A Modular Trial of Androgen Signaling Inhibitor Combinations Testing a Risk-Adapted Strategy in Patients with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

To determine the efficacy and safety of risk-adapted combinations of androgen signaling inhibitors and inform disease classifiers for metastatic castration-resistant prostate cancers (mCRPC).

EXPERIMENTAL DESIGN

In a modular, randomized phase II trial, 192 men were treated with 8 weeks of abiraterone acetate, prednisone and apalutamide (AAPA; Module 1), then allocated to Modules 2 or 3 based on Satisfactory (≥50% PSA decline from baseline and <5 CTC/7.5 mL) versus Unsatisfactory status. Men in the former were randomized to continue AAPA alone (Module 2A) or with ipilimumab (Module 2B). Men in the latter had carboplatin+cabazitaxel added to AAPA (Module 3). Optional baseline biopsies were subject to correlative studies.

RESULTS

Median overall survival (from allocation) was 46.4 (95% CI 39.2, 68.2), 41.4 (95% CI 33.3, 49.9) and 18.7 (95% CI 14.3, 26.3) months in Modules 2A (n=64), 2B (n=64) and 3 (n=59) respectively. Toxicities were within expectations. Of 192 eligible patients, 154 (80.2%) underwent pre-treatment metastatic biopsies. The aggressive variant prostate cancer molecular profile (defects in ≥2 of p53, RB1, and PTEN) was associated with Unsatisfactory status. Exploratory analyses suggested SPP1+ and IGFBP2+ macrophages, druggable myeloid cell markers, and germline pathogenic mutations were enriched in the Unsatisfactory group.

CONCLUSIONS

Adding ipilimumab to AAPA did not improve outcomes in men with androgen responsive mCRPC. Despite the addition of carboplatin+cabazitaxel, men in the Unsatisfactory group had shortened survivals. Adaptive designs can enrich for biologically and clinically relevant disease subgroups, to contribute to the development of marker-informed, risk-adapted therapy strategies in men with prostate cancer.

Durvalumab and tremelimumab before surgery in patients with hormone receptor positive, HER2-negative stage II-III breast cancer

A clinical trial was conducted to assess the feasibility of enrolling patients with Stage II or III hormone receptor positive (HR+)/HER2-negative breast cancer to pre-operative dual PD-L1/CTLA-4 checkpoint inhibition administered prior to neoadjuvant chemotherapy (NACT). Eight eligible patients were treated with upfront durvalumab and tremelimumab for two cycles. Patients then received NACT prior to breast surgery. Seven patients had baseline and interval breast ultrasounds after combination immunotherapy and the responses were mixed: 3/7 patients experienced a ≥30% decrease in tumor volume, 3/7 a ≥30% increase, and 1 patient had stable disease. At the time of breast surgery, 1/8 patients had a pathologic complete response (pCR). The trial was stopped early after 3 of 8 patients experienced immunotherapy-related toxicity or suspected disease progression that prompted discontinuation or a delay in the administration of NACT. Two patients experienced grade 3 immune-related adverse events (1 with colitis, 1 with endocrinopathy). Analysis of the tumor microenvironment after combination immunotherapy did not show a significant change in immune cell subsets from baseline. There was limited benefit for dual checkpoint blockade administered prior to NACT in our study of 8 patients with HR+/HER2-negative breast cancer.

Investigative needle core biopsies for multi-omics in Glioblastoma

Glioblastoma (GBM) is a primary brain cancer with an abysmal prognosis and few effective therapies. The ability to investigate the tumor microenvironment before and during treatment would greatly enhance both understanding of disease response and progression, as well as the delivery and impact of therapeutics. Stereotactic biopsies are a routine surgical procedure performed primarily for diagnostic histopathologic purposes. The role of investigative biopsies - tissue sampling for the purpose of understanding tumor microenvironmental responses to treatment using integrated multi-modal molecular analyses ('Multi-omics") has yet to be defined. Secondly, it is unknown whether comparatively small tissue samples from brain biopsies can yield sufficient information with such methods. Here we adapt stereotactic needle core biopsy tissue in two separate patients. In the first patient with recurrent GBM we performed highly resolved multi-omics analysis methods including single cell RNA sequencing, spatial-transcriptomics, metabolomics, proteomics, phosphoproteomics, T-cell clonotype analysis, and MHC Class I immunopeptidomics from biopsy tissue that was obtained from a single procedure. In a second patient we analyzed multi-regional core biopsies to decipher spatial and genomic variance. We also investigated the utility of stereotactic biopsies as a method for generating patient derived xenograft models in a separate patient cohort. Dataset integration across modalities showed good correspondence between spatial modalities, highlighted immune cell associated metabolic pathways and revealed poor correlation between RNA expression and the tumor MHC Class I immunopeptidome. In conclusion, stereotactic needle biopsy cores are of sufficient quality to generate multi-omics data, provide data rich insight into a patient's disease process and tumor immune microenvironment and can be of value in evaluating treatment responses.

One sentence summary

Integrative multi-omics analysis of stereotactic needle core biopsies in glioblastoma.

Exercise Training Reduces the Inflammatory Response and Promotes Intestinal Mucosa-Associated Immunity in Lynch Syndrome

PURPOSE

Lynch syndrome (LS) is a hereditary condition with a high lifetime risk of colorectal and endometrial cancers. Exercise is a non-pharmacologic intervention to reduce cancer risk, though its impact on patients with LS has not been prospectively studied. Here, we evaluated the impact of a 12-month aerobic exercise cycling intervention in the biology of the immune system in LS carriers.

PATIENTS AND METHODS

To address this, we enrolled 21 patients with LS onto a non-randomized, sequential intervention assignation, clinical trial to assess the effect of a 12-month exercise program that included cycling classes 3 times weekly for 45 minutes versus usual care with a one-time exercise counseling session as control. We analyzed the effects of exercise on cardiorespiratory fitness, circulating, and colorectal-tissue biomarkers using metabolomics, gene expression by bulk mRNA sequencing, and spatial transcriptomics by NanoString GeoMx.

RESULTS

We observed a significant increase in oxygen consumption (VO2peak) as a primary outcome of the exercise and a decrease in inflammatory markers (prostaglandin E) in colon and blood as the secondary outcomes in the exercise versus usual care group. Gene expression profiling and spatial transcriptomics on available colon biopsies revealed an increase in the colonic mucosa levels of natural killer and CD8+ T cells in the exercise group that were further confirmed by IHC studies.

CONCLUSIONS

Together these data have important implications for cancer interception in LS, and document for the first-time biological effects of exercise in the immune system of a target organ in patients at-risk for cancer.

Myeloid-specific KDM6B inhibition sensitizes glioblastoma to PD1 blockade

Glioblastoma (GBM) tumors are enriched in immune-suppressive myeloid cells and are refractory to immune checkpoint therapy (ICT). Targeting epigenetic pathways to reprogram the functional phenotype of immune-suppressive myeloid cells to overcome resistance to ICT remains unexplored. Single-cell and spatial transcriptomic analyses of human GBM tumors demonstrated high expression of an epigenetic enzyme-histone 3 lysine 27 demethylase (KDM6B)-in intratumoral immune-suppressive myeloid cell subsets. Importantly, myeloid cell-specific Kdm6b deletion enhanced proinflammatory pathways and improved survival in GBM tumor-bearing mice. Mechanistic studies showed that the absence of Kdm6b enhances antigen presentation, interferon response and phagocytosis in myeloid cells by inhibition of mediators of immune suppression including Mafb, Socs3 and Sirpa. Further, pharmacological inhibition of KDM6B mirrored the functional phenotype of Kdm6b-deleted myeloid cells and enhanced anti-PD1 efficacy. This study thus identified KDM6B as an epigenetic regulator of the functional phenotype of myeloid cell subsets and a potential therapeutic target for enhanced response to ICT.

Inflammation induced by tumor-associated nerves promotes resistance to anti-PD-1 therapy in cancer patients and is targetable by interleukin-6 blockade

While the nervous system has reciprocal interactions with both cancer and the immune system, little is known about the potential role of tumor associated nerves (TANs) in modulating anti-tumoral immunity. Moreover, while peri-neural invasion is a well establish poor prognostic factor across cancer types, the mechanisms driving this clinical effect remain unknown. Here, we provide clinical and mechniastic association between TANs damage and resistance to anti-PD-1 therapy. Using electron microscopy, electrical conduction studies, and tumor samples of cutaneous squamous cell carcinoma (cSCC) patients, we showed that cancer cells can destroy myelin sheath and induce TANs degeneration. Multi-omics and spatial analyses of tumor samples from cSCC patients who underwent neoadjuvant anti-PD-1 therapy demonstrated that anti-PD-1 non-responders had higher rates of peri-neural invasion, TANs damage and degeneration compared to responders, both at baseline and following neoadjuvant treatment. Tumors from non-responders were also characterized by a sustained signaling of interferon type I (IFN-I) - known to both propagate nerve degeneration and to dampen anti-tumoral immunity. Peri-neural niches of non-responders were characterized by higher immune activity compared to responders, including immune-suppressive activity of M2 macrophages, and T regulatory cells. This tumor promoting inflammation expanded to the rest of the tumor microenvironment in non-responders. Anti-PD-1 efficacy was dampened by inducing nerve damage prior to treatment administration in a murine model. In contrast, anti-PD-1 efficacy was enhanced by denervation and by interleukin-6 blockade. These findings suggested a potential novel anti-PD-1 resistance drived by TANs damage and inflammation. This resistance mechanism is targetable and may have therapeutic implications in other neurotropic cancers with poor response to anti-PD-1 therapy such as pancreatic, prostate, and breast cancers.

Validity Assessment of an Automated Brain Morphometry Tool for Patients with De Novo Memory Symptoms

BACKGROUND AND PURPOSE

Automated volumetric analysis of structural MR imaging allows quantitative assessment of brain atrophy in neurodegenerative disorders. We compared the brain segmentation performance of the AI-Rad Companion brain MR imaging software against an in-house FreeSurfer 7.1.1/Individual Longitudinal Participant pipeline.

