Abstract P1-03-01: An international multicenter study to evaluate reproducibility of automated scoring methods for assessment of Ki67 in breast cancer

Background: The nuclear proliferation biomarker Ki67 has multiple potential roles in breast cancer, including prognosis-based decisions, but unacceptable between-laboratory variability has limited its clinical value. The International Ki67 Working Group (IKWG) has undertaken a systematic program to determine whether Ki67 immunohistochemistry can be analytically validated and standardized across laboratories. Technological advances and broader availability of devices for automated assessment of stained slides raise the possibility that these machines may improve on reproducibility of traditional pathologist-based visual Ki67 assessment.

Aims: To characterize reproducibility of automated machine-measured Ki67 expression using slides previously analyzed in the IKWG phase 3 study that evaluated reproducibility of visual Ki67 assessment.

Methods: Two sets of 30 previously stained slides containing core-cut biopsy sections of breast tumors were circulated to 14 laboratories for scanning and automated assessment of Ki67 expression. Sites were instructed to return average and maximum percentage of tumor cells positive for Ki67 for each slide, where maximum is designed to reflect “hot spot” analysis. Two laboratories returned scores from 2 operators; not all laboratories reported values for maximum Ki67 scores. Different operators were treated as distinct laboratories in analyses. Sixteen and 10 score sets were available for average and maximum Ki67 analyses, respectively, encompassing 7 unique scanner and 10 software platforms. Pre-specified analyses included evaluation of reproducibility across all laboratories as well as within a subgroup limited to those using Aperio scanners. The primary reproducibility metric was intraclass correlation coefficient between laboratories (ICC), regardless of device platform or software.

Results: Geometric means across 30 cases for 16 operators ranged from 11.06% to 38.11% with overall mean 16.75% (95% CI:14.45-19.42) for average scores. Geometric means for 10 operators ranged from 16.44% to 68.73% with overall mean 25.16% (95% CI: 18.71-33.84) for maximum scores. ICC for automated average scores across 16 operators was 0.83 (95% CI: 0.73-0.91) and ICC for maximum scores across 10 operators was 0.63 (95% CI: 0.44-0.80) although one outlier lab dramatically affected results. For the laboratories using the Aperio platform (8 score sets), ICC for automated average scores was 0.89 (95% CI; 0.81-0.96). These results are similar to ICC of 0.87 (95%CI; 0.81-0.93) reported using these same slides in the Phase 3 visual assessment reproducibility study in which observers counted 500 cells per slide (Leung et al, NPJBrCancer, in press).

Conclusions: Between-laboratory reproducibility for automated machine assessment of average Ki67 is similar to that for pathologist-based visual assessment of Ki67. However, the observed ICC was markedly numerically lower for the maximum score method compared to the average method, suggesting that the maximum score may not be useful as a reproducible measure of proliferation. Automated average scoring methods show promise for standardization of Ki67 scoring, supporting future studies to clinically validate Ki67.

Citation Format: Rimm DL, McShane LM, Leung SCY, Bai Y, Bane AL, Bartlett JMS, Bayani J, Chang MC, Dean M, Denkert C, Enwere E, Galderisi C, Gholap A, Hugh JC, Jadhav A, Kornaga E, Laurinavicius A, Levenson R, Lima J, Miller K, Pantanowitz L, Piper T, Ruan J, Srinivasan M, Virk S, Wu Y, Yang H, Hayes DF, Nielsen TO, Dowsett M. An international multicenter study to evaluate reproducibility of automated scoring methods for assessment of Ki67 in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-01.

Abstract P4-21-40: In vitro and in vivo activity of HER2-targeted antibody-liposomal doxorubicin conjugate MM-302 in HER2-intermediate tumors

This abstract was withdrawn by the authors.

Abstract P6-12-04: Phase 1 study of the antibody-drug conjugate (ADC) SGN-LIV1A in patients with heavily pretreated metastatic breast cancer

Background

LIV-1, a transmembrane protein and downstream target of STAT3, is highly expressed in breast cancer cells. It is associated with lymph node involvement and metastatic progression. SGN-LIV1A is an anti-LIV-1 antibody conjugated via a protease-cleavable linker to monomethyl auristatin E (MMAE). Upon binding to cell-surface LIV-1, SGN-LIV1A is internalized and releases MMAE, which binds to tubulin and induces G2/M arrest and apoptosis.

Methods

This is an ongoing, phase 1 dose-escalation study evaluating safety, tolerability, pharmacokinetics, and antitumor activity of SGN-LIV1A (q3 wks IV) in women with LIV-1-positive, unresectable, locally advanced or metastatic breast cancer (LA/MBC) (NCT01969643). Patients (pts) with measurable disease and ≥2 prior cytotoxic regimens for LA/MBC were eligible. Pts with ≥Grade 2 neuropathy were excluded. Response was assessed per RECIST v1.1; pts with stable disease (SD) or better could continue treatment until disease progression or intolerable toxicity. At completion of dose escalation in hormone receptor-positive/HER2-negative (HR+/HER2–) and triple-negative (TN) pts, expansion cohorts were opened to further evaluate safety and antitumor activity of monotherapy in TN pts and combination therapy with trastuzumab (Tz) in HER2-positive (HER2+) pts. Pre- and post-treatment tumor biopsies were done to evaluate LIV-1 expression and other correlative endpoints.

