Abstract P5-18-01: Risk of contralateral breast cancer (CBC) in women with ductal carcinoma in situ (DCIS) with and without and synchronous lobular carcinoma in situ (LCIS)

Background: LCIS is considered a risk factor for bilateral breast cancer, but the effect of LCIS diagnosed concurrently with DCIS is not known. We sought to compare CBC and ipsilateral breast tumor recurrence (IBTR) rates in women with DCIS with and without synchronous LCIS treated with breast conserving surgery (BCS).

Methods: A prospectively maintained database of DCIS patients undergoing BCS from 2000-2011 was used to identify women with a contralateral breast at risk. Patients with synchronous ipsilateral LCIS found at core needle biopsy or surgical excision were included in the “DCIS + LCIS” group; those with contralateral or bilateral LCIS were excluded. Associations of patient, tumor, and treatment factors with CBC and IBTR were evaluated using logistic regression.

Results: Of the 1888 patients identified, 1475 (78%) had DCIS only and 413 (22%) had DCIS with synchronous LCIS. Median follow-up was 7.5 years (range 0-17 years). 305 patients had a subsequent breast event; 216 IBTR and 89 CBC.

The 5 and 10-year cumulative incidence of IBTR was similar in both groups: 6.3% and 14.4% for DCIS only, compared with 5.9% and 14.0% for DCIS + LCIS (p = 0.94), respectively. The 5 and 10-year cumulative incidence of CBC was significantly greater in the DCIS + LCIS group: 5.7% and 10.0%, compared with 2.4% and 5.0% for DCIS only (p < 0.001).

Table 1 summarizes uni-and multi-variable analyses of risk factors associated with CBC and IBTR among women with DCIS treated with BCS. After adjustment for other factors, CBC risk was more than 2-fold higher in the DCIS + LCIS group compared with the DCIS only group (HR 2.37, 95% CI 1.54-3.65, p < 0.001). There was no difference in IBTR risk based on presence of synchronous LCIS. Younger age and receipt of endocrine therapy were significantly associated with decreased risk of CBC.

Table 1:Risk factors associated with CBC and IBTR in patients with DCIS treated with BCS  Univariate Analysis Multivariate Analysis  Hazard Ratio (95% CI) Hazard Ratio (95% CI)  CBC IBTR CBC IBTRAge (continuous)1.02 (1.01-1.04) *0.99 (0.98-1.0)1.02 (1.0-1.04) *0.99 (0.97-1.0) *Presentation    Radiologic1111Clinical0.36 (0.11-1.14)1.56 (1.05-2.3) *0.41 (0.13-1.31)1.67 (1.12-2.47) *Family history    Yes1.32 (0.87-2.01)1.0 (0.76-1.32)1.33 (0.87-2.03)1.03 (0.78-1.35)Grade    Low1111Intermediate/high1.83 (1.0-3.37)1.32 (0.93-1.88)1.74 (0.92-3.29)1.62 (1.11-2.35) *Radiation    Yes1.16 (0.75-1.8)0.7 (0.54-0.92) *1.14 (0.71-1.82)0.64 (0.48-0.86) *Endocrine Therapy    Yes0.43 (0.23-0.81) *0.51 (0.35-0.74) *0.42 (0.22-0.8) *0.53 (0.36-0.77) *DCIS group    DCIS only1111DCIS + LCIS2.28 (1.49-3.5) *0.99 (0.71-1.36)2.37 (1.54-3.65) *0.99 (0.71-1.37)* p < 0.05

Conclusions: LCIS diagnosed concurrently with DCIS is not associated with IBTR, but increases the risk of CBC two-fold. Endocrine therapy should be considered both for the index DCIS and for prevention of subsequent CBC.

Citation Format: Miller ME, Muhsen S, Zabor EC, Flynn J, Olcese C, Giri D, Van Zee KJ, Pilewskie M. Risk of contralateral breast cancer (CBC) in women with ductal carcinoma in situ (DCIS) with and without and synchronous lobular carcinoma in situ (LCIS) [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 P5-18-01.

Abstract P5-07-05: Obesity, adipose inflammation, and race in patients with early stage breast cancer

Background: Elevated body mass index (BMI) is associated with increased risk of estrogen receptor-positive postmenopausal breast cancer. Mechanistically, most individuals with elevated BMI have breast white adipose tissue inflammation (WATi) which confers increased breast cancer risk, particularly in those with existing benign breast disease. Individuals with WATi have elevated in-breast expression of aromatase and several systemic changes that increase breast cancer risk, including hyperinsulinemia and higher levels of C-reactive protein. However, women with normal BMI but high levels of body fat are also likely to harbor WATi and are at increased risk of postmenopausal breast cancer. The accuracy of BMI for assessing adiposity and predicting obesity-related disorders, including cancer, varies across race and ethnicity. Whether the association between BMI and WATi varies by race is unknown. Here we aimed to characterize relationships among breast WATi and clinicopathologic features in a racially diverse cohort undergoing mastectomy for breast cancer treatment.

Methods: Non-tumorous breast tissue and fasting blood were collected from women undergoing mastectomy for breast cancer treatment or prevention at a single center serving a racially diverse patient population. Breast WATi was detected by the presence of crown-like structures in the breast (CLS-B), which are composed of a dead/dying adipocyte surrounded by CD68+ macrophages. Clinicopathologic data were abstracted from electronic medical records. Associations among categorical variables were examined using Fisher's exact test. Relationships between continuous variables were examined using the Spearman correlation.

Results: As of May 18, 2018 62 patients have been accrued; median age 55 (range 32 to 84). Self-reported race distribution was: 36 (58%) Asian, 5 African American (8%), 20 (32%) Caucasian, and 1 (2%) unknown. Breast tissue has been analyzed for WATi in 60 cases thus far. Clinicopathologic features stratified by the presence or absence of breast WATi are presented in. Breast WAT inflammation was associated with obesity (P=0.02) and a trend to association was observed with dyslipidemia (P<0.09).

VariableBreast WATi Absent (n=25)Breast WATi Present (n=35)Age, years  Median (range)51 (32 to 71)59 (36 to 80)BMI, kg/m2  Median (range)22.5 (18.1 to 35.3)28.0 (19.2 to 38.9)BMI Category  Underweight1 (4%)0 (0%)Normal16 (64%)10 (29%)Overweight5 (20%)18 (51%)Obese3 (12%)7 (20%)Race, n (%)  Asian15 (60%)19 (54%)African American2 (8%)3 (9%)Caucasian8 (32%)12 (34%)Unknown0 (0%)1 (3%)Menopausal Status, n (%)  Pre10 (40%)12 (34%)Post15 (60%)23 (66%)Hypertension, n (%)7 (28%)16 (46%)Diabetes mellitus, n (%)0 (0%)5 (14%)Dyslipidemia, n (%)1 (4%)11 (31%)

Conclusions: Breast adipose inflammation is associated with elevated BMI and possibly metabolic syndrome disorders in a racially diverse population. These findings are consistent with observations from predominantly Caucasian cohorts. Race-specific characteristics will also be examined. Study accrual is ongoing and updated results will be presented.

Citation Format: Iyengar NM, Siegel B, Malik M, Giri DD, Tsai J, Hughes M, Adam A, Williams S, Zhou XK, Rodgers W, Ginter P, Patel A, Yong F, Cherian A, August P, Dannenberg AJ. Obesity, adipose inflammation, and race in patients with early stage 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 P5-07-05.

Abstract PD5-05: Metabolic obesity, adipose inflammation and aromatase: Potential drivers of breast cancer risk in women with normal body mass index

Background: Elevated body mass index (BMI) is associated with increased risk of postmenopausal breast cancer, which may be partly attributable to an inflammation-aromatase axis. Most individuals with elevated BMI harbor white adipose tissue inflammation (WATi), defined by the presence of crown-like structures in the breast (CLS-B). CLS-B are composed of a dead/dying adipocyte surrounded by CD68+ macrophages. This inflammation is associated with activation of NF-κB and elevated expression of aromatase, which could contribute to tumor development. Additionally, WATi correlates with several circulating changes, including hyperinsulinemia, which increase breast cancer risk. Although breast WATi correlates with rising BMI, it is also present in some normal BMI individuals. Beyond inherited germline syndromes, the etiology of breast cancer in individuals with normal BMI is not well understood. Here we examined the impact of breast WATi on breast aromatase expression and circulating factors in women with normal BMI.

