Comparison of three scoring methods using the FDA-approved 22C3 immunohistochemistry assay to evaluate PD-L1 expression in breast cancer and their association with clinicopathologic factors

BACKGROUND

In the evaluation of PD-L1 expression to select patients for anti-PD-1/PD-L1 treatment, uniform guidelines that account for different immunohistochemistry assays, different cell types and different cutoff values across tumor types are lacking. Data on how different scoring methods compare in breast cancer are scant.

METHODS

Using FDA-approved 22C3 diagnostic immunohistochemistry assay, we retrospectively evaluated PD-L1 expression in 496 primary invasive breast tumors that were not exposed to anti-PD-1/PD-L1 treatment and compared three scoring methods (TC: invasive tumor cells; IC: tumor-infiltrating immune cells; TCIC: a combination of tumor cells and immune cells) in expression frequency and association with clinicopathologic factors.

RESULTS

In the entire cohort, positive PD-L1 expression was observed in 20% of patients by TCIC, 16% by IC, and 10% by TC, with a concordance of 87% between the three methods. In the triple-negative breast cancer patients, positive PD-L1 expression was observed in 35% by TCIC, 31% by IC, and 16% by TC, with a concordance of 76%. Associations between PD-L1 and clinicopathologic factors were investigated according to receptor groups and whether the patients had received neoadjuvant chemotherapy. The three scoring methods showed differences in their associations with clinicopathologic factors in all subgroups studied. Positive PD-L1 expression by IC was significantly associated with worse overall survival in patients with neoadjuvant chemotherapy and showed a trend for worse overall survival and distant metastasis-free survival in triple-negative patients with neoadjuvant chemotherapy. Positive PD-L1 expression by TCIC and TC also showed trends for worse survival in different subgroups.

CONCLUSIONS

Our findings indicate that the three scoring methods with a 1% cutoff are different in their sensitivity for PD-L1 expression and their associations with clinicopathologic factors. Scoring by TCIC is the most sensitive way to identify PD-L1-positive breast cancer by immunohistochemistry. As a prognostic marker, our study suggests that PD-L1 is associated with worse clinical outcome, most often shown by the IC score; however, the other scores may also have clinical implications in some subgroups. Large clinical trials are needed to test the similarities and differences of these scoring methods for their predictive values in anti-PD-1/PD-L1 therapy.

Abstract 4626: A TRIM24-like mutational signature predicts worse relapse-free survival (RFS) and overall survival (OS) in patients (pts) with metaplastic breast cancer (MpBC)

Background: TRIM24 is a multifunctional, epigenetic PHD/Bromodomain protein that negatively regulates p53, via an E3-ubiquitin ligase RING domain, and co-regulates transcription. Over-expression of TRIM24 in murine mammary epithelium results in the development of carcinosarcomas that bear close histologic resemblance to human MpBCs and are characterized by a distinct genomic signature. Here, we investigate the association between the presence of a TRIM24-like mutational signature and clinical outcomes in a cohort of human MpBCs.

Methods: 20 archived samples of human MpBC with annotated clinical data underwent whole exome sequencing. In parallel, we sequenced 7 spontaneously arising carcinosarcomas from a TRIM24 overexpressing mouse model. To compare the mutations with those seen in the human MpBCs, we grouped them into pathways and created a signature of pathway activation seen in TRIM24-driven tumors. Median RFS and OS were estimated using the Kaplan-Meier method and compared between pts with and without a TRIM24-like mutational signature.

Results: Baseline clinical characteristics are summarized in Table 1. Of the 20 MpBC pts, 5 had a TRIM24-like mutational signature and the remaining 15 pts did not. There were no statistically significant differences in baseline characteristics between the 2 groups. Median RFS for pts with a TRIM24-like mutational signature was 9 months (95% confidence interval [CI]: 8-undefined months). Median RFS for pts without a TRIM24-like mutational signature has not been reached (log-rank, p=0.0149). Median OS for pts with and without a TRIM24-like mutational signature was 17 months (95% CI: 10-undefined months) and 147 months (95% CI: 22-undefined months), respectively (log-rank, p=0.0402).

