DFE. Compared with the dilated Topcon images, graders 1 and 2 had sensitivity of 88% (95% CI: 81-93%) and 82% (95% CI: 73-88%) and specificity of 99% (95% CI: 96-100%) and 99% (95% CI: 95-100%).ConclusionsRemote graders had high sensitivity and specificity in diagnosing VTDR with undilated Smartscope images, suggesting utility where portability is a necessity.

Bilateral Cataract following Lightning Injury

PURPOSE

To report a case of bilateral cataract with posterior vitreous detachment induced by lightning injury.

METHODS

A case report of 30 year old man injured by lightning.

RESULTS

The patient developed visually significant bilateral cataract after four years of the initial insult on the scalp. The exit wound was noted on the right foot. Fundus evaluation after cataract extraction revealed posterior vitreous detachment.

CONCLUSIONS

Lightning can induce various ocular complications. Decrease in vision due to cataract is usually seen years after the initial lightning injury as the initial changes are in the mid-periphery and often missed in the acute setting. Posterior vitreous detachment induced by lightning can rarely lead to retinal tear formation and subsequently retinal detachment. The severity of entry and exit may not give a true picture of the internal organ damage.

Biomarker development for hepatocellular carcinoma early detection: current and future perspectives

Early detection of hepatocellular carcinoma (HCC) leads to improved survival; however, current early detection strategies for HCC surveillance are ineffective. Thus, there has been interest in developing biomarkers to aid in the early detection HCC. In this review, we discuss the five phases of biomarker discovery that are necessary for clinical implementation. We also describe the most promising investigational biomarkers and their phase of discovery. We review several promising technologies for the early detection of HCC, including miRNA, metabolomics and proteomics. Promisingly, there are samples from multiple longitudinal cohorts of patients with cirrhosis in the USA that are being collected in order to validate candidate biomarkers for HCC. A biomarker-based strategy has the potential to become the primary surveillance method for HCC detection.

Description of a multi-university education and collaborative care child psychiatry access program: New York State's CAP PC

OBJECTIVE

Although, child mental health problems are widespread, few get adequate treatment, and there is a severe shortage of child psychiatrists. To address this public health need many states have adopted collaborative care programs to assist primary care to better assess and manage pediatric mental health concerns. This report adds to the small literature on collaborative care programs and describes one large program that covers most of New York state.

PROGRAM DESCRIPTION

CAP PC, a component program of New York State's Office of Mental Health (OMH) Project TEACH, has provided education and consultation support to primary care providers covering most of New York state since 2010. The program is uniquely a five medical school collaboration with hubs at each that share one toll free number and work together to provide education and consultation support services to PCPs.

METHODS

The program developed a clinical communications record to track information about all consultations which forms the basis of much of this report. 2-week surveys following consultations, annual surveys, and pre- and post-educational program evaluations have also been used to measure the success of the program.

RESULTS

CAP PC has grown over the 6years of the program and has provided 8013 phone consultations to over 1500 PCPs. The program synergistically provided 17,523 CME credits of educational programming to 1200 PCPs. PCP users of the program report very high levels of satisfaction and self reported growth in confidence.

CONCLUSIONS

CAP PC demonstrates that large-scale collaborative consultation models for primary care are feasible to implement, popular with PCPs, and can be sustained. The program supports increased access to child mental health services in primary care and provides child psychiatric expertise for patients who would otherwise have none.

Longterm storage of post-packaged bread by controlling spoilage pathogens using Lactobacillus fermentum C14 isolated from homemade curd