MATERIALS AND METHODS

T1-weighted images of 45 participants with de novo memory symptoms were selected from the OASIS-4 database and analyzed through the AI-Rad Companion brain MR imaging tool and the FreeSurfer 7.1.1/Individual Longitudinal Participant pipeline. Correlation, agreement, and consistency between the 2 tools were compared among the absolute, normalized, and standardized volumes. Final reports generated by each tool were used to compare the rates of detection of abnormality and the compatibility of radiologic impressions made using each tool, compared with the clinical diagnoses.

RESULTS

We observed strong correlation, moderate consistency, and poor agreement between absolute volumes of the main cortical lobes and subcortical structures measured by the AI-Rad Companion brain MR imaging tool compared with FreeSurfer. The strength of the correlations increased after normalizing the measurements to the total intracranial volume. Standardized measurements differed significantly between the 2 tools, likely owing to differences in the normative data sets used to calibrate each tool. When considering the FreeSurfer 7.1.1/Individual Longitudinal Participant pipeline as a reference standard, the AI-Rad Companion brain MR imaging tool had a specificity of 90.6%-100% and a sensitivity of 64.3%-100% in detecting volumetric abnormalities. There was no difference between the rate of compatibility of radiologic and clinical impressions when using the 2 tools.

CONCLUSIONS

The AI-Rad Companion brain MR imaging tool reliably detects atrophy in cortical and subcortical regions implicated in the differential diagnosis of dementia.

Immune and pathologic responses in patients with localized prostate cancer who received daratumumab (anti-CD38) or edicotinib (CSF-1R inhibitor)

BACKGROUND

The prostate tumor microenvironment (TME) is immunosuppressive, with few effector T cells and enrichment of inhibitory immune populations, leading to limited responses to treatments such as immune checkpoint therapies (ICTs). The immune composition of the prostate TME differs across soft tissue and bone, the most common site of treatment-refractory metastasis. Understanding immunosuppressive mechanisms specific to prostate TMEs will enable rational immunotherapy strategies to generate effective antitumor immune responses. Daratumumab (anti-CD38 antibody) and edicotinib (colony-stimulating factor-1 receptor (CSF-1R) inhibitor) may alter the balance within the prostate TME to promote antitumor immune responses.

HYPOTHESIS

Daratumumab or edicotinib will be safe and will alter the immune TME, leading to antitumor responses in localized prostate cancer.

PATIENTS AND METHODS

In this presurgical study, patients with localized prostate cancer received 4 weekly doses of daratumumab or 4 weeks of daily edicotinib prior to radical prostatectomy (RP). Treated and untreated control (Gleason score ≥8 in prostate biopsy) prostatectomy specimens and patient-matched pre- and post-treatment peripheral blood mononuclear cells (PBMCs) and bone marrow samples were evaluated. The primary endpoint was incidence of adverse events (AEs). The secondary endpoint was pathologic complete remission (pCR) rate.

RESULTS

Twenty-five patients were treated (daratumumab, n=15; edicotinib, n=10). All patients underwent RP without delays. Grade 3 treatment-related AEs with daratumumab occurred in 3 patients (12%), and no ≥grade 3 treatment-related AEs occurred with edicotinib. No changes in serum prostate-specific antigen (PSA) levels or pCRs were observed. Daratumumab led to a decreased frequency of CD38+ T cells, natural killer cells, and myeloid cells in prostate tumors, bone marrow, and PBMCs. There were no consistent changes in CSF-1R+ immune cells in prostate, bone marrow, or PBMCs with edicotinib. Neither treatment induced T cell infiltration into the prostate TME.

CONCLUSIONS

Daratumumab and edicotinib treatment was safe and well-tolerated in patients with localized prostate cancer but did not induce pCRs. Decreases in CD38+ immune cells were observed in prostate tumors, bone marrow, and PBMCs with daratumumab, but changes in CSF-1R+ immune cells were not consistently observed with edicotinib. Neither myeloid-targeted agent alone was sufficient to generate antitumor responses in prostate cancer; thus, combinations with agents to induce T cell infiltration (eg, ICTs) will be needed to overcome the immunosuppressive prostate TME.

Abstract IA034: Compromised myoepithelial cell differentiation correlates with DCIS to IDC transition

DCIS, breast cancer confined to mammary ducts, shares genomic and transcriptomic signatures with IDC. However for DCIS patients, standard of care for localized breast cancer remains controversial, as treatment reduces local recurrence but does not reduce risk of distant recurrence or mortality. Further, as the risk of dying from DCIS is ~5-20 fold less than from early stage breast cancer, questions remain concerning treatment harms. The fact that treatment does not reduce DCIS death rates provides indirect evidence that DCIS-stage tumor cells can disseminate and serve as reservoirs for metastatic disease. Since presence of myoepithelium is the clinical determinate of non-invasive disease, death from DCIS also implies that myoepithelial cell loss is not required for tumor cell dissemination. Here, we investigate whether changes in myoepithelial cell differentiation, rather than overt cell loss, associate with DCIS tumor cell dissemination. Using murine DCIS models and human DCIS tissue, our group reported sequential loss of myoepithelial cell differentiation markers p63, calponin, and SMA prior to progression to IDC. In human DCIS lesions delineated into low and high risk (pure DCIS vs mixed DCIS with IDC), loss of myoepithelial p63, calponin and SMA occurred more frequently in high risk DCIS lesions. Mice transgenic for calponin knockdown in the myoepithelium were at increased risk for mammary cancer. Combined, these data implicate loss in myoepithelial cell differentiation as a mediator of DCIS progression and dissemination. In human DCIS, compromised myoepithelium correlates with microinvasion and an immune infiltrate enriched in PD1+CD8 T cells. To address the role of immune cells in myoepithelial cell barrier function, we investigated 6 different immune competent mouse models of intraductal cancer (DCIS). While loss of myoepithelial differentiation markers were evident, IDC lesions developed in the absence of DCIS. Similarly, in immune compromised hosts, only IDC lesions were detected after intraductal injection of murine tumor cells, whereas human tumor cells formed stable DCIS lesions. In vitro, murine mammary tumor cells were more motile than human lines, and when tumor cells were co-cultured with myoepithelial cells, fewer myoepithelial to myoepithelial cell contacts were observed in the presence of the mouse tumor cells. Finally, in women, we find the differentiation state of mammary myoepithelium to be modulated by reproductive state, with myoepithelium during weaning–induced gland involution (an established risk window for breast cancer progression) sharing similarities with myoepithelium of high-risk DCIS lesions. In rodents, recently weaned hosts support increased DCIS to IDC transition. In sum, these studies implicate intrinsic and extrinsic regulators of myoepithelial cells, highlight the need for immune competent mouse models of DCIS, and raise the question of whether species mismatch in xenograft models impacts cellular crosstalk between myoepithelial and tumor cells critical to our understanding of the DCIS to IDC transition.

Citation Format: Sarah M. Bernhardt, Elizabeth Mitchell, Tanya Russell, Sonali Jindal, Jayasri Narasimhan, Reuben J. Hoffmann, AeSoon Benson, Pepper Schedin. Compromised myoepithelial cell differentiation correlates with DCIS to IDC transition [abstract]. In: Proceedings of the AACR Special Conference on Rethinking DCIS: An Opportunity for Prevention?; 2022 Sep 8-11; Philadelphia, PA. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_1): Abstract nr IA034.

Young-Onset Breast Cancer Outcomes by Time Since Recent Childbirth in Utah

IMPORTANCE

Breast cancer diagnosed within 5 to 10 years after childbirth, called postpartum breast cancer (PPBC), is associated with increased risk for metastasis and death. Whether a postpartum diagnosis is an independent risk factor or a surrogate marker of cancer features associated with poor outcomes remains understudied.

OBJECTIVE

To determine whether diagnostic temporal proximity to childbirth is associated with features of breast cancer associated with poor outcomes, including tumor stage, estrogen receptor (ER) status, and risk for distant metastasis and breast cancer-specific mortality, using a population database from the state of Utah.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study using the Utah Population Database (UPDB) included individuals with stage I to III breast cancer diagnosed at age 45 years or younger between 1996 and 2017, followed-up until February 2020. Participant data were analyzed from November 2019 to August 2022.

EXPOSURE

The primary exposures were no prior childbirth or time between most recent childbirth and breast cancer diagnosis. Patients were grouped by diagnoses within less than 5 years, 5 to less than 10 years, or 10 years or more since recent childbirth.

MAIN OUTCOMES AND MEASURES

The 2 primary outcomes were distant metastasis-free survival and breast cancer-specific death. Cox proportional hazard models were used to investigate associations between exposures and outcomes adjusting for diagnosis year, patient age, tumor stage, and estrogen receptor (ER) status.

RESULTS

Of 2970 individuals with breast cancer diagnosed at age 45 years or younger (mean [SD] age, 39.3 [5.0] years; 12 Black individuals [0.4%], 2679 White individuals [90.2%]), breast cancer diagnosis within 5 years of recent childbirth was independently associated with approximately 1.5-fold elevated risk for metastasis (hazard ratio [HR], 1.5; 95% CI, 1.2-2.0) and breast cancer-specific death (HR, 1.5; 95% CI, 1.1-2.1) compared with nulliparous individuals. For cancers classically considered to have tumor features associated with good outcomes (ie, stage I or II and ER-positive), a postpartum diagnosis was a dominant feature associated with increased risk for metastasis and death (eg, for individuals with ER-positive disease diagnosed within <5 years of childbirth: age-adjusted metastasis HR, 1.5; 95% CI, 1.1-2.1; P = .01; age-adjusted death HR, 1.5; 95% CI, 1.0-2.1; P = .04) compared with nulliparous individuals. Furthermore, liver metastases were specifically increased in the group with diagnosis within 5 years postpartum and with positive ER expression (38 of 83 patients [45.8%]) compared with the nulliparous (28 of 77 patients [36.4%]), although the difference was not statistically significant. Overall, these data implicate parity-associated breast and liver biology in the observed poor outcomes of PPBC.