Methods: Non-tumorous breast tissue and fasting blood were collected from 72 women with BMI < 25 kg/m2 undergoing mastectomy at MSKCC. Breast inflammation was detected by the presence of CLS-B using CD68 immunohistochemistry. The primary objective was to determine if breast WATi in normal BMI individuals correlates with elevated aromatase levels in the breast, measured by qPCR, western blotting, immunofluorescence and enzyme activity. Secondary objectives included assessment of breast adipocyte size and circulating metabolic and inflammatory factors.

Results: Breast inflammation was present in 39% of women. Median BMI was 23.0 (range 18.4 to 24.9) in women with breast WATi versus 21.8 (range 17.3 to 24.6) in those without inflammation (P=0.04). Aromatase mRNA expression was positively correlated with WATi (CLS-B/cm2; P=0.002). Those with severe WATi had highest aromatase mRNA levels, compared to those with no or mild WATi (P=0.005). Aromatase protein, assessed by measuring adipose stromal cell-specific immunofluorescence or western blotting, and activity were also higher in CLS-B+ cases compared to CLS-B- (P<0.001). Breast WATi correlated with larger adipocytes (P=0.01) and higher circulating levels of C-reactive protein, leptin, insulin, and triglycerides (P<0.05). Insulin resistance, characterized by the homeostasis model (HOMA2-IR), correlated with breast WATi (P=0.004). Finally, leptin, a known inducer of aromatase and driver of cancer growth, correlated with higher breast aromatase levels (P=0.02) and larger adipocytes (P<0.01).

Conclusions: A metabolically unhealthy state occurs in women with inflamed breast adipose despite having a normal BMI. This subclinical inflammatory state is characterized by elevated aromatase in the breast, insulin resistance, and dysplipidemia. The presence of enlarged adipocytes in the breasts of normal BMI women with inflammation suggests a state of hyperadiposity which could not be predicted based on BMI alone. These findings indicate that normal BMI metabolic obesity may be associated with increased cancer risk. Our results suggest that objective measurements of adiposity rather than BMI may help to identify individuals at increased risk for disease.

Citation Format: Iyengar NM, Brown KA, Zhou XK, Subbaramaiah K, Giri DD, Gucalp A, Howe LR, Zahid H, Bhardwaj P, Wendel NK, Falcone DJ, Morrow M, Wang H, Williams S, Pollak M, Hudis CA, Dannenberg AJ. Metabolic obesity, adipose inflammation and aromatase: Potential drivers of breast cancer risk in women with normal body mass index [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 PD5-05.

Abstract S4-04: Lobular carcinoma in situ displays intra-lesion genetic heterogeneity and its progression to invasive disease involves clonal selection and variations in mutational processes

Introduction: Lobular carcinoma in situ (LCIS) is considered both a risk factor and non-obligate precursor of invasive breast cancer. We sought to determine the genomic landscape of LCIS and the mutational processes involved in the clonal evolution and progression from LCIS to ductal carcinoma in situ (DCIS) and invasive lobular carcinoma (ILC).

Methods: Patients with a history of LCIS undergoing therapeutic or prophylactic mastectomy were prospectively enrolled in an IRB approved protocol. Frozen tissue blocks were collected, screened for lesions of interest (LCIS, DCIS, ILC, invasive ductal carcinomas (IDC)) and subjected to microdissection and DNA/RNA extraction. Matched germline DNA was available for all cases. Whole exome sequencing was performed on a HiSeq2000 and data were aligned to the reference human genome and processed using GATK. Single nucleotide variants (SNVs) and small insertions/deletions were identified using MuTect and Varscan, respectively. Purity and ploidy estimates were calculated using ABSOLUTE. Clonal frequencies were estimated using Pyclone and the clonal structure of each sample was reconstructed using SubcloneSeeker. Shannon index and Simpson index metrics were used to calculate heterogeneity levels. Mutational signatures were defined according to their mutational trinucleotide context, and the expression levels of APOBEC gene family members were assessed by quantitative reverse transcription (qRT)-PCR.

Results: 30 LCIS, 10 ILCs, 7 DCIS and 5 IDCs from 15 patients qualified for data analysis. CDH1 was the most frequently mutated gene and found to be targeted by mutations in 26 LCIS samples (23 somatic, 3 germline). The repertoire of somatic mutations in LCIS was similar to that of luminal A breast cancers, with the exception of the significantly higher frequency of CDH1 mutations and the lower prevalence of TP53 mutations. ILCs were clonally related to at least one LCIS in 10 patients, and in 3/7 patients, DCIS was clonally related to at least one LCIS. Clonal composition analysis revealed that the presence of a minor clone(s) in LCIS, and the levels of intra-tumor genetic heterogeneity were significantly higher in LCIS clonally related with DCIS/ILC than in LCIS unrelated to DCIS/ILC. In two cases, a minor LCIS subclone constituted the major clone in the associated DCIS/ILC. A comparative analysis of the mutational signatures in the truncal and branch mutations of these cases revealed that whilst the truncal mutations displayed an aging signature, branch mutations were enriched for the APOBEC signature. qRT-PCR analysis demonstrated that cases displaying the APOBEC signature also harbored significantly higher levels of APOBEC3B expression than samples with the aging signature.

Conclusions: LCIS displays intra-lesion genetic heterogeneity, and the progression from LCIS to DCIS or ILC may involve the selection of clones resulting from distinct mutational processes during clonal evolution. Our findings also suggest that cytodine deamination driven by the overexpression of APOBEC3B may drive the progression of LCIS to DCIS/ILC in a subset of cases.

Citation Format: Reis-Filho JS, Schizas M, Piscuoglio S, Sakr RA, Ng CKY, Lim RS, Carniello JVS, Towers R, Martelotto L, Giri DD, de Andrade VP, Viale A, Solit DB, Weigelt B, King TA. Lobular carcinoma in situ displays intra-lesion genetic heterogeneity and its progression to invasive disease involves clonal selection and variations in mutational processes. [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 S4-04.

Multiple endocrine neoplasia syndromes 1 and 2: manifestations and management in childhood and adolescence

The identification of the genetic causes of the multiple endocrine neoplasia (MEN) syndromes 1 and 2, and associated genotype-phenotype relationships, has revolutionised the clinical care of affected patients. A genetic diagnosis can be made during infancy and careful clinical surveillance, coupled with early intervention, has the potential to improve both morbidity and mortality. These developments have seen the management of patients with MEN move into the arena of paediatric medicine. In this review article, we consider the genetic causes of MEN together with the clinical manifestations and management of these syndromes.

RECK controls breast cancer metastasis by modulating a convergent, STAT3-dependent neoangiogenic switch

Metastasis is the primary cause of cancer-related death in oncology patients. A comprehensive understanding of the molecular mechanisms that cancer cells usurp to promote metastatic dissemination is critical for the development and implementation of novel diagnostic and treatment strategies. Here we show that the membrane protein RECK (Reversion-inducing cysteine-rich protein with kazal motifs) controls breast cancer metastasis by modulating a novel, non-canonical and convergent signal transducer and activator of transcription factor 3 (STAT3)-dependent angiogenic program. Neoangiogenesis and STAT3 hyperactivation are known to be fundamentally important for metastasis, but the root molecular initiators of these phenotypes are poorly understood. Our study identifies loss of RECK as a critical and previously unknown trigger for these hallmarks of metastasis. Using multiple xenograft mouse models, we comprehensively show that RECK inhibits metastasis, concomitant with a suppression of neoangiogenesis at secondary sites, while leaving primary tumor growth unaffected. Further, with functional genomics and biochemical dissection we demonstrate that RECK controls this angiogenic rheostat through a novel complex with cell surface receptors to regulate STAT3 activation, cytokine signaling, and the induction of both vascular endothelial growth factor and urokinase plasminogen activator. In accordance with these findings, inhibition of STAT3 can rescue this phenotype both in vitro and in vivo. Taken together, our study uncovers, for the first time, that RECK is a novel regulator of multiple well-established and robust mediators of metastasis; thus, RECK is a keystone protein that may be exploited in a clinical setting to target metastatic disease from multiple angles.

