Utility of The Paris System (TPS) for upper urinary tract cytopathology: correlation with histology follow-up and UroVysion fluorescence in situ hybridization (FISH) analysis

INTRODUCTION

The Paris System (TPS) provides a uniform reporting system of urine cytology based on well-defined cytologic criteria. Due to their rarity, there are limited data on the utility of TPS in upper urinary tract (UUT) lesions and follow-up histology of cases with abnormal cytology. We aimed to evaluate the utility of TPS for UUT lesions by correlating the cytologic diagnoses using TPS criteria with subsequent histology. Additionally, the diagnostic utility of UroVysion (Abbott) fluorescence in situ hybridization (FISH) was assessed.

MATERIALS AND METHODS

A total of 148 UUT cytology specimens were retrospectively identified (2018-2022). Cytologic interpretation was performed using TPS, and then correlated with the findings of concurrent or subsequent histologic specimens. The performance of UroVysion FISH was analyzed. Sensitivity and specificity, positive predictive value (PPV) and negative predictive value (NPV) for detecting high-grade urothelial carcinoma (HGUC) were determined.

RESULTS

Among 83 patients who had concurrent or subsequent histologic specimens, cyto-histologic discrepancy was seen in 7 cases (8.4%). The sensitivity, specificity, PPV, and NPV using TPS criteria for detecting HGUC were 87%, and 92%, 96.4%, and 73%, respectively. UroVysion FISH was performed in 21 patients with atypical cytologic findings. The sensitivity and specificity of UroVysion for detecting HGUC was 75% and 86%, respectively, while PPV and NPV were 86% and 75%, respectively.

CONCLUSIONS

In our experience, the application of TPS criteria for reporting upper urinary cytology was reliable at detecting UUT lesions, especially HGUC. UroVysion FISH was a valuable ancillary test for detecting HGUC of UUT.

Intraoperative evaluation of sentinel lymph nodes in patients with breast cancer treated with systemic neoadjuvant therapy

AIMS

Touch preparation (TP) and frozen section (FS) are the two methods routinely used in the intraoperative evaluation (IOE) of sentinel lymph nodes (SLNs) to detect metastases in patients with breast cancer. Both methods are extremely sensitive and specific in the primary surgery (non-neoadjuvant systemic therapy (non-NST)) setting. Since NST introduces unique challenges in the IOE of SLNs, the aim was to determine the accuracy of TP and FS in the IOE of SLNs in the NST setting and compare the results with the non-NST setting and to examine factors that contribute to any differences.

METHODS

We analysed 871 SLNs from 232 patients (615 SLNs from NST and 256 SLNs from non-NST settings) between 2016 through 2019.

RESULTS

In the NST group, TP alone (n=366) had a sensitivity of 45.7% and specificity of 99.7%; FS alone (n=90) had a sensitivity of 83.3% and specificity of 100%. When both TP and FS (n=135) were used, the sensitivity was 80.3% and the specificity was 98.6%.In the non-NST group, TP alone (n=193) had a sensitivity of 66.7% and specificity of 100%; FS alone (n=22) had a sensitivity and specificity of 100%; and combined TP and FS (n=34) had a sensitivity and specificity of 100% and 96%, respectively.

CONCLUSIONS

Evaluating SLNs intraoperatively in the NST setting can be challenging secondary to therapy-related changes. In the NST setting, FS has higher sensitivity and specificity compared with TP for the IOE of SLNs and should be the preferred method.

Abstract P1-02-14: A comparative analysis of clinical and pathologic characteristics of patients with HER2 positive breast cancer treated with neoadjuvant versus adjuvant anti-HER2 therapy: Analysis of 397 cases

A comparative analysis of clinical and pathologic characteristics of HER2 positive breast cancer patients treated with adjuvant versus neoadjuvant antiHer2 therapy: an analysis of 397 cases. Introduction: Currently there are several anti-HER2 therapy options for patients with HER2 positive breast cancer. Surgery as an initial treatment is usually performed in patients with smaller, node negative tumors. Neoadjuvant therapy (NAT) is the treatment of choice for patients with higher stage disease. Detailed analysis of clinical and pathologic characteristics of patients who received adjuvant versus NAT anti-HER2 therapy has not been well elucidated. Objectives: A comparative analysis of clinical and pathologic findings including biomarker expression (ER, PR, HER2 and Ki67) was performed to determine if there were differences in tumor characteristics and clinical outcome in the two groups.Methods:We retrospectively analyzed data on HER2+ breast cancer patients treated with adjuvant and NAT anti-HER2 therapy from 2011 to 2017. Clinical and pathologic parameters including biomarker expression prior to the start of therapy were obtained from the electronic database after IRB approval. In the adjuvant group, patients were treated with initial surgery followed by anti-HER2 therapy plus chemotherapy. In the NAT group, anti-HER2 therapy plus chemotherapy was administered prior to definitive surgery. Types of anti-HER2 therapies and follow-up information were obtained from the electronic medical record. Results:We identified 258 (64.9%) patients who received NAT and 139 (35.0%) received adjuvant anti-HER2 therapy.