Conclusion: In this cohort, pts with MpBCs that exhibit a TRIM24-like mutational signature had worse RFS and OS. This finding should be confirmed in larger, prospective studies.

Table 1: Baseline Clinicopathological Characteristics by TRIM24 StatusTRIM24-like (n=5)Non TRIM24-like (n=15)p valueAge at diagnosis - Median (years, interquartile range)55 (50-61)56 (47-66)0.965Clinical Tumor SizeMean (cm, standard deviation)4.2 (1.5)3.4 (1.6)0.383Clinical Nodal StatusNegative - n (%)3 (60)11 (73)0.570Positive - n (%)2 (40)3 (20)Unknown - n (%)01 (7)ER/PR StatusNegative - n (%)5 (100)14 (93)1.000Positive - n (%)01 (7)HER2 StatusNegative - n (%)5 (100)15 (100)NAPositive - n (%)00HistologySpindle Cell - n (%)4 (80)7 (47)0.319Matrix-producing - n (%)1 (20)8 (53)

Citation Format: Clinton Yam, Aundrietta Duncan, Jeffrey T. Chang, Michael Z. Gilcrease, Vrutant V. Shah, Michelle Barton, Stacy L. Moulder. A TRIM24-like mutational signature predicts worse relapse-free survival (RFS) and overall survival (OS) in patients (pts) with metaplastic breast cancer (MpBC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4626.

Abstract P6-03-05: Risk of needle-track seeding with serial ultrasound guided biopsies in triple negative breast cancer

Background: Image-guided percutaneous needle biopsy of the breast is a common procedure. In breast cancer patients (pts) undergoing core biopsies and surgical resection on the same day, the rate of tumor cell displacement along the needle track has been reported to be up to 50%. However, the clinical significance of this finding in triple negative breast cancer (TNBC) patients (pts) undergoing serial biopsies while receiving neoadjuvant chemotherapy (NACT) is unknown. Here we report the incidence of needle-track seeding (NTS) in a cohort of TNBC pts enrolled on a molecular triaging protocol involving serial biopsies of the index breast lesion.

Methods: We reviewed the clinical records of 144 consecutive TNBC pts enrolled on a molecular triaging protocol at MD Anderson Cancer Center. Per protocol, all pts underwent a pre-treatment research biopsy and were initiated on anthracycline based NACT (AC). Pts with inadequate response to front-line NACT were encouraged to undergo additional biopsies of the index breast lesion prior to switching therapies. Serial breast ultrasound (US) was performed to monitor therapeutic response and incidental evidence of needle-track seeding noted on US was documented.

Results: Clinicopathological characteristics of the pts are summarized in Table 1. 89% (128/144) of pts had a diagnostic breast biopsy done at another center prior to presenting at MDACC. To date, we have performed 209 US guided biopsies of index breast lesions in 144 pts. 92% (193/209) of these biopsies were done mainly for research purposes. 1.4% (2/144) of pts were found to have evidence of NTS on follow up US. The first pt had a T1N0 (1.9cm), grade 3, invasive ductal carcinoma (IDC) at diagnosis. She underwent a diagnostic biopsy followed by a research biopsy before initiating AC. She was found to have NTS as well as progression of disease (PD) on follow up US after 2 cycles of AC. The second pt had a T2N0 (3cm), grade 3 IDC at diagnosis. She underwent a diagnostic biopsy at another center, followed by a research biopsy before initiating AC. Like the first pt, she was found to have NTS and PD on follow up US after 2 cycles of AC. Both pts are currently on neoadjuvant clinical trials of novel agents.

Conclusion: The rate of NTS detected on US in TNBC pts undergoing serial biopsies of index breast lesions while receiving NACT is low and further studies are needed to determine the impact of serial biopsies on long term outcomes in TNBC.