Statistical mechanics of DNA rupture: theory and simulations

We study the effects of the shear force on the rupture mechanism on a double stranded DNA. Motivated by recent experiments, we perform the atomistic simulations with explicit solvent to obtain the distributions of extension in hydrogen and covalent bonds below the rupture force. We obtain a significant difference between the atomistic simulations and the existing results in the literature based on the coarse-grained models (theory and simulations). We discuss the possible reasons and improve the coarse-grained model by incorporating the consequences of semi-microscopic details of the nucleotides in its description. The distributions obtained by the modified model (simulations and theoretical) are qualitatively similar to the one obtained using atomistic simulations.

Abstract OT3-3-01: A multicenter phase II study of docosahexaenoic acid (DHA) in triple negative breast cancer (TNBC) survivors

Background: The development of effective chemopreventive strategies to reduce the risk of TNBC, is a critical unmet need. Obesity is associated with a chronic inflammatory condition in the white adipose tissue of the breast, characterized microscopically by crown-like structures of the breast (CLS-B). The presence and extent of these lesions is associated with a series of proinflammatory mediators, including tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), interleukin-1β (IL-1β) and aromatase. Importantly these proinflammatory mediators are known to be involved in breast carcinogenesis. In translational studies to date, the strongest correlations have been seen between CLS-B and TNF-α. Therefore, we aim to evaluate whether treatment with a dietary supplement, DHA, an omega-3 fatty acid, with potent effects on TNF-α, can decrease obesity-related breast inflammation in women.

Trial design: This is a randomized phase II placebo-controlled, double-blinded study of DHA in overweight/obese patients (pts), defined as body mass index (BMI) ≥25 with a history of TNBC. Pts will receive DHA or placebo twice daily for 24 weeks and will undergo core biopsies from normal (non-irradiated contralateral) breast tissue before and after the treatment to determine whether DHA can decrease obesity-related breast inflammation.

Eligibility: Inclusion criteria: 1) Age ≥ 18. 2) BMI ≥ 25. 3) Completed treatment for stage I-III TNBC ≥ 6 months prior. 4) No clinical evidence of disease. 5) Adequate accessible breast tissue for pre- and post- treatment biopsy, consisting of one breast unaffected by invasive cancer, which has not been radiated or surgically augmented. 6) Adequate organ and bone marrow function. 7) ECOG status ≤2. Exclusion criteria: 1) DHA supplementation. 2) Aspirin/NSAID use in the month preceding and during the trial. 3) Therapeutic anticoagulation. 4) Regular use of statins, steroids, or immunomodulators.

Specific aims: The primary objective is to determine whether treatment with DHA for 24 weeks at 1,000 mg twice daily as compared to placebo reduces normal breast tissue levels of TNF-α in overweight/obese pts with a history of TNBC. The secondary objective is to evaluate the effect of DHA on the change from baseline in levels of the following tissue biomarkers: COX-2, IL-1β, aromatase, and CLS-B. Exploratory endpoints include assessment of age as a predictor of CLS-B and inflammatory biomarkers and the evaluation of red blood cell fatty acid levels as a surrogate of DHA compliance.

Statistical methods: Percent change in TNF-α mRNA levels in normal breast tissue between DHA and placebo arm will be compared using two-sample t-test. If normality assumptions are violated, a two-sample Wilcoxon rank-sum test will be used. With 30 subjects in each arm, we will have 80% power to detect effect size as small as 0.74 at 0.05 significance level using a two-sided, two-sample, Student t-test.

Accrual: A total of 60 evaluable pts will be enrolled. Assuming a 10% dropout rate and 10% non-evaluable rate, up to 76 participants will be randomized in this study. This trial is currently enrolling pts.

Contact information: For more information on this trial, please visit clinicaltrials.gov (NCT01849250) or contact Ayca Gucalp MD (gucalpa@mskcc.org).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT3-3-01.

Abstract P1-06-03: Validating the link between obesity and breast inflammation in women with breast cancer (BC)

Background: In post-menopausal women, obesity is a risk factor for the development of BC that expresses the estrogen and progesterone receptors (ER/PR). In mouse models of obesity, we previously described crown-like structures (CLS), consisting of macrophages surrounding dead adipocytes in white adipose tissue (WAT) of the mammary gland, which were associated with increased levels of proinflammatory mediators known to be involved in carcinogenesis. We translated these findings to women (n = 30), and provided the first evidence of CLS in the human breast (CLS-B). The presence and severity of CLS-B (CLS-B index) correlated with elevated body mass index (BMI), increased adipocyte size, activation of NF-κB, and increased levels of proinflammatory mediators (TNF-α, IL-1β, COX-2 and PGE2) and aromatase. We expanded our population to prospectively validate these preliminary findings.

Methods: We prospectively collected WAT from women undergoing breast and reconstructive surgery. WAT was subjected to immunohistochemistry for CD68, a macrophage marker, to detect CLS-B by light microscopy. Adipocyte diameter was measured on photomicrographs using the Canvas 11 Software. Endpoints were 1) CLS-B presence/absence and 2) CLS-B index (proportion of slides with CLS-B). Associations between CLS-B and clinicopathologic features were analyzed using logistic regression and Fisher's exact test.

Results: From 04/2010-02/2012, WAT (100 mastectomy and 5 abdominal reconstructions) was obtained from 101 women; median age 49 (range 26-80). CLS-B were found in 54 (53%) patients (pts). CLS-B were seen in 9/37 (24%) normal weight pts (BMI <25), 23/39 (59%) overweight pts (BMI 25-29.9), and 22/25 (88%) obese pts (BMI ≥30). Pts with CLS-B had significantly larger average adipocyte diameter (106.5 +/- 11.5 microns) compared to those without CLS-B (91.5 +/- 16.1 microns; p<0.001). Consistently, CLS-B index correlated with BMI (p<0.001) and adipocyte size (p<0.001). Breast inflammation was seen in pts with all tumor phenotypes: CLS-B were seen in 24/41 (59%) pts with ER/PR+, HER2- tumors; 7/16 (44%) pts with HER2+ tumors; and 3/10 (30%) pts with ER/PR/HER2- tumors. A higher CLS-B index was seen in WAT from ER+ tumors, but this was not statistically significant (p = 0.08). Regular use of nonsteroidal antiinflammatory drugs was protective against CLS-B (p = 0.17 for association with CLS-B, and p = 0.04 for association with CLS-B index in multivariable analyses). Among 25 pts with bilateral breast WAT, concordant CLS-B findings (+/-) were found in 20 (80%) pts. Among pts with paired breast and abdominal WAT, concordant findings were seen in 4/5 (80%) pts.

Conclusions: Findings from this prospective study, the largest reported to date, extend our previous observation that CLS-B are associated with BMI and adipocyte size. These results provide a plausible pathophysiological link between obesity and BC. Breast inflammation occurs in association with all BC phenotypes. Preliminary data suggest concordance between breasts and between abdominal and breast WAT. Hence, abdominal WAT may prove useful as a surrogate for breast WAT; biopsies of abdominal subcutaneous WAT are more easily done, which could prove useful in developing interventions to attenuate WAT inflammation.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-06-03.

Single polymer gating of channels under a solvent gradient

We study the effect of a gradient of solvent quality on the coil-globule transition for a polymer in a narrow pore. A simple self-attracting, self-avoiding walk model of a polymer in solution shows that the variation in the strength of the interaction across the pore leads the system to go from one regime (good solvent) to the other (poor solvent) across the channel. This may be thought to be analogous to thermophoresis, where the polymer goes from the hot region to the cold region under the temperature gradient. The behavior of short chains is studied using exact enumeration while the behavior of long chains is studied using transfer matrix techniques. The distribution of the monomer density across the layer suggests that a gatelike effect can be created, with potential applications as a sensor.

Abstract PD05-02: Novel mutations in lobular carcinoma in situ (LCIS) as uncovered by targeted parallel sequencing

Background: LCIS has traditionally been recognized as a marker of increased risk for the subsequent development of breast cancer, of either the lobular or ductal phenotype, yet due to the incidental nature of LCIS little is known about its underlying biology. Here we describe the first report of novel mutations in LCIS using targeted exome sequencing of fresh frozen tissue samples.