Table 1.VariablesNeoadjuvant groupAdjuvant groupp-valueAgeBelow 40 years42 (16.2%)11(7.9%)0.02940 years and above Total216 (83.7%) 258128 (92.0%) 139Menopausal statusPremenopausalPostmenopausal Total113 (45.3%)136 (54.6%) 24935 (25.1%)104 (74.8%) 139<0.001Nodal status on biopsyNegativePositive Total31 (18.1%)140 (81.8%) 17117 (53.1%)15 (46.8%) 32<0.001Tumor size by imaging (cm)Mean + SD3.87+2.832.24+1.76<0.001Tumor grade123 Total5 (2%)78 (31.3%167 (66.8%) 2507 (5.3%)49 (37.6%)74 (56.9%) 1300.068HER2 by IHC0 and 1+ (FISH +)2+ (FISH+)3+ Total11 (4.2%)61 (23.8%)184 (71.8%) 2564 (3.5%)41 (36.6%)67 (59.8%) 1120.042HER2 FISH copy no.Mean +SD15.44 ± 8.2512.64 ± 6.470.007HER2 ratioMean SD6.35 ± 3.445.57 ± 3.560.046ER statusNegativePositive Total113 (43.9%)144 (56.0%) 25745 (35.1%)83 (64.8%) 1280.122Percent positive71.38 ± 33.3778.74 ± 29.040.042ER intensity1+2+3+ Total24 (16.9%)38 (26.7%)80 (56.3%) 1422 (2.6%)26 (34.2%)48 (63.1%) 760.001PR statusNegative Positive Total147 (57.1%)110 (42.8%) 25766 (51.9%)61 (48.0%) 1270.389Percent positive42.33 ± 34.5444.72 ± 32.890.645PR intensity1+2+3+ Total20 (18.5%)41 (37.9%)47 (43.5%) 10810 (17.5%)30 (52.6%)17 (29.8%) 570.012KI67 indexPercent positive49.44 ± 22.6638.56 ± 22.36<0.001Anti-HER2 therapyHerceptinHerceptin+ Perjeta Total72 (31.0)160 (68.9%) 23291 (89.2%)11 (10.7%) 102<0.001SurgeryTotal Partial BilateralModified radicalOther Total SurvivalAlive. Dead116 (44.95)75 (29.0%)25 (9.6%)38 (14.7%)04 (1.5%) 258 239 (92.6%) 19 (7.3%)55 (40.4%)56 (41.1%)18 (13.2%)5 (3.6%)02 (1.4%) 136 125 (89.9%) 14 (10.0%)0.002 0.458Conclusions:Patients who received NAT were significantly younger, premenopausal with more aggressive tumor biology (higher Ki67, HER2 expression). Recent advances in anti-HER2 therapy has improved the outcome of these patients despite having higher stage disease. Breast conserving surgery was higher in the adjuvant group since the tumors were smaller in size. There was no significant difference in overall survival when compared to the adjuvant group (p=0.458)

Citation Format: Venetia Sarode, Tricia Rood, Yulun Liu, Yisheng Fang, Sunati Sahoo, Yan Peng, Helena Hwang, Marilyn Leitch, Barbara Haley. A comparative analysis of clinical and pathologic characteristics of patients with HER2 positive breast cancer treated with neoadjuvant versus adjuvant anti-HER2 therapy: Analysis of 397 cases [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-02-14.

Stereotactic Vacuum-Assisted Needle Biopsy Outcomes of Non-calcified Mammographic Lesions

RATIONALE AND OBJECTIVES

To identify the outcomes of stereotactic vacuum-assisted large bore biopsies performed on sonographically-occult non-calcified mammographic lesions (NCL).

MATERIALS AND METHODS

In an IRB-approved retrospective study, we reviewed all NCL that underwent stereotactic biopsy from January 1, 2014 to December 31, 2017 at our institution, comparing patient age, lesion type, size and location with pathology outcome (benign, high-risk or malignant) using Wilcoxon-Mann-Whitney or Fisher's exact tests as appropriate. Multivariable logistic regression models were developed to decrease benign biopsies in our cohort with diagnostic performance assessed using receiver operating characteristic curve and area under the curve (AUC).

RESULTS

Of 222 biopsied lesions in 213 patients, 79.3% (176/222) were benign, 5.9% (13/222) malignant, and 14.9% (33/222) high-risk. NCL were less likely to be malignant compared to calcifications biopsied in the same period [5.9% vs 19.0% (243/1279), p < 0.001]. All 42 asymmetries and 33 architectural distortions were benign, while 8.7% (4/46) of masses and 8.9% (9/101) of focal asymmetries were malignant. Cancers were associated with older age (mean 65.2 vs 52.7 years, p < 0.001), smaller size (mean 9.5 mm vs 15.5 mm, p < 0.01), and concurrent breast cancer (p < 0.01) compared to benign/high-risk lesions. Multivariable logistic regression model using patient age >50 years, lesion type, and size <15 mm had a high diagnostic performance [AUC=0.89, 95%CI (0.83, 0.94)], and yielded the highest PPV [0.24; 95%CI (0.13, 0.38)], and highest number of avoided, unnecessary biopsies (172/209, 82%).

CONCLUSION

NCL biopsied under stereotactic guidance have low cancer yield (5.9%). A multivariate model integrating age, lesion size and type could potentially help avoid unwarranted biopsies in our cohort.

Significance of Oil-Red-O positive macrophages in bronchoalveolar lavage in diagnosing E-cigarettes or vaping product use-associated lung injury: A case series

BACKGROUND

Lipid-laden macrophages detected by Oil-Red-O (ORO) stain in fresh bronchoalveolar lavage (BAL) specimens have been proposed as a potential diagnostic marker for E-cigarettes or vaping product use-associated lung injury (EVALI). However, studies are few, and the sensitivity and specificity of the test have not been thoroughly investigated.

METHODS

We performed ORO stain on fresh BAL specimens from six confirmed EVALI and 36 non-EVALI patients. After semi-quantitative analysis, the sensitivity and specificity of ORO-positive macrophages (OPM) for detection of EVALI were calculated.

RESULTS

No significant difference in cytomorphology or raw macrophage count was observed between EVALI and non-EVALI groups (49% vs 55% of all nucleated cells). However, with ORO stain, all EVALI specimens (6/6) showed a high percentage (≥50% of all macrophages) of OPM (mean 87%), and large (≥25% of host macrophage nuclear size) lipid droplets (mean 42%), while the majority of non-EVALI specimens showed a low percentage of OPM (32/36, mean 10%), and small lipid droplets (34/36, mean 6%). The differences between the two groups in both high OPM and large lipid droplet rates are statistically significant (P < .0001 for both comparisons). The combined sensitivity and specificity of high OPM and large lipid droplets for diagnosing EVALI were 100% and 94%, respectively.

CONCLUSION

In BAL specimens obtained from patients with clinically suspected EVALI, a high percentage of OPM with large lipid droplets showed high sensitivity and specificity for the diagnosis of EVALI and may serve as a potentially useful tool in the evaluation of vaping-related lung injury, improving diagnostic accuracy.

Performance of a clinical and imaging-based multivariate model as decision support tool to help save unnecessary surgeries for high-risk breast lesions

PURPOSE

To investigate the performance of an imaging and biopsy parameters-based multivariate model in decreasing unnecessary surgeries for high-risk breast lesions.