Table 1: Patient CharacteristicsCharacteristicN=144Age - Median (years, interquartile range)55 (46-62)Tumor Size Mean (cm, standard deviation)3.4 (2.2)T1 – n(%)35 (24)T2 – n(%)89 (62)T3 – n(%)19 (13)T4 – n(%)1 (1)Clinical Nodal Status Negative – n(%)74 (51)Positive – n(%)70 (49)Grade 1 – n(%)1 (1)2 – n(%)17 (12)3 – n(%)124 (86)Unknown – n(%)2 (1)Histologic Subtype Invasive ductal carcinoma – n(%)121 (84)Invasive lobular carcinoma – n(%)2 (1)Mixed ductal and lobular carcinoma – n(%)3 (2)Metaplastic carcinoma – n(%)13 (9)Not specified – n(%)5 (3)Laterality Right – n(%)72 (50)Left – n(%)72 (50)

Citation Format: Yam C, Santiago L, Candelaria RP, Adrada BE, Rauch GM, Hess KR, Litton JK, Piwnica-Worms H, Mittendorf EA, Ueno NT, Lim B, Murthy RK, Damodaran S, Helgason T, Huo L, Thompson AM, Gilcrease MZ, Symmans WF, Moulder SL, Yang W. Risk of needle-track seeding with serial ultrasound guided biopsies in triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-03-05.

Abstract P1-07-22: Androgen receptor positivity is associated with nodal disease in triple negative breast cancer

Background: Gene expression profiling (GEP) has identified several molecularly distinct subtypes of triple negative breast cancer (TNBC). Currently, GEP-based molecular diagnostics are not routinely used in clinical decision making due to the lack of proven benefit, costs involved and long turnaround time. However, two molecularly distinct subtypes of TNBC, the luminal androgen receptor (AR) and mesenchymal subtypes, have surrogate CLIA-certified immunohistochemical (IHC) markers, AR and vimentin (VM), respectively, which have the potential for application in the clinic. Here we report the rates of AR and VM positivity and their association with clinicopathological characteristics in a cohort of TNBC pts receiving NACT.

Methods: As part of an ongoing molecular triaging protocol, 144 pts with stage I-III TNBC underwent a pretreatment biopsy for molecular characterization (MC) prior to initiating neoadjuvant chemotherapy (NACT). IHC for AR and VM were performed using commercially available antibodies. AR+ and VM+ were defined as ≥10% and ≥50% staining, respectively. Pts were randomized 2:1 to know (intervention arm, n=93) and not know (control arm, n=51) the MC results. The charts of pts randomized to the intervention arm were reviewed. Categorical variables were analyzed using Fisher's exact test. Ordinal and continuous variables were analyzed using the Wilcoxon rank-sum test and Student's t test as appropriate.

Results: 31% (29/93) and 16% (15/93) of pts were AR+ and VM+, respectively. Only 4% (4/93) of pts were both AR+ and VM+. Clinicopathological characteristics are summarized in Table 1. AR+ pts were more likely to have clinically node positive disease as compared to AR- pts (66% vs 34%, p=0.007). There were no significant differences in clinical tumor size or grade between AR+ and AR- pts. VM+ and VM- pts had similar clinicopathological characteristics.

Conclusion: Pts with AR+ TNBC were more likely to have node positive disease. The impact of AR+ on long term outcomes should be investigated in prospective studies.