Results

To date, 39 pts (18 HR+/HER2–, 21 TN) have received a median of 3 cycles (range, 1–10) of SGN-LIV1A monotherapy at doses of 0.5–2.8 mg/kg. Median age was 57 yrs (range, 33–79). At baseline, pts had a median of 4 prior cytotoxic regimens for LA/MBC (range, 2–8); 36 had visceral disease and 25 had bone involvement. No dose-limiting toxicities (DLT) occurred in 19 DLT-evaluable pts; maximum tolerated dose was not exceeded at 2.8 mg/kg. Treatment-emergent adverse events (AEs) reported in ≥30% of pts were: fatigue (64%), nausea (54%), alopecia (46%), decreased appetite (41%), constipation (39%), neutropenia (33%), and vomiting (31%). Peripheral neuropathy was reported in 9 pts (23%). Most AEs were Grade 1/2, except neutropenia (all ≥Grade 3). Four pts discontinued treatment due to AEs (acute respiratory distress syndrome, nausea, pneumonia, tachycardia). In dose escalation, modest activity was observed in 17 efficacy evaluable (EE) HR+/HER2- pts, with a disease control rate (DCR) of 59% (10 SD), including 1 pt with SD≥24 wks. Among the 17 EE TN pts (dose escalation plus cohort expansion), the overall response rate (ORR) was 41% (7 PR), DCR was 82% (7 PR, 7 SD) and clinical benefit rate (CBR=OR+SD≥24 wks) was 53% (9 pts). For TN pts, median PFS was 17.1 wks (95% CI: 6.0, 18.4); 6 pts remain on treatment.

Of 281 MBC tumor samples evaluated for LIV-1, 93% were positive; 81% had moderate-to-high expression (H-score ≥100).

Conclusions

LIV-1 is expressed in almost all MBC tumors. SGN-LIV1A monotherapy has been generally well tolerated and shown encouraging antitumor activity in heavily pretreated TN MBC, with a PR rate of 41% and a CBR at ≥24 wks of 53%. Response duration data continue to evolve. Enrollment continues in the TN monotherapy expansion cohort and the HER2+ combination cohort with Tz.

Citation Format: Forero-Torres A, Modi S, Specht J, Miller K, Weise A, Burris III H, Liu M, Krop I, Pusztai L, Kostic A, Li M, Mita M. Phase 1 study of the antibody-drug conjugate (ADC) SGN-LIV1A in patients with heavily pretreated metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-04.

Abstract P4-22-08: A single-arm phase 2 study to assess clinical activity, efficacy and safety of enzalutamide with trastuzumab in HER2+ AR+ metastatic or locally advanced breast cancer

Background:Androgen receptor (AR) expression has been observed in up to 77% of human epidermal growth factor receptor 2–positive (HER2+) breast cancer (BC).References:1 Enzalutamide (ENZA) is a potent AR inhibitor approved for patients (pts) with metastatic castration-resistant prostate cancer. In vitro, ENZA enhances antitumor activity of trastuzumab in HER2+ AR+ cell lines and inhibits proliferation in trastuzumab-resistant HER2+ cell lines.2

Methods:Pts with metastatic or locally advanced BC that was HER2+ AR+ by local or central laboratory assessment were enrolled in a single-arm, Simon 2-stage phase 2 study (NCT02091960). Key eligibility criteria included availability of a tissue sample, presence of measurable or evaluable disease per RECIST v1.1, progression on prior trastuzumab and ≥1 prior line of anti-HER2 therapy as the most recent regimen. Brain metastases and history of seizure were exclusionary. Evaluable pts were those with centrally confirmed nuclear AR expression≥10% by immunohistochemistry who received ≥1 dose of ENZA and had ≥1 postbaseline tumor assessment. Pts received ENZA 160 mg daily and trastuzumab 6 mg/kg every 21 days until disease progression. The primary objective was clinical benefit rate at 24 weeks (CBR24), defined as complete or partial response (CR or PR) or stable disease (SD) for ≥24 weeks in evaluable pts. Additional endpoints included safety and progression-free survival (PFS). CBR24 in ≥3 of 21 evaluable pts was required to continue to stage 2 and enrollment of up to 66 evaluable pts total. This design yields a 1-sided type 1 error of 5% and 90% power when the true response is 25%.