Methods: Fresh frozen tissue samples from patients with a prior history of LCIS undergoing therapeutic or risk-reducing mastectomy from 2003–08 were harvested and systematically reviewed to identify LCIS. Cells from individual LCIS lesions +/− associated cancers were collected by laser capture microdissection. For the purposes of this study, germline DNA (blood) and DNA from 12 unique LCIS lesions were subject to targeted parallel sequencing of exons corresponding to 230 cancer genes using the Illumina HiSeq 2000 platform. DNA from an associated ductal carcinoma in situ (DCIS) and/or an invasive ductal (IDC) or lobular (ILC) lesion was also available for 7 of these cases resulting in 41 samples from 12 pts for mutational analysis. Normalized (RMA) Affymetrix U133A gene expression data were also available.

Results: DNA profiling reliably identified 7 somatic mutations in 5/12 LCIS samples (41.7%). Of these, 4/7 mutations were base substitutions (missense mutations); and the others included: 1 deletion; 1 silent and 1 splice-site mutation. Mutations in LCIS were identified in 5/230 cancer genes analyzed, including: PIK3CA, CDH1, NOTCH4, PREX2 and ARAF. PIK3CA and CDH1 mutations were each identified in two samples, representing 4/7 (57.1%) mutations. Specific mutations found in LCIS and their frequencies are listed (table). Among 3 LCIS-ILC pairs, one shared the G914R mutation in PIK3CA, and 1/3 LCIS-IDC pairs exhibited an identical point mutation (R373W) in the NOTCH4 gene. No shared mutations were observed in 3 LCIS-DCIS pairs. Both CDH1 mutated cases were associated with decreased e-cadherin mRNA levels when compared to non-mutated cases (mean 9.88 vs 11.01), as was the NOTCH4 mutation (mean 6.02 vs 6.47). Mutations in ARAF and PREX2 were associated with increased mRNA levels, mean 7.07 vs 6.52 and 4.82 vs 4.22, respectively. The hotspot PIK3CA mutation (E545K) was also associated with increased gene expression (mean 5.15 vs 4.64) whereas the G914R mutant was associated with decreased expression (mean 4.13 vs 4.64).

Abstract P6-05-02: Endocrine biomarkers in response to AR-inhibition with bicalutamide for the treatment of AR(+), ER/PR(−) metastatic breast cancer (MBC) (TBCRC011)

Background: Our group and others have identified a subset of ER/PR(−) breast cancers characterized by expression of the androgen receptor (AR) and androgen-dependent growth (Doane 2006). We conducted a proof-of-concept multicenter phase II study to test the efficacy of the AR-antagonist, bicalutamide for the treatment of AR(+) ER/PR(−) MBC (NCT00468715). Results of the primary endpoint, clinical benefit rate (CBR), were presented at ASCO (Gucalp 2012). Data for the impact of bicalutamide on circulating hormone levels in women are limited. Elevations in serum testosterone (T) and estradiol (E) have been observed for men treated with bicalutamide. We hypothesized comparable patterns of change in circulating endocrine markers in response to bicalutamide for women with MBC.

Methods: Patients (pts) with AR(+) (IHC ≥10%), ER/PR(−) (IHC <10%) MBC were eligible for treatment (tx) if ECOG performance status ≤2 and normal organ function regardless of menopausal status. There was no limit to prior tx except prior trastuzumab required if HER2(+). Tx consisted of bicalutamide 150mg orally daily in 28-day cycles (C). Toxicity assessed q4 weeks, response q12wks. Primary endpoint was CBR. Peripheral blood was collected for total and free T, E and sex hormone binding globulin (SHBG) at baseline, start of C2 (C2) and at end of study (EOS). Standard institutional assays were used. A Wilcoxon signed-rank test was done to compare baseline to C2 and EOS values.

Results: 26 patients with AR(+) ER/PR(−) MBC were treated on study. Evaluable number (n) of pts at baseline, C2 and EOS are 26, 26 and 19 respectively. Two pts remain on study. Menopausal status: pre=2, post=24. Baseline median total and free T and estradiol were consistent with expected norms, however a wide range was observed (Table). There were no significant differences observed for median free T, total T, E or SHBG between baseline and C2 or baseline and EOS. Changes in hormone levels could not be stratified by menopausal status or response to bicalutamide given small sample size. Given the wide range of baseline values, we examined the percent change for each endocrine biomarker from baseline to C2 and EOS. As shown in the Table, there was no difference in median percent change observed across time points for each biomarker.

PD10-02: Sporadic Breast Cancers Show Defects in the BRCA1-BRCA2 Pathway of Homologous Recombination in All Biomarker-Defined Sub-Types of Breast Cancer

Background: Mutation carriers of BRCA1 and BRCA2 are well known to develop early onset breast cancer, with loss of the second allele occurring in the development of the tumor. However, by array comparative genomic hybridization (aCGH) studies, some sporadic breast cancers have a similar “genetic landscape” as BRCA-mutation carriers, showing large losses and gains across the genome. We have now identified that DNA repair defects involving the BRCA1-BRCA2 pathway can occur in the absence of mutations in either gene and in the absence of a deficiency in either protein.

Methods: Fresh human breast cancer samples were irradiated, ex-vivo, to look for the ability to assemble RAD51 protein macrocomplexes or foci. Primary breast cancer specimens were obtained from consented patients with non-metastatic, invasive carcinomas following lumpectomy or mastectomy, without neoadjuvant cytotoxic or hormonal therapy. A single cell suspension was prepared from the tumor, with one half irradiated to 10Gy and the other half mock-treated. After 4h, cells were mounted, fixed on slides, and stained with anti-Rad51, anti-BRCA1, and anti-γH2AX antibodies. At least 200 nuclei were examined and scored using confocal microscopy. A failure to induce RAD51 nuclear foci by 2-fold after ionizing radiation was designated as defective in homologous recombination (HR).

Results: For the 71 patient samples analyzed, we have 14 triple-negative tumors, of which 6 are HR-defective (42.8%); for Her2-amplified tumors, we have 6/19 (31.6%) that are HR-defective and for ER+ tumors 6/38 (15.8%). The overall incidence of HR-defective tumors is 18/71 (25.3%), which is substantially higher than we would have expected.

P4-16-06: Expression Patterns of Receptor Activator of Nuclear Factor-kB (RANK) and Src in a Series of Primary Breast Tumors (BT) and Bone Metastases (BM) in Patients (pts) with Metastatic Breast Cancer (MBC)

Background

BM develops in 65–70% of pts with MBC. RANK and its ligand (RANK-L) can be critical in the development and progression of BM. Src overexpression and deregulation occurs in many solid tumors but it has not been fully characterized although an association between Src activity defined by a gene expression signature and BM particularly in ER+ pts has been described. (Zhang XH et al. Cancer Cell. 2009) Our goal was to elucidate the relationship between Src and RANK expression in BT and BM in relation to estrogen-/progesterone-receptor (ER/PR)/HER2 expression and tumor histology (invasive ductal carcinoma (IDC) vs invasive lobular carcinoma (ILC)).

Methods: Immunohistochemistry (IHC) for RANK (R&D Systems clone 80707) and Src (Cell Applications Inc. Phospho Tyr-416) protein expression was performed on archived paraffin embedded BT and BM. Scoring: 0=negative, 1+=weak, 2+=intermediate, 3+=strong and the percent of positive tumor cells; RANK+ = 2–3+, > 1% of cells; Src+ = 1–3+; > 1% of cells. Associations between RANK/Src expression and tumor characteristics were assessed using the chi-square test or McNemar's test for pairs, as appropriate.

Results: From the MSKCC database, using an IRB-approved waiver of consent, we identified 54 pts with MBC who underwent surgical biopsy of a metastatic bone lesion at our center between 2005–2010, and had tissue available for further testing. 17 corresponding BT samples were identified. At the time of diagnosis, 43 (79.5%) primary tumors were ER or PR (+); 6 (11%) were HER2+; 41 (76%) were invasive ductal carcinoma. 87% of BM expressed RANK and 44% expressed Src. (Table 1) No significant correlation between RANK or Src expression in BM and ER/PR/HER2 status of BT was observed. A significant correlation between RANK expression and BT histology was observed, (p=0.0016): 93% of IDC were RANK (+), in comparison to 50% of invasive lobular carcinomas. RANK expression was not significantly different between primary tumor and metastatic bone samples (p=0.99). There was a borderline significant difference in Src expression between primary and metastatic site (p=.06).