METHODS

In an IRB-approved study, we retrospectively reviewed all high-risk lesions (HRL) identified at imaging-guided biopsy in our institution between July 1, 2014-July 1, 2017. Lesions were categorized high-risk-I (HR-I = atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ and atypical papillary lesion) and II (HR-II = Flat epithelial atypia, radial scar, benign papilloma). Patient risk factors, lesion features, detection and biopsy modality, excision and cancer upgrade rates were collected. Reference standard for upgrade was either excision or at least 2-year imaging follow-up. Multiple logistic regression analysis was performed to develop a multivariate model using HRL type, lesion and biopsy needle size for surgical cancer upgrade with performance assessed using ROC analysis.

RESULTS

Of 699 HRL in 652 patients, 525(75%) had reference standard available, and 48/525(9.1%) showed cancer at surgical excision. Excision (84.5% vs 51.1%) and upgrade (17.6%vs1.8%) rates were higher in HR-I compared to HR-II (p < 0.01). In HR-I, small needle size < 12G vs ≥ 12G [32.1% vs 13.2%, p < 0.01] and less cores [< 6 vs ≥ 6, 28.6%vs13.7%, p = 0.01] were significantly associated with higher cancer upgrades. Our multivariate model had an AUC = 0.87, saving 28.1% of benign surgeries with 100% sensitivity, based on HRL subtype, lesion size(mm, continuous), needle size (< 12G vs ≥ 12G) and biopsy modality (US vs MRI vs stereotactic) CONCLUSION: Our multivariate model using lesion size, needle size and patient age had a high diagnostic performance in decreasing unnecessary surgeries and shows promise as a decision support tool.

Abstract P3-03-16: Intraoperative evaluation of sentinel lymph nodes after neoadjuvant systemic therapy in breast cancer

Introduction:

Intraoperative evaluation of sentinel lymph nodes (SLN) in breast cancer patients are performed using Touch preparation (TP) and/or frozen section (FS). Touch preparation for intraoperative evaluation of SLN is quick and known to be a highly sensitive and specific method for detection of metastasis. Detecting metastases in SLN intraoperatively can be challenging in patients who receive neoadjuvant systemic therapy (NST). In our hospitals, we have been routinely evaluating SLN intraoperatively in patients who have undergone (NST), including those with known metastasis to an axillary lymph node (LN) prior to therapy.

Objective:

To compare the sensitivity and specificity of TP and frozen section (FS) in the intraoperative evaluation of SLN in the neoadjuvant setting.

Material and Methods:

This retrospective review study was approved by the institutional review board. Four hundred ninety-eight SLN from 142 patients were included in this study. The intraoperative results for TP and FS were compared with the final pathology results. Relevant clinical and pathological findings such as type of surgery, tumor grade, histologic subtype, and size of metastasis were reviewed.

Results:

Of the 498 SLN evaluated intraoperatively, 341 were by TP only, 57 by FS only and 100 by both.

Of the 341 SLN examined by TP only, 313 (92%) were interpreted as negative and 28 (8%) as positive for carcinoma intraoperatively. Eighteen LN turned out to be false negative (FN) with no false positives (FP) (sensitivity=62%, specificity=100%). In the false negative cases, 12 LN had micrometastasis, 6 macrometastasis and 1 showed isolated tumor cells (ITC). The size of the macrometastatic ranged from 3 mm to 10 mm.

Of the 57 LN examined by FS only, 48 were true negative and 9 were true positive (sensitivity=100%, specificity=100%).

Of the 100 LN evaluated by both TP and FS, 59 were interpreted as negative and 41 as positive for carcinoma. There were 8 false negatives and 1 false positive (sensitivity=83%, specificity=98%). Of the 8 false negatives, 7 showed micrometastasis and 1 LN had ITC.

Discussion:

In neoadjuvant cases, both the primary tumor as well as lymph node metastases can show therapy effect such as fibrosis, necrosis and/or histiocytic aggregates. Evaluating SLN in NST cases can be challenging secondary to these effects. The TP slides are often paucicellular in SLN with treatment effect. Residual tumor cells are often trapped in a fibrotic scar and do not transfer onto the TP slide leading to low sensitivity. Therefore, for optimal intraoperative evaluation of SLN in NST cases, frozen section with or without touch preparation, is recommended.

Citation Format: Sahoo S, Mir M, Sarode V, Fang Y, Peng Y, Gwin K, Hwang H. Intraoperative evaluation of sentinel lymph nodes after neoadjuvant systemic therapy in breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-16.

Phase 1 study of ARQ 761, a β-lapachone analogue that promotes NQO1-mediated programmed cancer cell necrosis

BACKGROUND

NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase expressed in multiple tumour types. ARQ 761 is a β-lapachone (β-lap) analogue that exploits the unique elevation of NQO1 found in solid tumours to cause tumour-specific cell death.

METHODS

We performed a 3+3 dose escalation study of 3 schedules (weekly, every other week, 2/3 weeks) of ARQ 761 in patients with refractory advanced solid tumours. Tumour tissue was analysed for NQO1 expression. After 20 patients were analysed, enrolment was restricted to patients with NQO1-high tumours (H-score ≥ 200).

RESULTS

A total of 42 patients were treated. Median number of prior lines of therapy was 4. Maximum tolerated dose was 390 mg/m² as a 2-h infusion every other week. Dose-limiting toxicity was anaemia. The most common treatment-related adverse events were anaemia (79%), fatigue (45%), hypoxia (33%), nausea (17%), and vomiting (17%). Transient grade 3 hypoxia, reflecting possible methemoglobinaemia, occurred in 26% of patients. Among 32 evaluable patients, best response was stable disease (n = 12); 6 patients had tumour shrinkage. There was a trend towards improved efficacy in NQO1-high tumours (P = 0.06).

CONCLUSIONS

ARQ 761 has modest single-agent activity, which appears associated with tumour NQO1 expression. Principal toxicities include anaemia and possible methemoglobinaemia.

