Immune-Related Adverse Events and Survival Among Patients With Metastatic NSCLC Treated With Immune Checkpoint Inhibitors

Importance

Immune-related adverse events (irAEs) secondary to immune checkpoint inhibitor (ICI) therapy reportedly improve overall survival (OS) in patients with non-small cell lung cancer (NSCLC). However, studies have been small and the association between irAE severity and OS remains poorly defined.

Objective

To examine the association between irAEs and their severity with OS in patients with locally advanced or metastatic NSCLC receiving ICIs.

Design, Setting, and Participants

This retrospective observational cohort study included patients with NSCLC receiving ICIs between March 1, 2014, and November 30, 2021, with follow-up until March 31, 2023. Data analysis was completed April 26, 2023. The Alberta Immunotherapy Database, a provincial, multicenter cohort, was used to capture data from patients receiving ICIs in Alberta, Canada. Participants included 803 patients 18 years or older who received at least 1 cycle of ICI (alone or with chemotherapy), agnostic to treatment line.

Exposure

Developing an irAE mandating delay or discontinuation of ICI therapy and/or systematic corticosteroids for management of toxic effects (hereinafter referred to as clinically meaningful irAEs).

Main Outcomes and Measures

The primary outcome was association between irAEs and OS according to Kaplan-Meier analysis. Clinically meaningful irAEs were identified. Patients with poor prognosis (survival <3 months) who may have died prior to irAE development were excluded from OS analysis, mitigating immortal time bias. Adjusted Cox proportional hazards regression analyses ascertained variables associated with OS.

Results

Among the 803 patients included in the analysis, the median age of patients with irAEs was 69.7 (IQR, 63.1-75.2) years and the median age of those without irAEs was 67.5 (IQR, 60.4-73.3) years, with comparable sex distribution (139 of 295 men [47.1%] and 156 of 295 women [52.9%] with irAEs vs 254 of 505 men [50.3%] and 251 of 505 women [49.7%] without irAEs). Mitigating immortal time bias (n = 611), irAEs were associated with OS (median OS with irAEs, 23.7 [95% CI, 19.3-29.1] months; median OS without irAEs, 9.8 [95% CI, 8.7-11.4] months; P < .001). No OS difference was associated with treatment in hospital vs as outpatients for an irAE (median OS, 20.8 [95% CI, 11.7-30.6] vs 25.6 [95% CI, 20.1-29.8] months; P = .33). Developing irAEs remained associated with OS in the total cohort after Cox proportional hazards regression with known prognostic characteristics (hazard ratio, 0.53 [95% CI, 0.40-0.70]; P < .001).

Conclusions and Relevance

In this cohort study of 803 patients with locally advanced or metastatic NSCLC receiving ICIs, developing a clinically meaningful irAE was associated with improved OS. This association was not compromised by hospitalization for severe toxic effects. Whether and how ICI therapy resumption after an irAE is associated with OS warrants further study.

Impact of Performance Status on Survival Outcomes and Health Care Utilization in Patients With Advanced NSCLC Treated With Immune Checkpoint Inhibitors

Introduction

Landmark trials testing immune checkpoint inhibitors (ICIs) in advanced NSCLC are difficult to extrapolate to real-world practice given the exclusion of patients with poor (i.e., ≥2) Eastern Cooperative Oncology Group performance status (ECOG PS). We sought to evaluate the impact of ECOG PS on clinical outcomes and health care utilization in patients with NSCLC treated with ICIs in real-world practice.

Methods

Patients with advanced NSCLC who received at least one dose of pembrolizumab or nivolumab were retrospectively identified from the Alberta Immunotherapy Database. The primary outcome was median overall survival, as stratified by ECOG PS. Secondary outcomes included median time-to-treatment failure and metrics of health care utilization, including emergency department visits, hospitalizations, and death in hospital.

Results

A total of 790 patients were included, with 29.2% having poor ECOG PS at initiation of ICI. These patients had significantly lower median overall survival (3.3 versus 13.4 mo) and median time-to-treatment failure (1.4 versus 4.9 mo) compared with those with favorable ECOG PS (p < 0.0001 for both outcomes). Patients with poor ECOG PS were also more likely to present to the emergency department, be admitted to the hospital, and die in the hospital during their first admission (risk ratio = 1.6, 2.3-2.7, p < 0.001).

Conclusions

Patients with NSCLC with poor ECOG PS treated with ICI had significantly worse survival outcomes and were significantly more likely to use health care services than those with favorable ECOG PS. The large proportion of patients with poor ECOG PS further justifies the urgent need for randomized trials evaluating the efficacy of ICI in this high-risk population.

Lung Immune Therapy Evaluation (LITE) Risk, a Novel Prognostic Model for Patients With Advanced Non-Small Cell Lung Cancer Treated With Immune Checkpoint Blockade

INTRODUCTION/BACKGROUND

Immune checkpoint inhibitors (ICI) have revolutionized non-small cell lung cancer (NSCLC). We aimed to identify baseline characteristics, that are prognostic factors for overall survival (OS) in patients with NSCLC treated with ICI monotherapy, in order to derive the Lung Immune Therapy Evaluation (LITE) risk, a prognostic model.

MATERIALS AND METHODS

Multi-center observational cohort study of patients with advanced NSCLC that received ≥1 dose of ICI monotherapy. The training set (n=342) consisted of patients with NSCLC who received first line ICI. The test set (n=153) used for external validation was a discrete cohort of patients who received second line ICI. 20 candidate prognostic factors were examined. Penalized Cox regression was used for variable selection. Multiple imputation was used to address missingness.

RESULTS

Three baseline characteristics populated the final model: ECOG (0, 1 or ≥2), lactate dehydrogenase>upper limit of normal, and derived neutrophil to lymphocyte ratio ≥3. Patients were parsed into 3 risk groups; favorable (n=146, risk score 0-1), intermediate (n=101, risk score 2) and poor (n=95, risk score ≥3). The c-statistic of the training cohort was 0.702 and 0.694 after bootstrapping. The test cohort c-statistic was 0.664. The median OS for favorable, intermediate and poor LITE risk were; 28.3 months, 9.1 months and 2.1 months respectively. Improving LITE risk group was associated with improved OS, intermediate vs favorable HR 2.08 (95%CI 1.46-2.97, P < .001); poor vs favorable HR 5.21 (95%CI 3.69-7.34, P < .001).

CONCLUSION

A simple prognostic model, utilizing accessible clinical data, can discriminate survival outcomes in patients with advanced NSCLC.

Impact of performance status on survival outcomes and health care utilization in patients with advanced non–small cell lung cancer treated with immune checkpoint inhibitors

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Background: Immune checkpoint inhibitors (ICIs) have revolutionized the treatment paradigm of non-small cell lung cancer (NSCLC). Despite the high prevalence of patients with poor Eastern Cooperative Oncology Group (ECOG) performance status (PS ≥2) in real-world practice, landmark studies have typically excluded this patient group from enrolment. The primary objective of this study was to evaluate the impact of ECOG PS on clinical outcomes and health care utilization in a large cohort of NSCLC patients treated with ICI in real-world practice. Methods: Using the Alberta Immunotherapy Database, we identified consecutive patients who received at least one dose of Pembrolizumab or Nivolumab for the treatment of advanced NSCLC between 1/1/2010 and 12/30/2019. The data cut-off date was 10/1/2020. Baseline clinical, pathological, and laboratory-based data were collected retrospectively. The primary outcome was median overall survival (mOS), as stratified by ECOG PS. The secondary outcomes were median time-to-treatment failure (mTTF) and metrics of health care utilization, including emergency department (ED) visits, hospitalizations, and death in hospital. Kaplan-Meier survival curves were used to determine survival outcomes, and compared with the log-rank test. The association between ECOG PS and healthcare utilization were represented with risk ratios and evaluated using chi-square tests. Results: A total of 790 patients were included. Median follow-up time was 20.6 months. 29.2% (n = 231) had PS ≥2 at the time of ICI initiation. As compared with the favorable PS group (PS < 2), patients with PS ≥2 had significantly lower mOS - 3.3 months (95% CI 2.5-4.0) versus 13.4 months (95% CI 11.7-16.0) (HR, 3.0; 95% CI 2.5-3.6, p < 0.0001), and mTTF – 1.4 months (95% CI 0.9-1.8) versus 4.9 months (95% CI 4.4-5.6) (HR, 2.2; 95% CI 1.9-2.6, p < 0.0001). 3- and 12-month survival rates were also significantly lower in the PS ≥2 group as compared with the PS < 2 group (52.8% versus 86.4% and 13.4% versus 41.0%, p < 0.0001 for both comparisons). Patients with PS ≥2 were also significantly more likely to present to the ED (RR 1.6; 95% CI, 1.3-2.0, p < 0.001) and be admitted to hospital (RR 2.3; 95% CI 1.7-3.0, p < 0.0001) within the first month after treatment initiation. These patients were also significantly more likely to die in hospital during their first admission (RR 2.7; 95% CI 1.8-4.1, p < 0.0001), as well as at any point during treatment (RR 2.2; 95% CI 1.60-3.0, p < 0.0001). Conclusions: NSCLC patients with poor ECOG PS at the time of ICI initiation had significantly worse survival outcomes and were significantly more likely to utilize health care services than those with favorable ECOG PS. The large proportion of patients with poor ECOG PS further justifies the urgent need for randomized trials evaluating the efficacy of ICI in this high-risk population.

Combining TMEM Doorway Score and MenaCalc Score Improves the Prediction of Distant Recurrence Risk in HR+/HER2- Breast Cancer Patients

PURPOSE

to develop several digital pathology-based machine vision algorithms for combining TMEM and MenaCalc scores and determine if a combination of these biomarkers improves the ability to predict development of distant metastasis over and above that of either biomarker alone.

METHODS

This retrospective study included a subset of 130 patients (65 patients with no recurrence and 65 patients with a recurrence at 5 years) from the Calgary Tamoxifen cohort of breast cancer patients. Patients had confirmed invasive breast cancer and received adjuvant tamoxifen therapy. Of the 130 patients, 86 cases were suitable for analysis in this study. Sequential sections of formalin-fixed paraffin-embedded patient samples were stained for TMEM doorways (immunohistochemistry triple staining) and MenaCalc (immunofluorescence staining). Stained sections were imaged, aligned, and then scored for TMEM doorways and MenaCalc. Different ways of combining TMEM doorway and MenaCalc scores were evaluated and compared to identify the best performing combined marker by using the restricted mean survival time (RMST) difference method.

RESULTS

the best performing combined marker gave an RMST difference of 5.27 years (95% CI: 1.71-8.37), compared to 3.56 years (95% CI: 0.95-6.1) for the associated standalone TMEM doorway analysis and 2.94 years (95% CI: 0.25-5.87) for the associated standalone MenaCalc analysis.