CONCLUSIONS AND RELEVANCE

In this cohort study of individuals with breast cancer diagnosed at age 45 years or younger, a postpartum breast cancer diagnosis was a risk factor associated with poor outcomes. Irrespective of ER status, clinical consideration of time between most recent childbirth and breast cancer diagnosis could increase accuracy of prognosis in patients with young-onset breast cancer.

Diet-Driven Inflammation and Insulinemia and Risk of Interval Breast Cancer

Interval breast cancers (IBCs) emerge after a non-suspicious mammogram and before the patient's next scheduled screen. Risk factors associated with IBC have not been identified. This study evaluated if the empirical dietary inflammatory pattern (EDIP) or empirical dietary index for hyperinsulinemia (EDIH) scores are associated with IBC compared to screen-detected breast cancer. Data were from women 50-79 years-old in the Women's Health Initiative cohort who completed food frequency questionnaires at baseline (1993-98) and were followed through March 31, 2019 for breast cancer detection. Women were identified as having either IBC diagnosed within 1-year after their last negative screening mammogram (N = 317) or screen-detected breast cancer (N = 1,928). Multivariable-adjusted logistic regression analyses were used to estimate odds ratios for risk of IBC compared to screen-detected cancer in dietary index tertiles. No associations were observed between EDIP or EDIH and IBC. Odds ratios comparing the highest to the lowest dietary index tertile were 1.08; 95%CI, 0.78-1.48 for EDIP and 0.92; 95%CI, 0.67-1.27 for EDIH. The null associations persisted when stratified by BMI categories. Findings suggest that diet-driven inflammation or insulinemia may not be substantially associated with IBC risk among postmenopausal women. Future studies are warranted to identify modifiable factors for IBC prevention.

A phase 1-2 trial of sitravatinib and nivolumab in clear cell renal cell carcinoma following progression on antiangiogenic therapy

The accumulation of immune-suppressive myeloid cells is a critical determinant of resistance to anti-programmed death-1 (PD-1) therapy in advanced clear cell renal cell carcinoma (ccRCC). In preclinical models, the tyrosine kinase inhibitor sitravatinib enhanced responses to anti-PD-1 therapy by modulating immune-suppressive myeloid cells. We conducted a phase 1-2 trial to choose an optimal sitravatinib dose combined with a fixed dose of nivolumab in 42 immunotherapy-naïve patients with ccRCC refractory to prior antiangiogenic therapies. The combination demonstrated no unexpected toxicities and achieved an objective response rate of 35.7% and a median progression-free survival of 11.7 months, with 80.1% of patients alive after a median follow-up of 18.7 months. Baseline peripheral blood neutrophil-to-lymphocyte ratio correlated with response to sitravatinib and nivolumab. Patients with liver metastases showed durable responses comparable to patients without liver metastases. In addition, correlative studies demonstrated reduction of immune-suppressive myeloid cells in the periphery and tumor microenvironment following sitravatinib treatment. This study provides a rationally designed combinatorial strategy to improve outcomes of anti-PD-1 therapy in advanced ccRCC.

Perioperative nivolumab monotherapy versus nivolumab plus ipilimumab in resectable hepatocellular carcinoma: a randomised, open-label, phase 2 trial

BACKGROUND

Hepatocellular carcinoma has high recurrence rates after surgery; however, there are no approved standard-of-care neoadjuvant or adjuvant therapies. Immunotherapy has been shown to improve survival in advanced hepatocellular carcinoma; we therefore aimed to evaluate the safety and tolerability of perioperative immunotherapy in resectable hepatocellular carcinoma.

METHODS

In this single-centre, randomised, open-label, phase 2 trial, patients with resectable hepatocellular carcinoma were randomly assigned (1:1) to receive 240 mg of nivolumab intravenously every 2 weeks (for up to three doses before surgery at 6 weeks) followed in the adjuvant phase by 480 mg of nivolumab intravenously every 4 weeks for 2 years, or 240 mg of nivolumab intravenously every 2 weeks (for up to three doses before surgery) plus one dose of 1 mg/kg of ipilimumab intravenously concurrently with the first preoperative dose of nivolumab, followed in the adjuvant phase by 480 mg of nivolumab intravenously every 4 weeks for up to 2 years plus 1 mg/kg of ipilimumab intravenously every 6 weeks for up to four cycles. Patients were randomly assigned to the treatment groups by use of block randomisation with a random block size. The primary endpoint was the safety and tolerability of nivolumab with or without ipilimumab. Secondary endpoints were the proportion of patients with an overall response, time to progression, and progression-free survival. This trial is registered with ClinicalTrials.gov (NCT03222076) and is completed.

FINDINGS

Between Oct 30, 2017, and Dec 3, 2019, 30 patients were enrolled and 27 were randomly assigned: 13 to nivolumab and 14 to nivolumab plus ipilimumab. Grade 3-4 adverse events were higher with nivolumab plus ipilimumab (six [43%] of 14 patients) than with nivolumab alone (three [23%] of 13). The most common treatment-related adverse events of any grade were increased alanine aminotransferase (three [23%] of 13 patients on nivolumab vs seven [50%] of 14 patients on nivolumab plus ipilimumab) and increased aspartate aminotransferase (three [23%] vs seven [50%]). No patients in either group had their surgery delayed due to grade 3 or worse adverse events. Seven of 27 patients had surgical cancellations, but none was due to treatment-related adverse events. Estimated median progression-free survival was 9·4 months (95% CI 1·47-not estimable [NE]) with nivolumab and 19·53 months (2·33-NE) with nivolumab plus ipilimumab (hazard ratio [HR] 0·99, 95% CI 0·31-2·54); median time to progression was 9·4 months (95% CI 1·47-NE) in the nivolumab group and 19·53 months (2·33-NE) in the nivolumab plus ipilimumab group (HR 0·89, 95% CI 0·31-2·54). In an exploratory analysis, three (23%) of 13 patients had an overall response with nivolumab monotherapy, versus none with nivolumab plus ipilimumab. Three (33%) of nine patients had a major pathological response (ie, ≥70% necrosis in the resected tumour area) with nivolumab monotherapy compared with three (27%) of 11 with nivolumab plus ipilimumab.

INTERPRETATION

Perioperative nivolumab alone and nivolumab plus ipilimumab appears to be safe and feasible in patients with resectable hepatocellular carcinoma. Our findings support further studies of immunotherapy in the perioperative setting in hepatocellular carcinoma.

FUNDING

Bristol Myers Squibb and the US National Institutes of Health.

Abstract P2-14-14: Durvalumab and tremelimumab before surgery in patients with hormone receptor positive, HER2 negative stage II-III breast cancer

Background: The checkpoint inhibitors atezolizumab (anti-PD-L1) and pembrolizumab (anti-PD-1) are FDA approved for the treatment of patients with PD-L1 positive, metastatic triple negative breast cancer in combination with chemotherapy. The response rates to checkpoint blockade in hormone receptor positive, HER2 negative metastatic breast cancer have been less encouraging (RR 12% for pembrolizumab in KEYNOTE-028 and RR 2.8% for avelumab in the phase 1b trial JAVELIN). We conducted a feasibility trial and enrolled patients with Stage II-III hormone receptor positive, HER2 negative breast cancer to treatment with 2 cycles of durvalumab (anti-PD-L1) plus tremelimumab (anti-CTLA-4) prior to standard neoadjuvant chemotherapy and breast surgery.Methods: Eligible patients were treated with durvalumab at a dose of 1500 mg and tremelimumab at a dose of 75 mg, both administered intravenously, on days 1 and 28. Pre- and post-treatment tumor biopsies and blood samples were available for 5 out of 8 patients and were analyzed by CyTOF, IHC, and NanoString. Patients then received standard neoadjuvant chemotherapy prior to breast surgery. The target enrollment was 20 patients. Results: After 8 patients were enrolled and treated on protocol, the trial was stopped early due to toxicity, slow accrual, and delays in patients receiving standard neoadjuvant chemotherapy. The median age of the patients was 55 (range 39-66) and all 8 patients were women. All patients had ER/PR positive, HER2 negative invasive ductal carcinoma (2 with lobular features, 1 with focal mucinous features) and all patients had clinical Stage II disease. Five patients received both cycles of durvalumab/tremelimumab and the remaining 3 patients only received the first cycle. One patient discontinued therapy out of concern for progression, though repeat breast and lymph node biopsies were benign and she went on to have a pathologic complete response after standard neoadjuvant chemotherapy. The remaining 2 patients discontinued treatment after the first cycle due to Grade 3 colitis (Patient #1) and Grade 3 thyroiditis/adrenal insufficiency (Patient #8). Both patients required treatment with steroids and experienced delays in receiving standard therapy due to these adverse events (AEs). The other AEs reported were all Grade 1 or 2. A post-durvalumab/tremelimumab breast ultrasound was performed in 7 of 8 patients and the percentage change in volume of each patient’s primary breast mass was: -55%, +104% (biopsy benign), +65%, -30%, +90%, -8%, and -53%. Patient #1 (colitis) had chemotherapy administered adjuvantly and Patient #8 (thyroiditis, adrenal insufficiency) declined chemotherapy. Only 1 of 8 patients had a pathologic complete response at the time of surgery. IHC, CYTOF, and gene expression analyses showed an increase in immune cell subsets in tumor stroma post neoadjuvant immunotherapy. Conclusions: We conducted a feasibility trial of neoadjuvant durvalumab plus tremelimumab administered prior to standard neoadjuvant chemotherapy in patients with hormone receptor positive/HER2 negative Stage II or III breast cancer. The trial was stopped early after 2 of 8 patients experienced Grade 3 immune-related adverse events (colitis in 1 patient and thyroiditis/adrenal insufficiency in another patient).

Citation Format: Haven R. Garber, Sreyashi Basu, Sonali Jindal, Akshara Singareeka Raghavendra, Lumarie Santiago, Beatriz E. Adrada, Padmanee Sharma, James P. Allison, Jennifer Litton. Durvalumab and tremelimumab before surgery in patients with hormone receptor positive, HER2 negative stage II-III breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-14-14.

