Faculty Bibliography

INTRODUCTION: Inflammatory breast cancer (IBC) is an aggressive and rare cancer with a poor prognosis and a need for novel targeted therapeutic strategies. Preclinical IBC data showed strong activation of the phosphatidylinositide-3-kinase/mammalian target of rapamycin (mTOR) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathways, and expression of inflammatory cytokines and tumor-associated macrophages (TAMs). PATIENTS AND METHODS: Archival tumor tissue from 3 disease types (IBC treated with neoadjuvant chemotherapy [NAC], n = 45; invasive ductal carcinoma [IDC] treated with NAC [n = 24; 'treated IDC'; and untreated IDC [n = 27; 'untreated IDC']) was analyzed for the expression of biomarkers phospho-S6 (pS6) (mTOR), phospho-JAK2 (pJAK2), pSTAT3, interleukin (IL)-6, CD68 (monocytes, macrophages), and CD163 (TAMs). Surrounding nontumor tissue was also analyzed. RESULTS: Biomarker levels and surrogate activity according to site-specific phosphorylation were shown in the tumor tissue of all 3 disease types but were greatest in IBC and treated IDC and least in untreated IDC for pS6, pJAK2, pSTAT3, and IL-6. Of 37 IBC patients with complete biomarker data available, 100% were pS6-positive and 95% were pJAK2-positive. In nontumor tissue, biomarker levels were observed in all groups but were generally greatest in untreated IDC and least in IBC, except for JAK2. CONCLUSION: IBC and treated IDC display similar levels of mTOR and JAK2 biomarker activation, which suggests a potential mechanism of resistance after NAC. Biomarker levels in surrounding nontumor tissue suggested that the stroma might be activated by chemotherapy and resembles the oncogenic tumor-promoting environment. Activation of pS6 and pJAK2 in IBC might support dual targeting of the mTOR and JAK/STAT pathways, and the need for prospective studies to investigate combined targeted therapies in IBC.

Use of nipple-sparing mastectomy (NSM) for risk-reduction and therapeutic breast cancer resection is growing. The role for intraoperative frozen section of the nipple-areolar complex remains controversial. Records of patients undergoing NSM at our institution from 2006 to 2013 were reviewed. Records from 501 nipple-sparing mastectomies were reviewed (216 therapeutic, 285 prophylactic). Of the 480 breasts with sub-areolar biopsies, 307 had intraoperative frozen sections and 173 were evaluated with permanent paraffin section only. Among the 307 intraoperative frozen sections, 12 biopsies were positive on permanent paraffin section (3.9% or 12/307). Of the 12 positive permanent biopsies, five were false negative and the remaining seven concordant intraoperatively. Sensitivity and specificity of sub-areolar frozen section were 0.58 and 1, respectively. Positive sub-areolar biopsies consisted primarily of ductal carcinoma in situ (62% or 13/21). The nipples or nipple-areolar complex were resected in a separate procedure following mastectomy (10/21), intraoperatively following frozen section results (7/21) or during second-stage breast reconstruction (3/21; 1 additional scheduled). Only 30% (6/20) of resected specimens had abnormal residual pathology. Intraoperative frozen section is highly specific and moderately sensitive for the detection of positive sub-areolar biopsies in NSM. Its use can help guide intraoperative reconstructive planning. The presence of positive sub-areolar biopsies in both contralateral and high-risk prophylactic mastectomy specimens emphasizes the need to perform sub-areolar biopsies in all nipple-sparing mastectomies.