Abstract P4-06-07: PI3K Mutations Are More Common in Low Grade DCIS

Background: DCIS is a non-obligate precursor to invasive breast cancer yet it remains difficult to predict which lesions will progress or over what time interval. Factors associated with a higher risk of progression include high histologic grade and HER2 amplification. HER2 signaling via the PI3K pathway is associated with accelerated invasiveness in laboratory models and mutations in the helical domain of PI3K have been associated with a worse prognosis in invasive cancer. We hypothesized that PI3K pathway mutations are associated with higher risk of progression in DCIS and therefore would be more common in high grade DCIS.

Methods: 195 cases of pure DCIS were identified from the MSKCC breast service database (1999-2003). All cases were reviewed by a single pathologist to assign histologic grade. Sections were obtained from archived formalin-fixed paraffin embedded (FFPE) blocks for manual microdissection to isolate pure DCIS lesions for DNA extraction. Multiplex array (Sequenom®) genotyping for PIK3CA was performed on prePCR amplified DNA. Comparisons were made between high and low grade DCIS using Fisher's exact test.

Results: Among 195 pure DCIS cases, 89 were classified as high grade and 106 as low grade. Sequenom® analysis was informative in all cases. PIK3CA mutations were identified in 4/89 (4%) cases of high grade DCIS and in 24/106 (23%) cases of low grade DCIS (p=0.000). All 4 mutations in high grade DCIS were located in the kinase domain, whereas in low grade DCIS, 9/24 (37%) mutations were in the kinase domain (H1047R) and 15/24 (67%) mutations were in the helical domain (E542K, E545K, N345K).

Conclusion: PI3K mutations were relatively uncommon in pure high grade DCIS as compared to low grade DCIS. PI3K mutations in low grade DCIS were observed in both the kinase and helical domain. These findings support the hypothesis that breast tumorigenesis differs by grade and PI3K mutations may be more prominent in low grade carcinogenesis. The significance of helical domain mutations in low grade lesions requires further investigation.

Dissociation of the E-Cadherin-Catenin-Complex (CCC) Is an Early and Progressive Event in Lobular Neoplasia

Recent data suggests that some lobular carcinoma in situ (LCIS) lesions may behave as precursors to invasive lobular carcinoma (ILC). Loss of E-cadherin (E-CD) mediated cell adhesion is characteristic of both LCIS and ILC and is reflected in the dis-cohesive appearance of the individual cells. Subsequent dissociation of the intracellular E-cadherin-catenin-complex (CCC) facilitates tumor progression, invasion and migration. Whether disruption of the CCC plays a role in the progression of select LCIS lesions to ILC remains unclear. The aim of this study was to evaluate the relation between loss of E-CD and dissociation of the CCC in pure LCIS and LCIS with concurrent ILC (LCIS w/ILC). Methods Thirty patients undergoing mastectomy for LCIS alone or LCIS w/ ILC were prospectively enrolled to an IRB-approved protocol. FFPE blocks were retrieved and sections prepared for IHC. 18 cases had LCIS w/ ILC, 12 cases had pure-LCIS. IHC was performed for ER, PR, E-CD, N-cadherin (N-CD), and α-, β- and phospho-β-catenin. ER/PR positivity was scored as any nuclear staining, and E-CD and N-CD by any membranous staining. a- and β-catenin expression was scored by site (membranous/cytoplasmic/nuclear) of staining compared to normal. Dissociation of the CCC was defined by loss of membranous α- and β-catenin expression.Results Median age at surgery was 51yrs (range 40-79); patients with pure LCIS were younger than those with LCIS w/ ILC (median 48yrs vs 57yrs, p=.0002). Among 18 cases of LCIS w/ ILC, the median tumor size was 2cm (range 1.4-5.7), 9 patients had N1 disease and 1 had M1 disease. All pure LCIS, LCIS w/ ILC and ILC lesions were ER/PR positive and E-CD negative. N-CD expression was also absent in all pure LCIS, LCIS w/ ILC and ILC lesions. Normal α-catenin membranous expression was confirmed in all normal epithelial cells but decreased with the transition from in-situ to invasive disease: pure-LCIS lesions 83%; LCIS w/ ILC 28%; ILC 0%. Loss of membranous α-catenin expression was accompanied by cytoplasmic α-catenin expression in all lesions. A similar trend of decreasing membranous staining from in-situ to invasive disease was observed for β-catenin, however in contrast to α-catenin, cytoplasmic β-catenin expression decreased from 67% in pure LCIS to 11% in LCIS w/ ILC and 6% in ILC. Active β-catenin (nuclear staining) was not seen in pure LCIS lesions and was only present in one case of LCIS w/ ILC. Inactive (phospho) β-catenin expression was present in all lesions.Conclusion Loss of E-CD expression is an early event in lobular neoplasia however subsequent dissociation of the intracellular CCC a a ppears to be a progressive process with complete dissociation occurring only in invasive lesions. This finding suggests that complete disruption of the CCC may be required to facilitate maintenance of the invasive phenotype; however, the absence of N-CD expression and predominance of inactive β-catenin in both in situ and invasive lesions suggests that alternate mechanisms are also required to mediate the pro-invasive effects of CCC dissociation. Further studies into the mechanisms of CCC dissociation and downstream events in lobular carcinoma are needed to define the role of this process in the transition from in-situ to invasive disease.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6149.

Role of pulling direction in understanding the energy landscape of proteins

Single-molecule force spectroscopy provide details of the underlying energy surfaces of proteins which are essential to the understanding of their unfolding process. Recently, it has been observed experimentally that by pulling proteins in different directions relative to their secondary structure, one can gain a better understanding of the shape of the energy landscape. We consider simple lattice models which are anisotropic in nature to study the response of a force in unfolding of a polymer. Our analytical solution of the model, supported by extensive numerical calculations, reveal that the force temperature diagrams are very different depending on the direction of the applied force. We find that either unzipping or shearing kind transitions dominate the dynamics of the unfolding process depending solely on the direction of the applied force.

Cyanobacteria in Antarctica: ecology, physiology and cold adaptation

Cyanobacterial species composition of fresh water and terrestrial ecosystems and chemical environment of water in Schirmacher Oasis in Continental Antarctica was investigated. Over 35 species of cyanobacteria were recorded. Diazotrophic species both heterocystous and unicellular contributed more than half to the count except in lake ecosystem. The species composition varied among the fresh water as well as terrestrial ecosystems. The physico-chemical analyses of water revealed its poor nurient content which might have supported the growth of diazotrophic cyanobacteria in an Antarctic environment. Among the cyanobacteria Oscillatoria, Phormidium and Nostoc commune were the dominant flora in most of the habitats. The physiological characteristics of isolated cyanobacteria strains indicated that N2-fixation, nitrate uptake, nitrate-reduction, ammonium-uptake, GS-transferase activity and photosynthesis was unaffected at low temperature (5 degrees C) which indicated low temperature adaptation for Antarctic cyanobacteria. This phenomenon was not evident in different strains of tropical origin. The temperature optima for N2-fixation for the different Antarctic cyanobacterial strains was in the range of 15-25 degrees C, nearly 10 degrees C lower than their respective reference strains of tropical origin. Similar results were obtained for cyanobacteria-moss association. The low endergonic activation energy exhibited by the above metabolic activities supported the view that cyanobacteria were adapted to Antarctic ecosystem.

Role of fibroblast growth factor receptor signaling in prostate cancer cell survival

BACKGROUND

Expression of fibroblast growth factors (FGFs) is increased in a substantial fraction of human prostate cancers in vivo and in prostate cancer cell lines. Altered FGF signaling can potentially have a variety of effects, including stimulating cell proliferation and inhibiting cell death. To determine the biologic significance of altered FGF signaling in human prostate cancer, we disrupted signaling by expression of a dominant-negative (DN) FGF receptor in prostate cancer cell lines.