Preventing ovariectomy-induced weight gain decreases tumor burden in rodent models of obesity and postmenopausal breast cancer

BACKGROUND

Obesity and adult weight gain are linked to increased breast cancer risk and poorer clinical outcomes in postmenopausal women, particularly for hormone-dependent tumors. Menopause is a time when significant weight gain occurs in many women, and clinical and preclinical studies have identified menopause (or ovariectomy) as a period of vulnerability for breast cancer development and promotion.

METHODS

We hypothesized that preventing weight gain after ovariectomy (OVX) may be sufficient to prevent the formation of new tumors and decrease growth of existing mammary tumors. We tested this hypothesis in a rat model of obesity and carcinogen-induced postmenopausal mammary cancer and validated our findings in a murine xenograft model with implanted human tumors.

RESULTS

In both models, preventing weight gain after OVX significantly decreased obesity-associated tumor development and growth. Importantly, we did not induce weight loss in these animals, but simply prevented weight gain. In both lean and obese rats, preventing weight gain reduced visceral fat accumulation and associated insulin resistance. Similarly, the intervention decreased circulating tumor-promoting growth factors and inflammatory cytokines (i.e., BDNF, TNFα, FGF-2), with greater effects in obese compared to lean rats. In obese rats, preventing weight gain decreased adipocyte size, adipose tissue macrophage infiltration, reduced expression of the tumor-promoting growth factor FGF-1 in mammary adipose, and reduced phosphorylated FGFR indicating reduced FGF signaling in tumors.

CONCLUSIONS

Together, these findings suggest that the underlying mechanisms associated with the anti-tumor effects of weight maintenance are multi-factorial, and that weight maintenance during the peri-/postmenopausal period may be a viable strategy for reducing obesity-associated breast cancer risk and progression in women.

Pilot study of Tremelimumab with and without cryoablation in patients with metastatic renal cell carcinoma

Cryoablation in combination with immune checkpoint therapy was previously reported to improve anti-tumor immune responses in pre-clinical studies. Here we report a pilot study of anti-CTLA-4 (tremelimumab) with (n = 15) or without (n = 14) cryoablation in patients with metastatic renal cell carcinoma (NCT02626130), 18 patients with clear cell and 11 patients with non-clear cell histologies. The primary endpoint is safety, secondary endpoints include objective response rate, progression-free survival, and immune monitoring studies. Safety data indicate ≥ grade 3 treatment-related adverse events in 16 of 29 patients (55%) including 6 diarrhea/colitis, 3 hepatitis, 1 pneumonitis, and 1 glomerulonephritis. Toxicity leading to treatment discontinuation occurs in 5 patients in each arm. 3 patients with clear cell histology experience durable responses. One patient in the tremelimumab arm experiences an objective response, the median progression-free survival for all patients is 3.3 months (95% CI: 2.0, 5.3 months). Exploratory immune monitoring analysis of baseline and post-treatment tumor tissue samples shows that treatment increases immune cell infiltration and tertiary lymphoid structures in clear cell but not in non-clear cell. In clear cell, cryoablation plus tremelimumab leads to a significant increase in immune cell infiltration. These data highlight that treatment with tremelimumab plus cryotherapy is feasible and modulates the immune microenvironment in patients with metastatic clear cell histology.

352 Target modulation within the tumor microenvironment (TME) by daratumumab (anti-CD38) but not edicotinib (CSF-1R inhibitor) in men with high-risk localized prostate cancer

Background

Prostate cancer is ”immunologically cold,” with enrichment of myeloid populations, immunosuppressive cytokines, and few T cells within the tumor microenvironment (TME). CD38 is expressed on myeloid cells, T cells, plasma B cells, and NK cells. Macrophage colony-stimulating factor-1 receptor (CSF-1R) controls macrophage differentiation and function. We hypothesized that either anti-CD38 (daratumumab) or CSF-1R inhibitor (edicotinib) would be safe and well-tolerated for primary prostate cancer, with successful target modulation on immune populations within the TME.

Methods

In this single-center, open-label, presurgical study, patients were enrolled into Arm A (daratumumab, four weekly doses pre-surgery) or Arm B (edicotinib, orally daily for four weeks pre-surgery). Patients had high-risk localized or locally advanced prostate cancer (at least 1 core Gleason ≥8) appropriate for radical prostatectomy (RP), ≥3 biopsies involved with cancer, and no radiographic evidence of metastatic disease. Treated and untreated (Gleason-matched) fresh and formalin-fixed paraffin-embedded prostatectomy specimens and paired blood (PBMCs), bone marrow biopsies (BMBx) and aspirates (BMA) were evaluated for target modulation using IHC (prostate, BMBx) and flow cytometry (prostate, BMA, PBMCs). The primary endpoint was incidence of adverse events (AEs). The secondary endpoint was pathologic complete remission (pCR) rate.

Results

Twenty-five patients were treated (Arm A, n=15; Arm B, n=10) and completed four doses of daratumumab or four weeks of edicotinib prior to RP. The most common AEs were Arm A: daratumumab infusion reaction (33%, 5/15); Arm B: increased aspartate aminotransferase (40%, 4/10). Grade 3 related AEs in Arm A occurred in 3 patients (12%; infusion reaction, n=2; urticaria, n=1), with no Grade 4/5 related events. No ≥Grade 3 related AEs occurred in Arm B. All patients completed surgery, however no patients achieved pCR. IHC revealed lower density of CD38+ cells in daratumumab-treated vs. untreated prostate tumors and in patient-matched post-treatment vs. pre-treatment BMBx. Similarly, flow cytometry showed decreased frequency of CD38+ T cells and macrophages in daratumumab-treated vs. untreated prostate tumors and patient-matched post-treatment vs. pre-treatment PBMCs and BMAs. Edicotinib did not demonstrate an impact on CSF-1R+ immune cells in prostate, bone marrow, or PBMCs.

Conclusions

Daratumumab and edicotinib were safe and well-tolerated as presurgical therapy for high-risk localized prostate cancer, with no pCRs. Evidence of target modulation was consistently observed in prostate tumors, bone marrow, and PBMCs for daratumumab, but not edicotinib. Myeloid-targeted agents such as daratumumab alone are insufficient to generate anti-tumor responses in prostate cancer.

Trial Registration

NCT03177460

Ethics Approval

This study was approved by MD Anderson Cancer Center Institutional Review Board; protocol numbers 2017–0103 and PA13-0291.

Combined CTLA-4 and PD-L1 blockade in patients with chemotherapy-naïve metastatic castration-resistant prostate cancer is associated with increased myeloid and neutrophil immune subsets in the bone microenvironment

BACKGROUND

Immune checkpoint therapy (ICT) has low response rates in patients with metastatic castration-resistant prostate cancer (mCRPC), in part due to few T cells in the tumor microenvironment (TME). Anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4) promotes intratumoral T cell infiltration but induces upregulation of PD-1 and programmed death ligand-1 (PD-L1) within the prostate TME. Combined anti-CTLA-4 plus anti-PD-1 can partly overcome this adaptive resistance and was recently shown to augment responses in patients with mCRPC with measurable disease. Although bone is the most common site of metastasis in prostate cancer, patients with bone-predominant disease are frequently excluded from trials because they lack measurable disease, which limits assessment of disease progression and tissue sampling. We therefore designed this study to investigate combined ICT in mCRPC to bone.

HYPOTHESIS

Combined anti-CTLA-4 (tremelimumab) plus anti-PD-L1 (durvalumab) is safe and well tolerated in patients with chemotherapy-naïve mCRPC to bone.

PATIENTS AND METHODS

In this single-arm pilot study, men with chemotherapy-naïve mCRPC to bone received tremelimumab (75 mg intravenous) plus durvalumab (1500 mg intravenous) every 4 weeks (up to four doses), followed by durvalumab (1500 mg intravenous) maintenance every 4 weeks (up to nine doses). The primary endpoint was incidence of adverse events. Secondary endpoints included serum prostate-specific antigen (PSA), progression-free survival (PFS), radiographic PFS (rPFS), and maximal PSA decline.

RESULTS

Twenty-six patients were treated between August 8, 2017 and March 28, 2019. Grade ≥3 treatment-related adverse events (TRAEs) occurred in 11 patients (42%), with no grade 4 or 5 events. TRAEs leading to discontinuation occurred in three patients (12%). PSA decline ≥50% occurred in three patients (12%). Six patients (24%) achieved stable disease for >6 months. At a median follow-up of 43.6 months, median rPFS was 3.7 months (95% CI: 1.9 to 5.7), and median overall survival was 28.1 months (95% CI: 14.5 to 37.3). Post-treatment evaluation of the bone microenvironment revealed transcriptional upregulation in myeloid and neutrophil immune subset signatures and increased expression of inhibitory immune checkpoints.

CONCLUSIONS

Tremelimumab plus durvalumab was safe and well tolerated in patients with chemotherapy-naïve mCRPC to bone, with potential activity in a small number of patients as measured by rPFS. Combination of CTLA-4 and PD-L1 blockade with therapies targeting the myeloid compartment or other inhibitory immune receptors may be necessary to overcome mechanisms of resistance within prostate bone microenvironment.

TRIAL REGISTRATION NUMBER

NCT03204812.

Abstract 790: A Utah Population Data Base Study of young women's breast cancer outcomes by parity status

Importance: A diagnosis of breast cancer after childbirth is reported to increase risk for metastasis and death in patients ≤45 years of age. Data to discern if a postpartum diagnosis is an independent risk factor for poor outcomes remain limited.

Objective: Determine associations between time since last pregnancy and time to metastasis and breast cancer-specific death using cases available from the Utah Population Data Base (UPDB). Secondary objectives are time to metastasis and breast cancer specific-death delineated by tumor stage and ER status. Study Design: This is a population-based study of 2,977 women with stage I, II, or III breast cancer (BC) diagnosed at ≤ 45 years of age from 1996 to 2017. The study population was identified from the UPDB, a statewide dynamic database of linked data received from the Utah SEER Cancer Registry, birth certificates, death certificates, and medical records. Clinical prognostic factors include patient age at diagnosis, year of diagnosis, tumor size, stage, and estrogen receptor (ER) status. The primary exposures are no prior childbirth or time between the most recent childbirth and a breast cancer diagnosis, and primary outcomes are distant metastasis-free survival and breast cancer specific death.