Results:Here we present results from stage 1 (data cutoff: Mar 23, 2016), with 22 evaluable pts enrolled (pts 21 and 22 enrolled simultaneously); 18 had received ≥4 prior lines of therapy. Median duration of ENZA exposure was 144 days (range, 22-495), mean number of complete trastuzumab infusions was 6.5. CBR24 was 27.3% (95% confidence interval [CI], 10.7-50.2); 2 confirmed PR and 4 SD ≥24 weeks. Median PFS was 108 days (95% CI, 56-144). All pts experienced ≥1 adverse event (AE) any grade; 5 pts experienced AEs grade ≥3. ENZA-related AEs were reported in 16 pts (72.7%), the most common (in ≥10% of pts) were fatigue (22.7%), nausea (18.2%), diarrhea (13.6%) and arthralgia (13.6%). Serious AEs were reported in 6 pts (27.3%; 2 each of infection and back pain, 1 each of abdominal pain, nausea, vomiting, pyrexia, urinary retention and pulmonary edema). Two pts discontinued due to drug-related AEs: 1 related to both drugs, 1 related to trastuzumab. One on-study death from pulmonary edema was reported, which was not considered related to either drug.

Conclusion:Stage 1 met its primary objective. No new safety signals were identified, and the safety profile in this study was similar to that in men with prostate cancer and women with other BC subtypes treated with ENZA. These results are encouraging for a heavily pretreated population with advanced HER2+ AR+ BC. Enrollment in stage 2 continues with the combination of ENZA and trastuzumab.

1. Micello D et al. Virchows Arch. 2010;457:467-476.

2. Richer J. Presented at AACR Advances in Breast Cancer, San Diego, CA, 2013.

Citation Format: Krop I, Cortes J, Miller K, Huizing MT, Provencher L, Gianni L, Chan S, Trudeau M, Steinberg J, Sugg J, Liosatos M, Paton VE, Peterson A, Wardley A. A single-arm phase 2 study to assess clinical activity, efficacy and safety of enzalutamide with trastuzumab in HER2+ AR+ metastatic or locally advanced breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-08.

[Strategies for First-Line Treatment of mCRPC]

At present, abiraterone acetate and enzalutamide are the most commonly used substances in the first-line treatment of asymptomatic or mildly symptomatic metastatic castration-resistant prostate carcinoma (mCRPC). Since the relevant pivotal trials have demonstrated comparable clinical efficacy for both substances, further factors should be considered for the choice of treatment. As mCRPC patients usually receive several lines of treatment, different adaptation and resistance mechanisms leading to treatment failure could be important. This is indicated by daily routine observations and some initial clinical studies on resistance and different sequences of therapy. However, until the clinical relevance has been confirmed, it is mostly adverse events and comorbidities that are taken into account for the choice of first-line therapy. Also potential interactions with comedications and patient preferences should be considered. In the first-line treatment of mCRPC, ongoing discussions not only centre around the choice of medication for first-line mCRPC therapy, but also around the point in time they are started. For abiraterone acetate, for example, there is confirmed evidence that patients may benefit from early use within the approved indication. If the clinical importance of the different resistance mechanisms and differences in efficacy of various sequences could be confirmed, this would be a strong argument for therapy decisions and should therefore be further analysed in prospective clinical studies.

[Implications of PI-RADS Version 1 and Updated Version 2 on the Scoring of Prostatic Lesions in Multiparametric MRI]

BACKGROUND

A revised version of the PI-RADS scoring system has been introduced and score-related variability between version 1 and 2 may be suspected. This study aimed to assess the PI-RADS scores derived from version 1 (v1) and the updated version 2 (v2).

MATERIAL AND METHODS

61 patients with biopsy-proven prostate cancer (PCa) and 90 lesions detected on pre-biopsy 3-Tesla multiparametric MRI were included in this retrospective analysis. 2 experienced radiologists scored all lesions in consensus. Lesion scores differing between PI-RADS v1 and v2 were further analyzed. Histology data from radical prostatectomy (RP) were included when available.

RESULTS

The PI-RADS v1 and v2 score differed in 52% of patients (32/61) and in 39% of lesions (35/90). On a lesion basis, the reason for the differences were related to sum score in v1 vs. categorical system in v2 in 51% (18/35) of lesions, cutoff between PI-RADS 4 and 5 based on lesion size in v2 as opposed to the sum score in v1 in 31% (11/35) and were inconclusive in 17% (6/35). The RP subgroup indicates enhanced detection of PCas with GS 3+3 and GS 3+4 in v2.

CONCLUSION

PI-RADS scores of prostatic lesions frequently differed between v1 and v2, the major reasons for these differences being score-related. In men undergoing RP, PI-RADS v2 improved detection of low risk PCa, but did not increase accuracy for discrimination of GS 3+4 vs. GS≥4+3 compared to v1. Urologists should be aware of the system-related differences when interpreting PI-RADS scores.