METHODS

PC-3, LNCaP, and DU145 prostate cancer cells were stably transfected with DN FGFR constructs, and LNCaP and DU145 cells were infected with a recombinant adenovirus expressing DN FGFR-1. The effect of DN FGFR-1 expression was assessed by colony-formation assays, cell proliferation assays, flow cytometry, and cytogenetic analysis. Key regulators involved in the G(2)-to-M cell cycle transition were assessed by western blotting to examine cyclin B1 expression and by in vitro kinase assay to assess cdc2 kinase activity.

RESULTS

Stable transfection of the DN FGFR-1 construct inhibited colony formation by more than 99% in all three cell lines. Infection of LNCaP and DU145 prostate cancer cells with adenovirus expressing DN FGFR-1 led to extensive cell death within 48 hours. Flow cytometry and cytogenetic analysis revealed that the DN FGFR-1 receptor led to arrest in the G(2) phase of the cell cycle before cell death. Cyclin B1 accumulated in DN FGFR-1-infected LNCaP cells, but cdc2 kinase activity was decreased.

CONCLUSIONS

These findings reveal an unexpected dependence of prostate cancer cells on FGF receptor signal transduction to traverse the G(2)/M checkpoint. The mechanism for the G(2) arrest is not clear. Our results raise the possibility that FGF-signaling antagonists might enhance the cell death induced by other prostate cancer therapies.

Interleukin-6 is an autocrine growth factor in human prostate cancer

Prostate cancer is the most common cancer in American men and the second leading cause of cancer deaths in this group. We have found that interleukin (IL)-6 protein concentrations are increased approximately 18-fold in clinically localized prostate cancers when compared to normal prostate tissue. Normal and neoplastic prostatic epithelial cells in culture, with the exception of LNCaP cells, secrete IL-6. Addition of exogenous IL-6 to primary epithelial cells in culture or the LNCaP prostate cancer cell line leads to phosphorylation of Stat-3 and increases in net cell proliferation. The concentration of IL-6 receptor is increased eightfold in the prostate cancer tissues and is increased in the cancer cells by immunohistochemistry. The increased expression of IL-6 receptor is correlated with increased proliferation of prostate cancer cells in vivo as assessed by Ki67 immunohistochemistry. These findings strongly support the hypothesis that IL-6 acts as a significant autocrine growth factor in vivo for primary, androgen-dependent prostate cancers.

Haploinsufficiency of the Pten tumor suppressor gene promotes prostate cancer progression

The PTEN gene encodes a lipid phosphatase that negatively regulates the phosphatidylinositol 3-kinase pathway and is inactivated in a wide variety of malignant neoplasms. High rates of loss of heterozygosity are observed at the 10q23.3 region containing the human PTEN gene in prostate cancer and other human malignancies, but the demonstrated rate of biallelic inactivation of the PTEN gene by mutation or homozygous deletion is significantly lower than the rate of loss of heterozygosity. The transgenic adenocarcinoma of mouse prostate model is a well characterized animal model of prostate cancer. Analysis of prostate cancer progression in transgenic adenocarcinoma of mouse prostate mice bred to Pten(+/-) heterozygous mice, coupled with analysis of the Pten gene and protein in the resulting tumors, reveals that haploinsufficiency of the Pten gene promotes the progression of prostate cancer in this model system. This observation provides a potential explanation for the discordance in rates of loss of heterozygosity at 10q23 and biallelic PTEN inactivation observed in prostate cancer and many human malignancies.

Interleukin-8 is a paracrine inducer of fibroblast growth factor 2, a stromal and epithelial growth factor in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an extremely common disease of older men in which there is benign overgrowth of the prostatic transition zone, leading to obstruction of urine outflow. Fibroblast growth factor (FGF) 2, a potent growth factor for prostatic stromal and epithelial cells, is increased twofold in BPH and its concentration is correlated with stromal proliferation in this condition. Immunohistochemistry of normal and hyperplastic prostate revealed that FGF2-expressing stromal cells were present in higher numbers near the epithelial acini, implying that epithelial cells may express a factor that induces FGF2 expression by stromal cells. Conditioned medium from primary cultures of prostatic epithelial cells was capable of inducing increased expression of FGF2 by primary stromal cultures. Blocking experiments with neutralizing anti-interleukin (IL)-8 antibodies and pretreatment with lipopolysaccharide, which down-regulates the IL-8 receptor, show that this inducing activity is because of the presence of IL-8 in the epithelial-conditioned medium. Analysis of normal prostatic peripheral zone and BPH tissue by enzyme-linked immunosorbent assay reveals that IL-8 is present at increased levels in hyperplastic prostate. Therefore IL-8 produced by prostatic epithelial cells can induce FGF2, a potent stromal and epithelial growth factor, and in this manner promote the abnormal proliferation of the prostatic transition zone that is critical in the pathogenesis of BPH.

Alternative splicing of fibroblast growth factor receptors in human prostate cancer

BACKGROUND

Fibroblast growth factors (FGFs) are known to play an important role in the growth of normal prostatic epithelial cells and may promote proliferation of neoplastic prostatic epithelial cells via autocrine or paracrine mechanisms. The affinity of FGFs for FGF receptors 1-3 is critically dependent on an alternative splicing event involving the coding region for the carboxy terminal portion of the third extracellular immunoglobulin-like domain that leads to two different isoforms of each receptor (IIIb and IIIc). We therefore sought to determine whether changes in alternative splicing of FGF receptors occur in human prostate cancer.

METHODS

RNAs from normal prostate and clinically localized or metastatic prostate cancers were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) followed by digestion of products with restriction enzymes specific for each FGF receptor isoform and quantitation of the relative amounts of each isoform after electrophoresis. For FGFR-2, this was correlated with immunohistochemistry to determine the localization of the protein product.

RESULTS

FGFR-1 is expressed exclusively as the IIIc isoform in prostate cancer while FGFR-3 is expressed predominantly as the IIIb isoform, similar to the expression pattern in normal prostatic epithelial cells. In contrast, there was variable expression of the FGFR-2 IIIb and IIIc isoforms. In the majority of cases the FGFR-2 IIIb isoform was the predominant or exclusive isoform expressed, similar to normal epithelial cells, but in a subset of cases the IIIc isoform was increased, indicating a change in alternative splicing of FGFR-2 in some cases.

CONCLUSIONS

In most cases of prostate cancer there are no changes in alternative splicing of FGF receptors, but in a subgroup there is increased expression of the FGFR-2 IIIc isoform. Given that the affinity of FGFs is highly dependent on the isoform of FGF receptor expressed, this information is critical in understanding the effects of FGFs on prostate cancer cells in vivo.

Synchronous water-clear cell double parathyroid adenomas a hitherto uncharacterized entity?

Water-clear cell hyperplasia is a rare but well-documented cause of primary hyperparathyroidism. Parathyroid adenomas of the water-clear cell type are exceptionally rare, and only 2 cases have been reported. We describe a patient with synchronous water-clear cell double parathyroid adenomas, an entity that has not previously been reported. In our case, the enlarged superior parathyroid glands were completely replaced by water-clear cells, with only a minute rim of extracapsular, histologically unremarkable parathyroid tissue. The inferior parathyroid glands were grossly unremarkable, and incisional biopsy specimens were histologically normal (no foci of water-clear cells were identified). The findings in this case are most consistent with the diagnosis of double adenomas of the water-clear cell type. We acknowledge that despite molecular proof of monoclonality of the 2 lesions, it is not possible to entirely exclude the possibility that this unusual case could be due to asymmetric hyperplasia.

Are microinvasion and micrometastasis in breast cancer mountains or molehills?

BACKGROUND

The increased rate of early detection of breast cancer due to widespread mammographic screening has led to an increased incidence of in situ as well as microinvasive carcinoma. The enhanced pathological examination to which sentinel lymph nodes are subjected has led to an increased rate of detection of micrometastatic carcinoma. Despite the augmented rate of diagnoses of both diseases, the pathological diagnoses as well as clinical management of these entities continue to be controversial.

DATA SOURCES

A computerized literature search was performed on the Medline and PubMed database from 1990 to date. Relevant earlier publications were also perused. The database of the Department of Pathology at New York Presbyterian Hospital-Well Medical College of Cornell University were also accessed.