Results: Among the 2,977 predominantly white women from the state of Utah, USA, the reproductive histories of the breast cancer patients were grouped as nulliparous (n = 867), and parous: diagnosed 0-5 years (n = 614), &gt;5-10 years (n = 615) and &gt;10 years (n = 881) since last childbirth. We find a breast cancer diagnosis within 5 years of childbirth is associated with elevated risk for metastasis after controlling for diagnosis year, diagnosis age, tumor stage, and ER status [HR (95% CI) =1.64 (1.16, 2.32)], particularly in Stage I/II disease [HR (95% CI) =1.89 (1.24, 2.87)]. The 0-5 year group also had elevated risk of breast cancer-specific death [HR (95% CI) =1.57 (1.07, 2.32)]. While ER-negative tumors were enriched in women diagnosed 0-5 years postpartum, this enrichment could be attributed largely to the younger age of this reproductive group. Further, postpartum breast cancer patients diagnosed with ER-positive disease within 5 years of a completed pregnancy had significantly worse distant metastasis-free survival than nulliparous patients with ER-negative disease.

Conclusions: In this population level study from the state of Utah, a diagnosis of breast cancer within 5 years postpartum is a risk factor for metastasis and breast cancer-specific death that is independent of known clinical parameters, including ER status. The increased risk for poor outcomes is highest in stage I/II diagnoses. Relevance: For women with breast cancers classically considered as having good prognostic tumor features, i.e. stage I or II and ER-positive, a postpartum diagnosis is a dominant demographic feature of increased risk for metastasis and death.

Citation Format: Pepper Schedin, Sonali Jindal, Solange Bassale, Zhenzhen Zhang, Alison Fraser, Emily Guinto, Virginia F. Borges, Motomi Mori, Ken R. Smith. A Utah Population Data Base Study of young women's breast cancer outcomes by parity status [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 790.

Design improvement and experimental study on shell and tube condenser for bio-oil recovery from fast pyrolysis of wheat straw biomass

In this study, the design improvement was done in a shell and tube condenser for improved heat transfer and condensation of bio-oil vapour. The developed condenser has split shell and segmental baffles, which divide the shell in various zones and condensate collection points. The fast pyrolysis of wheat straw was done and the bio-oil vapour condensate collected from various outlets located at bottom of condenser shell. From experimental results it was found that production of bio-oil increased from 10.2 to 20.8% with increase in cooling water flow rate from 1000 to 2500 L/h; but, further increasing it beyond 2500 L/h provide marginal effects on production of bio-oil. The production of bio-oil increased from 15.2 to 20.7% as sweep gas flow rate was increased from 20 to 40 L/min at 2500 L/h of cooling water flow rate. But, further increase in sweep gas flow rate beyond 40 L/min resulted in to decrease in production of bio-oil. The novelty of this work is development of improved condenser with segmental baffles, which help in fractional condensation of bio-oil vapour, split shell for cleaning of outer surface of the cooling water tubes and compact design of condenser for optimal condensation of bio-oil.

S-nitrosylated and non-nitrosylated COX2 have differential expression and distinct subcellular localization in normal and breast cancer tissue

Immunohistochemical (IHC) staining in breast cancer shows both gain and loss of COX2 expression with disease risk and progression. We investigated four common COX2 antibody clones and found high specificity for purified human COX2 for three clones; however, recognition of COX2 in cell lysates was clone dependent. Biochemical characterization revealed two distinct forms of COX2, with SP21 recognizing an S-nitrosylated form, and CX229 and CX294 recognizing non-nitrosylated COX2 antigen. We found S-nitrosylated and non-nitrosylated COX2 occupy different subcellular locations in normal and breast cancer tissue, implicating distinct synthetic/trafficking pathways and function. Dual stains of ~2000 breast cancer cases show early-onset breast cancer had increased expression of both forms of COX2 compared to postmenopausal cases. Our results highlight the strengths of using multiple, highly characterized antibody clones for COX2 IHC studies and raise the prospect that S-nitrosylation of COX2 may play a role in breast cancer biology.

Erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers and fatty acid synthase: a nested case-control study

BACKGROUND

Previous studies of fatty acids and breast cancer risk have shown mixed results, which may be due in part to tumor heterogeneity. Prior research has also illustrated an important role of specific fatty acids in immune regulation, T cell function, and inflammation, indicating that the effects of specific fatty acids on breast cancer risk may vary by tumor expression of immuno-inflammatory markers. We therefore aimed to evaluate the relationships between prediagnostic erythrocyte membrane fatty acids and breast cancer risk by tumor tissue expression of immuno-inflammatory markers (CD4, CD8, CD20, CD163, COX-2) and fatty acid synthase (FAS).

METHODS

We conducted a matched case-control study nested within the Nurses' Health Study II (n = 235 cases and 235 controls). Blood samples were collected from 1996 to 1999. Tumor tissue blocks were collected for cases diagnosed after blood collection and through 2006. Unconditional nominal polytomous logistic regression adjusted for matching factors and potential confounders was used to assess whether associations between fatty acids and breast cancer risk varied by tumor expression subtype, ascertained via immunohistochemistry. Odds ratios (OR) and 95% confidence intervals (CI) were estimated separately by tumor expression subtype using unconditional logistic regression.

RESULTS

Associations between fatty acids and breast cancer risk did not vary substantially by tumor CD4, CD20, CD163, or COX-2. However, n-3 polyunsaturated fatty acids (PUFAs) were inversely associated with CD8^low but not CD8^high cancers (CD8^low OR_{T3 vs T1} = 0.45, 95% CI 0.23-0.87, P_trend = 0.02; CD8^high OR_{T3 vs T1} = 1.19, 95% CI 0.62-2.26, P_trend = 0.62; P_het = 0.04). n-6 PUFAs were suggestively inversely associated with CD8^high but not CD8^low cancers (CD8^high OR_{T3 vs T1} = 0.61, 95% CI 0.32-1.14, P_trend = 0.11; CD8^low OR_{T3 vs T1} = 1.63, 95% CI 0.87-3.04, P_trend = 0.12; P_het = 0.02). Trans fatty acids were positively associated with FAS^high but not FAS^low tumors (FAS^high OR_{T3 vs T1} = 2.94, 95% CI 1.46-5.91, P_trend = 0.002; FAS^low OR_{T3 vs T1} = 0.99, 95% CI 0.52-1.92, P_trend = 0.97; P_het = 0.01).

CONCLUSION

Results indicate that the effects of n-3 PUFAs, n-6 PUFAs, and trans fatty acids on breast cancer risk may vary by tumor tissue expression subtypes. Findings suggest potential immuno-modulatory and FAS-mediated mechanisms.

Loss of myoepithelial calponin-1 characterizes high-risk ductal carcinoma in situ cases, which are further stratified by T cell composition

A hallmark of ductal carcinoma in situ (DCIS) progression is a loss of the surrounding ductal myoepithelium. However, whether compromise in myoepithelial differentiation, rather than overt cellular loss, can be used to predict the risk of DCIS progression is unknown. Here we address this question utilizing pure and mixed DCIS cases (N = 30) as surrogates for DCIS at low and high risk for progression, respectively. We used multiplex immunohistochemical staining to evaluate the relationship between myoepithelial cell differentiation and lymphoid immune cell types associated with poor prognostic DCIS. Our results show that myoepithelial calponin-1 discriminates between pure and mixed DCIS lesions better than histological subtype, presence of necrosis, or nuclear grade. Additionally, focal loss of myoepithelial cells associated with increased PD-1+CD8+ T cells, which suggests a link between the myoepithelium and immune surveillance. To identify associations between calponin-1 expression and immune response, we performed unsupervised hierarchical clustering of myoepithelial and immune cell biomarkers on 219 DCIS lesions from 30 cases. Notably, the majority of pure (low-risk) DCIS lesions clustered in a high calponin-1, T cell low group, whereas the majority of mixed (high-risk) DCIS lesions clustered in a low calponin-1, T cell high group, specifically with CD8+ and PD-1+CD8+ T cells. However, a subset of pure DCIS lesions had a similar calponin-1 and immune signature as the majority of mixed DCIS lesions, which have low calponin-1 and T cell enrichment-raising the possibility that these pure DCIS lesions might be at a high risk for progression.

Comparison of Mortality Among Participants of Women's Health Initiative Trials With Screening-Detected Breast Cancers vs Interval Breast Cancers

IMPORTANCE

Interval breast cancers (IBCs) are cancers that emerge after a mammogram with negative results but before the patient's next scheduled screening. Interval breast cancer has a worse prognosis than cancers detected by screening; however, it is unknown whether the length of the interscreening period is associated with prognostic features and mortality.

OBJECTIVE

To compare the prognostic features and mortality rate of women with IBCs diagnosed within 1 year or between 1 and 2.5 years of a mammogram with negative results with the prognostic features and mortality rate of women with breast cancers detected by screening.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used mammography data, tumor characteristics, and patient demographic data from the Women's Health Initiative study, which recruited participants from 1993 to 1998 and followed up with participants for a median of 19 years. The present study sample for these analyses included women aged 50 to 79 years who participated in the Women's Health Initiative study and includes data collected through March 31, 2018. There were 5455 incidents of breast cancer; only 3019 women compliant with screening were retained in analyses. Statistical analysis was performed from October 25, 2018, to November 24, 2019. Breast cancers detected by screening and IBCs were defined based on mammogram history, date of last mammogram, type of visit, and results of examination. Interval breast cancers were subdivided into those occurring within 1 year or between 1 and 2.5 years after the last protocol-mandated mammogram with negative results.

MAIN OUTCOMES AND MEASURES

The primary outcome of this study was breast cancer-specific mortality for each case of breast cancer detected by screening and IBCs detected within 1 year or between 1 and 2.5 years from a mammogram with negative results. Secondary outcomes included prognostic and tumor characteristics for each group. Comparisons between groups were made using the t test, the χ2 test, and Fine-Gray multivariable cumulative incidence regression analyses.