CONCLUSIONS

combining TMEM doorway and MenaCalc scores as a new biomarker improves prognostication over that observed with TMEM doorway or MenaCalc Score alone in this cohort of 86 patients.

Effectiveness and Safety of First-Line Pembrolizumab in Older Adults with PD-L1 Positive Non-Small Cell Lung Cancer: A Retrospective Cohort Study of the Alberta Immunotherapy Database

The emergence of immunotherapy revolutionized the treatment of non-small-cell-lung cancer (NSCLC), with multiple landmark clinical trials establishing the efficacy of these agents. However, many patients who receive immunotherapy in clinical practice would be considered clinical trial ineligible. One such population that is often under-represented in clinical trials is older adults. In the current study, we evaluated clinical and safety outcomes in this population. Overall, older adults (>70 years of age) and younger adults had comparable clinical outcomes with an equivalent objective response rate (ORR), time to treatment failure (TTF), and median overall survival (p = 0.67, p = 0.98, and p = 0.91, respectively). Furthermore, the safety outcomes were equivalent between the cohorts with similar rates of immune-related adverse events (irAEs), irAE-related hospitalizations, and all-cause hospitalization (p = 0.99, p = 0.63, and p = 0.74, respectively). While older age was not found to impact overall survival, multivariant analysis revealed that a poor Eastern Cooperative Oncology Group (ECOG) status, low body-mass-index (BMI), and poor/intermediate lung immune prognostic index (LIPI) were all associated with worse survival. In conclusion, age does not impact the efficacy or safety of pembrolizumab in NSCLC, and therefore advanced age should not be a deterrent for treating these patients with pembrolizumab. Physicians and care providers can thus focus on other factors that may influence therapeutic outcomes.

A biomarker-guided, prospective, phase 2 trial of pre-emptive graft-versus-host disease therapy using anti-thymocyte globulin

BACKGROUND AIMS

Intensified immunosuppressive prophylaxis for graft-versus-host disease (GVHD) may be toxic and therefore warranted only in patients at high risk of developing GVHD. In patients who underwent allogeneic hematopoietic cell transplant at the authors' center, high serum soluble IL-2 receptor alpha (sIL-2Rα) and low IL-15 levels on day 7 post-transplant were found to predict a high risk of developing clinically significant GVHD (sGVHD), defined as grade 2-4 acute GVHD or moderate to severe chronic GVHD.

METHODS

This was a prospective, phase 2 trial in which high-risk patients (serum sIL-2Rα >4500 ng/L or IL-15 <31 ng/L) received rabbit anti-thymocyte globulin (ATG) 3 mg/kg on day 8 post-transplant. Controls consisted of patients who had their sIL-2Rα/IL-15 levels measured but did not participate in the trial. A total of 68 trial patients and 143 controls were accrued to this study. The primary endpoint was incidence of sGVHD.

RESULTS

There was a reduction in sGVHD in high-risk trial patients (received day 8 ATG) compared with high-risk controls (did not receive day 8 ATG) (sub-hazard ratio [SHR] = 0.48, P < 0.05). There was no significant difference between the groups in overall survival or relapse; however, there was a greater incidence of non-GVHD-associated non-relapse mortality in high-risk trial patients (SHR = 3.73, P < 0.05), mostly related to infections. This may be due in part to the biomarkers ineffectively stratifying GVHD risk.

CONCLUSIONS

Pre-emptive ATG therapy is both feasible and effective at reducing sGVHD without increasing relapse. Further mitigation strategies are needed to reduce the risk of infection associated with intensified GVHD prophylaxis. This study was registered at ClinicalTrials.gov (NCT01994824).

Evaluation of the modified immune prognostic index to prognosticate outcomes in metastatic uveal melanoma patients treated with immune checkpoint inhibitors

Background

Metastatic uveal melanoma (MUM) is associated with poor survival and inferior response to immune checkpoint inhibitor (ICI) therapy when compared with metastatic cutaneous melanoma. Currently, prognostic biomarkers are lacking to guide treatment decisions.

Patients and Methods

We conducted a multicenter, retrospective cohort study using a centralized, province‐wide cancer database in Alberta, Canada. We identified 37 patients with histologically confirmed MUM who received at least one dose of single‐agent pembrolizumab or nivolumab, or combination therapy nivolumab and ipilimumab. A modified immune prognostic index (IPI), based on the previously reported lung immune prognostic index, was used to stratify patients into favorable and poor IPI groups. Survival analyses were conducted using the Kaplan–Meier method and Cox proportional hazards models, adjusting for baseline age (≥60) and ECOG performance status, to assess the associations between IPI and overall survival (OS). Time to treatment failure (TTF) was also assessed using the Kaplan–Meier method. The association between IPI and objective response rate was examined using chi‐squared tests. Logistic regression was used to determine the association between IPI and immune‐related adverse events (irAEs).

Results

Median OS was 15.6 (range 0.6–57.6) months with 45.9% 1‐year survival rate at a median follow‐up of 11.8 months. We found that a favorable IPI was significantly associated with OS [median 30.5 (12.0‐not reached) months in the favorable IPI group compared with 4.6 (2.1–16.0) months in the poor IPI group (p = 0.001)] (HR=4.81, 95% CI; 1.64–14.10, p = 0.004), TTF [median 5.1 (95% CI; 2.1–10.4) months in the favorable IPI group compared with 3.7 (95% CI; 1.4–6.4) months in the poor IPI group (p = 0.0191)], and irAE (HR=6.67, 95% CI; 1.32–33.69, p = 0.0220).

Conclusions

The modified IPI may be a useful tool in clinical practice for identifying MUM patients who are more likely to experience irAEs and realize a survival benefit from ICI treatment.

Abstract 4655: Social jetlag and lung cancer incidence in the Alberta's Tomorrow Project: A prospective cohort study

Objectives: Increased lung cancer risk has been associated with markers of circadian disruption (e.g., overly short or long sleep duration, shift work, circadian gene mutation) in both human and animal studies. However, no study to date has reported the association of social jetlag, the misalignment between the internal clock and the socially required timing of activities, with lung cancer risk. We, therefore, aim to investigate this association in the Alberta's Tomorrow Project (ATP), a population-based prospective cohort study in Alberta, Canada, and the potential effect modification of smoking behavior.

Methods: Data on sleep patterns were collected on 19,436 (37.6% male) Albertans aged 35-69 years recruited from 2001-2015. Social jetlag was defined as the absolute difference in waking time between free day and workday that accounted for sleep debt, and categorized into three levels, 0 hours (32.52%), &gt;0-1 hours (32.44%), and &gt;1-4 hours (35.04%). Incident lung cancer cases were determined through linkage with the Alberta Cancer Registry by June 2018. Smoking behavior was defined as never smokers, former smokers, and current smokers. Hazard ratios (HR) were estimated using a series of Cox proportional hazards regressions, adjusting for age, sex, recreational physical activity, sitting time, daily calorie consumption, body mass index, marital status, education, employment status, total household income, smoking and drinking behavior, family history of cancer and preexistence of medical condition.

Results: A total of 117 incident lung cancer cases were identified during a medium of 9.6 years of follow-up, yielded 179,028 person-years. In the multivariable-adjusted model, a suggestive significant association between social jetlag and lung cancer risk was observed (&gt;1-4 hours vs. 0: HR=1.67, 95% CI: 0.96-2.92, p for trend = 0.047). The increased lung cancer risk with social jetlag was retrained and heightened among daily smokers (&gt;1-4 hours vs. 0: HR=2.72, 95% CI: 1.26-5.84, p for trend = 0.010), and attended to null among never smokers (&gt;1-4 hours vs. 0: HR=0.98, 95% CI: 0.15-6.54, p for trend = 0.91) and former smokers (&gt;1-4 hours vs. 0: HR=0.76, 95% CI: 0.27-2.12, p for trend = 0.63). Latency multivariate-adjusted model excluding those diagnosed with cancer within 2 years of baseline assessment returned similar results.

Conclusion: Increased risk for lung cancer was observed among adults who reported social jetlag, particularly daily smokers. Our findings suggest a potential lung cancer risk associated with switching sleep patterns between work and free days among smokers. Further studies are necessary to confirm these findings and elucidate the biological mechanisms.

Citation Format: Benny Rana, Andrew Harper, Grace Shen-Tu, Cheryl Peters, Darren Brenner, Don G. Morris, Lin Yang. Social jetlag and lung cancer incidence in the Alberta's Tomorrow Project: A prospective cohort study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4655.

Abstract P3-06-10: Temozolomide & vorinostat as a targeted therapy strategy for triple negative breast cancer

Approximately 15% of newly diagnosed breast cancers (BC) are classified as triple negative (TNBC), which have a worse prognosis than hormonal receptor-positive BCs. Standard treatment for TNBC includes cytotoxic chemotherapies that are associated with significant toxicities. Currently the only targeted therapy (PARP inhibition) exists for the 10% of TNBC patients who have germline BRCA mutations. There is an ongoing unmet need for TNBC that may include targeted strategies to improve outcomes.

The alkylating agent temozolomide (TMZ) is an oral chemotherapy drug used in the treatment of glioblastomas. The therapeutic benefit of TMZ largely depends on cells not being able to fully repair the DNA damage it causes. O6-methylguanine-DNA methyltransferase (MGMT) is normally expressed and able to repair damage caused by TMZ; however, MGMT is often silenced by promoter methylation in many tumours (mMGMT), and such tumours show a better response to TMZ than those with unmethylated promoters (uMGMT). MGMT has been shown to be methylated in up to 50% of TNBC, suggesting TMZ may be a targeted treatment option. Additionally, studies in other tumour sites suggest that adding an HDAC inhibitor (HDACi) to TMZ can increase response and early phase trials have shown this combination is well tolerated.

We have previously shown cytotoxicity with TMZ in mMGMT TNBC cell lines and now hypothesize that the addition of HDAC inhibition to TMZ will have synergistic effects. Using in vitro models, we explored the efficacy of Vorinostat (HDACi) alone and in combination with TMZ and/or cisplatin utilizing TNBC cell lines: HTB132 (uMGMT) and HTB26 (mMGMT). Cytotoxicity assays were utilized to determine median effective dose (EC50) for each treatment and then we performed EC50 synergy testing. Percent viability was calculated as the absorbance ratio of treated/untreated cells X 100. The EC50 was then determined by calculating the intercept of the log effect vs log RV dose.