Table 1: Association between patient characteristics and AR/VM status AR  VM   AR+ (n=29)AR- (n=64)p-valueVM+ (n=15)VM- (n=78)p-valueAge - Median (years, interquartile range)58 (48-65)52 (46-61)0.05855 (48-64)56 (47-62)0.88Clinical Tumor Size      Mean (cm, standard deviation)3.5 (1.8)3.0 (1.8)0.2872.7 (1.7)3.3 (1.9)0.31T1 – n(%)5 (17)21 (33)0.2307 (47)19 (24)0.098T2 – n(%)21 (72)36 (56) 7 (47)50 (64) T3 – n(%)3 (10)7 (11) 1 (7)9 (12) Clinical Nodal Status      Negative – n(%)10 (34)42 (66)0.0078 (53)44 (56)1.00Positive – n(%)19 (66)22 (34) 7 (47)34 (44) Grade      2 – n(%)6 (21)5 (8)0.0763 (20)8 (10)0.293 – n(%)23 (79)59 (92) 12 (80)70 (90) 

Citation Format: Yam C, Huo L, Hess KR, Litton JK, Yang W, Piwnica-Worms H, Mittendorf EA, Ueno NT, Lim B, Murthy RK, Damodaran S, Helgason T, Thompson AM, Santiago L, Candelaria RP, Rauch GM, Adrada BE, Symmans WF, Gilcrease MZ, Moulder SL. Androgen receptor positivity is associated with nodal disease in triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-22.

Abstract 4736: ADAMs: potential biomarkers and oncotargets in breast cancer

Background: There is growing evidence that ADAM (a disintegrin and metalloproteinase) family proteins are involved in multiple types of cancer, including breast cancer. More than 50 members of the ADAM family have been identified thus far. Previous studies have focused on one or two ADAMs but comparative research among the members of the family is lacking. This study was undertaken to identify the most important ADAMs associated with breast cancer.

Methods: We analyzed mRNA expression of ADAMs in tumor bed stroma and paired normal adjacent stroma from 31 breast cancer patients. The original raw data was adapted from a breast dataset (Finak et al, 2008). We next analyzed RNA expression of 35 ADAMs in different subtypes of breast cancers [dataset from Affymetrix U133A arrays using methods available in the R statistical software package (http://cran.r-project.org)]. We further evaluated protein expression of ADAMs and related signaling molecules in 187 breast cancers, including 110 untreated primary tumors and 77 residual tumors after neoadjuvant chemotherapy, and 167 matched ‘normal’ mammary tissues using reverse phase protein arrays (RPPA). The association between ADAMs expression and survival was analyzed using Kaplan–Meier analysis.

Results: The microarray analysis of tumor bed stroma revealed significantly elevated mRNA levels of 12 ADAMs, including ADAM8, ADAM 12, ADAM 19, ADAM 21, ADAM 17, ADAM 10, ADAM 28, ADAM 7, ADAM 33, ADAM 22, ADAM 6 and ADAMTS20, compared to their normal adjacent stroma. We evaluated the expression of 35 ADAMs in total 369 breast cancers, including 201 hormone receptor positive (HR+), 60 HER2 amplified (HER2+) and 108 triple negative (TN) patients using RNA array and demonstrated that 24 of 35 ADAMs were significantly upregulated in TNBC compared to that in HR+ and HER2+ subtypes. We further analyzed protein expression of ADAMs in 189 breast cancers and 172 matched “normal” breast tissues with RPPA. Compared to “normal” breast tissues, ADAM17, ADAM10, ADAM15, ADAM8 and ADAM9 were significantly increased in tumors (P < 0.0001, respectively), while ADAM20, ADAM23, ADAM29, and ADAM30 exhibited lower level. Kaplan–Meier analysis showed that 13-year overall survival rate in high expression of ADAM 17, ADAM 15 or ADAM10 group was significantly decreased compared to that in the low expression group (40% vs. 12%, P = 0.0026; 50% vs. 11%, P = 0.0104; 53% vs. 9%, P < 0.0001, respectively), suggesting that upregulation of ADAM17, ADAM15, or ADAM10 was significantly associated with poor outcome. ADAM17, ADAM9 or ADAM10 expression was tightly associated with elevation of anti-apoptotic molecule Bcl-X, cyclins (E1, E2, B1), PTPN12, and phosphorylation of 4-EBP1.