RESULTS

Among the 3019 participants in this analysis, all were women with a mean (SD) age of 63.1 (6.8) years at enrollment and 68.5 (7.1) years at diagnosis. A total of 1050 cases of IBC were identified, with 324 (30.9%) diagnosed within 1 year from a mammogram with negative results and 726 (69.1%) diagnosed between 1 and 2.5 years after last mammogram with negative results. The remaining 1969 cases were breast cancers detected by screening. Interval breast cancers diagnosed within 1 year from a mammogram with negative results had significantly more lobular histologic characteristics (13.0% vs. 8.1%), a larger tumor size (1.97 cm vs 1.43 cm), a higher clinical stage (28.4% vs 17.3% regional and 3.7% vs 0.6% distant), and more lymph node involvement (27.1% vs 17.0%) than cancers detected by screening. Unadjusted breast cancer-specific mortality hazard ratios were significantly higher for IBCs diagnosed within 1 year from a mammogram with negative results compared with breast cancers detected by screening (hazard ratio, 1.92; 95% CI, 1.39-2.65). Higher breast cancer-specific mortality remained statistically significant for IBCs diagnosed within 1 year after adjusting for trial group, molecular subtype, waist to hip ratio, histologic characteristics, and either tumor size (hazard ratio, 1.46; 95% CI, 1.03-2.08) or lymph node involvement (hazard ratio, 1.44; 95% CI, 1.03-2.01). However, significance was lost when tumor size and lymph node involvement were both included in the model (hazard ratio, 1.34; 95% CI, 0.96-1.88). Interval breast cancers diagnosed between 1 and 2.5 years from a mammogram with negative results were not different from breast cancers detected by screening based on prognostic factors or mortality.

CONCLUSIONS AND RELEVANCE

Women with IBCs diagnosed within 1 year of negative mammogram results overall were associated with worse survival than women with breast cancers detected by screening. These differences in survival may be due to a uniquely aggressive biology among IBC cases.

RNA-seq from archival FFPE breast cancer samples: molecular pathway fidelity and novel discovery

BACKGROUND

Formalin-fixed, paraffin-embedded (FFPE) tissues for RNA-seq have advantages over fresh frozen tissue including abundance and availability, connection to rich clinical data, and association with patient outcomes. However, FFPE-derived RNA is highly degraded and chemically modified, which impacts its utility as a faithful source for biological inquiry.

METHODS

True archival FFPE breast cancer cases (n = 58), stored at room temperature for 2-23 years, were utilized to identify key steps in tissue selection, RNA isolation, and library choice. Gene expression fidelity was evaluated by comparing FFPE data to public data obtained from fresh tissues, and by employing single-gene, gene set and transcription network-based regulon analyses.

RESULTS

We report a single 10 μm section of breast tissue yields sufficient RNA for RNA-seq, and a relationship between RNA quality and block age that was not linear. We find single-gene analysis is limiting with FFPE tissues, while targeted gene set approaches effectively distinguish ER+ from ER- breast cancers. Novel utilization of regulon analysis identified the transcription factor KDM4B to associate with ER+ disease, with KDM4B regulon activity and gene expression having prognostic significance in an independent cohort of ER+ cases.

CONCLUSION

Our results, which outline a robust FFPE-RNA-seq pipeline for broad use, support utilizing FFPE tissues to address key questions in the breast cancer field, including the delineation between indolent and life-threatening disease, biological stratification and molecular mechanisms of treatment resistance.

A way forward for cancer prevention therapy: personalized risk assessment

Cancer is characterized by genetic and molecular aberrations whose number and complexity increase dramatically as cells progress along the spectrum of carcinogenesis. The pharmacologic application of agents in the context of a lower burden of dysregulated cellular processes constitutes an efficient strategy to enhance therapeutic efficacy, and underlies the rationale for using cancer prevention agents in high-risk populations. A longstanding barrier to implementing this strategy is that the risk in the general population is low for any given cancer, many people would have to be treated in order to benefit a few. Therefore, identifying and treating high-risk individuals will improve the risk: benefit ratio. Currently, risk is defined by considering a relatively low number of factors. A strategy that considers multiple factors has the ability to define a much-higher-risk cohort than the general population. This article will review the rationale for evaluating multiple risk factors so as to identify individuals at highest risk. It will use breast and lung cancer as examples, will describe currently available risk assessment tools, and will discuss ongoing efforts to expand the impact of this approach. The high potential of this strategy to provide a way forward for developing cancer prevention therapy will be highlighted.

Abstract LB-140: Myoepithelial-immune cell crosstalk in the transition from non-invasive to invasive breast cancer

The incidence of ductal carcinoma in situ (DCIS), a pre-invasive malignancy of the breast, has increased in the U.S. since the 1980s, from 3% to 20% of all breast cancer diagnoses. This increase is largely attributed to mammographic screening. Common treatments of DCIS are breast-conserving surgery followed by adjuvant radiation therapy or mastectomy. Further, despite efforts to detect and treat early stage cancer, the incidence of invasive breast cancer (IBC) has not declined, suggesting that many women with DCIS are over treated. Thus, prognostic markers that predict risk of DCIS progression are needed. Genomic studies have yet to find tumor intrinsic alterations that predict DCIS progression to IBC. In contrast, genetic changes in the myoepithelium are found at the transition from DCIS to IBC, suggesting myoepithelial cells may play a role in progression. To investigate the myoepithelium for potential biomarkers, we advanced a non-surgical intraductal tumor cell delivery model in mice using human DCIS.com cells. We reported a progressive loss in myoepithelial differentiation markers p63, calponin, and smooth muscle actin (SMA) prior to transition to IBC, observations that were confirmed in human DCIS. Thus, compromise in the myoepithelium may be an early warning for DCIS at high risk for progression. Here, we hypothesize that the myoepithelial differentiation state informs immune response, and that DCIS lesions with loss of myoepithelial Calponin and SMA will be associated with a pro-tumorigenic immune milieu. This hypothesis is based on observations by us and others showing lymphocyte infiltration in areas where the DCIS myoepithelium has been focally compromised. To address this, we analyzed the expression of 10 myoepithelial and lymphoid biomarkers using multiplex immunohistochemistry to analyze the relationship between myoepithelial cell integrity and immune cells (N=36 cases). DCIS in the background of IBC (mixed DCIS) is assumed to be high-risk DCIS. We find compromised myoepithelial calponin in mixed compared to pure DCIS. Mixed lesions also show reduced infiltration of immune and T-cells, consistent with reduced immune surveillance. However, calponin loss in pure DCIS cases was associated with a decrease in Foxp3+ T-regulatory cells and increase in CD8+PD-1+ T-cells. Next we found that DCIS areas with focal loss of the myoepithelium and micro-invasion showed an increase in immune infiltration, increased T-cells, and increased PD-1+CD8+ T-cells. These data suggest that early compromise in the myoepithelial layer may associate with activation of cytotoxic effectors, consistent with increased immune surveillance. However, since we find T-cell numbers are reduced in mixed DCIS, effective immune surveillance may be dampened with progression. These data support an unreported relationship between myoepithelial cell integrity and the activation state of local immune cells.

Citation Format: Elizabeth Mitchell, Sonali Jindal, Tiffany Chan, Jayasri Narasimhan, Sheila Weinmann, Pepper Schedin. Myoepithelial-immune cell crosstalk in the transition from non-invasive to invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-140.

Association of p53 expression with poor prognosis in patients with triple-negative breast invasive ductal carcinoma

TP53 gene is mutated in approximately 80% of triple-negative breast cancer (TNBC). However, the prognostic significance of immunohistochemical (IHC)-detected p53 protein expression remains controversial in TNBC. In this study, we retrospectively analyzed the association between IHC-detected p53 expression and the prognosis in a cohort of 278 patients with stage I-III triple-negative breast invasive ductal carcinoma (IDC), who received surgery at the department of breast surgery in the Fourth Hospital of Hebei Medical University from 2010-01 to 2012-12. We found a positive expression ratio of IHC-detected p53 in triple-negative breast IDC of 58.6% (163/278). Furthermore, levels of expression were significantly associated with vessel tumor emboli and higher histologic grade (P = .038, P = .043, respectively), with the highest expression level observed in G3 breast cancer (64.7%). Additionally, Kaplan-Meier analysis showed that p53 expression indicated worse overall survival (OS) in the whole cohort (79.6% vs 89.6%, Log-rank test P = .025) as well as in stratified prognostic stage II patients (90.8% vs 100%, Log-rank test P = .027). The mortality risk of p53 expression patients was 2.22 times higher than that of p53 negative patients (HR: 2.222; 95%CI: 1.147-4.308). In addition, p53 expression was also associated with poor disease-free survival (DFS) (76.7% vs 86.8%, P = .020). Cox proportional hazard ratio model showed p53 expression was an independent risk factor for OS (P = .018) and DFS (P = .018) after controlling for tumor size, lymph node status, and vessel tumor emboli. Altogether, our data showed that IHC-detected p53 expression is a promising prognostic candidate for poor survival in triple-negative breast IDC patients. However, more studies are needed to determine if p53 may be applied to clinical practice as a biomarker and/or novel therapeutic target for TNBC.

INFRASTRUCTURE, RESOURCES, SERVICES EVALUATION AND GAP ANALYSIS OF INTEGRATED MATERNAL AND CHILD DEVELOPMENT SERVICES IN INDIA

Background. Integrated Child Development Services (ICDS) is an Indian community-centric government program organized under Anganwadi centres catering to supplementary nutrition, health and preschool education, primary healthcare, growth monitoring and counselling the children under six years old along with their mothers. It is the world’s largest outreach program in a developing country covering a population of 1.35 billion; the variations in service delivery were analysed involving cross-sectional rural and urban Anganwadi centers in New Delhi. Methods. Data were collected by assessment of children and mothers, interview of Anganwadi workers and observation of service delivery parameters and conduction of activities. Infrastructural, beneficiaries, services and content were evaluated by a suitable pre-tested questionnaire based on the National Institute of Public Cooperation and Child Development (NIPCCD) evaluation proforma. The data was analysed by a descriptive statistics. Results. Gaps were found in respect of infrastructure, resources, health and nutrition facilities especially at rural Anganwadi centre which was inadequate in terms of implementation of nutrition and health program, supplementary nutrition, preschool education and nutrition rehabilitation centre for existing beneficiaries. Both Anganwadi centres were not catering for new WHO growth standards and adolescent health. Conclusions. Gaps found in respect of infrastructure, resources, health and nutrition facilities can affect performance of ICDS program and the services delivered by Anganwadi centres, which need a boost. Both urban and rural centres have a direct opportunity towards delivering adolescent health program focusing on nutrition and education of girls prior to their pregnancy, and adoption of new WHO growth standards.