CONCLUSIONS

Based on cumulative data, patients diagnosed with either microinvasive or micrometastatic carcinoma of breast have a relatively favorable, albeit guarded, prognosis. Treatment recommendations for both of these disease entities continue to be controversial, and may remain so until additional refined clinicopathological data becomes available.

FGF-10 is expressed at low levels in the human prostate

BACKGROUND

Fibroblast growth factors (FGFs) are known to play an important role in the growth of normal prostatic epithelial cells. FGF-10 is a secreted growth factor that binds to FGF receptor-2 IIIb, which is expressed in prostatic epithelial cells and thus can potentially act as a growth factor for these cells. Prior work has indicated that FGF10 may play an important role in the development of the rat prostate, but its role in the adult human prostate is unclear.

METHODS

Expression of FGF10 in human prostate tissue and primary cultures of prostatic epithelial and stromal cells was assessed by reverse-transcriptase PCR (RT-PCR) and Northern blotting. Growth response to FGF10 was assessed by the addition of recombinant FGF-10 to primary cultures of prostatic epithelial and stromal cells.

RESULTS

FGF10 is expressed at levels detectable by RT-PCR and can act as a growth factor for prostatic epithelial cells, but is not active as a growth factor for stromal cells. However, FGF10 is expressed at extremely low levels relative to FGF7, which has a similar biological activity.

CONCLUSIONS

While FGF10 may play a role in prostatic development, it is unlikely to play a major role in prostate growth in normal or hyperplastic adult human prostate, due to its extremely low expression compared to FGF7.

Increased expression of fibroblast growth factor 6 in human prostatic intraepithelial neoplasia and prostate cancer

Fibroblast growth factors (FGFs) are known to play an important role in the growth of normal prostatic epithelial cells. In addition to their effects on proliferation, FGFs can promote cell motility, increase tumor angiogenesis, and inhibit apoptosis, all of which play an important role in tumor progression. To determine whether FGFs are overexpressed in human prostate cancers, we analyzed 26 prostate cancer RNAs by reverse transcription-PCR for expression of FGF3, FGF4, and FGF6, which cannot be detected in normal prostate tissue by this technique. Fourteen of 26 prostate cancers expressed FGF6 mRNA. No expression of FGF3 or FGF4 was detected. An ELISA of tissue extracts of normal prostate, high-grade prostatic intraepithelial neoplasia (PIN), and prostate cancer for FGF6 showed that this growth factor was undetectable in normal prostate but was present at elevated levels in 4 of 9 PIN lesions and in 15 of 24 prostate cancers. Immunohistochemical analysis with anti-FGF6 antibody revealed weak staining of prostatic basal cells in normal prostate that was markedly elevated in PIN. In the prostate cancers, the majority of cases revealed expression of FGF6 by the prostate cancer cells themselves. In two cases, expression was present in prostatic stromal cells. Exogenous FGF6 was able to stimulate proliferation of primary prostatic epithelial and stromal cells, immortalized prostatic epithelial cells, and prostate cancer cell lines in tissue culture. FGF receptor 4, which is the most potent FGF receptor for FGF6, is expressed in the human prostate in vivo and in all of the cultured cell lines. Thus, FGF6 is increased in PIN and prostate cancer and can promote the proliferation of the transformed prostatic epithelial cells via paracrine and autocrine mechanisms.

Interleukin-1alpha is a paracrine inducer of FGF7, a key epithelial growth factor in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is an extremely common disease of older men in which there is benign overgrowth of the prostatic transition zone, leading to obstruction of urine outflow. FGF7, a potent growth factor for prostatic epithelial cells, is increased by threefold in BPH and is correlated with increased epithelial proliferation in this condition. Immunohistochemistry of normal and hyperplastic prostate revealed that FGF7-expressing fibroblastic cells were present in higher numbers near the epithelial acini, implying that epithelial cells may express a factor that induces FGF7 expression by stromal cells. Conditioned medium (CM) from primary cultures of prostatic epithelial cells was capable of inducing a two- to sixfold increase in the expression of FGF7 by primary stromal cultures. Blocking experiments with neutralizing anti-interleukin-1alpha (Il-1alpha) antibodies and IL-1Ra, an Il-1alpha receptor antagonist, show that this inducing activity was due to the presence of Il-1alpha in the epithelial CM. Analysis of normal prostatic peripheral zone and BPH tissue by enzyme-linked immunoabsorption assay reveal that Il-1alpha is present at increased levels in hyperplastic prostate and that levels of Il-1alpha correlate strongly with tissue FGF7 concentration in BPH. Therefore Il-1alpha is produced by prostatic epithelial cells and can induce FGF7, a potent epithelial growth factor, which can in turn lead to further epithelial growth and increased Il-1alpha secretion, thus establishing a double paracrine loop that is functionally equivalent to an autocrine growth loop. This double paracrine loop may play a key role in the abnormal proliferation of the transition zone, which is critical to the pathogenesis of BPH.

Cytologic diagnosis of metastatic basal cell carcinoma. Report of a case with immunocytochemical and molecular pathologic considerations

BACKGROUND

Metastases of basal cell carcinoma (BCC) are extraordinarily rare events, with only about 200 published reports. The usefulness of immunohistochemical markers in the diagnosis of metastatic BCC was previously established on cytologic material. Furthermore, in recent years, numerous molecular markers have been studied to explain its pathogenesis and relatively indolent behavior.

CASE REPORT

A 62-year-old, white male presented with lymphadenopathy in the right side of the neck. The patient had a long-standing history of multiple excisions of BCCs during the previous 30 years. Fine needle aspiration biopsy revealed tight clusters and sheets of small, round tumor cells with hyperchromatic nuclei, small nucleoli and minimal cytoplasm. In addition, in some of the clusters the tumor cells showed peripheral palisading. Based on the cytomorphology and diffuse immunohistochemical positivity for a low-molecular-weight cytokeratin marker, MNF 116, and negativity for AE1/AE3, Cam5.2, synaptophysin and chromogranin, a diagnosis of metastatic BCC was rendered. Subsequent histopathologic examination of metastatically involved lymph nodes removed in a radical neck dissection confirmed this diagnosis. In addition, on histologic sections the metastatic tumor cells were found to express bcl-2 and CD44, markers that have been recently studied in cutaneous tumors.

CONCLUSION

In acquiring metastatic potential, this lesion did not lose the molecular characteristics of bcl-2 and CD44 expression, the two features deemed to be important in the indolent behavior of BCC.

Microinvasive carcinoma (T1mic) of the breast: clinicopathologic profile of 21 cases

Clinicopathologic data on microinvasive carcinoma of the breast (MICB) as defined by the 1997 TNM criteria (T1mic < or = 1 mm) is scarce. Histologic slides of 109 cases from 1993 through 1997, in which microinvasion was either suspected or diagnosed initially, were reviewed. A double immunoenzyme-labeling technique using antismooth muscle actin and anticytokeratin antibody on the same section was used to confirm invasion in equivocal cases. All foci of invasion were measured by ocular micrometer. Twenty-one cases were confirmed to be MICB. The mean age of the patients was 60.9 years. Thirteen patients presented with mammographic abnormalities on routine examination (60.9%). MICB was ductal in 18 patients, including one tubular carcinoma, and was lobular in three patients. The mean number of invasive foci was two per patient (range, one to seven foci). The accompanying duct carcinoma in situ had high-grade nuclei and necrosis in 16 of 18 patients (89%), 13 of which (72%) were comedo-type. Two of the 15 patients had one positive axillary lymph node each (13.3%). Eleven patients underwent mastectomy, nine received radiation therapy, one received chemotherapy, and two underwent lumpectomy only. Median follow up was 28 months (range. 18-63 months). One patient had a chest wall recurrence of infiltrating duct carcinoma and another recurred with duct carcinoma in situ.

Microinvasive carcinoma of the breast: can it be diagnosed reliably and is it clinically significant?

Deciding whether in-situ breast carcinoma is associated with microinvasion is a common problem. Histological features resembling invasion can be simulated by in-situ carcinoma distorted by inflammatory and reparative changes. Having expended the effort to diagnose genuine microinvasion, just how useful is this diagnosis in planning further treatment and follow-up? In the following articles, Hoda et al. comment on the utility of immunohistochemistry in resolving uncertainty about the presence of microinvasion, and Ellis et al. critically appraise the definition of microinvasion and its clinical significance.