One potent lactic acid bacterial strain C14 with strong antifungal activity was isolated from homemade curd. Based on morphological as well as biochemical characters and 16S rDNA sequence homology the strain was identified as Lactobacillus fermentum. It displayed a wide antimicrobial spectrum against both Gram-positive and Gram-negative pathogenic bacteria, and also against number of food spoilage, plant and human pathogenic fungi. The cell free supernatant (CFS) of the strain C14 was also effective against the fungi tested. Inhibition of radial growth of Penicillium digitatum, Trichophyton rubrum and Mucor sp. was noticed in the presence of CFS of C14 even at low concentration (1%). More than 94.3 ± 1.6% and 91.5 ± 2.2% inhibition of conidial germination of P. digitatum and Mucor sp. were noticed in the presence of 10-fold-concentrated CFS of C14. Massive deformation of the fungal mycelia was observed by SEM studies, and losses of cellular proteins and DNA are also evident upon its treatment with C14. HPLC analysis revealed the presence of phenyl lactic acid, lactic acid along with some unidentified compounds in the antifungal extract. Challenge experiment showed immense potential of the strain C14 in preventing the spoilage of bread samples caused by Mucor sp. and Bacillus subtilis. The bread samples remained fresh upto 25 days even after inoculation with Mucor sp. (3.7 × 104 spores /ml) and B. subtilis (4.6 × 104 CFU /ml). Along with the antifungal properties, the isolated lactic acid bacterial strain also showed very good antioxidant activities. Unchanged level of liver enzymes serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase in albino mice upon feeding with C14 also suggested non-toxic nature of the bacterial isolate.

Activation of tumor suppressor LKB1 by honokiol abrogates cancer stem-like phenotype in breast cancer via inhibition of oncogenic Stat3

Tumor suppressor and upstream master kinase Liver kinase B1 (LKB1) plays a significant role in suppressing cancer growth and metastatic progression. We show that low-LKB1 expression significantly correlates with poor survival outcome in breast cancer. In line with this observation, loss-of-LKB1 rendered breast cancer cells highly migratory and invasive, attaining cancer stem cell-like phenotype. Accordingly, LKB1-null breast cancer cells exhibited an increased ability to form mammospheres and elevated expression of pluripotency-factors (Oct4, Nanog and Sox2), properties also observed in spontaneous tumors in Lkb1^-/- mice. Conversely, LKB1-overexpression in LKB1-null cells abrogated invasion, migration and mammosphere-formation. Honokiol (HNK), a bioactive molecule from Magnolia grandiflora increased LKB1 expression, inhibited individual cell-motility and abrogated the stem-like phenotype of breast cancer cells by reducing the formation of mammosphere, expression of pluripotency-factors and aldehyde dehydrogenase activity. LKB1, and its substrate, AMP-dependent protein kinase (AMPK) are important for HNK-mediated inhibition of pluripotency factors since LKB1-silencing and AMPK-inhibition abrogated, while LKB1-overexpression and AMPK-activation potentiated HNK's effects. Mechanistic studies showed that HNK inhibited Stat3-phosphorylation/activation in an LKB1-dependent manner, preventing its recruitment to canonical binding-sites in the promoters of Nanog, Oct4 and Sox2. Thus, inhibition of the coactivation-function of Stat3 resulted in suppression of expression of pluripotency factors. Further, we showed that HNK inhibited breast tumorigenesis in mice in an LKB1-dependent manner. Molecular analyses of HNK-treated xenografts corroborated our in vitro mechanistic findings. Collectively, these results present the first in vitro and in vivo evidence to support crosstalk between LKB1, Stat3 and pluripotency factors in breast cancer and effective anticancer modulation of this axis with HNK treatment.

Single-Step Step Ladder Expansive Cranioplasty

Background Recently, a concept of an “expansive cranioplasty” was forwarded as a feasible single-step alternative to performing a decompressive hemicraniectomy followed by cranioplasty at a later date.

Materials and Methods Procedure of single-step step ladder expansive cranioplasty following craniotomy with removal of subdural hematoma (SDH) was done in a case of acute SDH at our center. The author presents the clinical presentation, operative steps, pre- and postoperative neuroimagings, and outcome of the case.

Results Postoperative NCCT of the head film showed an increase in biparietal diameter by 10 mm. Measured from the craniectomy margin, the distance of the inner table of the bone was 2.81 mm. Preoperative midline shift of 10.2 mm reduced to 7.9 mm, whereas the GCS improved from E1VTM3 to E2VTM5 in the immediate postoperative period. On his review at the end of 3 months, the patient had no surgery-related complication.