Background: Data from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) indicates that common variation in the BRCA1 locus modifies the penetrance of mutations. The rs5820483 variation is one such polymorphism in which patients homozygous for the major allele have a greater risk of breast cancer. The BRCA1 gene contains 24 exons that generate a full-length (FL) protein. Major alternatively spliced isoforms include skipping of exon 11 (DELTA11) and a truncated form (IRIS), each of which appear to have distinct roles in cellular processes. rs5820483 is the only variant that maps to intron 10, flanking exon 11. Experimental models suggest that deregulation of the FL/D11 isoform ratio can have profound functional consequences. We have shown that cells from patients with the major rs5820483 allele express more FL relative to DELTA11 compared to cells from patients with the minor allele. Breast cancer exhibit increased IGF-1 and IGF-1 activity in patients with BRCA1 mutations relative to breast cancer in women without BRCA1 mutations. IGF-1 produced in the mammary stroma mediates estrogen dependent proliferation. Here we test whether the rs5820483 allele affects IGF-1 activity in breast tissue of BRCA1 mutation carriers. Design: We assessed the zygosity of the rs5820483 alleles in 28 BRCA1 mutation carriers. Phosphorylated IGF-1 receptor (p-IGF-1R rabbit polyclonal Ab39398, Abcam, MA) was measured by immunofluorescence and Ki-67 was measured by immunohistochemistry in sections from histologically normal breast tissue from these cases were compared to heterozygous controls. Image analysis was used to assess the intensity of the p-IGF-1R immunofluorescence at the epithelial cell membrane with appropriate controls. Ki67 mmunohistochemistry was also performed on these specimens. Results:The rs5820483 allele was heterozygous in 10 specimens, homozygous for the major allele in 11 and homozygous for the minor allele in 7. The intensity of p-IGF-1R was higher in major homozygous cases (140+/-54 SD) than in either the minor homozygous (99+/-24) or heterozygous cases (95+/-44). The frequency of Ki-67+ cells was higher in the major homozygous case (3.1+/-2.9 SD) than in either the minor homozygous (1.5+/-1.9 SD) or heterozygous cases (2.2+/-2.5 SD). However, neither p-IGF-IR immunoreactivity nor frequency of Ki-67+ cells was statistically different between groups. Conclusion: Breast cancer risk in BRCA1 mutation carriers is modified by common genetic variation at the corresponding locus. We have identified a variation at rs5820483 that affects the isoform ratio. Our preliminary analysis suggests that IGF-1 activity increases in those women homozygous for the major allele, concomitant with increased Ki-67. Corroboration of this analysis in a larger series is ongoing. A statistically significant difference might have fundamental implications for cancer prevention in those carriers

Treatment protocols for breast cancer depend predominantly on receptor status with respect to estrogen (estrogen receptor alpha), progesterone (progesterone receptor) and human epidermal growth factor [human epidermal growth factor receptor 2 (HER2)]. The presence of one or more of these receptors suggests that a treatment targeting these pathways might be effective, while the absence of, or in the case of HER2, lack of overexpression of, all of these receptors, termed triple negative breast cancer (TNBC), indicates a need for the more toxic chemotherapy. In an effort to develop targeted therapies for TNBC, it will be necessary to differentiate among specific TNBC subtypes. The subset of TNBC that expresses androgen receptor (AR) has been determined to express genes consistent with a luminal subtype and therefore may be amenable to therapies targeting either AR, itself, or other pathways typical of a luminal subtype. Recent investigations of the AR signal pathway within breast cancer lead to AR as a significant target for breast cancer therapy with several clinical trials currently in progress. The subclass of TNBC that lacks AR, which we have termed quadruple negative breast cancer (QNBC) currently lacks a defined targetable pathway. Unlike AR-positive TNBC, QNBC predominantly exhibits a basal-like molecular subtype. Several subtypes and related pathway proteins are preferentially expressed in QNBC that may serve as effective targets for treatment, such as ACSL4, SKP2 and EGFR. ACSL4 expression has been demonstrated to be inversely correlated with expression of hormone/growth factor receptors and may thus serve as a biomarker for QNBC as well as a target for therapy. In the following review we summarize some of the current efforts to develop alternatives to chemotherapy for TNBC and QNBC.