Association Between Postpartum Breast Cancer Diagnosis and Metastasis and the Clinical Features Underlying Risk

IMPORTANCE

In women 45 years or younger, breast cancer diagnosis after childbirth increases the risk for metastasis and death, yet limited data exist to define this window of risk and associated prognostic factors.

OBJECTIVE

To assess the window of elevated risk for metastasis following a postpartum breast cancer (PPBC) diagnosis and whether clinical prognostic factors are associated with the increased risk.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study conducted using cases from the Colorado Young Women's Breast Cancer Cohort diagnosed between January 1, 1981, and December 31, 2014, included 701 women 45 years or younger with stage I to III invasive breast cancer for whom parity data, including time of last childbirth, were available. Data analysis was conducted from July 1 to September 30, 2017. This study involved a tertiary care academic hospital-based breast center and its regional affiliates with cases from the greater Rocky Mountain region.

EXPOSURES

Primary exposures were prior childbirth or no childbirth, time between most recent childbirth and breast cancer diagnosis, and time between breast cancer diagnosis and metastasis.

MAIN OUTCOMES AND MEASURES

The primary outcome was distant metastasis-free survival.

RESULTS

A total of 701 women 45 years or younger from the greater Rocky Mountain states region were included in the analysis; mean (SD) age at diagnosis was 37.9 (5.1) years. Breast cancer diagnosis within 10 years after parturition was associated with elevated risk for metastasis, particularly in women with stage I or II disease. In addition, women with PPBC diagnosed within 10 years of a completed pregnancy that was estrogen receptor-positive showed distant metastasis-free survival similar to that of nulliparous patients with estrogen receptor-negative cancer, and women with estrogen receptor-negative PPBC had further reduced metastasis-free survival. Moreover, women with PPBC had increased lymphovascular invasion and lymph node involvement. In addition, tumor-associated Ki67 positivity identified 129 patients with luminal B cancer in the cohort that, independent of parity status, had poorer prognosis compared with patients with luminal A cancer, although it did not reach statistical significance.

CONCLUSIONS AND RELEVANCE

Diagnosis of PPBC within 10 years post partum appears to be associated with an increased risk for metastasis. This increased risk was highest in stages I and II cancer at diagnosis and present in both patients with estrogen receptor-positive and estrogen receptor-negative cancer, persisting in estrogen receptor-positive cases for up to 15 years after diagnosis. Postpartum breast cancer diagnoses were not associated with increased Ki67 index but were associated with increased lymphovascular invasion and lymph node involvement compared with breast cancer in nulliparous patients.

Ibuprofen supports macrophage differentiation, T cell recruitment, and tumor suppression in a model of postpartum breast cancer

BACKGROUND

Women diagnosed with breast cancer within 5 years postpartum (PPBC) have poorer prognosis than age matched nulliparous women, even after controlling for clinical variables known to impact disease outcomes. Through rodent modeling, the poor prognosis of PPBC has been attributed to physiologic mammary gland involution, which shapes a tumor promotional microenvironment through induction of wound-healing-like programs including myeloid cell recruitment. Previous studies utilizing immune compromised mice have shown that blocking prostaglandin synthesis reduces PPBC tumor progression in a tumor cell extrinsic manner. Given the reported roles of prostaglandins in myeloid and T cell biology, and the established importance of these immune cell populations in dictating tumor growth, we investigate the impact of involution on shaping the tumor immune milieu and its mitigation by ibuprofen in immune competent hosts.

METHODS

In a syngeneic (D2A1) orthotopic Balb/c mouse model of PPBC, we characterized the impact of mammary gland involution and ibuprofen treatment on the immune milieu in tumors and draining lymph nodes utilizing flow cytometry, multiplex IHC, lipid mass spectroscopy and cytokine arrays. To further investigate the impact of ibuprofen on programming myeloid cell populations, we performed RNA-Seq on in vivo derived mammary myeloid cells from ibuprofen treated and untreated involution group mice. Further, we examined direct effects of ibuprofen through in vitro bone marrow derived myeloid cell cultures.

RESULTS

Tumors implanted into the mammary involution microenvironment grow more rapidly and display a distinct immune milieu compared to tumors implanted into glands of nulliparous mice. This milieu is characterized by increased presence of immature monocytes and reduced numbers of T cells and is reversed upon ibuprofen treatment. Further, ibuprofen treatment enhances Th1 associated cytokines as well as promotes tumor border accumulation of T cells. Safety studies demonstrate ibuprofen does not impede gland involution, impact subsequent reproductive success, nor promote auto-reactivity as detected through auto-antibody and naïve T cell priming assays.

CONCLUSIONS

Ibuprofen administration during the tumor promotional microenvironment of the involuting mammary gland reduces overall tumor growth and enhances anti-tumor immune characteristics while avoiding adverse autoimmune reactions. In sum, these studies implicate beneficial prophylactic use of ibuprofen during the pro-tumorigenic window of mammary gland involution.

Abstract SY38-02: Postpartum tissue remodeling drives breast cancer metastasis

Women diagnosed with breast cancer within 10 years of a completed pregnancy are at ~2-3 fold increased risk for developing metastatic disease (1,2). This increased risk for metastasis is independent of tumor stage and biologic subtype, implicating a tumor-extrinsic biology unique to the postpartum woman (3,4). Further, 30-50% of all young women diagnosed with breast cancer have had a completed pregnancy within the last 10 years (4), making a postpartum diagnosis an independent poor prognostic indicator for a significant number of patients. One postpartum event that may drive tumor progression in rodents (5-8) and women (9) is weaning-induced mammary gland involution, a physiologic tissue remodeling process that shares numerous attributes with protumorigenic wound healing. We have developed rodent models designed to mimic this highly metastatic subset of young women's breast cancer and find that weaning-induced mammary gland involution supports breast cancer growth, dissemination, and escape to secondary organs in a COX-2 dependent manner (6,10,11). Here we extend these studies by investigating the mammary gland from a mucosal organ perspective, as identifying links with mucosal biology and its associated immune suppression may provide insight into the poor prognosis of postpartum breast cancers. While the mammary gland is not classically considered a mucosal organ, bacteria routinely interface with luminal epithelium during lactation, necessitating barrier function. Similar barrier defenses are anticipated during weaning-induced mammary gland involution, as milk stasis increases risk for mastitis. One key immunologic hallmark of a mucosal organ is the presence of a distinct CD4+ helper T-cell subset, Th17 cells. Th17 cells stimulate epithelial cell junction integrity and epithelial secretion of mucins and defensins, mechanisms that barricade against bacterial activation of antitumor Th1 immune cells. Within the mammary gland we find a baseline mucosal program of Th17 T cells, which is elevated within lactating and involuting mammary glands. Mucosal features are further expanded during involution to include tolerogenic dendritic cell phenotypes, barrier-supportive antimicrobials, alternatively activated Th2 CD4+ cells, and immunosuppressive Treg CD4+T cells. Further, during involution, we find suppression of mammary-derived antigen-dependent CD4+ T-cell activation, data consistent with immune tolerance. We also find antigen-independent accumulation of memory Th17- Treg CD4+ T cells, data consistent with weaning-induced mammary inflammation. Overall, these data elucidate strong mucosal immune programs within the lactating gland and immune-suppressive programs within the involuting gland. Tumor cells within the involution immunologic microenvironment are anticipated to avoid immune detection and readily escape the mammary gland, a mechanism that may contribute to increased metastasis observed in postpartum breast cancer patients. Importantly, to successfully metastasize, a tumor cell must not only escape from the primary tumor, but also seed and grow within the secondary site. Thus, an additional potential mechanism by which a postpartum diagnosis may confer increased risk of metastasis is through involution-specific changes at metastatic sites. We report evidence for such a metastatic advantage within the liver of postpartum hosts. Using both intracardiac and portal vein liver metastasis models, we find that the post-weaning liver supports increased seeding of murine mammary tumor cells compared to livers of nulliparous control mice (12). Relevance to women is suggested by data obtained from a cohort of young women's breast cancer patients, where liver metastatic tropism is observed specifically in postpartum patients. In rodents, the biology driving this metastatic advantage is weaning-induced liver involution, a previously unrecognized tissue remodeling process. Post weaning, we find a 50% reduction in liver volume, hepatocyte cell death, deposition of fibrillar collagen and tenascin-c, increased matrix metalloproteinase activity, and influxes of immune cell populations with immune-suppressive phenotypes (12,13). These tissue-level changes are consistent with the establishment of a prometastatic niche during liver involution. Combined, our studies are supportive of the mammary gland being a hormone-responsive, immune-suppressed mucosal organ, and suggest the liver as a hormone-responsive organ that is functionally coordinated with the mammary gland during the cycle of pregnancy, lactation, and weaning. Further, we identify stromal remodeling in the mammary gland and liver as a mediator of breast cancer metastasis in the postpartum window. These findings shed light on how normal reproductive physiology, specifically mucosal biology interfaced with tissue remodeling, alters site-specific metastasis. These findings provide the framework necessary to investigate postpartum involution as a target for the prevention of breast cancer metastasis in young women.References:

1. Johansson AL et al. Increased mortality in women with breast cancer detected during pregnancy and different periods postpartum. Cancer Epidemiol Biomarkers Prev 2011;20(9):1865-72.