Conclusion “Step ladder expansive cranioplasty” has a promise and deserves a trial in more number of cases. If proven acceptable, it can be especially useful for patients for whom coming back for a second surgery may not be all that easy.

High resolution anatomical and quantitative MRI of the entire human occipital lobe ex vivo at 9.4T

Several magnetic resonance imaging (MRI) contrasts are sensitive to myelin content in gray matter in vivo which has ignited ambitions of MRI-based in vivo cortical histology. Ultra-high field (UHF) MRI, at fields of 7 T and beyond, is crucial to provide the resolution and contrast needed to sample contrasts over the depth of the cortex and get closer to layer resolved imaging. Ex vivo MRI of human post mortem samples is an important stepping stone to investigate MRI contrast in the cortex, validate it against histology techniques applied in situ to the same tissue, and investigate the resolutions needed to translate ex vivo findings to in vivo UHF MRI. Here, we investigate key technology to extend such UHF studies to large human brain samples while maintaining high resolution, which allows investigation of the layered architecture of several cortical areas over their entire 3D extent and their complete borders where architecture changes. A 16 channel cylindrical phased array radiofrequency (RF) receive coil was constructed to image a large post mortem occipital lobe sample (~80×80×80 mm³) in a wide-bore 9.4 T human scanner with the aim of achieving high-resolution anatomical and quantitative MR images. Compared with a human head coil at 9.4 T, the maximum Signal-to-Noise ratio (SNR) was increased by a factor of about five in the peripheral cortex. Although the transmit profile with a circularly polarized transmit mode at 9.4 T is relatively inhomogeneous over the large sample, this challenge was successfully resolved with parallel transmit using the kT-points method. Using this setup, we achieved 60μm anatomical images for the entire occipital lobe showing increased spatial definition of cortical details compared to lower resolutions. In addition, we were able to achieve sufficient control over SNR, B₀ and B₁ homogeneity and multi-contrast sampling to perform quantitative T₂* mapping over the same volume at 200 μm. Markov Chain Monte Carlo sampling provided maximum posterior estimates of quantitative T₂* and their uncertainty, allowing delineation of the stria of Gennari over the entire length and width of the calcarine sulcus. We discuss how custom RF receive coil arrays built to specific large post mortem sample sizes can provide a platform for UHF cortical layer-specific quantitative MRI over large fields of view.

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Custom-built 16 channel 9.4 T RF-coil to image large post mortem samples at high resolution.

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Parallel transmit techniques allow homogenization of B₁⁺ for 3D GRE imaging at UHF.

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60 μm anatomical MRI of the entire human occipital lobe.

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200 μm isotropic quantitative T₂^* mapping of the entire human occipital lobe.

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A platform for future UHF cortical layer specific qMRI over large FoVs.

Abstract P3-03-18: An ex-vivo platform predicts anti-tumor outcome of metabolically-targeted, algorithm-driven combination therapy in triple-negative breast cancer

Cancer cells undergo phenotypic cell state transitions in response to chemotherapy as a mechanism that can confer transient resistance. However, such cell state transitions can also unlock unique vulnerabilities that can be exploited using temporally-sequenced combination chemotherapy. Here, utilizing a primary breast cancer ex-vivo functional assay that captures tumor heterogeneity, we report that in response to a chemotherapeutic agent, a subset of cancer cells can mount an acutely-induced phenotypic adaptive resistance to future cytotoxic pressure via the transient acquisition of a unique metabolic state defined by augmented glycolysis together with mitochondrial proficiency. These cells activate two complex, temporally-interdependent pathways that enable a glucose shunt towards the pentose phosphate pathway (PPP), which confers an adaptive cross-tolerance to different chemotherapeutic agents. Mathematically modeling these pathways, and simulating drug schedules, we define a rationally-designed 3-drug combination therapy of metabolic inhibitors and cytotoxic agents, which results in improved cancer survival. Our findings highlight a new bioenergetics-based adaptive resistance mechanism through which cancer cells can survive combinations of chemotherapy. Administration of metabolic inhibitors in rational, temporal sequence with existing chemotherapy can emerge as a new paradigm in the treatment of cancer.