We found that Cisplatin and HDAC inhibition showed similar cytotoxicities in both cell lines. The addition of cisplatin to either TMZ or HDACi increased cytotoxicity compared to either treatment alone in the mMGMT cell line HTB26; however, the addition of cisplatin to TMZ in the uMGMT cell line showed the greatest cytotoxicity. Interestingly, we also saw an increase in cytotoxicity when cells were treated with the combination TMZ and HDACi, regardless of methylation status of the MGMT promotor. Finally, the triple combination therapy did not increase cytotoxicity.

Although HDAC inhibition showed cytotoxicity regardless of methylation status of the MGMT promotor; it was increased by the combination with TMZ in both cell lines evaluated. Further, the addition of cisplatin to TMZ did not improve cytotoxicity in the mMGMT cell line but did increase cytotoxicity in the uMGMT cell line. There appears to be no benefit to triple therapy in either cell line. We are currently evaluating these combinations in a xenograft murine model to provide pre-clinical support for a Phase II funded clinical trial in TNBC patients.

Citation Format: Elizabeth N Kornaga, Ailian Yang, Kathy Gratton, Zhong Qiao Shi, Nancy A Nixon, Gloria Roldan Urgoiti, Don G Morris. Temozolomide & vorinostat as a targeted therapy strategy for triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-06-10.

The Lung Immune Prognostic Index Discriminates Survival Outcomes in Patients with Solid Tumors Treated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICI) have revolutionized the treatment landscape of several solid tumor types. However, as patient outcomes are heterogeneous, clinical tools to aid in prognostication are needed. The Lung Immune Prognostic Index (LIPI) correlates with outcomes in patients with non-small cell lung cancer (NSCLC) treated with ICI, but its applicability beyond NSCLC is poorly defined. We sought to determine whether LIPI is associated with overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) in a pooled, real-world, retrospective cohort of patients with solid tumors treated with ICI. Of the total pooled cohort (N = 578), 47.2%, 38.2% and 14.5% of patients were stratified into good, intermediate and poor LIPI group, respectively. Median OS were 22.8 (95% CI 17.4–29.5), 7.8 (95% CI 6.6–9.6), and 2.5 months (95% CI 1.4–3.4) (p < 0.0001). Median PFS were 9.9 (95% CI 7.2–11.5), 3.6 (95% CI 2.7–4.3), and 1.4 months (95% CI 1.2–2.2) (p < 0.0001). ORR was also associated with LIPI group (p < 0.001). Intermediate and poor LIPI were independently prognostic of OS compared to good LIPI, with hazard ratios (HR) of 1.8 (95% CI 1.4–2.3, p < 0.001) and 3.6 (95% CI 2.5–5.1, p < 0.001), respectively. These data are the first to suggest that in a real-world setting, the prognostic value of LIPI may be tumor agnostic.

Association of Indoor Tanning Exposure With Age at Melanoma Diagnosis and BRAF V600E Mutations

There is limited information on how indoor tanning promotes melanoma development. We investigated indoor tanning use in patients with melanomas in sun-exposed skin and studied the clinicopathological and molecular characteristics in relation to indoor tanning exposure. Patients from a multidisciplinary clinic for cutaneous cancers completed standardized questionnaires on risk factors for melanoma as a component of medical history at their initial consultations. For this study, we included patients from December 2013 to May 2015. The 114 patients who reported indoor tanning exposure were younger at diagnosis than the 222 patients who did not (51.5 vs 64.0 years, two-sided P < .001). BRAF V600E genotype was more prevalent in ever-users than in nonusers (42.9% vs 28.3%, two-sided P = .04) and higher in ever-users who initiated indoor tanning prior to age 25 years compared with age 25 years or older (62.2% vs 31.1%, two-sided P = .003). There were more melanomas in intermittently sun-exposed skin in ever-users than nonusers (65.7% vs 51.9%, respectively, two-sided P = .02). Our data suggest indoor tanning may promote melanomas that arise in skin with low-chronic sun-induced damage through BRAF V600E-mediated melanomagenesis.

Oncolytic Reovirus and Immune Checkpoint Inhibition as a Novel Immunotherapeutic Strategy for Breast Cancer

As the current efficacy of oncolytic viruses (OVs) as monotherapy is limited, exploration of OVs as part of a broader immunotherapeutic treatment strategy for cancer is necessary. Here, we investigated the ability for immune checkpoint blockade to enhance the efficacy of oncolytic reovirus (RV) for the treatment of breast cancer (BrCa). In vitro, oncolysis and cytokine production were assessed in human and murine BrCa cell lines following RV exposure. Furthermore, RV-induced upregulation of tumor cell PD-L1 was evaluated. In vivo, the immunocompetent, syngeneic EMT6 murine model of BrCa was employed to determine therapeutic and tumor-specific immune responses following treatment with RV, anti-PD-1 antibodies or in combination. RV-mediated oncolysis and cytokine production were observed following BrCa cell infection and RV upregulated tumor cell expression of PD-L1. In vivo, RV monotherapy significantly reduced disease burden and enhanced survival in treated mice, and was further enhanced by PD-1 blockade. RV therapy increased the number of intratumoral regulatory T cells, which was reversed by the addition of PD-1 blockade. Finally, dual treatment led to the generation of a systemic adaptive anti-tumor immune response evidenced by an increase in tumor-specific IFN-γ producing CD8⁺ T cells, and immunity from tumor re-challenge. The combination of PD-1 blockade and RV appears to be an efficacious immunotherapeutic strategy for the treatment of BrCa, and warrants further investigation in early-phase clinical trials.

Abstract P3-07-08: Temozolomide as a targeted therapy strategy for triple negative breast cancer

BACKGROUND:

Approximately 15% of newly diagnosed breast cancers are classified as triple negative (TNBC). TNBCs are considered more aggressive and have a worse prognosis as no targeted therapies are currently available. These tumors are routinely treated with chemotherapy agents with only modest proven efficacy.

Temozolomide (TMZ) is an oral chemotherapy agent commonly used for the treatment of brain tumors and melanoma. TMZ is an alkylating agent, and its therapeutic benefit depends on its ability to alkylate/methylate DNA, most commonly at the N-7 or O-6 positions of guanine residues. This process leads to DNA damage and subsequently triggers cell death. Cells that express the enzyme O6-Methylguanine-DNA Methyltransferase (MGMT) are able to repair damage caused by TMZ. Tumors that lack expression of MGMT, owing to methylation of the gene promoter, demonstrate a better response to TMZ treatment as a result of synthetic lethality.

It was first reported in 2012 that TNBCs were more likely to be MGMT methylated, which was confirmed by another group that reported up to 64% of wild-type BRCA1 TNBC exhibited MGMT gene methylation. In 2013 it was found that basal-like breast cancers were more likely to be MGMT methylated and linked to larger tumor size. Together these findings suggest that a sub-population of TNBCs lack MGMT expression, due to promoter methylation.

Currently, TMZ is not a treatment option for breast cancers given the modest efficacy of TMZ noted in breast cancer clinical trials; however, most of these trials have focused on using this agent to either treat or prevent brain metastases, due to TMZs ability to cross the blood-brain barrier. Importantly, none of these trials investigated MGMT expression or specifically TNBC populations.

We hypothesize that TMZ may be a viable and efficacious treatment option for TNBCs that lack MGMT expression, due to promoter methylation.

METHODS:

We analyzed 12 archival specimens and 4 TNBC cell lines (HTB132, HTB26, HTB126 and HCC1806) for MGMT expression using a qRT-PCR clinical assay available from Calgary Laboratory Services. Additionally, we also looked at MGMT protein expression in the cell lines using Western Blot analysis to confirm the qRT-PCR results. Finally, we performed an in vitro assay with TNBC cell lines to determine cytotoxicity of TMZ.

RESULTS:

Analysis of the archival specimens found that 33% of samples analyzed had MGMT promoter methylation by qRT-PCR. Additionally, we found that HTB26 and HTB126 cell lines showed MGMT promoter methylation by qRT-pCR analysis. Western Blot analysis confirmed lack of MGMT expression in these two cell lines, and also identified another cell line (HCC1806) lacking MGMT protein that was classified as unmethylated by the qRT-PCR clinical assay. Moreover, our in vitro assay found that two cell lines (HTB26 and HCC1806) showed a noticeable response to treatment with TMZ. Interestingly, HTB126 did not show response to TMZ, suggesting that there may be another putative resistance pathway.

CONCLUSIONS:

Preliminary findings suggest that TMZ may be a viable targeted treatment option for TNBCs. Currently, we are investigating drug response using in vivo mouse models, as well as investigating synergistic combination therapy options.

Citation Format: Kornaga EN, Gratton K, Shi Q, Yang A, Nixon NA, Roldan Urgoiti G, Morris DG. Temozolomide as a targeted therapy strategy for triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-07-08.

Current Immunotherapeutic Strategies to Enhance Oncolytic Virotherapy

Oncolytic viruses (OV) represent a promising strategy to augment the spectrum of cancer therapeutics. For efficacy, they rely on two general mechanisms: tumor-specific infection/cell-killing, followed by subsequent activation of the host’s adaptive immune response. Numerous OV genera have been utilized in clinical trials, ultimately culminating in the 2015 Food and Drug Administration approval of a genetically engineered herpes virus, Talminogene laherparepvec (T-VEC). It is generally accepted that OV as monotherapy have only modest clinical efficacy. However, due to their ability to elicit specific antitumor immune responses, they are prime candidates to be paired with other immune-modulating strategies in order to optimize therapeutic efficacy. Synergistic strategies to enhance the efficacy of OV include augmenting the host antitumor response through the insertion of therapeutic transgenes such as GM-CSF, utilization of the prime-boost strategy, and combining OV with immune-modulatory drugs such as cyclophosphamide, sunitinib, and immune checkpoint inhibitors. This review provides an overview of these immune-based strategies to improve the clinical efficacy of oncolytic virotherapy.

Abstract P6-09-20: Clinical utility of PgR with various cutpoints using 3 commercial assays relative to 15yr survival

Introduction:

Hormone receptors ER and PgR are routinely assessed by pathologists using immunohistochemical (IHC) assays to guide treatment decisions. Patients who are hormone receptor positive are offered hormonal therapy, such as tamoxifen, which improves survival. Although both ER and PgR are evaluated, ER is primarily utilized for patient management as the clinical utility of PgR has not been clearly established according to CAP/ASCO guidelines. Notably, a meta-analysis by the Early Breast Cancer Trialists' Collaborative Group reported that PgR status was not significantly predictive of response to adjuvant tamoxifen, suggesting that PgR may not have a role in breast cancer management. More recently, the level of PgR expression has been hypothesized to be important in predicting response to endocrine therapy, where high PgR levels are more indicative of estrogen-dependent tumors, and thus more sensitive to hormonal treatment.