Factors underlying metastatic breast cancer patients' perceptions of symptom importance: a qualitative analysis

The symptom literature in cancer has primarily examined symptom severity, frequency and distress. Assessing cancer patients' perceptions of symptom importance-how important it is for them to see improvement in a symptom following an intervention-and factors influencing these judgments would also inform patient-centred care, but this analysis has not been undertaken. This qualitative study aimed to identify factors underlying perceptions of symptom importance among 25 symptomatic metastatic breast cancer (MBC) patients. Participants were recruited from a cancer centre in the Midwestern USA. Semi-structured interviews focused on patients' rationale for considering common symptoms (i.e., anxiety, sadness, sleep problems, pain or fatigue) to be important. Thematic analyses revealed five interrelated factors underlying MBC patients' perceptions of symptom importance: activity restriction, concentration difficulties, exacerbation of other physical symptoms, symptom-related long-term health concerns and negative impact on their relationships with others. Patients most frequently stated that a physical or psychological symptom was important because of the resulting activity restriction. Additionally, some patients considered pain to be important because it signalled potential long-term health concerns, such as worsening metastatic disease. Findings suggest that clinicians should take into account MBC patients' perceptions of symptom importance and factors underlying these judgments when making shared treatment decisions.

[Drug therapy of hormone-sensitive metastatic prostate cancer : Consensus paper of the AKO/AUO]

BACKGROUND

The standard treatment of patients with metastatic, hormone-sensitive prostate cancer (mCSPC) currently consists of medical or surgical castration. The addition of a cytotoxic chemotherapy was unable to provide a survival benefit over castration alone in several clinical trials using different chemotherapy regimens.

RESULTS

Even a preliminary clinical trial using a docetaxel-based chemohormonal combination did not show a survival benefit. In contrast, two more recently published clinical trials (CHAARTED and STAMPEDE) using docetaxel in combination with castration provided evidence for a substantial improvement in overall survival. The survival benefit was 14 and 22 months in the two trials. In addition, the CHAARTED trial showed that patients with high volume disease may benefit most from chemohormonal treatment.

CONCLUSION

According to the current available evidence, the new standard of treatment for patients therefore consists of castration in combination with docetaxel-based chemotherapy and should be offered to all patients who are fit to receive chemotherapy.

[Malignant Sertoli cell tumors of the testes]

Sertoli cell tumors are a rare malignancy which account for approximately 1.5 % of all testicular tumors. Although malignant Sertoli cell tumors are uncommon, they are associated with a poor prognosis. So far 36 cases of malignant courses of disease have been described. We present a patient with a lymphogenic metastasized Sertoli cell tumor, who 24 months after orchiectomy and extended retroperitoneal lymphadenectomy is relapse-free.

Site-directed mutagenesis, in vivo electroporation and mass spectrometry in search for determinants of the subcellular targeting of Rab7b paralogue in the model eukaryote Paramecium octaurelia

Protein products of paralogous genes resulting from whole genome duplication may acquire new functions. The role of post-translational modifications (PTM) in proper targeting of Paramecium Rab7b paralogue (distinct from that of Rab7a directly involved in phagocytosis) was studied using point mutagenesis, proteomic analysis and double immunofluorescence after in vivo electroporation of the mutagenized protein. Here we show that substitution of Thr200 by Ala diminished the incorporation of [P³²] by 37% and of [C^14-]UDP-glucose by 24% into recombinant Rab7b_200 in comparison to the non-mutagenized control. Double confocal imaging revealed that Rab7b_200 was mistargeted upon electroporation into living cells in contrast to non-mutagenized recombinant Rab7b correctly incorporated in the cytostome area. Using nano LC-MS/MS to compare the peptide map of Rab7b with that after deglycosylation with a mixture of five enzymes of different specificity we identified a peptide ion at m/z=677.6³⁺ representing a glycan group attached to Thr200. Based on its mass and quantitative assays with [P³²] and [C¹⁴]UDP-glucose, the suggested composition of the adduct attached to Thr200 is (Hex)1(HexNAc)1(Phos)3 or (HexNAc)1 (Deoxyhexose)1 (Phos)1 (HexA)1. These data indicate that PTM of Thr200 located in the hypervariable C-region of Paramecium octaurelia Rab7b is crucial for the proper localization/function of this protein. Moreover, the two Rab7 paralogues differ also in another PTM: substantially more phosphorylated amino acid residues are in Rab7b than in Rab7a.

ID: 42: FACTORS ASSOCIATED WITH TREATMENT SEEKING IN VETERANS WITH LATE-ONSET PTSD

Background and Significance

Post-traumatic stress disorder (PTSD) is a chronic anxiety disorder with a lifetime prevalence of 6.8% in the general population and up to 30% among Vietnam War veterans. While presentation of PTSD is typically acute, delayed onset of PTSD (i.e., 6 months post trauma) is considered to be relatively rare. There is anecdotal evidence supporting reactivation of trauma memories and symptoms of PTSD among aging veterans who previously had no symptoms or treatment for PTSD. Clinically this type of presentation appears to be different from those presenting with symptoms earlier in life. It is unclear what might precipitate or reactivate these symptoms many years following trauma exposure. The Veterans Health Administration has a growing population of aging veterans exposed to combat during their military service. Current treatment guidelines provide limited guidance towards the management of late-onset PTSD. The prevalence of PTSD among OEF/OIF veterans is very high and as this cohort ages, we need to be better equipped to manage clinical changes seen across the lifespan. Understanding the clinical phenomenology, risk factors and potential biomarkers of this condition could pave the way for better screening methods and treatment interventions for clinicians.