PAM50 intrinsic breast cancer subtypes are prognostic independent of standard clinicopathologic factors. CALGB 9741 demonstrated improved recurrence-free (RFS) and overall survival (OS) with 2-weekly dose-dense (DD) versus 3-weekly therapy. A significant interaction between intrinsic subtypes and DD-therapy benefit was hypothesized. Suitable tumor samples were available from 1,471 (73%) of 2,005 subjects. Multiplexed gene-expression profiling generated the PAM50 subtype call, proliferation score, and risk of recurrence score (ROR-PT) for the evaluable subset of 1,311 treated patients. The interaction between DD-therapy benefit and intrinsic subtype was tested in a Cox proportional hazards model using two-sided alpha = 0.05. Additional multivariable Cox models evaluated the proliferation and ROR-PT scores as continuous measures with selected clinical covariates. Improved outcomes for DD therapy in the evaluable subset mirrored results from the complete data set (RFS; hazard ratio = 1.20; 95% confidence interval = 0.99-1.44) with 12.3-year median follow-up. Intrinsic subtypes were prognostic of RFS (P < 0.0001) irrespective of treatment assignment. No subtype-specific treatment effect on RFS was identified (interaction P = 0.44). Proliferation and ROR-PT scores were prognostic for RFS (both P < 0.0001), but no association with treatment benefit was seen (P = 0.14 and 0.59, respectively). Results were similar for OS. The prognostic value of PAM50 intrinsic subtype was greater than estrogen receptor/HER2 immunohistochemistry classification. PAM50 gene signatures were highly prognostic but did not predict for improved outcomes with DD anthracycline- and taxane-based therapy. Clinical validation studies will assess the ability of PAM50 and other gene signatures to stratify patients and individualize treatment based on expected risks of distant recurrence.

Background: Adding either Cb or Bev to standard NACT significantly increases pCR rates in TNBC (Sikov et al, SABCS 2013). Genomic analysis may help us to identify determinants of response within this clinical phenotype. Methods: Patients (pts) with clinical stage II-III TNBC received weekly paclitaxel x 12 followed by ddAC x 4 +/- Cb and/or Bev. Pre-treatment biopsies were collected in formalin, RNAlater and OCT; residual disease at surgery was biopsied when possible. Illumina mRNA sequencing (RNAseq) was performed. Gene expression values were normalized to a TCGA subset of clinically TNBC samples prior to downstream analysis. pCR was defined as the absence of residual invasive cancer in the breast (ypT0/is). For each molecular signature, prognostic (effect on pCR in the overall study population) and predictive (effect of the addition of Cb or Bev, separately, on pCR) relationships were explored with logistic regression models. Results: PAM50 subtype analysis was performed on 367 pre-treatment samples (of 443 pts who started NACT); pCR results were available for 360, comprising the analysis subset. 87% of these displayed a basal-like gene expression pattern, 2% claudin-low, 4% HER2-enriched, <1% luminal A and 7% normal-like. In pts with basal-like tumors, pCRs rose from 47% to 61% with the addition of Cb (p=0.014), an increment which did not differ significantly from the overall study population (adding in the small number of non-basal-like tumors) (interaction p=0.93). In contrast, the addition of Bev increased pCRs in basal-like tumors from 45% to 64% (p=0.0009), while reducing pCRs in non-basal-likes from 60% to 43% (interaction p=0.024); thus, a basal-like gene expression pattern was predictive of benefit from Bev. Expression of a variety of immune signatures (B cell, T cell, IgG) was positively associated with pCR, but not predictive of increased benefit from either Cb or Bev. High expression of the HER2 amplicon signature was uncommon and not prognostic for pCR overall but was associated with reduced benefit from Cb (interaction p = 0.025). High proliferation, high p53 mutation and low IE (estrogen signaling) signatures were prognostic for higher pCR rates and predictive of benefit from Bev (interaction p=0.031, 0.0017, 0.0002, respectively). In basal-like pts with residual disease, surgical samples often (52%) displayed a normal-like PAM50 pattern, though this might be due to 'contamination' in low volume residual disease. Conclusions: Selection criteria led to accrual of a high % of pts with basal-like tumors, limiting our ability to assess prognostic or predictive impact of intrinsic subtype on pCR. Given that limitation, the magnitude of pCR benefit with Cb was consistent across subtypes, while a basal-like pattern was predictive of greater pCR increment with Bev. Ongoing studies will test a large number of other gene signatures and biomarkers, including the Lehmann et al subtypes. Recognition of clinically relevant subpopulations within TNBC may distinguish pts likely to achieve a pCR from those for whom an investigational approach might be considered