Citation Format: Goldman A, Majumder B, Dhawan A, Kohandel M, Majumder P, Sengupta S. An ex-vivo platform predicts anti-tumor outcome of metabolically-targeted, algorithm-driven combination therapy in triple-negative breast cancer [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 P3-03-18.

Abstract P3-17-01: Long-term rates of breast preservation after breast-conserving therapy for ductal carcinoma in situ

Background: Despite evidence that radiotherapy (RT) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) halves the risk of recurrence, the benefit of RT in the management of DCIS continues to be a matter of controversy. One argument against the use of RT after BCS is that patients who develop ipsilateral local recurrence (LR) can be salvaged with further breast-conserving surgery such that the omission of RT will lead to high rates of breast preservation while minimizing exposure to RT. Breast preservation is an important determinant of quality of life for women with early stage breast cancer and DCIS. Yet the management of LR and the impact of RT on the resultant long-term risks of bilateral breast preservation in a population of women with DCIS are unclear. We assessed the treatment of LR, the impact of RT on the use of salvage mastectomy and the long-term risks of bilateral breast preservation achieved in a population of women with DCIS treated with BCS alone or BCS+RT.

Methods: A population-based analysis of women diagnosed with DCIS from 1994-2003 treated with BCS alone or BCS+RT with pathology review. Treatment and outcomes, including the development of LR and contralateral breast events, were determined by administrative databases with validation by review of operative or pathology reports. Median follow-up was 10.2 years for cases treated by BCS alone, 11.6 years for those treated by BCS+RT. We used a propensity-adjusted Cox proportional hazards model to evaluate factors associated with the use of salvage mastectomy for LR and to evaluate factors associated with any mastectomy. We assessed the risk of long-term breast preservation by calculating the KM 10-year risk of ipsilateral mastectomy and any mastectomy.

Results: The population cohort includes 3303 women with pure DCIS;1649 (50%) were treated by BCS alone, 1654 (50%) received BCS+RT. Women treated with RT had more high risk features of DCIS than those treated by BCS alone. LR developed in 343 (21%) women treated by BCS alone and in 257 (15.5%) women treated by BCS+RT (p<0.01). Most women who developed LR received salvage mastectomy, irrespective of age at diagnosis and histology. Salvage mastectomy was used in 57.4% (197/343) of cases that recurred after BCS alone and in 67.6% (173/257) that recurred after BCS+RT. The likelihood of receiving salvage mastectomy for LR was similar in patients initially treated by BCS+RT vs. those initially treated BCS alone. Most (90%) of mastectomies were performed for a LR. Overall, individuals initially treated by BCS+RT had a 29% lower probability of having a mastectomy at 10 years compared to those treated by BCS alone (HR=0.71, 95%CI: 0.60,0.84,p<0.0001). The 10 year mastectomy-free survival rates are 82.7% for women initially treated by BCS alone and 87.3% for those treated by BCS+RT (p=0.0096).

Conclusion: Women who received RT after BCS for DCIS experience a greater likelihood of long-term bilateral breast preservation. This is attributable to the lower risks of LR and that most local recurrences after breast-conserving therapy are treated by salvage mastectomy. Long-term breast preservation should be considered in discussions weighing the benefits and risks of RT after conservative surgery for DCIS.

Citation Format: Rakovitch E, Nofech-Mozes S, Hanna W, Gu S, Fong C, Tuck A, Sengupta S, Elavathil L, Jani P, Done S, Miller N, Youngson B, Bonin M, Chang M, Paszat L. Long-term rates of breast preservation after breast-conserving therapy for ductal carcinoma in situ [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 P3-17-01.

Abstract P6-09-04: Nuclear grade has a limited role in predicting recurrence in DCIS following breast conserving surgery: A population-based study

This abstract was not presented at the symposium.