Objective

To identify the characteristics and risk factors among late-life post-traumatic stress disorder (PTSD) treatment seekers.

Methods

The study is a retrospective chart review of patients diagnosed with PTSD after the age of 55 and a comparison group of veterans diagnosed with PTSD prior to the age of 55 in the VA Nebraska–Western Iowa Health Care System.

Results

Primary variables for analysis included demographic factors, military history, age at treatment seeking, PTSD Checklist (PCL) scores, PTSD treatment, recent stressors/reasons for seeking treatment (e.g., recent life changes, another trauma or reminder), and comorbid medical conditions.

Conclusions

A number of explanations have been proposed for the development of late-onset PTSD, including chronic inflammation and cumulative stress. We are conducting a separate study to determine whether plasma concentration of the inflammatory marker C-reactive protein (CRP) might help in predicting late-onset PTSD. Further studies are needed to evaluate the contributions of other factors (e.g., physical or cognitive decline, sleep disturbances, other traumas) to late-onset PTSD.

[Cardiovascular risks of androgen deprivation therapy for prostate cancer]

Androgen deprivation therapy (ADT) is the standard treatment for metastatic prostate cancer. It has increasingly been used in other stages of the disease as well. Besides well-known side effects caused by the lack of testosterone (impotency, osteoporosis, fatigue, loss of muscle mass), an increase of cardiovascular (CV) morbidity and mortality has recently been discussed in association with ADT. Cardiovascular side effects cannot be sufficiently explained by low testosterone levels. This review gives an overview of the recent literature, interprets the results, and offers clinical consequences.

Abstract OT3-01-01: HERMIONE: A phase 2, randomized, open label trial comparing MM-302 plus trastuzumab with chemotherapy of physician's choice plus trastuzumab, in anthracycline naive HER2-positive, locally advanced/metastatic breast cancer patients previously treated with pertuzumab and ado-trastuzumab emtansine (T-DM1)

Background: Although HER2-targeted therapies such as pertuzumab and T-DM1 have improved patient outcomes, treatment resistance typically occurs. MM-302 is a HER2-targeted liposomal doxorubicin in development by Merrimack Pharmaceuticals. In a Phase 1 study, patients with HER2-positive metastatic breast cancer (MBC) were treated with MM-302 alone and in combination with trastuzumab with or without cyclophosphamide. MM-302 had an acceptable safety profile and promising efficacy was observed in patients not previously exposed to an anthracycline.

Trial design: HERMIONE (NCT02213744) is a randomized Phase 2, two-arm, open-label trial designed to evaluate if MM-302 can address an unmet medical need in patients with anthracycline naïve, trastuzumab-, pertuzumab- and T-DM1-pretreated HER2-positive locally advanced breast cancer (LABC)/MBC. Patients are randomized 1:1 to receive MM-302 (30mg/m2, Q3W) plus trastuzumab (6mg/kg, Q3W) or chemotherapy of physician's choice (vinorelbine, capecitabine, or gemcitabine) plus trastuzumab (6mg/kg, Q3W).

Eligibility criteria: Centrally confirmed HER2-positive LABC/MBC, no prior anthracycline exposure, prior trastuzumab in any setting, prior pertuzumab and T-DM1 in the LABC/MBC setting, unlimited prior lines of therapy, ECOG 0-1 and LVEF ≥50%. CNS metastases are permitted if stable and without symptoms or steroids for 4 weeks.

Specific aims: The primary endpoint is independently assessed progression free survival (PFS). Secondary endpoints include investigator assessed PFS, overall survival, response rate, safety and patient related outcomes.

Statistics: 250 patients will be enrolled to observe 191 PFS events for 90% power to detect a Hazard Ratio of 0.625. The MM-302 arm will be compared to the control arm on the primary endpoint of PFS using a stratified log-rank test at one-sided 0.025 level.

Accrual status: First patient in was December 2014 and enrollment is expected to be complete in late 2016. Sites are open in the US, Canada and Western Europe and are currently enrolling patients.

Citation Format: Miller K, Cortes J, Hurvitz SA, Krop IE, Tripathy D, Verma S, Riahi K, Reynolds JG, Wickham T, Molnar I, Yardley DA. HERMIONE: A phase 2, randomized, open label trial comparing MM-302 plus trastuzumab with chemotherapy of physician's choice plus trastuzumab, in anthracycline naive HER2-positive, locally advanced/metastatic breast cancer patients previously treated with pertuzumab and ado-trastuzumab emtansine (T-DM1). [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 OT3-01-01.