Conclusion: Several ADAM proteins have elevated expression in breast cancer and are associated with decreased patient survival. ADAMs may, therefore, serve as potential biomarkers for predicting outcomes and oncotargets in breast cancer.

Citation Format: Shuying Liu, Michael Z. Gilcrease, Huiqin Chen, Wenbin Liu, Fan Zhang, Kim-Anh Do, Gordon B. Mills, William F. Symmans, Naoto T. Ueno, Ana M. Gonzales-Angulo, Gabriel N. Hortobagyi, Debasish Tripathy. ADAMs: potential biomarkers and oncotargets in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4736. doi:10.1158/1538-7445.AM2017-4736

Abstract OT3-02-05: NCI-2016-00367: A phase IIB study of neoadjuvant ZT regimen (enzalutamide therapy in combination with weekly paclitaxel) for androgen receptor (AR)-positive triple-negative breast cancer (TNBC)

BACKGROUND: Approximately 50% of TNBC expresses AR by immunohistochemical (IHC) staining. Luminal androgen receptor (LAR) subtype is heavily enriched in hormonally regulated genes, yet negative for ER by IHC. LAR is associated with low pCR rates and long survival. Preclinical data have shown that taxanes inhibit translocation of AR from the cytoplasm to the nucleus where AR is activated. Combining paclitaxel with enzalutamide may inhibit the AR pathway synergistically thereby increasing pCR rates. We hypothesized that patients with AR-positive TNBC who have chemo-insensitive disease (CID) after initial anthracycline-based chemotherapy treated with ZT would have higher RCB-0 and RCB-I rates than those who receive conventional taxane-based chemotherapy. Our team developed a clinical trial to identify patients with CID (ARTEMIS: A Randomized, TNBC Enrolling trial to confirm Molecular profiling Improves Survival). In the ARTEMIS trial, treatment-naïve patients with localized TNBC undergo a pretreatment biopsy and then begin anthracycline-based chemotherapy. Molecular testing results and radiographic response assessment are used to identify CID and will guide the second phase of neoadjuvant chemotherapy (NACT) to overcome CID.

PRIMARY OBJECTIVE: To determine RCB-0 and RCB-I rates of patients with TNBC who have CID to initial anthracycline-based chemotherapy and who received ZT.

TRIAL DESIGN AND STATISTICAL METHODS: Patients with CID from the ARTEMIS trial can enroll in the 12-week ZT (paclitaxel, 80 mg/m2 intravenously per week; enzalutamide, 160 mg orally per day). We will define pCR (RCB-0) or RCB-I as a response, using a Simon optimal 2-stage design with alpha=beta=10% and then setting the threshold for an acceptable pCR or RCB-I rate at 20%. We will enroll 12 patients into the first stage. If no patients experience pCR or RCB-I, we will stop the study after the first stage. If at least 1 patient experiences pCR or RCB-I, we will enroll 25 more patients for a total of 37 patients. We would declare the treatment worthy of further study if at least 4 of the 37 patients experience pCR or RCB-I. This design has a 54% probability of early termination after the first stage if the true pCR or RCB-I probability is 5%. Because patients with CID have a very low chance (5%) of achieving pCR with additional chemotherapy, improving pCR rates to 20% in this patient population would be clinically meaningful.

BRIEF ELIGIBILITY CRITERIA: Inclusion criteria: Primary invasive TNBC patients who have CID under the ARTEMIS trial; AR+ ≥1% nuclear staining by IHC; and adequate physical, organ, bone marrow, and cardiac functions. Exclusion criteria: Pregnant or lactating patients, history of colitis or absorption abnormality, known or suspected brain metastasis or leptomeningeal disease, or history of seizure.

CORRELATIVE SCIENCE: Enumeration of circulating tumor cells (CTCs) and expression of CTC-related gene transcripts will be measured to correlate CTC characteristics and/or gene profiles related to the AR pathway and treatment response to ZT.