In this study, we evaluate PgR expression using the current cut-point (Allred&gt;2), as well as an optimized cut-point (Allred&gt;5 to identify PgR high tumors), with regards to 15yr disease-free survival (DFS) and disease-specific overall survival (DSOS) using three commercially available ready-to-use (RTU) IHC assays from Dako, Leica and Ventana in an ER+ cohort.

Methods:

The Calgary tamoxifen breast cancer cohort (Calgary cohort) is a TMA series that includes 532 patients diagnosed with primary breast cancer (1985-2000) who received tamoxifen treatment regardless of hormone receptor status. All RTU assays followed vendor recommended protocols. Specific details regarding the cohort and IHC assays have been previously described (Kornaga et al. Mod Path 2016). All analyses were performed using Stata 12, and multivariate models were adjusted for age, grade, size, lymph node and HER2 status. ER status was defined by the corresponding vendor specific IHC assay.

Results:

Multivariate models looking at DFS are presented in Table 1. None of the assays were significant when the clinical cut-point was used; however, when the optimized cut-point was investigated, all assays found high expression of PgR was significantly associated with improved DFS. Table 2 presents the multivariate models looking at DSOS. Similarly, PgR was not found to be associated with improved DSOS using the current cut-point. When the optimized cut-point was examined, Dako and Leica assays were significantly associated with improved DSOS: The Ventana assay did not reach significance.

Table 1 PgR15YR DFS CutpointHR95% CIp-valueDako&gt;20.830.40-1.730.624Dako&gt;50.560.35-0.910.020Leica&gt;21.130.45-2.830.792Leica&gt;50.520.30-0.890.017Ventana&gt;20.730.32-1.670.460Ventana&gt;50.570.34-0.970.037

Table 2 PgR15YR DSOS CutpointHR95% CIp-valueDako&gt;20.740.33-1.650.464Dako&gt;50.550.32-0.950.031Leica&gt;20.880.35-2.220.780Leica&gt;50.440.24-0.790.006Ventana&gt;20.590.25-1.370.218Ventana&gt;50.630.35-1.150.134

Conclusions:

High PgR expression (Allred&gt;5) is associated with improved 15yr DFS and DSOS in a tamoxifen-treated cohort, where PgR positivity defined using current guidelines is not associated with improved DFS or DSOS. Additionally, differences were noted between the vendor RTU assays with regards to DSOS.

Citation Format: Kornaga EN, Paterson AHG, Feng X, Morris DG, Magliocco AM, Klimowicz AC. Clinical utility of PgR with various cutpoints using 3 commercial assays relative to 15yr survival [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-20.

A systematic comparison of three commercial estrogen receptor assays in a single clinical outcome breast cancer cohort

Breast cancers are routinely assessed for estrogen receptor status using immunohistochemical assays to assist in patient prognosis and clinical management. Specific assays vary between laboratories, and several antibodies have been validated and recommended for clinical use. As numerous factors can influence assay performance, many laboratories have opted for ready-to-use assays using automated stainers to improve reproducibility and consistency. Three commonly used autostainer vendors-Dako, Leica, and Ventana-all offer such estrogen receptor assays; however, they have never been directly compared. Here, we present a systematic comparison of three platform-specific estrogen receptor ready-to-use assays using a retrospective, tamoxifen-treated, breast cancer cohort from patients who were treated in Calgary, Alberta, Canada from 1985 to 2000. We found all assays showed good intra-observer agreement. Inter-observer pathological scoring showed some variability: Ventana had the strongest agreement followed closely by Dako, whereas Leica only showed substantial agreement. We also analyzed each estrogen receptor assay with respect to 5-year disease-free survival, and found that all performed similarly in univariate and multivariate models. Determination of measures of test performance found that the Leica assay had a lower negative predictive value than Dako or Ventana, compared with the original ligand-binding assay, while other measures-sensitivity, specificity, positive predictive value, and accuracy-were comparable between the three ready-to-use assays. When comparing against disease-free survival, the difference in negative predictive value between the vendor assays were not as extreme, but Dako and Ventana still performed slightly better than Leica. Despite some discordance, we found that all ready-to-use assays were comparable with or superior to the ligand-binding assay, endorsing their continued use. Our analysis also allowed for exploration of estrogen receptor-negative, progesterone receptor-positive cases, and we discovered that this phenotype was not consistent across the assays, suggesting this might be an artifact.

Abstract P5-07-07: Fluorescence quantitative image analysis of HER2 evaluation against current clinical HER2 assays in breast cancer testing

BACKGROUND: Presently, therapy for treatment of breast cancer is based on the evaluation of formalin fixed, paraffin embedded (FFPE) pathological specimens using a combination of immunohistochemistry (IHC) and gene copy assessment by in-situ hybridization (-ISH) techniques, following current testing guidelines from the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP). Patients with specimens found to have marked overexpression and amplification of the human epidermal receptor 2 (HER2) are approved for treatment with trastuzumab. While IHC and –ISH assays represent the current clinical standard, these assays are subject to pre-analytical variation, which could lead to false negative results. There are novel laboratory technologies which may improve the accuracy of HER2 measurements and lead to improved patient selection for therapy.

AIM: In this comparative study, we assessed the utility of testing HER2 expression by the fluorescence IHC using AQUA® - a novel computer assisted platform to enable quantitative assessment of protein expression in FFPE tissue specimens – against current clinical assays (IHC and –ISH).

METHODS: Local cases from 2008-2010 clinically evaluated for HER2 were identified for further pathological review. FFPE tissue specimens were retrieved from a total of 207 cases with sufficient tumor present, and placed into a tissue microarray (TMA). TMA sections underwent assessment for IHC HER2 (Clone 4B5, Ventana), HER2/Chromosome 17 gene copy number (Inform HER2 dual-ISH DNA Probe Cocktail Assay, Ventana), and fluorescence IHC (Clone SP3, Thermo Fisher).

RESULTS: HER2 results were available for 142 patients for IHC, and 134 patients for dual–ISH and fluorescence IHC. A comparison of the current clinical methods revealed 11 discordant cases. The average median fluorescence IHC cytoplasmic HER2 expression (cAQUA) was found to be 225.65, (70.65-419.95). HER2 cAQUA was strongly correlated with dual-ISH, and cases with low level amplification had low cAQUA expression. There were cases having high cAQUA expression that did not show amplification by dual-ISH. Only a few amplfied cases demonstrated low cAQUA expression. Dichotomizing cAQUA at the 256 showed an improvement of the receiver operating characteristic compared to the clinical HER2 IHC assay (cAQUA=0.903, p&lt;0.001; IHC=0.833, p=0.006).

CONCLUSIONS: Measurement of HER2 expression using human interpretation can be imprecise as there is still some discordance between HER2 IHC and dual-ISH assays. Evaluation of HER2 protein expression using the novel AQUA assay showed correlation with IHC and dual-ISH, and AQUA may present a more precise way to quantify HER2 protein expression. HER2 cAQUA used a different antibody clone than the clinical IHC assay; however, previous studies have shown strong correlation between these two antibodies. The AQUA assay may identify a previously unrecognized group of breast cancers with elevated HER2 expression. The significance of this finding requires further investigation, particularly in regards with cAQUA HER2 serving as a marker for response to anti-HER2 therapy.

Citation Format: Kornaga EN, Feng X, Klimowicz AC, Dean ML, Guggisberg N, Morris DG, Magliocco AM. Fluorescence quantitative image analysis of HER2 evaluation against current clinical HER2 assays in breast cancer testing. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-07-07.

Abstract A12: PDL-1 blockade and Sunitinib enhance the efficiency of oncolytic viral therapy

Purpose: Oncolytic viruses (OV) are attractive for use against multiple tumours given their ability to prime therapeutic immune responses in addition to their direct cytotoxic effects. We investigated the utility of reovirus, an OV currently in phase III clinical trials, as a novel immunotherapeutic against renal cell (RCC), non small cell lung (NSCLC) and breast carcinomas (BrCa) as both a monotherapy and in combination with sunitinib, a first line metastatic RCC agent. In addition the utility of adding an immune checkpoint inhibitor was investigated.

Experimental Design: In-vitro, cytotoxicity, viral replication and chemokine production were assessed in a panel of human and murine cancer cell lines following exposure to reovirus, sunitinib or their combination. In-vivo, RENCA (murine renal cell carcinoma) cells were implanted subcutaneously into female balb/c mice to establish a syngeneic immunocompetent model of RCC. Tumor growth and overall survival were assessed following treatment with reovirus, sunitinib or their combination. IFN-γ, myeloid-derived suppressor cells (MDSC), and protective immunity were assessed by ELISA, flow cytometry (Gr1+/CD11b+) and adoptive transfer experiments, respectively. PDL-1 and PD-1 expression on both tumour and immune cells were assayed.

Results: In vitro, exposure of RCC cell lines to reovirus resulted in an inflammatory cytotoxic response that was augmented through combination with sunitinib. In vivo, reovirus significantly reduced RENCA tumor burden and generated an anti-tumor immune response that was augmented by sunitinib. Combinations with sunitinib also lead to a decrease in myeloid-derived suppressor cells (MDSC) and resulted in improved overall survival and enhanced protective immunity. Preliminary results in NSCLC and BrCa are suggestive that this strategy maybe applicable to many cancer histologies. Both PDL-1 and PD-1 expression were up regulated by RV (similar to IFN gamma) in the majority of cell lines tested suggesting a potential role for checkpoint blockade (CB).

Conclusions: Reovirus has both direct oncolytic and immunotherapeutic activity against RCC, which is augmented through combination with sunitinib. The role of immune CB is ongoing. These proof-of-principle investigations provide clear rationale to investigate RV/sunitinib/immune CB as a promising approach for early phase clinical trials as a novel treatment strategy for cancer.

Citation Format: Ahmed Mostafa, Kathy Gratton, Keith A. Lawson, Zhong-Qiao Shi, Chandini Thirukkumaran, Don G. Morris. PDL-1 blockade and Sunitinib enhance the efficiency of oncolytic viral therapy. [abstract]. In: Proceedings of the AACR Special Conference: Tumor Immunology and Immunotherapy: A New Chapter; December 1-4, 2014; Orlando, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2015;3(10 Suppl):Abstract nr A12.

Abstract 5355: Oncolytic viral therapy with immune modulation is an effective novel treatment strategy for non-small cell lung cancer

Background: Lung cancer is the leading cause of cancer mortality worldwide. Non-small cell lung cancer (NSCLC) represents approximately 85% of these diagnoses and despite incremental improvements with cytotoxic chemotherapy and targeted therapeutics, the five-year overall survival is only 17%. Recently improved understanding of immune checkpoint pathways and immunosuppresive cellular populations such as myeloid-derived suppressor cells (MDSCs) have led to a resurgence in immunotherapeutic strategies. Reovirus (RV) is an oncolytic virus that only targets cancer cells with certain aberrant signaling pathways such as Ras while avoiding normal cells. Furthermore, its role in stimulating an anti-tumor immune response has been recently described. Additionally, Sunitinib (S), a multitargeted tyrosine kinase inhibitor (anti-VEGFR, C-Kit and PDGFRa) also affects tumor microenvironment Tregs and MDSC numerically, which could consequentially augment RV immunotherapeutic potential.