Phase 1 study of ARQ 761, a β-lapachone analog that promotes NQO1-mediated programmed cancer cell necrosis

2517

Background: NAD(P)H:quinone oxidoreductase 1 (NQO1) is a two-electron oxidoreductase expressed in multiple tumor types at levels 5- to 200-fold above normal tissue. ARQ761 is a β-lapachone hydroquinone analog that exploits the unique elevation of NQO1 found in solid tumors to cause tumor-specific cell death by eliciting a futile redox cycle generating high levels of reactive oxygen species and ultimately PARP1 hyperactivation-dependent cell death. Methods: 3+3 dose escalation study of 3 schedules (weekly, every other week, 2/3 weeks) of ARQ 761 as a 1-hr or 2-hr infusion. Eligible patients had refractory advanced solid tumors, ECOG 0-1, adequate organ function, and central venous access. Blood samples were analyzed for ARQ761 levels and NQO1 polymorphisms. Archival tumor tissue was analyzed for NQO1 staining intensity and prevalence. After 18 patients were analyzed, enrollment was restricted to patients with NQO1-positive tumors (defined as Histo-score ≥200). Results: A total of 42 patients were treated. Median number of prior lines of therapy was 4. For all schedules, the maximum tolerated dose (MTD) was 390 mg/m2 as a 2-hr infusion. DLT was hemolytic anemia. The most common treatment-related adverse events were anemia (79%), fatigue (45%), hypoxia (33%), hemolysis (17%), nausea (17%) and vomiting (17%). Transient grade 3 hypoxia, due to methemoglobinemia, occurred in 26% of patients. Among 31 evaluable patients, the best response was stable disease (n = 11) and progressive disease (n = 19). For the 18 analyzed cases analyzed prior to NQO1 enrollment biomarker, clinical benefit appeared associated with tissue NQO1 expression: disease control rate was 65% in NQO1-positive tumors and 18% in NQO1-negative tumors ( P=0.06). Analysis of all 31 evaluable patients did not show a significant difference in progression-free survival (PFS) according to NQO1 status ( P=0.26), but 3-mo PFS rate was numerically greater among NQO1-positive cases (40% versus 20%). Conclusions: ARQ 761 has clinical activity in NQO1-positive tumors. Principal toxicities include hemolytic anemia and methemoglobinemia. Combination studies are underway.

Using a novel NQO1 bioactivatable drug, beta-lapachone (ARQ761), to enhance chemotherapeutic effects by metabolic modulation in pancreatic cancer

Novel, tumor-selective therapies are needed to increase the survival rate of pancreatic cancer patients. K-Ras-mutant-driven NAD(P)H:quinone oxidoreductase 1 (NQO1) is over-expressed in pancreatic tumor versus associated normal tissue, while catalase expression is lowered compared to levels in associated normal pancreas tissue. ARQ761 undergoes a robust, futile redox cycle in NQO1+ cancer cells, producing massive hydrogen peroxide (H₂ O₂ ) levels; normal tissues are spared by low NQO1 and high catalase expression. DNA damage created by ARQ761 in pancreatic cancer cells "hyperactivates" PARP1, causing metabolic catastrophe and NAD ± keresis cell death. NQO1: catalase levels (high in tumor, low in normal tissue) are an attractive therapeutic window to treat pancreatic cancer. Based on a growing body of literature, we are leading a clinical trial to evaluate the combination of ARQ761 and chemotherapy in patients with pancreatic cancer.

Leveraging an NQO1 Bioactivatable Drug for Tumor-Selective Use of Poly(ADP-ribose) Polymerase Inhibitors

Therapeutic drugs that block DNA repair, including poly(ADP-ribose) polymerase (PARP) inhibitors, fail due to lack of tumor-selectivity. When PARP inhibitors and β-lapachone are combined, synergistic antitumor activity results from sustained NAD(P)H levels that refuel NQO1-dependent futile redox drug recycling. Significant oxygen-consumption-rate/reactive oxygen species cause dramatic DNA lesion increases that are not repaired due to PARP inhibition. In NQO1⁺ cancers, such as non-small-cell lung, pancreatic, and breast cancers, cell death mechanism switches from PARP1 hyperactivation-mediated programmed necrosis with β-lapachone monotherapy to synergistic tumor-selective, caspase-dependent apoptosis with PARP inhibitors and β-lapachone. Synergistic antitumor efficacy and prolonged survival were noted in human orthotopic pancreatic and non-small-cell lung xenograft models, expanding use and efficacy of PARP inhibitors for human cancer therapy.

Tumor-selective use of DNA base excision repair inhibition in pancreatic cancer using the NQO1 bioactivatable drug, β-lapachone

Base excision repair (BER) is an essential pathway for pancreatic ductal adenocarcinoma (PDA) survival. Attempts to target this repair pathway have failed due to lack of tumor-selectivity and very limited efficacy. The

NAD(P)H

Quinone Oxidoreductase 1 (NQO1) bioactivatable drug, ß-lapachone (ARQ761 in clinical form), can provide tumor-selective and enhanced synergy with BER inhibition. ß-Lapachone undergoes NQO1-dependent futile redox cycling, generating massive intracellular hydrogen peroxide levels and oxidative DNA lesions that stimulate poly(ADP-ribose) polymerase 1 (PARP1) hyperactivation. Rapid NAD(+)/ATP depletion and programmed necrosis results. To identify BER modulators essential for repair of ß-lapachone-induced DNA base damage, a focused synthetic lethal RNAi screen demonstrated that silencing the BER scaffolding protein, XRCC1, sensitized PDA cells. In contrast, depleting OGG1 N-glycosylase spared cells from ß-lap-induced lethality and blunted PARP1 hyperactivation. Combining ß-lapachone with XRCC1 knockdown or methoxyamine (MeOX), an apyrimidinic/apurinic (AP)-modifying agent, led to NQO1-dependent synergistic killing in PDA, NSCLC, breast and head and neck cancers. OGG1 knockdown, dicoumarol-treatment or NQO1- cancer cells were spared. MeOX + ß-lapachone exposure resulted in elevated DNA double-strand breaks, PARP1 hyperactivation and TUNEL+ programmed necrosis. Combination treatment caused dramatic antitumor activity, enhanced PARP1-hyperactivation in tumor tissue, and improved survival of mice bearing MiaPaca2-derived xenografts, with 33% apparent cures.

SIGNIFICANCE

Targeting base excision repair (BER) alone has limited therapeutic potential for pancreatic or other cancers due to a general lack of tumor-selectivity. Here, we present a treatment strategy that makes BER inhibition tumor-selective and NQO1-dependent for therapy of most solid neoplasms, particularly for pancreatic cancer.