Abstract P1-01-16: Performance evaluation of two ready-to-use antibodies under development for the Dako Omnis automated staining platform on breast carcinoma specimens: Anti-estrogen receptor α clone EP1 and anti-progesterone receptor clone PgR 1294

Background: The expression of estrogen receptor alpha (ERα) and progesterone receptor (PR) in breast carcinomas is a strong predictor of the efficacy of hormonal therapy for breast cancer patients as well as providing a degree of prognostic information. Anti-ERα (clone EP1) and anti-PR (clone PgR 1294) configured as FLEX ready-to-use antibodies have been tested on the Dako Omnis automated staining platform. These products are in performance evaluation and are not commercially available. A series of concordance studies were performed to evaluate the performance characteristics of these monoclonal antibodies on breast cancer tissue specimens: anti-ERα clone EP1/Dako Omnis was compared to (a) anti-ERα clone EP1/Autostainer Link 48 (238 specimens) and to (b) anti-ERα clone SP1/Autostainer (116 specimens), and anti-PR clone PgR 1294/Dako Omnis was compared to (a) anti-PR clone PgR 636/Autostainer Link 48 (289 specimens) and to (b) anti-PR clone 16 (Leica Biosystems, Newcastle, UK) (144 specimens). In addition, the specificity of the ER and PR antibodies for Dako Omnis was evaluated on a set of normal tissue specimens.

Methods: Formalin-fixed, paraffin-embedded (FFPE) human breast carcinoma specimens and normal tissues were obtained from commercial providers or local hospitals. The specimens had no associated personal information and were not traceable back to the tissue donors. Tissue pretreatment and immunohistochemical staining were performed using the recommended protocol for each antibody and staining platform. The stained slides were evaluated for nuclear ER or PR expression according to ASCO/CAP guidelines (≥1% cut-off for positive) by pathologists who were blinded from the staining method and specimen ID. The concordance studies included breast cancer specimens covering the clinical range of ER or PR expression with approximately half the specimens in the negative (<1%) category, and at least 10% of the specimens in the weakly positive (≥1 ≤10%) category in each study. Two-sided Wilson Score 95% Confidence Intervals were calculated using JMP software (SAS Institute, USA). For the analytical specificity studies the presence or absence of specific staining in the various normal tissue types was recorded.

Results: High concordance rates were observed with both anti-ERα clone EP1/Dako Omnis and anti-PR clone PgR 1294/Dako Omnis compared to the other ER/PR antibodies, with overall agreement rates exceeding 95% in all of the comparative studies. On a set of normal tissues, specific positive nuclear staining was observed only in tissue types known to express ERα or PR.

Conclusions: Monoclonal antibodies anti-ERα clone EP1 and anti-PR clone PgR 1294 configured as FLEX ready-to-use on Dako Omnis are sensitive and specific assays for detecting estrogen receptor and progesterone receptor in FFPE tissues. In comparison testing for assessment of hormonal receptor status on breast carcinoma specimens, anti-ERα clone EP1/Dako Omnis and anti-PR clone PgR 1294/Dako Omnis were highly concordant with commercially-available ER or PR antibodies.

Citation Format: Viale G, Dell'Orto P, Falzon M, Fält A, Hicks D, Hoff K, Jakobsen K, Jensen LB, Levy YY, McMahon L, Miller K, Russo L. Performance evaluation of two ready-to-use antibodies under development for the Dako Omnis automated staining platform on breast carcinoma specimens: Anti-estrogen receptor α clone EP1 and anti-progesterone receptor clone PgR 1294. [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 P1-01-16.

Abstract OT2-01-04: E2112: Randomized phase III trial of endocrine therapy plus entinostat/placebo in patients with hormone receptor-positive advanced breast cancer. A trial of the ECOG-ACRIN cancer research group

Background:

A potential mechanism of resistance to endocrine therapy in breast cancer involves changes in gene expression secondary to epigenetic modifications, which might be modulated with the use of histone deacetylase (HDAC) inhibitors such as entinostat. ENCORE 301, a phase II study evaluating the addition of entinostat to the steroidal aromatase inhibitor (AI) exemestane in patients with hormone receptor (HR)-positive advanced breast cancer who had experienced disease progression after a non-steroidal AI (NSAI), showed a significant improvement in progression-free survival (PFS), and overall survival (OS). Entinostat has been designated a Breakthrough Therapy by the FDA.

Methods:

E2112 is a multicenter randomized double-blind placebo-controlled phase III study (NCT02115282) enrolling patients with advanced HR-positive, HER2-negative breast cancer with prior disease progression on a NSAI (n=600). Patients receive exemestane 25mg po daily and entinostat/placebo 5mg po every week. Eligibility: Postmenopausal women and men, ECOG 0-1, locally advanced/metastatic invasive adenocarcinoma of the breast: ER/PR-positive, HER2-negative, measurable or non-measurable (20% cap) disease. Disease progression after NSAI use in the metastatic setting OR relapse while on or within ≤ 12 months of end of adjuvant NSAI therapy.

Statistics: Both PFS (central review) and OS are primary endpoints, and the study is designed to show an improvement in either PFS or OS. Secondary endpoints include: Safety and tolerability, objective response rate, changes in lysine acetylation status in peripheral blood mononuclear cells, patient-reported symptom burden and treatment toxicities, adherence. One-sided type 1 error 0.025 split between two hypotheses tests: 0.001 for PFS test and 0.024 for OS. PFS is tested in the first 360 pts, 88.5% power to detect 42% reduction in the hazard of PFS failure (median PFS 4.1 to 7.1 months); OS is tested in all 600 pts, 80% power to detect 25% reduction in the hazard of death (median OS 22 to 29.3 months).