Hypothesis: RV and S combination therapy is an effective treatment modality for NSCLC via direct oncolysis, tumor immunosuppression reversal, and host anti-tumor immune response stimulation.

Methods: To determine the relative susceptibility of selected NSCLC cell lines to RV, S and combination therapy, a WST-1 cell viability assay was conducted. Four human NSCLC cell lines A549, H460, H1299, and H1975 and the mouse Lewis lung carcinoma (LLC) cell line LL2 were tested, and the combination index (CI) was calculated using Calcusyn software to determine in vitro synergy. The LLC syngeneic C57BL/6 immunocompetent mouse model bearing LL2 cells in the right hind-flank was treated with PBS, S, RV, UV-inactivated RV (DV), or combination therapies (N = 6 mice/group). Mice were sacrificed on day 27. Spleens, blood, and tumors were harvested for analysis. Splenocytes were subject to flow cytometry CD11b and Gr-1 detection for MDSC quantification. Splenocyte CD8+ enrichment was performed, co-cultured with LL2, RV, DV, S or combinations and subject to IFN-γ quantification via ELISA to determine immune recognition.

Results: Treatment resulted in efficacy and synergy of RV/S in A549, H460, and H1299 in vitro as indicated by CI values &lt; 1. LL2 showed additive to synergistic responses at varying treatment concentrations. When LLC tumors in a C57BL/6 immunocompetent murine model were treated with the combination of RV/S, a significant tumor reduction occurred compared to monotherapies and untreated controls (non-overlapping 95% confidence intervals). Furthermore, an increase in anti-tumor immunity stimulating IFN-γ was detected in mice samples upon RV and combination exposure at 0.13μg/mL and 0.09μg/mL compared to PBS treated mice at 0μg/mL. Both S and RV/S treated mice had a significant splenocyte MDSC reduction. These results indicate that Reovirus and Sunitinib combination therapy holds promise as a novel treatment strategy for NSCLC.

Citation Format: Jianrui Liu, Jason Spurrel, Zhong Qiao Shi, WenQian Chen, Don G. Morris. Oncolytic viral therapy with immune modulation is an effective novel treatment strategy for non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5355. doi:10.1158/1538-7445.AM2015-5355

Abstract P5-10-16: Evaluation of RT-qPCR and luminex-based methodolgies in HER2 breast cancer testing

*Co-First Authors

Background: Currently, patients diagnosed with breast carcinoma undergo HER2 testing to direct clinical treatment decisions. At present, immunohistochemical (IHC) and in-situ hybridization methodologies are employed in the clinical setting to ascertain HER2 status. While these tests represent the current standard, their interpretation and variability of results with respect to HER2 prognostic and predictive value remains an outstanding issue.

Aim: In this comparative study we assessed the utility of testing HER2 gene expression by RT-qPCR and the Luminex Quantigene® Plex 2.0 (Affymetrix) methodology against the clinically accepted IHC assay.

Methods: Local cases from 2008-2010 that were clinically evaluated for HER2 were identified and underwent further pathologist review. In cases where there was sufficient tumor, formalin fixed paraffin embedded samples were retrieved. A total of 207 cases were identified which met selection criteria. Tumour sections were stained for HER2 and scored 0-3, following ASCO/CAP guidelines. For molecular assessment total RNA was extracted from tumours and those samples with sufficient RNA yield and quality were assessed for Her2 transcript level expression by RT-qPCR (n=129) and Luminex Quantigene® Plex 2.0 assays (n=166).

Results: Results for RT-qPCR are relative to two normal breast calibrator samples and reported as the mean relative quantification (RQ) value. For HER2 IHC negative cases (0/1+), the mean score was 0.13 (0.004-1.84, SD ±0.22); equivocal cases (2+), mean score was 0.19 (0.007-0.72, SD ±0.18); and positive cases (3+), mean score was 1.51 (0.03-6.78, SD ±1.61). Student’s t-test was performed to compare the means between groups and results are as follows: negative vs. equivocal p=0.17; equivocal vs. positive p=0.0002; and negative vs. positive p&lt;0.0001. Luminex methodology is reported as the normalized mean fluorescence intensity (nMFI) for each group. For HER2 IHC negative cases (0/1+), the mean score was 0.28 (0.01-1.19, SD ±0.23); equivocal cases (2+), mean score was 0.42 (0.10-1.23, SD ±0.27); and positive cases (3+), mean score was 4.74 (0.1-9.09, SD ±2.5). Student’s t-test to compare the means between groups was again utilized, and results are as follows: negative vs. equivocal p=0.0036; equivocal vs. positive p&lt; 0.0001; and negative vs. positive p&lt; 0.0001.Conclusions: Results demonstrate that both RT-qPCR and Luminex Quantigene® Plex 2.0 methods are able to discern strong positive HER2 cases (IHC 3+) from negative HER2 (IHC 0/1+). For cases with moderate IHC staining (2+), the Luminex-based assay was found to perform better than RT-qPCR. For each reporting group, the range of HER2 gene expression values were observed to overlap; thus no distinct cut point could be assigned. While the results from this pilot study are promising, the adoption of molecular methods for HER2 diagnostic testing will require further rigorous investigation before any clinical considerations can be made.

Citation Format: Elizabeth N Kornaga, John B McIntyre, Alexander C Klimowicz, Natalia Guggisberg, Don G Morris, Anthony M Magliocco. Evaluation of RT-qPCR and luminex-based methodolgies in HER2 breast cancer testing [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-10-16.

Oncolytic Viral Therapy Using Reovirus

Current mainstays in cancer treatment such as chemotherapy, radiation therapy, hormonal manipulation, and even targeted therapies such as Trastuzumab (herceptin) for breast cancer or Iressa (gefitinib) for non-small cell lung cancer among others are limited by lack of efficacy, cellular resistance, and toxicity. Dose escalation and combination therapies designed to overcome resistance and increase efficacy are limited by a narrow therapeutic index. Oncolytic viruses are one such group of new biological therapeutics that appears to have a wide spectrum of anticancer activity with minimal human toxicity. Since the malignant phenotype of tumors is the culmination of multiple mutations that occur in genes eventually leading to aberrant signaling pathways, oncolytic viruses either natural or engineered specifically target tumor cells taking advantage of this abnormal cellular signaling for their replication. Reovirus is one such naturally occurring double-stranded RNA virus that exploits altered signaling pathways (including Ras) in a myriad of cancers. The ability of reovirus to infect and lyse tumors under in vitro, in vivo, and ex vivo conditions has been well documented previously by us and others. The major mechanism of reovirus oncolysis of cancer cells has been shown to occur through apoptosis with autophagy taking place during this process in certain cancers. In addition, the synergistic antitumor effects of reovirus in combination with radiation or chemotherapy have also been demonstrated for reovirus resistant and moderately sensitive tumors. Recent progress in our understanding of viral immunology in the tumor microenvironment has diverted interest in exploring immunologic mechanisms to overcome resistance exhibited by chemotherapeutic drugs in cancer. Thus, currently several investigations are focusing on immune potentiating of reovirus for maximal tumor targeting. This chapter therefore has concentrated on immunologic cell death induction with reovirus as a novel approach to cancer therapy used under in vitro and in vivo conditions, as well as in a clinical setting. Reovirus phase I clinical trials have shown indications of efficacy, and several phase II/III trials are ongoing at present. Reovirus's extensive preclinical efficacy, replication competency, and low toxicity profile in humans have placed it as an attractive anticancer therapeutic for ongoing clinical testing that are highlighted in this chapter.

Immunotherapy for Lung Cancer: Has it Finally Arrived?

The possible link between infection/inflammation/immune activation and a cancer patient’s outcome from both a causative and outcome point of view has long been postulated. Substantial progress in the understanding of tumor-associated antigens/epitopes, immune cellular subpopulations, cytokine pathways/expression, the tumor microenvironment, and the balance between tumor-immune suppression and stimulation have been made over the past decade. This knowledge has heralded a new era of tumor immunotherapy utilizing vaccines, immune checkpoint inhibition, and oncolytic viruses. Despite significant progress in the molecular era now with targeted therapeutics such as EGFR tyrosine kinase inhibitors and ALK fusion protein inhibitors that have significantly improved the outcome of these specific lung cancer subpopulations, the overall 5 year survival for all non-small cell lung cancer (NSCLC) is still <20%. Unlike malignancies such as malignant melanoma, renal cell carcinoma, and neuroblastoma given their documented spontaneous remission rates lung cancer historically has been felt to be resistant to immune approaches likely related to an immunosuppressive tumor microenvironment and/or lack of immune recognition. Defining responding populations, understanding the mechanism(s) underlying durable immune responses, and the role of chemotherapy, radiation, oncolytic viruses, and other tumor disrupting agents in augmenting immune responses have led to improved optimization of immune therapeutic strategies. The purpose of this review is to focus on the recent advances in lung immunotherapy with an emphasis on recent clinical trials in the last 5 years in NSCLC.

Reovirus as a successful ex vivo purging modality for multiple myeloma

Autologous stem cell rescue (ASCT) following high-dose myeloablative chemotherapy is considered to be a therapeutic option for many multiple myeloma (MM) patients; however relapse post ASCT presents a major challenge. The oncolytic potential of reovirus has been previously demonstrated and is currently undergoing phase I monotherapy clinical trials for MM and phase II/III clinical trials for solid tumors. Here we tested the hypothesis that reovirus can successfully purge MM in a murine model that partially recapitulates human MM. RPMI 8226, MM1S, H929 and U266 human myeloma cell lines were exposed to reovirus and oncolysis was assessed. Apheresis product admixed with MM cells was purged with live reovirus (LV) or dead virus (DV) and purging efficacy was monitored via flow cytometry, reverse transcribed-PCR (RT-PCR) and disease relapse in non obese diabetic/severe combined immune deficient (NOD/SCID) mice. Significant LV purging was seen with MM1S, H929 and U266 and the complete ex vivo purging achieved with RPMI 8226 was confirmed by flow cytometry, RT-PCR and absence of disease relapse in vivo. Mice that received LV-purged autografts exhibited 100% survival in comparison to mice that received DV-purged controls. Reovirus's unique ability to kill MM while sparing hematopoietic stem cells places it as an attractive purging agent for MM during ASCT.