Significantly increased PELP1 protein expression in primary and metastatic triple-negative breast carcinoma: comparison with GATA3 expression and PELP1's potential role in triple-negative breast carcinoma

PELP1 is a novel coregulator of nuclear hormone receptors and is implicated in playing a role in driving breast cancer and enhancing metastatic potential. The PELP1 protein expression and potential role of PELP1 in triple-negative breast carcinoma (TNBC) have not been well characterized. We investigated PELP1 expression by immunohistochemistry in primary and metastatic triple-negative tumors in human tissues and compared its expression with GATA-binding protein 3 (GATA3), a novel diagnostic marker for TNBC. We examined the expression of PELP1 and GATA3 in 70 primary TNBC cases and found that PELP1 had a significantly higher frequency of expression compared to GATA3 (96% versus 46%; P < .0001). The mean extent score of expression of PELP1 was also significantly higher than GATA3's expression (3.87 ± 0.07 versus 0.91 ± 0.15; P < .0001). PELP1 had stronger staining intensity than GATA3. Furthermore, PELP1 immunoreactivity was consistently maintained in paired primary and metastatic TNBC cases (100%). The frequency of PELP1 expression (100%) in metastatic triple-negative tumors was higher than that of GATA3 (40%) in the same tumors (P < .0001). These findings indicate that PELP1 is a much more sensitive marker than GATA3 for TNBCs. PELP1 may have diagnostic utility for metastatic TNBC in appropriate settings, such as history of primary TNBC in cases where the primary is negative for GATA3, mammaglobin, and GCDFP-15. The diffuse and strong nuclear immunoreactivity of PELP1 in most cases suggests that PELP1 may be a molecular target for the treatment of TNBC. We hope that this study will provide insights into the role of PELP1 in TNBC.

Autocrine VEGF signaling promotes proliferation of neoplastic Barrett's epithelial cells through a PLC-dependent pathway

BACKGROUND & AIMS

Tumor cells express vascular endothelial growth factor (VEGF), which induces angiogenesis. VEGF also activates VEGF receptors (VEGFRs) on or within tumor cells to promote their proliferation in an autocrine fashion. We studied the mechanisms of autocrine VEGF signaling in Barrett's esophagus cells.

METHODS

Using Barrett's epithelial cell lines, we measured VEGF and VEGFR messenger RNA and protein, and studied the effects of VEGF signaling on cell proliferation and VEGF secretion. We studied the effects of inhibiting factors in this pathway on levels of phosphorylated phospholipase Cγ1 (PLCG1), protein kinase C, and extracellular signal-regulated kinases (ERK)1/2. We performed immunohistochemical analysis of phosphorylated VEGFR2 on esophageal adenocarcinoma tissues. We studied effects of sunitinib, a VEGFR2 inhibitor, on proliferation of neoplastic cells and growth of xenograft tumors in mice.

RESULTS

Neoplastic and non-neoplastic Barrett's cells expressed VEGF and VEGFR2 messenger RNA and protein, with higher levels in neoplastic cells. Incubation with recombinant human VEGF significantly increased secretion of VEGF protein and cell number; knockdown of PLCG1 markedly reduced the recombinant human VEGF-stimulated increase in levels of phosphorylated PLCG1 and phosphorylated ERK1/2 in neoplastic cells. Esophageal adenocarcinoma tissues showed immunostaining for phosphorylated VEGFR2. Sunitinib inhibited VEGF signaling in neoplastic cells and reduced weight and volume of xenograft tumors in mice.

CONCLUSIONS

Neoplastic and non-neoplastic Barrett's epithelial cells have autocrine VEGF signaling. In neoplastic Barrett's cells, VEGF activation of VEGFR2 initiates a PLCG1-protein kinase C-ERK pathway that promotes proliferation and is self-sustaining (by causing more VEGF production). Strategies to reduce autocrine VEGF signaling (eg, with sunitinib) might be used to prevent or treat cancer in patients with Barrett's esophagus.

Phase I and pharmacodynamic study of the histone deacetylase (HDAC) inhibitor romidepsin plus erlotinib in previously treated advanced non-small cell lung cancer (NSCLC)

8088^

Background: Preclinical studies have demonstrated anti-tumor efficacy of the combination of the HDAC inhibitor romidepsin plus erlotinib in NSCLC models insensitive to erlotinib monotherapy (eg, KRAS mutation, EGFR resistance mutation, EGFR wild type). Methods: This phase I study evaluated safety, pharmacodynamics, and preliminary activity of romidepsin (8-10 mg/m2) given IV days 1, 8, and 15 every 28 days plus erlotinib 150 mg PO daily in previously treated advanced NSCLC. In Cycle 1, erlotinib was initiated on Day 3, permitting pharmacodynamic analysis of romidepsin alone and in combination. Results: As of January 31, 2013, 15 patients (pts) have been treated: median age 60 years; 7 F, 8 M; all former or current smokers; 6 had prior erlotinib exposure; 8 adenocarcinoma, 6 squamous, 1 large cell; 5 EGFR wild type 1 KRAS mutation, 9 unknown mutation status. Most common related AEs regardless of grade were nausea (87%), vomiting (73%), fatigue (60%), diarrhea and rash (both 53%), and decreased appetite (47%). Grade 3-4 AEs (all grade 3) included nausea and vomiting (both 20%); decreased appetite, diarrhea, fatigue (each 13%). Dose-limiting nausea and vomiting occurred at romidepsin 10 mg/m2 level despite aggressive antiemetic prophylaxis and treatment. At romidepsin 8 mg/m2, related grade 3 AEs included fatigue (n=1) and diarrhea (n=1), with no grade 3 nausea or vomiting. 9 pts were evaluable by RECIST; best response SD (n=6), PD (n=3). Median PFS was 3.3 months (range 1.4-16.5 months). At romidepsin 8 mg/m2, PFS range 2.0-16.5 months. At both dose levels, romidepsin inhibited HDAC activity and increased histone H3 and H4 acetylation status in peripheral blood mononuclear cells. Romidepsin also inhibited EGFR phosphorylation and, in 60% of pts, MAPK phosphorylation in skin biopsies. Conclusions: Romidepsin 8 mg/m2 plus erlotinib appears well tolerated, has encouraging evidence of disease control, and exhibits effects on relevant molecular targets in an unselected advanced NSCLC population. Further studies are underway. Clinical trial information: NCT01302808.

Implementation of routine screening for Lynch syndrome in university and safety-net health system settings: successes and challenges

PURPOSE

Routine screening for evidence of DNA mismatch repair abnormalities can identify colorectal cancer patients with Lynch syndrome, but impact in usual care settings requires study. After implementing routine screening at our university and safety-net health systems as usual practice, our aims were to determine outcomes, including screening process quality.