Citation Format: Fujii T, Lim B, Helgason T, Hess KR, Gilcrease MZ, Willey JS, Tripathy D, Litton JK, Moulder S, Krishnamurthy S, Yang W, Reuben JM, Symmans WF, Ueno NT. NCI-2016-00367: A phase IIB study of neoadjuvant ZT regimen (enzalutamide therapy in combination with weekly paclitaxel) for androgen receptor (AR)-positive triple-negative breast cancer (TNBC) [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 OT3-02-05.

Role of RPL39 in Metaplastic Breast Cancer

Background: Metaplastic breast cancer is one of the most therapeutically challenging forms of breast cancer because of its highly heterogeneous and chemoresistant nature. We have previously demonstrated that ribosomal protein L39 (RPL39) and its gain-of-function mutation A14V have oncogenic activity in triple-negative breast cancer and this activity may be mediated through inducible nitric oxide synthase (iNOS). The function of RPL39 and A14V in other breast cancer subtypes is currently unknown. The objective of this study was to determine the role and mechanism of action of RPL39 in metaplastic breast cancer.

Methods: Both competitive allele-specific and droplet digital polymerase chain reaction were used to determine the RPL39 A14V mutation rate in metaplastic breast cancer patient samples. The impact of RPL39 and iNOS expression on patient overall survival was estimated using the Kaplan-Meier method. Co-immunoprecipitation and immunoblot analyses were used for mechanistic evaluation of RPL39.

Results: The RPL39 A14V mutation rate was 97.5% (39/40 tumor samples). High RPL39 (hazard ratio = 0.71, 95% confidence interval = 0.55 to 0.91, P = .006) and iNOS expression (P = .003) were associated with reduced patient overall survival. iNOS inhibition with the pan-NOS inhibitor N^G-methyl-L-arginine acetate decreased in vitro proliferation and migration, in vivo tumor growth in both BCM-4664 and BCM-3807 patient-derived xenograft models (P = .04 and P = .02, respectively), and in vitro and in vivo chemoresistance. Mechanistically, RPL39 mediated its cancer-promoting actions through iNOS signaling, which was driven by the RNA editing enzyme adenosine deaminase acting on RNA 1.

Conclusion: NOS inhibitors and RNA editing modulators may offer novel treatment options for metaplastic breast cancer.

Improved Axillary Evaluation Following Neoadjuvant Therapy for Patients With Node-Positive Breast Cancer Using Selective Evaluation of Clipped Nodes: Implementation of Targeted Axillary Dissection

PURPOSE

Placing clips in nodes with biopsy-confirmed metastasis before initiating neoadjuvant therapy allows for evaluation of response in breast cancer. Our goal was to determine if pathologic changes in clipped nodes reflect the status of the nodal basin and if targeted axillary dissection (TAD), which includes sentinel lymph node dissection (SLND) and selective localization and removal of clipped nodes, improves the false-negative rate (FNR) compared with SLND alone.

METHODS

A prospective study of patients with biopsy-confirmed nodal metastases with a clip placed in the sampled node was performed. After neoadjuvant therapy, patients underwent axillary surgery and the pathology of the clipped node was compared with other nodes. Patients undergoing TAD had SLND and selective removal of the clipped node using iodine-125 seed localization. The FNR was determined in patients undergoing complete axillary lymphadenectomy (ALND).

RESULTS

Of 208 patients enrolled in this study, 191 underwent ALND, with residual disease identified in 120 (63%). The clipped node revealed metastases in 115 patients, resulting in an FNR of 4.2% (95% CI, 1.4 to 9.5) for the clipped node. In patients undergoing SLND and ALND (n = 118), the FNR was 10.1% (95% CI, 4.2 to 19.8), which included seven false-negative events in 69 patients with residual disease. Adding evaluation of the clipped node reduced the FNR to 1.4% (95% CI, 0.03 to 7.3; P = .03). The clipped node was not retrieved as an SLN in 23% (31 of 134) of patients, including six with negative SLNs but metastasis in the clipped node. TAD followed by ALND was performed in 85 patients, with an FNR of 2.0% (1 of 50; 95% CI, 0.05 to 10.7).