Clinical trials involving the oncolytic virus, reovirus: ready for prime time?

The use of oncolytic viruses as a potential cancer therapeutic has been studied extensively over the past 15 years and is now in Phase III human clinical testing. One of the most promising of the viruses is the nonattenuated reovirus type-3 Dearing (RT3D; Reolysin(®), Oncolytics Biotech Inc., AB, Canada). The virus is a laboratory strain of a ubiquitous common environmental virus commonly infecting the respiratory and GI tracts of humans without major sequelae. The Phase I/II clinical trial conducted by Karapanagiotou et al. involved dose escalation of Reolysin to 3 × 10(10) tissue culture infectious dose 50 (TCID(50)) daily for 5 days in combination with paclitaxel (175 mg/m(2)) and carboplatin (area under the curve 5) given on day 1 every 3 weeks. Maximum tolerated dose was not reached in the dose-escalation phase and was only limited by manufacturing concentration limitation. Efficacy was suggested in this heavily pretreated head and neck cancer predominate patient population with a 26.9% response rate (seven out of 26 evaluable patients) of the 34 patients intended to treat. Although this was not a randomized trial, the fact that many of the patients (83%) had already received a platinum agent and subsequently progressed and then responded is of interest.

Reovirus modulates autophagy during oncolysis of multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell malignancy that accounts for 10-15% of newly diagnosed hematological cancers. Although significant advances have been made in the treatment of MM the disease still remains incurable. The oncolytic potential of reovirus has previously been demonstrated by others and us and is currently in phase III clinical trials for solid tumors. In addition a phase I clinical trial has recently been initiated for MM. Despite the clinical activity, the mechanism(s) of cell death caused by reovirus in MM is yet not yet well elucidated. A comprehensive understanding of reovirus-mediated histology-specific cell death mechanisms is imperative if this therapeutic is to become a standard of care for patients. Previously we have shown that reovirus-mediated cell death of breast and prostate cancer is orchestrated via apoptosis. The present study demonstrates for the first time that in addition to inducing apoptosis reovirus also upregulates autophagy during oncolysis of MM.

Abstract P1-07-10: Comparison of three commercial ER/PR assays on a single clinical outcome series

Introduction: Adjuvant tamoxifen is the standard therapy for early stage hormone receptor+ breast cancers (BC). Estrogen receptor (ER) and progesterone receptor (PR) analysis is routinely performed by immunohistochemical (IHC) testing on BC specimens to assist in determining hormone receptor status and patient treatment. ER/PR IHC methodologies and guidelines have recently come under review. Many clinical laboratories have opted to use platform specific, ready-to-use (RTU) ER/PR assays provided by three companies: Dako, Leica and Ventana. While each of these companies are using antibodies that were validated on BC clinical outcome series, these platform specific RTU assays have never been directly compared using the same clinical outcome series. We present a systematic comparison of the three platform specific RTU ER/PR assays, using a retrospective BC cohort, to evaluate the concordance and reproducibility of the RTU ER/PR assays, and to assess the ability of the RTU ER assays to predict tamoxifen response.

Methods: The Calgary Tamoxifen Cohort is a retrospective database containing demographic, clinical and pathological data for 820 BC patients diagnosed between 1985–2000 at the Tom Baker Cancer Centre (Calgary, Canada). Formalin-fixed paraffin-embedded tissue blocks were available for 511 patients, and replicate 0.6mm cores were taken and built into tissue microarrays (TMAs). The TMAs were stained using the platform specific assays on the DakoLink Plus, Ventana BenchMark Ultra, or Bond-III Leica autostainers. Slides were manually scored by the Allred method.

Results: Ventana and Dako had the best concordance for ER (κ=0.90). Substantial agreement was seen for ER staining between Leica and Ventana (κ=0.79), and Dako and Leica (κ=0.66). Agreement was more consistent between the three platforms for PR staining (κ=0.78–0.82). Inter-observer reproducibility was evaluated for all three platforms between three observers: Dako ER (κ=0.80–0.92) and PR (κ=0.69–0.90); Leica ER (κ=0.67–0.83) and PR (κ=0.70–0.89); Ventana ER (κ=0.88–1.00) and PR (κ=0.78–0.94). TMAs were rescored and intra-observer agreement was calculated: Dako ER (κ=1.00) and PR (κ=0.98); Leica ER (κ=0.91) and PR (κ=0.94); Ventana ER (κ=1.00) and PR (κ=0.94). ER Allred scores were dichotomized using current standards and univariate analysis for 5-year disease free survival was performed. All platforms achieved significance with the logrank test and hazard ratio (HR) estimates (p &lt; 0.0001). Cox models were also run to adjust for lymph node status, grade, size and HER2 status. ER status determined by Dako [HR=0.37(0.19–0.74), p = 0.005] and Ventana [HR=0.40(0.18–0.87), p = 0.021] maintained significance, while ER status determined by Leica [HR=0.61(0.31–1.20), p = 0.154] did not.

Conclusions: Concordance between RTU assays demonstrated more variation for ER than PR. All assays showed substantial agreement for inter- and intra- observer reproducibility. Although ER RTU assays from all vendors performed as expected in univariate analysis, multivariate models demonstrated differences. Dako and Ventana appeared equivalent in the multivariate analysis, each providing prognostic information, whereas Leica did not achieve independence in this analysis.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-07-10.

Embryo death in cattle: an update

For heifers, beef and moderate-yielding dairy cows, fertilisation generally exceeds 90%. In high-producing dairy cows, it may be lower and possibly more variable. The major component of embryo loss occurs before Day 16 following breeding, with emerging evidence of greater losses before Day 8 in high-producing dairy cows. Late embryo loss causes serious economic losses because it is often recognised too late to rebreed females. Systemic concentrations of progesterone during the cycles both preceding and following insemination affect embryo survival; too-high or too-low a concentration has been shown to be negatively associated with survival rate. Energy balance and dry matter intake during the 4 weeks after calving are critically important in determining conception rate when cows are inseminated 70 to 100 days after calving. More balanced breeding strategies with greater emphasis on fertility, feed intake and energy must be developed. Genetic variability for fertility traits can be exploited; genomic technology will not only provide scientists with an improved understanding of the underlying biological processes involved in fertilisation and the establishment of pregnancy, but could identify genes responsible for improved embryo survival. Their incorporation into breeding objectives would increase the rate of genetic progress for embryo survival. There is a range of easily adoptable management factors, under producer control, that can either directly increase embryo survival or ameliorate the consequences of low embryo survival rates. The correction of minor deficits in several areas can have a substantial overall effect on herd reproductive performance.

Reovirus as a viable therapeutic option for the treatment of multiple myeloma

PURPOSE

Despite the recent advances made in the treatment of multiple myeloma, the disease still remains incurable. The oncolytic potential of reovirus has previously been shown and is currently in phase III clinical trials for solid tumors. We tested the hypothesis that reovirus can successfully target human multiple myeloma in vitro, ex vivo, and in vivo without affecting human hematopoietic stem cell (HHSC) re-population/differentiation in a murine model that partially recapitulates human multiple myeloma.

EXPERIMENTAL DESIGN

Human myeloma cell lines and ex vivo tumor specimens were exposed to reovirus and oncolysis and mechanisms of cell death were assessed. RPMI 8226(GFP+) cells were injected intravenously to non-obese diabetic/severe combined immune deficient (NOD/SCID) mice and treated with live reovirus (LV) or dead virus (DV). Multiple myeloma disease progression was evaluated via whole-body fluorescence and bone marrow infiltration. HHSCs exposed to LV/DV were injected to NOD/SCID mice and re-population/differentiation was monitored.

RESULTS

A total of six of seven myeloma cell lines and five of seven patient tumor specimens exposed to reovirus showed significant in vitro sensitivity. Tumor response of multiple myeloma by LV, but not DV, was confirmed by comparison of total tumor weights (P = 0.05), and bone marrow infiltration (1/6, LV; 5/6, DV). Mice injected with LV- or DV-exposed HHSCs maintained in vivo re-population/lineage differentiation showing a lack of viral effect on the stem cell compartment. Reovirus oncolysis was mediated primarily by activation of the apoptotic pathways.

CONCLUSIONS

The unique ability of reovirus to selectively kill multiple myeloma while sparing HHSCs places it as a promising systemic multiple myeloma therapeutic for clinical testing.

A Phase II Study of Flavopiridol in Patients With Previously Untreated Advanced Soft Tissue Sarcoma

Purpose. Flavopiridol is a potent cyclin-dependent kinase (CDK) inhibitor that has preclinical activity in many tumours. This synthetic flavonoid was tested in a phase II nonrandomized, nonblinded multicentre clinical trial to determine its activity and toxicity in patients with previously untreated metastatic or locally advanced soft tissue sarcoma. Methods. A total of 18 patients with histologically confirmed nonoperable soft tissue was treated with flavopiridol administered at a dose of 50 mg/m² IV over 1 hour daily ×3 days every 3 weeks. Results. Eighteen patients were accrued to the study over a period of 6 months. No objective responses were noted in the seventeen evaluable patients. Eight patients (47%) exhibited stable disease after 2 cycles (median duration of 4.3 months (range 1.4–6.9 months). Kaplan-Meier estimates for 3- and 6-month progression-free survivial rates were 44 percent and 22 percent, respectively. The only grade 3 toxicities were diarrhea (N = 2), nausea (N = 2), gastritis (N = 1), and fatigue (N = 1). Ninety-four percent of patients received ≥ 90% of the planned dose intensity, during 55 treatment cycles. Conclusions. Flavopiridol was well tolerated at the dose and schedule used in this study, however, no objective treatment responses were seen and thus our results do not support further exploration of flavopiridol as a monotherapy at this dose and schedule in soft tissue sarcomas.

Negative energy balance and hepatic gene expression patterns in high-yielding dairy cows during the early postpartum period: a global approach

In high-yielding dairy cows the liver undergoes extensive physiological and biochemical changes during the early postpartum period in an effort to re-establish metabolic homeostasis and to counteract the adverse effects of negative energy balance (NEB). These adaptations are likely to be mediated by significant alterations in hepatic gene expression. To gain new insights into these events an energy balance model was created using differential feeding and milking regimes to produce two groups of cows with either a mild (MNEB) or severe NEB (SNEB) status. Cows were slaughtered and liver tissues collected on days 6–7 of the first follicular wave postpartum. Using an Affymetrix 23k oligonucleotide bovine array to determine global gene expression in hepatic tissue of these cows, we found a total of 416 genes (189 up- and 227 downregulated) to be altered by SNEB. Network analysis using Ingenuity Pathway Analysis revealed that SNEB was associated with widespread changes in gene expression classified into 36 gene networks including those associated with lipid metabolism, connective tissue development and function, cell signaling, cell cycle, and metabolic diseases, the three most significant of which are discussed in detail. SNEB cows displayed reduced expression of transcription activators and signal transducers that regulate the expression of genes and gene networks associated with cell signaling and tissue repair. These alterations are linked with increased expression of abnormal cell cycle and cellular proliferation associated pathways. This study provides new information and insights on the effect of SNEB on gene expression in high-yielding Holstein Friesian dairy cows in the early postpartum period.