METHODS

We conducted a retrospective cohort study from 1 May 2010 to 1 May 2011. Screening included reflexive immunohistochemistry to evaluate DNA mismatch repair protein expression for patients with colorectal cancer aged ≤70 years, with a cancer genetics team following up results. Screening outcomes, as well as challenges to a high-quality screening process were evaluated.

RESULTS

We included 129 patients (mean age 56 years, 36% female); 100 had immunohistochemistry screening completed. Twelve patients had abnormal immunohistochemistry: four with definite Lynch syndrome, four with probable Lynch syndrome, and three without Lynch syndrome; one patient had an incomplete work-up. Lynch syndrome was confirmed for 6/13 asymptomatic relatives tested. Screening process quality was optimal for 77.5% of patients. Barriers to optimal quality screening included ensuring reflexive immunohistochemistry completion, complete follow-up of abnormal immunohistochemistry, and timely incorporation of results into clinical decision making.

CONCLUSION

Usual care implementation of routine screening for Lynch syndrome can result in significant rates of detection, even in a largely safety-net setting. To optimize implementation, challenges to high-quality Lynch syndrome screening, such as ensuring reflexive screening completion and clinically indicated genetic testing and follow-up for abnormal screens, must be identified and addressed.

Abstract P1-07-04: Comparison of HER2 expression by immunohistochemistry (IHC) using automated imaging system and fluorescence in situ hybridization (FISH). A retrospective analysis of 2853 cases

Background: Accurate assessment of HER2 status is critical for selecting patients who will benefit from trastuzumab therapy. There is still no consensus regarding the optimal method to assess HER2 status. Computerized image analysis has been shown to provide a more accurate and objective way for quantification of HER2 expression by IHC than manual evaluation. It has been suggested that the use of image analysis may help to resolve some of the discrepancies between IHC and FISH assay.

We compared the results of HER2 expression by IHC using automated image analysis with fluorescent in situ hybridization (FISH) assay.

Design: Testing for HER2 expression by IHC and FISH was performed on 2853 specimens at UT Southwestern Medical Center between the years 2002 to 2011. Quantification of IHC HER2 expression was done by image analysis and scored as positive (&gt;2.0), borderline (1.5 to 2.0) and negative. (&lt;1.5). The PathVysion kit was used for FISH assay to evaluate HER2 amplification. Ratios &gt;2.0, 1.8 to 2.0 and &lt;1.8 were defined positive, borderline and negative amplification respectively.

Results: IHC compared to FISH

The clinical consequences of hemizygosity across 2 MB of 10q23 are restricted to Cowden syndrome

Cowden syndrome is caused by germline mutations in PTEN and clinically characterized by hamartomas, macrocephaly, classic dermatologic stigmata, and an estimated 85 % lifetime risk of female breast cancer. A young woman with macrocephaly, tricholemmomas, AV malformations, and mammary papillomatosis was found to be hemizygous for PTEN in her germline DNA. Using MLPA, comparative genomic hybridization, and DNA sequencing, we identified a 2-Mb deletion in chromosome 10 spanning 344-kb centromeric and 1.7-Mb telomeric of PTEN. Her father who has a clinical history including macrocephaly, Hashimoto's thyroiditis, colonic polyposis, acral keratoses, and goiter was also found to have the same deletion. In benign breast tissue from the hemizygous female, PTEN protein expression was significantly reduced in luminal and stromal cells but present in the myoepithelium. Compared with a typical papilloma of the breast which had intense cytoplasmic PTEN staining, the majority of the patient's papilloma had significantly decreased PTEN expression while some cells had mislocalized perinuclear PTEN expression. In addition to PTEN, 22 other protein-coding genes were deleted including two predicted haploinsufficient genes and five additional genes that have previously been associated with hereditary predispositions to certain diseases. However, because all significant clinical features of the proband and her father are common to patients with genetic alterations in PTEN, the other 22 hemizygous protein-coding genes appear to be haplosufficient.

Decreased androgen receptor expression is associated with distant metastases in patients with androgen receptor-expressing triple-negative breast carcinoma

To characterize prognostic values of androgen receptor (AR) in triple-negative (TN) breast cancers, we investigated AR expression status and levels, explored an association of AR expression with metastatic disease, and correlated AR expression with Ki-67 in TN invasive breast carcinomas. AR expression was analyzed with immunohistochemistry in 121 cases of TN tumors. Thirty-nine cases had distant metastatic disease and 82 had locoregional disease only. AR was positive in 38 (31.4%) of the 121 cases. Our results indicate that among the AR-positive TN tumors, distant metastases are significantly associated with lower expression of AR compared with cases with only locoregional disease, and that AR expression negatively correlates with Ki-67 expression. These findings suggest that decreased intratumoral AR expression may be predictive of distant metastatic disease and AR expression levels may have potential prognostic value in AR-expressing TN tumors.

Tamoxifen downregulates ets oncogene family members ETV4 and ETV5 in benign breast tissue: implications for durable risk reduction

Five years of tamoxifen reduces breast cancer risk by nearly 50% but is associated with significant side effects and toxicities. A better understanding of the direct and indirect effects of tamoxifen in benign breast tissue could elucidate new mechanisms of breast carcinogenesis, suggest novel chemoprevention targets, and provide relevant early response biomarkers for phase II prevention trials. Seventy-three women at increased risk for breast cancer were randomized to tamoxifen (20 mg daily) or placebo for 3 months. Blood and breast tissue samples were collected at baseline and posttreatment. Sixty-nine women completed all study activities (37 tamoxifen and 32 placebo). The selected biomarkers focused on estradiol and IGFs in the blood; DNA methylation and cytology in random periareolar fine-needle aspirates; and tissue morphometry, proliferation, apoptosis, and gene expression (microarray and reverse transcriptase PCR) in the tissue core samples. Tamoxifen downregulated Ets oncogene transcription factor family members ETV4 and ETV5 and reduced breast epithelial cell proliferation independent of CYP2D6 genotypes or effects on estradiol, ESR1, or IGFs. Reduction in proliferation was correlated with downregulation of ETV4 and DNAJC12. Tamoxifen reduced the expression of ETV4- and ETV5-regulated genes implicated in epithelial-stromal interaction and tissue remodeling. Three months of tamoxifen did not affect breast tissue composition, cytologic atypia, preneoplasia, or apoptosis. A plausible mechanism for the chemopreventive effects of tamoxifen is restriction of lobular expansion into stroma through downregulation of ETV4 and ETV5. The human equivalent of murine multipotential progenitor cap cells of terminal end buds may be the primary target.