2. Lambe M et al. Transient increase in the risk of breast cancer after giving birth. N Engl J Med 1994;331(1):5-9.

3. Schedin P. Pregnancy-associated breast cancer and metastasis. Nat Rev Cancer 2006;6(4):281-91.

4. Callihan EB et al. Postpartum diagnosis demonstrates a high risk for metastasis and merits an expanded definition of pregnancy-associated breast cancer. Breast Cancer Res Treat 2013;138(2):549-59.

5. Guo Q et al. Physiologically activated mammary fibroblasts promote postpartum mammary cancer. JCI Insight 2017;2(6):e89206.

6. Martinson HA et al. Wound healing-like immune program facilitates postpartum mammary gland involution and tumor progression. Int J Cancer 2015;136(8):1803-13.

7. McDaniel SM et al. Remodeling of the mammary microenvironment after lactation promotes breast tumor cell metastasis. Am J Pathol 2006;168(2):608-20.

8. O'Brien J et al. Alternatively activated macrophages and collagen remodeling characterize the postpartum involuting mammary gland across species. Am J Pathol 2010;176(3):1241-55.

9. Jindal S et al. Postpartum breast involution reveals regression of secretory lobules mediated by tissue-remodeling. Breast Cancer Res 2014;16(2):R31.

10. Lyons TR et al. Cyclooxygenase-2-dependent lymphangiogenesis promotes nodal metastasis of postpartum breast cancer. J Clin Invest 2014;124(9):3901-12.

11. Lyons TR et al. Postpartum mammary gland involution drives progression of ductal carcinoma in situ through collagen and COX-2. Nat Med 2011;17(9):1109-15.

12. Goddard ET et al. The rodent liver undergoes weaning-induced involution and supports breast cancer metastasis. Cancer Discov 2017;7(2):177-87.

13. Goddard ET et al. Quantitative extracellular matrix proteomics to study mammary and liver tissue microenvironments. Int J Biochem Cell Biol 2016;81(Pt A):223-32.

Citation Format: Courtney Betts, Nathan Pennock, Erica Goddard, Qiuchen Guo, Sonali Jindal, Virginia F. Borges, Pepper Jo Schedin, Alex Quackenbush. Postpartum tissue remodeling drives breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr SY38-02.

Metformin inhibits stromal aromatase expression and tumor progression in a rodent model of postmenopausal breast cancer

BACKGROUND

Obesity and type II diabetes are linked to increased breast cancer risk in postmenopausal women. Patients treated with the antidiabetic drug metformin for diabetes or metabolic syndrome have reduced breast cancer risk, a greater pathologic complete response to neoadjuvant therapy, and improved breast cancer survival. We hypothesized that metformin may be especially effective when targeted to the menopausal transition, as this is a lifecycle window when weight gain and metabolic syndrome increase, and is also when the risk for obesity-related breast cancer increases.

METHODS

Here, we used an 1-methyl-1-nitrosourea (MNU)-induced mammary tumor rat model of estrogen receptor (ER)-positive postmenopausal breast cancer to evaluate the long-term effects of metformin administration on metabolic and tumor endpoints. In this model, ovariectomy (OVX) induces rapid weight gain, and an impaired whole-body response to excess calories contributes to increased tumor glucose uptake and increased tumor proliferation. Metformin treatment was initiated in tumor-bearing animals immediately prior to OVX and maintained for the duration of the study.

RESULTS

Metformin decreased the size of existing mammary tumors and inhibited new tumor formation without changing body weight or adiposity. Decreased lipid accumulation in the livers of metformin-treated animals supports the ability of metformin to improve overall metabolic health. We also found a decrease in the number of aromatase-positive, CD68-positive macrophages within the tumor microenvironment, suggesting that metformin targets the immune microenvironment in addition to improving whole-body metabolism.

CONCLUSIONS

These findings suggest that peri-menopause/menopause represents a unique window of time during which metformin may be highly effective in women with established, or at high risk for developing, breast cancer.

A METHOD FOR QUANTIFICATION OF CALPONIN EXPRESSION IN MYOEPITHELIAL CELLS IN IMMUNOHISTOCHEMICAL IMAGES OF DUCTAL CARCINOMA IN SITU

Ductal carcinoma in situ (DCIS) is breast cancer confined within mammary ducts, surrounded by an intact myoepithelial cell layer that prevents local invasion. A DCIS diagnosis confers increased lifetime risk of developing invasive breast cancer (IBC) and results in surgical excision with radiation, and possibly endocrine- or chemo-therapy. DCIS is known to be over treated, with associated co-morbidities. Biomarkers are needed that delineate patients at low risk of DCIS progression from patients requiring more aggressive treatment. Investigating the role of myoepithelial cell differentiation in barrier function is anticipated to provide insight into DCIS progression and delineate between low and high risk lesions. Here, we develop a high throughput technique to assess loss of myoepithelial differentiation markers. This method facilitates automated analysis of a clinically relevant histopathologic feature, as demonstrated by a high correlation with pathologist annotation (r = 0.959), and further, contributes analytical foundations to a multiplexed immunohistochemistry (IHC) approach.

Bilateral Asymmetrical Fracture Dislocation of Shoulder with Rare Combination of Injuries after Epileptic Seizure: A Case Report

The incidence of bilateral gleno-humeral joint dislocation is rare, is almost always posterior and is usually caused by sports injuries, epileptic seizures, electrical shock, or electroconvulsive therapy. Bilateral fracture-dislocation is even rarer, with a few cases reported in the literature. We report an unusual case with dislocation of the both glenohumeral joints in opposite direction after a seizure episode, with fracture of greater tuberosity on one side and of the lesser tuberosity on the contralateral side. Although there have been a few reports of bilateral asymmetric fracture dislocations of the shoulder in the past, an injury pattern resembling our case has, to the best of our knowledge, not been described in the literature so far. This report includes a detailed discussion regarding the mechanism of injury in a case of asymmetrical dislocation following a seizure episode. At final follow-up, the patient had healed fractures, painless near normal range of motion with no redislocations.

Myoepithelial cells in lobular carcinoma in situ: distribution and immunophenotype

Myoepithelial cells have important physical and paracrine roles in breast tissue development, maintenance, and tumor suppression. Recent molecular and immunohistochemical studies have demonstrated phenotypic alterations in ductal carcinoma in situ-associated myoepithelial cells. Although the relationship of lobular carcinoma in situ (LCIS) and myoepithelial cells was described in 1980, further characterization of LCIS-associated myoepithelial cells is lacking. We stained 27 breast specimens harboring abundant LCIS with antibodies to smooth muscle myosin heavy chain, smooth muscle actin, and calponin. Dual stains for E-cadherin/smooth muscle myosin heavy chain and CK7/p63 were also performed. In each case, the intensity and distribution of staining in LCIS-associated myoepithelial cells were compared with normal breast tissue on the same slide. In 78% of the cases, LCIS-associated myoepithelial cells demonstrated decreased staining intensity for one or more myoepithelial markers. The normal localization of myoepithelial cells (flat against the basement membrane, pattern N) was seen in 96% of LCIS, yet 85% of cases had areas with myoepithelial cell cytoplasm oriented perpendicular to the basement membrane (pattern P), and in 30% of cases, myoepithelial cells appeared focally admixed with LCIS cells (pattern C). This study characterizes detailed architectural and immunophenotypic alterations of LCIS-associated myoepithelial cells. The finding of variably diminished staining favors application of several myoepithelial immunostains in clinical practice. The interaction of LCIS with myoepithelial cells, especially in light of the perpendicular and central architectural arrangements, deserves further mechanistic investigation.

Myoepithelial cell differentiation markers in ductal carcinoma in situ progression

We describe a preclinical model that investigates progression of early-stage ductal carcinoma in situ (DCIS) and report that compromised myoepithelial cell differentiation occurs before transition to invasive disease. Human breast cancer MCF10DCIS.com cells were delivered into the mouse mammary teat by intraductal injection in the absence of surgical manipulations and accompanying wound-healing confounders. DCIS-like lesions developed throughout the mammary ducts with full representation of human DCIS histologic patterns. Tumor cells were incorporated into the normal mammary epithelium, developed ductal intraepithelial neoplasia and DCIS, and progressed to invasive carcinoma, suggesting the model provides a rigorous approach to study early stages of breast cancer progression. Mammary glands were evaluated for myoepithelium integrity with immunohistochemical assays. Progressive loss of the myoepithelial cell differentiation markers p63, calponin, and α-smooth muscle actin was observed in the mouse myoepithelium surrounding DCIS-involved ducts. p63 loss was an early indicator, calponin loss intermediate, and α-smooth muscle actin a later indicator of compromised myoepithelium. Loss of myoepithelial calponin was specifically associated with gain of the basal marker p63 in adjacent tumor cells. In single time point biopsies obtained from 16 women diagnosed with pure DCIS, a similar loss in myoepithelial cell markers was observed. These results suggest that further research is warranted into the role of myoepithelial cell p63 and calponin expression on DCIS progression to invasive disease.

Perception of Simulation-based Learning among Medical Students in South India

Background:

Traditional methods of educating medical students are no longer sufficient in the current era largely influenced by multimedia. Simulation-based techniques may play a pivotal role in bridging this educational gap.

Aim:

This study was conducted to explore the perception of medical students towards simulation based learning (SBL).

Subjects and Methods:

This cross-sectional study was conducted in May 2013 in a private medical college in Mangalore, Karnataka, India. A total of 247 participants from fourth, sixth, eighth semester and internship were chosen by convenience sampling method. Attitudinal data on perception towards SBL were collected using a self-administered questionnaire with responses in a 5-point Likert's scale.

Results:

The mean age of students was 21.3 (standard deviation 1.9) years, and males constituted 55.5% (137/247). Most participants 72.5% (179/247) had favorable perceptions of SBL, with scores of92–118 out of a possible 118 points. Favorable perception towards SBL was seen significantly more among female students (P = 0.04) and senior MBBS students of sixth and eighth semesters (P = 0.05). Nearly, all students (90.7%; 224/247) agreed that simulation supports the development of clinical skills. As many as 29.6% (73/247) agreed that real patients might be replaced with simulated patients in practical examinations.

Conclusion:

SBL was perceived as favorable by a large number of participants in this study indicating a bright prospect for its implementation in the medical curriculum.