CONCLUSION

Marking nodes with biopsy-confirmed metastatic disease allows for selective removal and improves pathologic evaluation for residual nodal disease after chemotherapy.

GATA-binding protein 3 enhances the utility of gross cystic disease fluid protein-15 and mammaglobin A in triple-negative breast cancer by immunohistochemistry

AIMS

We have demonstrated previously that gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin A (MAM) are of limited utility in triple-negative breast cancer (TNBC). GATA-binding protein 3 (GATA-3) is an emerging breast-associated immunohistochemical (IHC) marker with limited data in TNBC. Here, we examined GATA-3 expression in TNBC in comparison with GCDFP-15 and MAM.

METHODS AND RESULTS

We studied GATA-3, GCDFP-15 and MAM IHC expression in 62 primary and 68 metastatic TNBCs. In primary TNBCs, GATA-3 staining was observed in 25 cases (40%), including 16 cases that were negative for GCDFP-15 and MAM. In metastatic TNBCs, GATA-3 staining was observed in 30 cases (44%), including 16 cases that were negative for GCDFP-15 and MAM. The expression frequency of any of the markers was 56% in primary and 62% in metastatic TNBCs. However, when focal staining was excluded, the expression frequency of any marker dropped to 31% and 44%, respectively.

CONCLUSION

GATA-3 is expressed at a higher frequency by IHC in TNBC compared to GCDFP-15 and MAM, although the tissue specificity of the latter markers may be superior. When evaluating a triple-negative tumour, including GATA-3 in a panel of markers may increase the diagnostic accuracy for tissue origin in the appropriate clinical setting.

Abstract OT2-2-06: Phase II single arm study of liposomal doxorubicin (D), bevacizumab (A), and temsirolimus (T) for treatment of triple negative early breast cancer refractory to standard neoadjuvant chemotherapy

Background: Historically, triple negative breast cancers (TNBCs) were categorized into an ill-defined group that lacked estrogen receptors, progesterone receptors, and overexpression of human epidermal growth factor receptor 2. When TNBCs are treated with standard neoadjuvant chemotherapy (NAC), a pathologic complete response (pCR) is achieved in only 30-50% of the time. In an effort to improve outcomes for chemotherapy - refractory disease, emerging subtypes of TNBC have been identified through advances in molecular profiling leading to the discovery of distinct molecular aberrations which may be targeted. For example, mesenchymal-like TNBCs are a subset with aberrations that activate the PI3K/AKT/mTOR axis. Similar to mesenchymal-like, metaplastic breast cancers are commonly triple negative, refractory to standard therapy, and also harbor a high rate of molecular aberrations that lead to activation of the PI3K pathway. As such, metaplastic tumors may act as a morphologically identified ‘surrogate of response’ to evaluate the activity of targeted therapy regimens in mesenchymal-like TNBC. Based upon favorable results noted in a phase I trial of liposomal doxorubicin, bevacizumab, and the mTOR inhibitor temsirolimus (DAT) in metastatic metaplastic tumors, we will conduct this single arm phase II trial with neoadjuvant DAT for chemotherapy-refractory mesenchymal-like TNBC.

Trial Design: At our institution, women with TNBC who are receiving NAC will be enrolled onto a triaging protocol, where they will be randomized in a 2:1 fashion to be evaluated by a microarray-based predictive signature to determine chemotherapy sensitivity and categorized as chemotherapy-sensitive (CS) or chemotherapy-insensitive (CI). Subsequently, patients will be treated with standard anthracycline-based chemotherapy (AC or FAC) for 4 cycles. Patients with CI tumors with <80% decrease in tumor size and those with CS tumors with <10% decrease in tumor size will be deemed non-responders. Mesenchymal-like non-responders will be recommended for this single arm phase II study of DAT. Eligible patients will receive D at a dose of 30mg/m2 IV on day 1, A at 15 mg/kg IV on Day 1, and T at 25mg IV on Days 1, 8, and 15 for 4 cycles.