PURPOSE: One third of patients with triple-negative breast cancer (TNBC) achieve pathologic complete response (pCR) with standard neoadjuvant chemotherapy (NACT). CALGB 40603 (Alliance), a 2 x 2 factorial, open-label, randomized phase II trial, evaluated the impact of adding carboplatin and/or bevacizumab. PATIENTS AND METHODS: Patients (N = 443) with stage II to III TNBC received paclitaxel 80 mg/m(2) once per week (wP) for 12 weeks, followed by doxorubicin plus cyclophosphamide once every 2 weeks (ddAC) for four cycles, and were randomly assigned to concurrent carboplatin (area under curve 6) once every 3 weeks for four cycles and/or bevacizumab 10 mg/kg once every 2 weeks for nine cycles. Effects of adding these agents on pCR breast (ypT0/is), pCR breast/axilla (ypT0/isN0), treatment delivery, and toxicities were analyzed. RESULTS: Patients assigned to either carboplatin or bevacizumab were less likely to complete wP and ddAC without skipped doses, dose modification, or early discontinuation resulting from toxicity. Grade >/= 3 neutropenia and thrombocytopenia were more common with carboplatin, as were hypertension, infection, thromboembolic events, bleeding, and postoperative complications with bevacizumab. Employing one-sided P values, addition of either carboplatin (60% v 44%; P = .0018) or bevacizumab (59% v 48%; P = .0089) significantly increased pCR breast, whereas only carboplatin (54% v 41%; P = .0029) significantly raised pCR breast/axilla. More-than-additive interactions between the two agents could not be demonstrated. CONCLUSION: In stage II to III TNBC, addition of either carboplatin or bevacizumab to NACT increased pCR rates, but whether this will improve relapse-free or overall survival is unknown. Given results from recently reported adjuvant trials, further investigation of bevacizumab in this setting is unlikely, but the role of carboplatin could be evaluated in definitive studies, ideally limited to biologically defined patient subsets most likely to benefit from this agent.

IntroductionEstrogen inhibition is effective in preventing breast cancer in only up to 50% of women with precancerous lesions and many experience side effects that are poorly tolerated. As insulin-like growth factor I (IGF-I) underlies both estrogen and progesterone actions and has other direct effects on mammary development and carcinogenesis, we hypothesized that IGF-I inhibition might provide a novel approach for breast cancer chemoprevention.MethodsIn total, 13 women with core breast biopsies diagnostic of atypical hyperplasia (AH) were treated for 10 days with pasireotide, a somatostatin analog which uniquely inhibits IGF-I action in the mammary gland. They then had excision biopsies. 12 patients also had proliferative lesions and one a ductal carcinoma in situ (DCIS). Primary outcomes were changes in cell proliferation and apoptosis after treatment. Expression of estrogen receptor (ER), progesterone receptor (PR), and phosphorylated Insulin-like growth factor I receptor (IGF-1R), protein kinase B (AKT) and extracellular signal-regulated kinases 1/2 (ERK1/2) were also assessed. Core and excision biopsies from 14 untreated patients served as non-blinded controls. Hyperglycemia and other side effects were carefully monitored.ResultsPasireotide decreased proliferation and increased apoptosis in all AH (from 3.6 inverted question mark+/- inverted question mark2.6% to 1.3 inverted question mark+/- inverted question mark1.2% and from 0.3 inverted question mark+/- inverted question mark0.2% to 1.5 inverted question mark+/- inverted question mark1.6%, respectively) and proliferative lesions (from 3.8 inverted question mark+/- inverted question mark2.5% to 1.8 inverted question mark+/- inverted question mark1.8% and from 0.3 inverted question mark+/- inverted question mark0.2% to 1.3 inverted question mark+/- inverted question mark0.6%, respectively). The DCIS responded similarly. ER and PR were not affected by pasireotide, while IGF-1R, ERK1/2 and AKT phosphorylation decreased significantly. In contrast, tissue from untreated controls showed no change in cell proliferation or phosphorylation of IGF-1R, AKT or ERK 1/2. Mild to moderate hyperglycemia associated with reduced insulin levels was found. Glucose fell into the normal range after discontinuing treatment. Pasireotide was well tolerated and did not cause symptoms of estrogen deprivation.ConclusionsIGF-I inhibition by pasireotide, acting through the IGF-1R, was associated with decreased proliferation and increased apoptosis in pre-malignant breast lesions and one DCIS. Assuming hyperglycemia can be controlled, these data suggest that inhibiting the IGF-I pathway may prove an effective alternative for breast cancer chemoprevention.Trial registration NCT01372644 Trial date: July 1, 2007.