E2112 was activated in March 2014 and accrual is anticipated to complete in 40 months.

Citation Format: Connolly R, Zhao F, Miller K, Tevaarwerk A, Wagner L, Lee M, Murray J, Gray R, Piekarz R, Zujewski JA, Sparano J. E2112: Randomized phase III trial of endocrine therapy plus entinostat/placebo in patients with hormone receptor-positive advanced breast cancer. A trial of the ECOG-ACRIN cancer research group. [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 OT2-01-04.

[Mechanisms of Resistance in Antihormone Therapies of Advanced Prostate Cancer]

With the development of Abiraterone and Enzalutamide new treatment option have become available in addition to Docetaxel for first-line treatment of castration resistant prostate cancer. However, resistance and ultimately failure occurs inevitably with all available treatment options. Moreover, cross-resistance leads to considerably reduced efficacy in second-line treatment. Preclinical data suggest discriminative mechanisms of resistance development for Abiraterone and Enzalutamide. Clinical confirmation of these putative mechanisms for treatment failure might facilitate recommendations for future sequencing of these drugs.

The Incorporation of an Advanced Donation Program Into Kidney Paired Exchange: Initial Experience of the National Kidney Registry

The continued growth of kidney paired donation (KPD) to facilitate transplantation for otherwise incompatible or suboptimal living kidney donors and recipients has depended on a balance between the logistics required for patients and the collaborating transplant centers. The formation of chains for KPD and the shipping of kidneys have permitted networks such as the National Kidney Registry (NKR) to offer KPD to patients over a transcontinental area. However, over the last 3 years, we have encountered patient requests for a more flexible experience in KPD to meet their individual needs often due to rigid time constraints. To accommodate these requests, we have developed an Advanced Donation Program (ADP) in which the donor desires to donate by a specific date, but their paired recipient has not yet been matched to a specific donor or scheduled for surgery. After obtaining careful informed consent from both the donor and paired recipient, 10 KPD chains were constructed using an ADP donor. These 10 ADP donors have facilitated 47 transplants, and thus far eight of their paired recipients have received a kidney within a mean of 178 (range 10-562) days. The ADP is a viable method to support time limited donors in a KPD network.

[New biomarkers in serum and urine for detection of prostate cancer]

Prostate-specific antigen (PSA) has revolutionized the management of prostate cancer (PCa) within the last 3 decades. This widely used tumour marker strongly correlates with the risk of harbouring a PCa but it lacks specificity. Therefore there is an urgent need for new biomarkers especially to detect clinically significant and aggressive PCa. Of all PSA-based markers, only the FDA-approved prostate health index phi shows improved specificity over percent free (%fPSA) and total PSA. Other serum kallikreins or sarcosine in serum or urine show more ambiguous data. In urine, the FDA-approved prostate cancer gene 3 (PCA3) has also proven its utility in the detection and management of early PCa with advantages as compared with PSA and %fPSA. However, some aspects of its correlation with aggressiveness and the low sensitivity at very high values have to be re-examined. The detection of alterations of the androgen regulated TMPRSS2 and ETS transcription factor genes in tissue of ~50% of all PCa patients was a milestone in PCa research. But only the combination of the urinary assays for TMPRSS2:ERG gene fusion and PCA3 (both use the same platform) show the expected improved accuracy for PCa detection. Comparisons of phi and PCA3, the best available PCa biomarkers so far, show an equal performance of both parameters.

[Interdisciplinary recommendations for the treatment of metastatic renal cell carcinoma]

Patients with metastatic renal cell carcinoma have a life-limiting prognosis. Therefore, the aim of therapy is normally palliative care. Nevertheless, substantial achievements have been made in the past years. Cytokines as long-term standard therapy have been replaced by new targeted therapies. Sunitinib, the combination of bevacizumab+interferon-alfa, pazopanib and temsirolimus are now approved for first-line therapy. Sunitinib and pazopanib can also be administered as second-line options - for pazopanib the use is restricted to the event of cytokine failure. Everolimus (after TKI therapy) und sorafenib (after cytokines) are other compounds now available for second-line therapy. In addition, axitinib was approved for second-line therapy after failure of sunitinib or cytokines. For questions regarding the optimal sequence, first study results are now available from the phase III trial.The purpose of an interdisciplinary expert meeting held in 2014 was to debate about which criteria should influence the therapy decision. The members discussed several aspects of treating patients with the disease. Results from the 2012 conference provided the basis for the 2014 meeting 1. As in previous years, the experts intended to provide common recommendations for clinical practice. The results of the 2012 conference are presented as short theses and a current therapy algorithm.