Effects of changes in the concentration of systemic progesterone on ions, amino acids and energy substrates in cattle oviduct and uterine fluid and blood

Early embryo loss is a major factor affecting the conception rate in cattle. Up to 40% of cattle embryos die within 3 weeks of fertilisation while they are nutritionally dependent on oviduct and uterine fluids for their survival. Inadequate systemic progesterone is one of the factors contributing to this loss. We have characterised the effects of changes in systemic progesterone on amino acid, ion and energy substrate composition of oviduct and uterine fluids on Days 3 and 6, respectively, of the oestrus cycle in cattle. Oviduct and uterine fluids were collected in situ following infusion of progesterone. There was no effect of progesterone on oviduct fluid secretion rate; however, uterine fluid secretion rate was lowered. Progesterone increased uterine glucose, decreased oviduct sulfate and, to a lesser degree, oviduct sodium, but had no effect on any of the ions in the uterus. The most marked effect of progesterone was on oviducal amino acid concentrations, with a twofold increase in glycine, whereas in the uterus only valine was increased. These results provide novel information on the maternal environment of the early cattle embryo and provide further evidence of progesterone regulation of oviduct amino acid concentrations in cattle.

Oncolytic viral therapy for prostate cancer: efficacy of reovirus as a biological therapeutic

Reovirus is a nonattenuated double-stranded RNA virus that exploits aberrant signaling pathways allowing selective cytotoxicity against multiple cancer histologies. The use of reovirus as a potential treatment modality for prostate cancer has not previously been described, and in this study evidence of in vitro and in vivo activity against prostate cancer was seen both in preclinical models and in six patients. The human prostate carcinoma cell lines PC-3, LN-CaP, and DU-145 exposed to replication-competent reovirus showed evidence of infection as illustrated by viral protein synthesis, cytopathic effect, and release of viral progeny. This oncolytic effect was found to be manifested through apoptosis, as DNA fragmentation, Apo 2.7 expression, Annexin V binding, and poly(ADP-ribose) polymerase cleavage were observed in live reovirus-infected cells, but not in uninfected or dead virus-treated cells. In vivo, hind flank severe combined immunodeficient/nonobese diabetic murine xenograft showed reduction in tumor size when treated with even a single intratumoral injection of reovirus. Finally, intralesional reovirus injections into a cohort of six patients with clinically organ-confined prostate cancer resulted in minimal side effects and evidence of antitumor activity. Histologic analysis after prostatectomy found a significant CD8 T-cell infiltration within the reovirus-injected areas as well as evidence of increased caspase-3 activity. These findings suggest that reovirus therapy may provide a promising novel treatment for prostate cancer and also imply a possible role for viral immune targeting of tumor.

Differences in the expression of genes involved in the somatotropic axis in divergent strains of Holstein-Friesian dairy cows during early and mid lactation

Differences in genetic selection criteria for dairy cows internationally have led to divergence in the Holstein-Friesian breed. The objective of this study was to compare hepatic expression of genes of the somatotropic axis in the North American Holstein-Friesian and the New Zealand Holstein-Friesian strains of dairy cow at early and mid lactation. Mature cows of both the North American Holstein-Friesian (n = 10) and New Zealand Holstein-Friesian (n = 10) strains were selected. Liver tissue was collected by percutaneous punch biopsy from all cows at 35 and 140 d postpartum, representing early and mid lactation, respectively. Total RNA was extracted and the hepatic expression of genes involved in the control of the somatotropic axis was examined. Abundance of insulin-like growth factor (IGF)-1 mRNA was greater in the New Zealand strain, concomitant with a tendency for increased expression of acid-labile subunit mRNA. Across strains, mRNA abundance of IGF-binding protein-1, IGF-binding protein-2, and growth hormone receptor 1A decreased from d 35 to 140 postpartum, whereas expression of IGF-1 and acid-labile subunit tended to increase. Abundance of suppressor of cytokine signaling-3 mRNA was increased at d 140 postpartum. Both the strain of Holstein-Friesian cow and the stage of lactation influenced expression of genes controlling the somatotropic axis in hepatic tissue.

Granulomatous bronchiolitis of Crohn's disease successfully treated with inhaled budesonide

A 39-year-old white woman with longstanding Crohn's disease presented with the rare complication of granulomatous bronchiolitis. Rapid resolution after inhaled budesonide is highlighted, as this is the first case described in the literature successfully treated without the need for systemic therapy. This less toxic approach to therapy is warranted in granulomatous bronchiolitis of Crohn's disease to avoid unwanted side effects of steroids and infliximab.

Pleiotropic effects of negative energy balance in the postpartum dairy cow on splenic gene expression: repercussions for innate and adaptive immunity

Increased energy demands to support lactation, coupled with lowered feed intake capacity results in negative energy balance (NEB) and is typically characterized by extensive mobilization of body energy reserves in the early postpartum dairy cow. The catabolism of stored lipid leads to an increase in the systemic concentrations of nonesterified fatty acids (NEFA) and β-hydroxy butyrate (BHB). Oxidation of NEFA in the liver result in the increased production of reactive oxygen species and the onset of oxidative stress and can lead to disruption of normal metabolism and physiology. The immune system is depressed in the peripartum period and early lactation and dairy cows are therefore more vulnerable to bacterial infections causing mastitis and or endometritis at this time. A bovine Affymetrix oligonucleotide array was used to determine global gene expression in the spleen of dairy cows in the early postpartum period. Spleen tissue was removed post mortem from five severe NEB (SNEB) and five medium NEB (MNEB) cows 15 days postpartum. SNEB increased systemic concentrations of NEFA and BHB, and white blood cell and lymphocyte numbers were decreased in SNEB animals. A total of 545 genes were altered by SNEB. Network analysis using Ingenuity Pathway Analysis revealed that SNEB was associated with NRF2-mediated oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, natural killer cell signaling, p53 signaling, downregulation of IL-15, BCL-2, and IFN-γ; upregulation of BAX and CHOP and increased apoptosis with a potential negative impact on innate and adaptive immunity.

Oncolytic viral therapy using reovirus

Current mainstays in cancer treatment such as chemotherapy, radiation therapy, hormonal manipulation, and even targeted therapies such as trastuzumab (Herceptin) for breast cancer or erlotinib (Tarceva) for non-small cell lung cancer are limited by lack of efficacy, cellular resistance, and toxicity. Dose escalation and combination therapies designed to overcome resistance and increase efficacy are limited by a narrow therapeutic index. Oncolytic viruses are one such group of new biological therapeutics that appears to have a wide spectrum of anticancer activity with minimal human toxicity. Because the malignant phenotype of tumours is the culmination of multiple mutations that occur in several genes eventually leading to aberrant signalling pathways, oncolytic viruses, either natural or engineered, specifically target tumour cells, taking advantage of this cellular deviant signalling for their replication. Reovirus is one such naturally occurring double-stranded RNA (dsRNA) virus that exploits altered Ras signalling pathways in a myriad of cancers. The ability of reovirus to infect and lyse tumours both solid and haematological, under in vitro, in vivo, and ex vivo conditions, is discussed in this chapter. The major mechanism of reovirus oncolysis of cancer cells has been shown to occur through apoptosis. In addition, the synergistic anti-tumour effects of reovirus in combination with radiation or chemotherapy has also been demonstrated for reovirus-resistant and moderately sensitive tumours. In most of the clinical trials undertaken to date, an anti-reovirus immune response has been seen likely circumventing efficacy. Investigation into the use of reovirus as an immune adjuvant is currently underway to try and re-direct this immune response to tumour. Reovirus phase I clinical trials have shown indications of efficacy and several phase I/II trials are ongoing at present. The extensive pre-clinical efficacy, replication competency, and low toxicity profile in humans has placed the reovirus as an attractive anti-cancer therapeutic for ongoing clinical testing.

Embryonic and early foetal losses in cattle and other ruminants

Embryo survival is a major factor affecting production and economic efficiency in all systems of ruminant milk and meat production. For heifers, beef and moderate yielding dairy cows, does and camelids it appears that fertilization generally lies between 90% and 100%. In high-producing dairy cows there is a less substantive body of literature, but it would appear that it is somewhat lower and perhaps more variable. In cattle, the major component of embryo loss occurs before day 16 following breeding with some evidence of greater losses before day 8 in high-producing dairy cows. In cattle late embryo loss, while numerically much smaller than early embryo mortality loss, nevertheless, causes serious economic losses to producers because it is often too late to rebreed females when they repeat. In multiple ovulating small ruminants, the loss rate is positively related to ovulation rate. Systemic concentrations of progesterone, during both the cycle preceding and following insemination, affect embryo survival rate with evidence that too high or indeed too low a concentration being negatively associated with survival rate. Uterine expression of mRNA for progesterone receptor, oestradiol receptor and retinol-binding protein appears to be sensitive to changes in peripheral concentrations of progesterone during the first week after artificial insemination. Energy balance and dry matter intake during 4 weeks after calving are critically important in determining conception rate when cows are inseminated at 70-100 days post-calving. Concentrate supplementation of cows at pasture during the breeding period has minimal effects on conception rates though sudden reductions in dietary intake should be avoided. For all systems of milk production, more balanced breeding strategies with greater emphasis on fertility and feed intake and/or energy balance must be developed. There is sufficient genetic variability within the Holstein breed for fertility traits. Alternative dairy breeds such as the Jersey or Norwegian Red could also be utilized. Genomic technology will not only provide scientists with an improved understanding of the underlying biological processes involved in fertilization and the establishment of pregnancy, but also, in the future, identify genes responsible for improved embryo survival. Its incorporation into breeding objectives would increase the rate of genetic progress for embryo survival.