Abstract P4-08-07: Correlation of Oncotype Dx Recurrence Score and Luminal Subtypes of Breast Cancer

Background: Molecular subtypes of breast cancer have been characterized by gene expression analysis. Luminal subtypes are hormone receptor (HR) positive and Her2/neu negative. Immunohistochemistry (IHC) has been used as a surrogate test for gene expression. Ki67 is a proliferation marker that identifies high-risk subtype of luminal breast cancer. Recently, the proposed Ki67 index (KI) of 14% was suggested as a cut-off to distinguish between luminal A and luminal B tumors (JNCI. 2009;101:736-750). The oncotype dx (ODx) is a 21- gene test that provides prognostic and predictive information in early stage HR-positive breast cancer patients. The test is reported as low (&lt;18), intermediate (18-30) and high (&gt;30) risk recurrence scores (RS)

Design: We investigated the relationship between ODx RS and luminal subtypes of breast cancers using the KI of 14% as the cut-off for distinguishing luminal A and B tumors. Biomarker analysis (ER, PR, Her2/neu, Ki67 and p53) was performed as part of the diagnostic work-up using standard IHC procedures. Scoring was done by automated image analysis. Her2/neu FISH was performed on all IHC 2+ and 3 + results.

Pathologic parameters such as, tumor size, grade, and presence of LVI were evaluated. Ploidy was performed by the Autocyte system (Tripath) on Feulgen stained paraffin sections.

Results: We identified 106 patients with HR positive breast cancer who were tested for ODx from February 2006 to May 2010. 85/106 had Ki67 data available for analysis. 46/85 (54%) were luminal A and 39/85 (46%) luminal B tumors. The mean KI in luminal A was 6.93% versus 31.1% in luminal B (P&lt;0.0001). The mean tumor size was 1.94 and 1.92 cm in luminal A and B respectively. Grade 1, 2 and 3 comprised 28/85 (32.9%), 49 (57.6%) and 8 (9.41%) of all tumors respectively. Of the grade1 tumors, 75% were luminal A, and grade 3 tumors were predominantly luminal B (p=0.013). LVI was present in 16 cases, 11 (68.8%) in luminal B and 5/16 (31.2%) in luminal A tumors (p=0.0416). Luminal A tumors were predominantly diploid 30/45 (66.6%) and luminal B were mostly aneuploid 21/32 (65.6%) (p=0.019). The overall mean RS in luminal A and B tumors was 14.67 and 20.15 respectively (P&lt;0.0004). Luminal A tumors had low RS in 32/46 (66.6%). and luminal B tumors had predominantly intermediate/high RS in 23/39 (62.1%) (p=0.0082). ER Allred Scores were 7.1 and 7.3 and percent positivity was 88.1% and 91% respectively for luminal A and B subtypes. PR Allred scores were 5.6 and 5.8, and percent positivity was 62.1 and 52.9% for A and B tumors respectively. Information regarding treatment was available in 72 cases. 19 (26.3%) were treated by a combination of chemo and anti-hormonal therapy and 53 (73.6%) were treated by anti hormonal therapy alone, 8 of the 19 (42.1%) luminal A patients received combination therapy versus 11 (57.8%) in the luminal B category (p=0.277).

Conclusion: Ki67 is a useful marker that showed significant correlation with RS by ODx. Luminal A tumors are more likely to be low grade, diploid with low RS compared to luminal B tumors. Ki67 in conjunction with other pathologic parameters may serve as a surrogate marker for the ODx RS.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-07.

Abstract P4-08-10: Correlation of Oncotype Dx Recurrence Score with Histologic Parameters, Biomarker Expression and KI-67 Index

Background: Oncotype Dx (ODx) is a 21-gene RT-PCR based assay that provides prognostic and predictive information in patients with hormone receptor (HR) positive breast cancer. The test predicts the likelihood of disease recurrence in the form of a recurrence score (RS), which is categorized into low, intermediate and high-risk types. We examined the relationship between ODx RS and histologic parameters, DNA ploidy, tumor markers (ER, PR, Her2, Ki67, p53) expression by immunohistochemistry (IHC).

Design: We identified 106 patients with HR-positive invasive breast cancer who were tested for ODx from the department files. Pathologic variables such as, tumor size, grade, histologic type, lymphovascular invasion (LVI) were reviewed. Tumor markers ER, PR, Her2, p53 expression, Ki67 index (KI) and ploidy were performed as part of the patient's diagnostic work-up using standard procedures. Scoring was done by automated image analysis. Results of biomarker expression were compared to the ODx RS. All Her2neu 3+ and 2+ results by IHC were confirmed by FISH. Ploidy was performed by the Autocyte system (Tripath) on Feulgen stained sections. Oncotype RS was reported as low (&lt;18), intermediate (18-30) and high risk (&gt;30).

Results: Mean tumor size was 1.96 cm. Of the 106 cases, 87 (82%), 14 (13.2%) and 2(1.8%) were ductal, lobular and mixed types respectively. Grade 1, 2 and 3 comprised 35 (33.0%), 62 (58.4%) and 9 (8.5%) respectively. Twenty-one (19.8%) had LVI. Oncotype RS was low in 56 (52.8%), intermediate in 45 (42.4%) and high in 5 (4.7%). Mean tumor size in low RS group was 2.2 cm versus 1.6 cm in the intermediate/high RS group (p &lt;0.05). There was no significant association of grade and LVI with RS. ER Allred score was 7.2, 7.2 and 8.0 and percent positivity was 88.0%, 91.1% and 96.3% in low, intermediate and high RS respectively (p=0.6325). The PR Allred score was 6.0, 5.3 and 3.5 and percent positivity was 64.7%, 51.8% and 16.6% in low, intermediate and high RS respectively (p=0.0432). There was 100% concordance between ER by IHC and ODx. Concordance for PR was 71/75 (94.6%). The four discordant PR results by ODx had mean score of 20% by IHC. The mean KI was 14.4%, 21.8% and 25.6% in low, intermediate and high RS respectively (p=0.0248). Low KI (&lt;14%) and high KI (&gt;14%) showed significant correlation with RS (p=0.0055). Her2neu IHC was negative in 43/49 (87.7%) and borderline in 6/49 (12.2%) and all were negative by FISH. Her2 FISH showed 100% (44/44) concordance with Her2 results by ODx. There was no association between DNA ploidy and RS (p=0.7143). P53 expression showed no significant correlation with RS (p=0.2602). Patients in the intermediate/high RS group were more likely to be treated with a combination of chemo plus anti-hormonal therapy (P&lt;0.0001) and radiation (P&lt;0.05) compared to the low RS group.