[Biomarkers in metastatic castration-resistant prostate cancer]

Therapy for metastatic castration-resistant prostate cancer (mCRPC) has become more complex due to recent medical findings. Today different options for first- and second-line treatment are available. Therefore scientific attention focuses on possible sequences and combinations. Besides, biomarkers play an important role as they can support therapeutic decisions and may enable more focused therapies. A new evaluation of biomarkers for advanced prostate cancer is necessary since the tumour biology is changing. One prognostic marker in mCRPC is PSA but this marker has to be interpreted with caution in this situation. Validated predictive markers for mCRPC are still lacking. In some studies potential predictive markers have been analysed.

[Propensity score comparison of the various radical surgical techniques for high-risk prostate cancer]

INTRODUCTION

The optimal surgical treatment of patients with a high risk prostate cancer (PCa) in terms of radical prostatectomy (RP) is still controversial: open retropubic RP (RRP), laparoscopic RP (LRP), or robot-assisted (RARP). We aimed to investigate the influence of the different surgical techniques on pathologic outcome and biochemical recurrence.

PATIENTS AND METHODS

A total of 805 patients with a high risk PCa (PSA >20 ng/mL, Gleason Score ≥8, or clinical stage ≥cT2c) were included. A comparison of 407 RRP patients with 398 minimally invasive cases (LRP+RARP) revealed significant confounders. Therefore all 110 RARP cases were propensity score (PS) matched 1:1 with LRP and RRP patients. PS included age, clinical stage, preoperative PSA, biopsy Gleason score, surgeon's experience and application of a nerve sparing technique. Comparison of overall survival (OS) and recurrence-free survival (RFS) was done with the log rank test. Predictors of RFS were analyzed by means of Cox regression models.

RESULTS

Within the post-matching cohort of 330 patients a pathologic Gleason score < 7, = 7 and > 7 was found in 1.8, 55.5 and 42.7% for RARP, in 8.2, 36.4, 55.5% for LRP and in 0, 60.9 and 39.1% for RRP (p=0.004 for RARP vs. LRP and p=0.398 for RARP vs. RRP). Differences in histopathologic stages were not statistically significant. The overall positive surgical margin rate (PSM) as well as PSM for ≥ pT3 were not different. PSM among patients with pT2 was found in 15.7, 14.0 and 20.0% for RARP, LRP and RRP (statistically not significant). The respective mean 3-year RFS rates were 41.4, 77.9, 54.1% (p<0.0001 for RARP vs. LRP and p=0.686 for RARP vs. RRP). The mean 3-year OS was calculated as 95.4, 98.1 and 100% respectively (statistically not significant).

CONCLUSION

RARP for patients with a high risk PCa reveals similar pathologic and oncologic outcomes compared with LRP and RRP.

[Real-time MRI/US fusion-guided biopsy in biopsy-naïve and pre-biopsied patients with suspicion for prostate cancer]

BACKGROUND

Magnetic resonance imaging (MRI)/ultrasound (US) fusion-guided biopsy detects more prostate cancer (PCa) than transrectal US (TRUS)-guided biopsy in patients with an indication for prostate re-biopsy. The aim of this study was a) to compare the detection rates of MRI/US fusion-guided biopsy with conventional TRUS in a double centre cohort and b) to investigate the influence of the number of pre-biopsies on the PCa detection rate.

MATERIAL AND METHODS

In the period from January 2012 to July 2014, 310 consecutive patients gave written informed consent and underwent 3 Tesla MRI scans of the prostate. All patients had at least one PCa suspicious lesion in the MRI and were biopsied by MRI/US fusion followed by a conventional 10-core biopsy of the prostate. Detection rates based on technique, Gleason score and number of pre-biopsies were calculated.

RESULTS

The overall detection rate of the study was 51% (158 patients). Among these 158 patients a histopathological Gleason score of 6 was detected in 60 patients (38%), a Gleason score of 7 in 54 patients (34%) and a Gleason score≥8 in 44 patients (28%). MRI/US fusion-guided biopsy detected 110 (69.7%) of the overall detected 158 PCa. TRUS-guided biopsy detected a higher rate of Gleason score 6 (54%) and a lower rate of Gleason score≥8 (15%) lesions in comparison to 38% Gleason 6 and 28% Gleason≥8 in the MRI/US fusion-guided biopsy, respectively. Furthermore, a lower Gleason score was observed in patients with more than one pre-biopsy. The detection rate in biopsy-naïve patients undergoing MRI/US fusion was 75% (40 patients) among 75% detected Gleason score≥7.

CONCLUSION

MRI/US fusion-guided biopsy detected more PCa and also more clinically significant cancer than conventional TRUS. In our cohort patients with more than one pre-biopsy showed lower Gleason scores. The included patients with an initial MRI/US fusion-guided biopsy should be further investigated.

Diffuse dermal angiomatosis: a contributory factor to ulceration in a patient with renal transplant

We present the case of a 54-year-old patient with renal transplant who developed unusual vascular changes on the forearm distal to a functioning arteriovenous fistula, as well as a painful ulcerated lesion on her anterior abdominal wall. We believe that the diffuse dermal angioendotheliomatosis variant of reactive angioendotheliomatosis had a role in the pathogenesis of this patient's lesions.