Energy substrates in bovine oviduct and uterine fluid and blood plasma during the oestrous cycle

Up to 40 percent of cattle embryos die within 3 weeks of fertilization but there is little or no published information on the composition of the oviduct and uterine fluids essential for their survival during this time. We have measured the concentrations of the energy substrates, glucose, lactate, and pyruvate in cattle oviduct fluid on Days 0, 2, 4, and 6 and uterine fluid on Days 6, 8, and 14 of the oestrous cycle and corresponding blood samples. Oviduct and uterine fluids were collected in situ. Glucose concentrations in oviduct and uterine fluids were similar on all days and lower than in plasma (P < 0.05). Oviduct lactate concentration was up to eightfold higher than uterine or plasma concentration (P < 0.01). Oviduct pyruvate concentrations were similar on all days and lower than plasma concentrations on Days 0 and 2 (P < 0.005). Pyruvate concentrations were similar in the uterus and in plasma except on Day 14 when the concentration in plasma was higher (P < 0.05). There were no associations between systemic progesterone or oestradiol and glucose, lactate or pyruvate. There was a linear positive relationship (P < 0.001) between oviduct fluid secretion rate and oviduct glucose concentration and a linear negative relationship (P < 0.001) between oviduct fluid secretion rate and oviduct lactate, but no association between uterine fluid secretion rate and energy substrates. The different concentrations and associations between the energy substrates in oviduct and uterine fluids and blood plasma indicate a differential regulation of the secretion of these energy substrates by the oviduct and uterine epithelium.

Influence of negative energy balance on cyclicity and fertility in the high producing dairy cow

The peripartum period is of critical importance to subsequent health and fertility. Most cows enter a state of negative energy balance (NEB) associated with many metabolic changes which have carry over effects on the resumption and normality of estrous cyclicity and the success of subsequent inseminations. A dataset on 500 lactations explored the relationships between metabolic traits measured before and after calving with fertility. Stepwise multiple regression analysis showed that longer calving to conception intervals were associated with altered profiles of IGF-I, urea and body condition score. These relationships between metabolic profiles and fertility differed between first lactation cows (which are still growing but produce less milk) and mature animals. Early postpartum the liver undergoes extensive biochemical and morphological modifications to adapt to NEB, the uterus is extensively remodeled and must clear bacterial infections, and the ovary must resume ovulatory cycles. RNA isolated from liver and uterine tissues harvested 2 weeks postpartum from cows in mild (MNEB) and severe (SNEB) energy balance was used to screen the Affymetrix 23K bovine microarray. In liver, SNEB resulted in differential expression of key genes involved in lipid catabolism, gluconeogenesis, and the synthesis and stability of IGF-I. This was accompanied by reduced systemic concentrations of IGF-I which is likely to impact on ovarian function and early embryo development. Within endometrium, cows in SNEB showed histological evidence for higher levels of inflammation and the microarray analysis identified groups of differentially expressed genes involved in tissue remodeling and immune response. This may delay uterine repair after calving, likely contributing to the observed reduction in fertility.

Ion concentrations in oviduct and uterine fluid and blood serum during the estrous cycle in the bovine

In the bovine up to 40% of embryos die before implantation but despite the importance of ions in oviduct and uterine fluid formation and in gamete, zygote and early embryo development there is very little published information on the ion concentrations of oviduct or uterine fluid. The free anions chloride, phosphate and sulphate and the free cations sodium, calcium, magnesium and potassium were measured in oviduct fluid on days 0, 2, 4 and 6 and in uterine fluid on days 6, 8 and 14 and in corresponding blood samples. Oviduct and uterine fluids were collected in situ. Sodium was 25-fold higher than potassium and 80-fold higher than the other ions and chloride was 10-fold higher than potassium and 40-fold higher than the other ions in oviduct and uterine fluid. Phosphate, sulphate, magnesium, potassium and calcium were at lower concentrations in all fluids. Oviduct calcium and sodium were higher on day 0 than other days. The most striking uterine differences were the higher potassium and lower chloride, sodium and magnesium on day 14 than other days. There were significant positive associations between oviduct and blood chloride, sulphate, magnesium and calcium while only uterine sulphate was positively related to its blood concentration. There was no relationship between fluid secretion rate and no association between the concentrations of systemic progesterone or oestradiol and any ion in oviduct or uterine fluid. The different concentrations and associations between ions in the oviduct, uterus and blood suggest a differential regulation of ion secretion by the oviduct and uterine epithelia.

Viral purging of haematological autografts: should we sneeze on the graft?

High-dose cytotoxic chemotherapy followed by autologous haematopoietic stem cell transplantation (ASCT) is extensively used for the treatment of many haematopoietic, as well as several epithelial cancers. Disease relapse may be the result of tumour contamination within autograft as evidenced by gene marking studies. The multiple purging strategies that have been described to date have not proven effective in most ASCT settings. This review addresses the possibility of using oncolytic viruses as a novel purging strategy. DNA viruses such as genetically engineered adenoviral vectors have widely been used to deliver either a prodrug-activating enzyme or express wild-type p53 selectively in tumour cells in ex vivo purging protocols. In addition, conditionally replicating adenoviruses that selectively replicate in tumour cells and herpes simplex virus type 1 are other DNA viruses that have been tested as ex vivo purging agents under laboratory conditions. Vesicular stomatitis virus (VSV) and reovirus are naturally occurring RNA viruses that appear to hold promise as purging agents under ex vivo and in vivo settings. Preclinical data demonstrate reovirus's purging potential against breast, monocytic and myeloma cell lines as well as patient-derived tumours of diffuse large B-cell lymphoma, chronic lymphocytic leukaemia, Waldenstrom macroglobulinemia and small lymphocytic lymphoma. In addition, VSV has shown effective killing of leukaemic cell lines and multiple myeloma patient specimens. Given the increasing interest in the utilization of viruses as purging agents, the following review provides a timely summary of the potential and the challenges of oncolytic viruses as purging modalities during ASCT.

Associations between milk progesterone concentration on different days and with embryo survival during the early luteal phase in dairy cows

The relationships between the concentration of milk progesterone and early embryo survival on Days 4-8 inclusive and between the concentration of progesterone on different days from Days 0-8 inclusive following ovulation and insemination were examined in dairy cows. The relationships were examined following 77 randomly chosen artificial inseminations to cows in standing oestrus. There was a significant (P < 0.05) linear and quadratic relationship between the concentration of milk progesterone on each of Days 4-6 after ovulation and the probability of embryo survival. There was no association (P > 0.05) between milk progesterone concentration and probability of embryo survival on Days 7 and 8 after ovulation. There were no associations between milk progesterone concentration on Days 0-2 and the concentrations on Days 4-7, however, progesterone concentrations on Days 4 and 5 were highly predictive of the concentration on Days 6 and 7, respectively. Overall, the results indicate that suboptimal progesterone support during the early luteal phase is likely to deleteriously affect embryo viability and in addition, that it is possible to predict milk progesterone concentrations during the early luteal phase based on earlier stage concentrations and thus identify cows at risk of early embryo loss.

Effect of systemic progesterone concentration on the expression of progesterone-responsive genes in the bovine endometrium during the early luteal phase

Increasing evidence indicates an association between the concentration of systemic progesterone during the early luteal phase of the oestrous cycle and embryo survival rate in cattle. We examined the relationship between the concentration of systemic progesterone on Days 4 to 8 post-ovulation and expression of progesterone receptor (PGR), oestrogen receptor α (ESR1) and retinol-binding protein (RBP) mRNA in the bovine endometrium. Heifers were blood sampled from the day of ovulation (Day 0) to Day 8 post-ovulation. On Day 4, animals were divided into low progesterone control (LC) and high progesterone control (HC) groups based on their plasma progesterone concentrations. Half of each group was supplemented with exogenous progesterone resulting in two further groups, low progesterone supplemented (LS) and high progesterone supplemented (HS). Endometrial tissues were recovered from all groups on Day 6 or Day 8 and gene expression was analysed following Northern blotting. Increasing progesterone concentrations were associated with decreased PGR and ESR1 expression. Duration-dependent effects of progesterone supplementation on ESR1 were evident and there was an effect of systemic progesterone concentrations between Day 0 and Day 4 on the expression of RBP at Days 6 and 8. Such progesterone-responsive changes in uterine gene expression are likely to affect embryo development.

Biological purging of breast cancer cell lines using a replication-competent oncolytic virus in human stem cell autografts

Autologous hematological stem cell transplantation (ASCT) is used for the treatment of many hematological and several solid cancers. ASCT, however, has proven disappointing as a therapeutic strategy for breast cancer. Our group and others have previously shown that breast cancer micrometastases found in patients' apheresis products (APs) predict shorter progression-free and overall survival. The implications of this finding are twofold: (i) contaminating tumor cells (CTCs) in AP reflect a higher systemic disease burden and/or (ii) reinfused CTCs contribute to relapse/progressive disease. To date, purging strategies have been disappointing. We have previously demonstrated the oncolytic properties of reovirus in in vitro, in vivo and ex vivo systems. In the present study, we tested the hypothesis that reovirus purges CTCs in a breast cancer cell line purging model. Reovirus-infected human breast cancer cell lines (HTB 133, HTB 132, SKBR3 and MCF7) exhibited cell death within days. Admixtures of AP with cells from breast tumor cell lines, which were then exposed to reovirus, showed complete purging of CTCs (assessed via flow cytometry/tumor cell outgrowth analysis) without deleterious effect on CD34+ cells. Our results provide preclinical support for the ex vivo use of reovirus as a purging modality for breast cancer during ASCT.

Preoperative Chemoradiotherapy (Modified Eilber Protocol) Provides Maximum Local Control and Minimal Morbidity in Patients With Soft Tissue Sarcoma

BACKGROUND

Local recurrence rates of 15% to 30% after treatment of soft tissue sarcoma (STS) are still common but unacceptable. Our hypothesis was that a refined neoadjuvant chemotherapy and radiation protocol (modified Eilber protocol) improves local control rates while minimizing major morbidity.

METHODS

Consecutive patients with STS deep to the fascia of the extremity or trunk during 1984 to 1996 were treated with 3 days of doxorubicin (30 mg/day) and sequential radiation (300 cGy/day for 10 days). Wide excision with limb preservation was performed 4 to 8 weeks after radiation completion. Treatment complications, margins, local recurrence, and survival were prospectively documented.

RESULTS

Of 75 patients, 66% had tumors >5 cm, and 71% were grade 2/3. In eight patients, negative margins were not achieved, and four of these had amputation (95% limb salvage). Three of the remaining four had local recurrence with a 5- and 7-year actuarial local control rate of 50% and 25%, respectively. In contrast, of the 67 patients with negative margins, a local control rate of 97% at 5 years and 94% at 7 years and an overall survival of 63% were achieved. Although margin (P = .001) and stage (P = .035) were correlated, these were not significant on multivariate Cox regression analysis. Risk factors for death included tumor stage (hazard ratio, 1.54; P = .001) and tumor grade (hazard ratio, 1.4; P = .02). Three patients (4%) required reoperation for tissue loss, and eight patients (10.6%) developed minor wound complications.

CONCLUSIONS

This modified Eilber protocol seems to maximize local control and minimize major wound complications for extremity/truncal STS.