Conclusions: This study shows a complete concordance between ER IHC and Her2 FISH with RT-PCR by ODx. Low PR scores and high KI predict

high RS by ODx. There is a significant association between KI and ODx RS. Ki67 index identifies low and high RS groups, which correspond to the luminal A, and B subtypes of breast cancer respectively.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-08-10.

Impact of routine cavity shave margins on breast cancer re-excision rates

PURPOSE

Breast-conserving therapy (BCT) is an accepted method of treating early breast cancer. We hypothesized that routine excision of additional cavity shave margins (CSM) at time of initial partial mastectomy reduces the need for additional surgery.

METHODS

A single-institution retrospective review was performed of women, 18 years or older, with a new diagnosis of breast cancer who underwent partial mastectomy between 1 January 2004 and 1 October 2009. Five hundred thirty-three charts were reviewed. Of those, 69 patients underwent CSM at time of initial operation. These 69 patients were matched with patients who had undergone partial mastectomy without CSM by tumor size, presence of extensive intraductal component, and primary histology.

RESULTS

The two groups were well matched for age, nuclear grade, associated lymphovascular invasion (LVI), receptor status, and multifocality. We found that 31.9% (44/138) required return to the operating room (OR) for re-excision of margins. Rate of return to the OR was 21.7% (15/69) in the CSM group and 42.0% (29/69) in the matched group (p = 0.011). Multivariate analysis found factors significantly associated with need for additional operation included lack of CSM (odds ratio 9.2, 95% CI 2.8-30.5, p = 0.0003), larger extent of intraductal component (odds ratio 7.0, 95% CI 1.8-27.0, p = 0.005), and lack of directed re-excision (odds ratio 6.4, 95% CI 1.7-25.1, p = 0.007).

CONCLUSIONS

CSM at time of initial partial mastectomy decreases rate of re-excision by as much as ninefold. CSM should be considered at time of initial operation to reduce the need for subsequent reoperation.

Sentinel node biopsy performed in the neoadjuvant setting for breast cancer: results from the I-SPY TRIAL (CALGB 150007/150012 & ACRIN 6657)

Abstract #202

Introduction: Controversy remains over whether to perform sentinel node biopsy (SNB) before or after neoadjuvant chemotherapy (NAC). We examined the practice patterns, feasibility, and accuracy of this procedure in high risk breast cancer patients treated with NAC in a multi-institutional correlative science study.&#x2028; Methods: Patients with biopsy-proven breast cancer &gt;3 cm enrolled into the I-SPY TRIAL to undergo 4 weeks of anthracycline-based NAC, 4 weeks of taxane treatment, then surgical intervention. Study protocol did not dictate axillary treatment. Timing of SNB was dictated by the surgeon. Practice patterns, outcome of SNB and axillary lymph node dissection (ALND), locoregional recurrence and distant metastases were recorded with a mean follow-up of 2.9 years.&#x2028; Results: 237 patients enrolled, 221 completed the trial, 210 had complete data at the time of analysis; Table 1 shows axillary practice patterns.&#x2028; &#x2028; Overall, 43% had a positive SNB and/or ALND after NAC. 129 (61% of 210) patients presented with clinically positive nodes, 39 of which had a post-NAC SNB. 5/39 had no ALND (all SNB negative). Table 2 shows results for those who had a post-NAC SNB and ALND. For this subset of patients, sentinel node ID, accuracy, and false negative (FN) rates were 80%, 91% and 15% respectively. If SNB was negative, 20% of patients still had a positive ALND. 81 (39% of 210) patients presented with clinically negative nodes, 22 of which had a post-NAC SNB. 8/22 post-NAC SNB patients had no ALND (6 negative, 2 positive for 1mm disease). Table 2 shows results for those who had a post-NAC SNB and ALND. For this subset of patients, sentinel node ID, accuracy, and FN rates were 100%, 100% and 0%.&#x2028; &#x2028; Overall, there were 26 deaths; 96% occurred in those who presented with clinically positive nodes, 77% had positive post-NAC nodes. A negative axilla post-NAC was predictive of longer DFS over those with axillary disease post-NAC (p&lt;0.05).&#x2028; Conclusions: In clinically node negative patients, post-NAC SNB is feasible and accurate before or after NAC. Our data suggests that a post-NAC SNB is sufficient; this avoids an additional operation and allows us to gain information on post-NAC axillary status which is of prognostic significance. In clinically positive patients, SNB does not adequately reflect axillary disease; even when SNB was negative, 20% still had axillary disease. At this time, we recommend that ALND be performed on all clinically node positive patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 202.

Laser scanning cytometric analysis of cyclin B1 in primary human malignancies

Cyclins are key components of the cell cycle progression machinery. They activate their partner-dependent kinases (CDKs) and target them to respective substrate proteins within the cell. CDK-mediated phosphorylation of specific sets of proteins drives the cell through particular phases or checkpoints of the cell cycle. During unperturbed growth of normal cells, the timing of expression of several cyclins is discontinuous, occurring at discrete and well-defined periods of the cell cycle. Immunocytochemical detection of cyclins in relation to cell cycle position (DNA content) by multiparameter flow cytometric techniques has provided a new approach to cell cycle studies. This approach, like no other method, can be used to detect the "unscheduled" expression of cyclins, namely, the presentation of G1 cyclins by cells in G2/M and of G2/M cyclins by G1 cells, without the need for cell synchronization. By use of multiparameter flow cytometric and laser scanning cytometric analysis, we correlated the expression of cyclin B1 with cell cycle position in normal lymphocytes stimulated to proliferate by the mitogen phytohemagglutinin and in 28 primary human tumors of different organ and type. Eighteen of the 28 tumors expressed the cyclin B1 in more than 5% of cells (B1 positive), and the rest showed cyclin expression from 2.1 to 5% (B1 negative). In normal lymphocytes, the expression of cyclin B1 was restricted to very late S and G2 + M phases of the cell cycle. In 15 of 18 primary tumors studied, the expression of cyclin B1 was "unscheduled" (unrestricted to particular phases of the cycle). The data suggest that the "unscheduled" expression of cyclin B1 might be a common defect in neoplasia.