FGF7 and FGF2 are increased in benign prostatic hyperplasia and are associated with increased proliferation

PURPOSE

To determine if overexpression of FGF7 and FGF2 occurs in benign prostatic hyperplasia (BPH) and if so, whether such overexpression is correlated with increased proliferation of epithelial and/or stromal cells.

MATERIALS AND METHODS

The FGF7 and FGF2 content of protein extracts of normal peripheral zone, normal transition zone and hyperplastic prostatic tissues were determined by enzyme-linked immunoabsorption assay. Proliferation of epithelial and stromal cells was assessed by immunohistochemistry with anti-Ki67 antibodies on frozen sections of the same tissues used for protein extraction. The in vitro effects of FGF7 and FGF2 on proliferation were assessed by addition of recombinant growth factor to primary cultures of prostatic epithelial and stromal cells.

RESULTS

We have found that both FGF7 and FGF2 are overexpressed in hyperplastic prostate in comparison to normal peripheral and transition zone tissue. FGF7 is a potent mitogen for epithelial cells in culture. Consistent with these in vitro effects, quantitative analysis of cellular proliferation by Ki67 immunohistochemistry revealed a strong correlation of epithelial proliferation with FGF7 content in BPH tissue, consistent with a key role for this growth factor in driving the abnormal epithelial proliferation in BPH. FGF2 is mitogenic for stromal cells in culture and there was a weaker correlation of FGF2 content with increased stromal proliferation.

CONCLUSION

Overexpression of FGF7 and FGF2 may play an important role in the abnormal cellular proliferation seen in benign prostatic hyperplasia.

FGF9 is an autocrine and paracrine prostatic growth factor expressed by prostatic stromal cells

Polypeptide growth factors, including members of the fibroblast growth factor (FGF) family, play an important role in the growth and maintenance of the normal prostate. We have found that FGF9 is expressed at high levels in the normal peripheral and transition zone of the human prostate. Analysis of FGF9 production by primary cultures of prostatic epithelial and stromal cells has shown that FGF9 is produced and secreted by the prostatic stromal cells. Neither of these processes appears to be modulated by androgens. Production of FGF9 by stromal cells in vivo was confirmed by immunohistochemistry. FGF9 is a potent mitogen for both prostatic epithelial and stromal cells in culture and is a more potent mitogen for these cells than either FGF2 or FGF7, two other FGFs expressed in the human prostate. FGF9 is an abundant secreted growth factor that can act as both a paracrine mitogen for epithelial cells and an autocrine mitogen for stromal cells. Western blot analysis of tissue extracts from the normal and hyperplastic transition zone shows that FGF9 is present at two to threefold higher levels in the hyperplastic transition zone. Overexpression of this paracrine and autocrine growth factor may play an important role in the epithelial and stromal proliferation in benign prostatic hyperplasia.

Alterations in expression of basic fibroblast growth factor (FGF) 2 and its receptor FGFR-1 in human prostate cancer

Fibroblast growth factors (FGFs) play an important role in the growth and maintenance of the normal prostate. There is increasing evidence from both animal models and analysis of human prostate cancer cell lines that alterations of FGFs and/or FGF receptors (FGFRs) may play an important role in prostate cancer progression. To better define the role of FGF2 and FGF7 in human prostate cancer in vivo, we have quantified these two growth factors in clinically localized human prostate cancers and uninvolved prostate by ELISA and Western blotting and determined their localization by immunohistochemistry. The expression of two of the primary receptors for these growth factors, FGFR-1 and FGFR-2, were also analyzed by immunohistochemistry and Western blotting in these same samples. We have found that FGF2 is significantly increased in prostate cancers when compared with uninvolved prostate and that the FGF2 is present in the stromal fibroblasts and endothelial cells but not the cancer cells. In addition, we have observed overexpression of both FGFR-1 and FGFR-2 in the prostate cancer epithelial cells in a subset of prostate cancers and that such overexpression is correlated with poor differentiation. Thus, there is both an increase in FGF2 concentration in prostate cancers and an increased expression of a receptor capable of responding to this growth factor, establishing a potential paracrine stimulation of prostate cancer cells by the surrounding stromal cells, which may play an important role in prostate cancer progression.

Inactivation of the PTEN tumor suppressor gene is associated with increased angiogenesis in clinically localized prostate carcinoma

The PTEN tumor suppressor gene encodes a dual-specificity protein phosphatase that may play a key role in modulating integrin-mediated signals. Inactivation of the PTEN gene has been detected in a small percentage of clinically localized prostate cancers but is common in metastatic disease. It has been shown in glioblastoma cell lines that loss of chromosome 10q, where the PTEN gene is located, is associated with increased angiogenic activity in the conditioned medium attributable to downregulation of thrombospondin-1, a negative regulator of angiogenesis. Therefore, we wished to determine whether inactivation of PTEN might be associated with increased angiogenesis in prostate cancers, because increased angiogenesis in localized cancers is associated with development of metastatic disease. Angiogenesis was assessed by counting microvessels in areas of maximal neovascularization after immunostaining with anti-factor VIII-related antigen antibodies in eight cases with proven homozygous deletion of the PTEN gene and 24 control cases. There was a statistically significant correlation between PTEN inactivation and increased microvessel counts. The microvessel density was higher at all Gleason scores in the cases with PTEN inactivation compared with control cases with the same score. To determine whether the increased angiogenesis in cases with PTEN inactivation was caused by downregulation of expression of the angiogenesis inhibitor thrombospondin-1, we analyzed a subset of the cases by immunostaining with anti-thrombospondin-1 antibody. Approximately 25% of cases showed decreased staining of prostate cancer cells, but there was no correlation with PTEN inactivation. Thus, PTEN inactivation is associated with increased angiogenesis, but the increased angiogenesis is not attributable to downregulation of thrombospondin-1 expression.

Double immunolabeling with cytokeratin and smooth-muscle actin in confirming early invasive carcinoma of breast

Histopathological identification of invasive breast carcinoma in its earliest phases is fraught with pitfalls. Preinvasive malignant lesions complicated by radial scar, sclerosing adenosis, and lobular cancerization, among other lesions, may simulate invasive carcinoma. Fibrosis, inflammatory reaction, and other stromal changes around in situ carcinoma may mask microinvasive foci on routine stains. Conventional immunohistochemistry to demonstrate basement membrane or myoepithelial cell layer may not, by itself, be unequivocally diagnostic of invasion. We performed a novel double immunoenzyme labeling technique using an avidin-biotin complex peroxidase-diaminobenzidine system for smooth-muscle actin followed by an alkaline phosphatase anti-alkaline phosphatase-new fuchsin system for cytokeratin antigen on formalin-fixed, paraffin-embedded histology sections to evaluate 32 such problematic cases. The initial histologic impression with hematoxylin and eosin staining alone was as follows-first group: microinvasive carcinoma-10; second group: carcinoma in situ--"stromal invasion cannot be ruled out"--15; third group: frankly infiltrating carcinoma of various grades and morphologic types-6. The last group served as positive control for invasion. One fibroadenoma with fine-needle-aspiration-induced artifact simulating stromal invasion was also included. The double immunoenzyme labeling technique imparted a dark brown color to the myoepithelial cells and a vivid red color to the epithelial cells, making individual or loosely cohesive groups of malignant epithelial cells infiltrating the stroma easily detectable, whereas their in situ counterparts were contained within dark brown myoepithelial boundaries. The TNM 1997 definition of pT1mic, i.e., extension of malignant cells in the stroma with no focus measuring >0.1 cm, was followed to classify microinvasion. In the first group, microinvasion was confirmed in six cases but was not demonstrable in four. In the second group, definite invasion was identified in five cases, ruled out in nine, and in one case the suspicion of early invasion could not be entirely ruled out even after double immunoenzyme labeling. Thus, it was possible to render a definite opinion regarding presence or absence of invasion in 24 of 25 (96%) cases diagnosed as or suspected to be microinvasive. The precise and simultaneous elucidation of topography between malignant cells and myoepithelial cells on a single permanent section makes this technique a useful diagnostic tool in the evaluation of those cases of breast carcinoma that exhibit equivocal invasion.