Eligibility Criteria: Female; > 18 years of age; newly diagnosed stage I-III triple negative breast cancer; refractory to standard NAC; LVEF > 50% by Echocardiogram or MUGA; ECOG PS 0-1

Statistical Methods: The primary endpoint is pCR following therapy with DAT. Secondary objectives will include recurrence-free survival and overall survival. Using a Simon optimal two-stage design with alpha = beta = 10%, and then setting the threshold for an acceptable pCR rate at 20%, we would enroll 12 patients into the first stage. If we see 0 patients with pCR, we would stop the study after the first stage. If we see at least one patient with a pCR we will continue to enroll 25 more patients for a total of 37 patients. We would declare the treatment worthy of further study if we see at least 4 patients with pCR out of the 37 patients. This design has a 54% probability of early termination after the first stage if the true pCR probability is 5%.

Target Accrual: 37.

Citation Format: Rashmi K Murthy, Naoto T Ueno, William F Symmans, Jennifer K Litton, Banu K Arun, Nuhad K Ibrahim, Ricardo H Alvarez, Michael Z Gilcrease, Vicente Valero, Debasish Tripathy, Stacy L Moulder. Phase II single arm study of liposomal doxorubicin (D), bevacizumab (A), and temsirolimus (T) for treatment of triple negative early breast cancer refractory to standard neoadjuvant chemotherapy [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT2-2-06.

Gross cystic disease fluid protein-15 and mammaglobin A expression determined by immunohistochemistry is of limited utility in triple-negative breast cancer

AIMS

  In addition to oestrogen and progesterone receptors, gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin A (MAM) are the most common markers used to identify breast origin by immunohistochemistry. GCDFP-15 expression has been reported in approximately 60% of breast carcinomas and MAM expression in approximately 80%. Data on their expression in triple-negative breast cancer (TNBC) are very limited. The aim of this study was to examine the expression of these markers in TNBC to determine their utility in pathological diagnosis.

METHODS AND RESULTS

  We studied the immunohistochemical (IHC) expression of GCDFP-15 and MAM in 63 primary and 118 metastatic TNBCs. GCDFP-15 staining was present in 14% of primary and 21% of metastatic TNBCs. MAM staining was present in 25% of primary and 41% of metastatic TNBCs. The frequency of expression of GCDFP-15 and/or MAM was 30% in primary and 43% in metastatic TNBCs, and many positive tumours had only focal staining.

CONCLUSIONS

  Staining for GCDFP-15 and/or MAM in triple-negative carcinomas helps to confirm breast origin, but most tumours in this subgroup of breast carcinomas lack expression of either marker.

Tissue-based predictors of germ-line BRCA1 mutations: implications for triaging of genetic testing

BRCA testing of patients with breast cancer considered at high risk for having a germ-line BRCA mutation usually consists of comprehensive mutational analysis of both BRCA1 and BRCA2. A more cost-effective strategy of triaging patients for analysis of a single gene could be adopted if tissue-based predictors indicated a high risk specifically for either BRCA1 or BRCA2. To identify potentially useful tissue-based predictors of BRCA mutation status in breast cancer, we evaluated multiple histopathologic features of invasive breast carcinoma on archival tissue sections from 196 high-risk patients who had undergone BRCA testing, and we analyzed which individual or combination of features was most associated with BRCA mutations. Of the 196 patients with invasive breast carcinoma, there were 44 (22%) with a deleterious BRCA1 mutation and 27 (14%) with a deleterious BRCA2 mutation. For patients with available untreated surgical resection specimens for evaluation (n=172), estrogen receptor-positive phenotype was inversely associated with the presence of a BRCA1 mutation (odds ratio, 0.243; 95% confidence interval, 0.070-0.840; P=.025), and high mitotic activity (≥25 mitotic figures per 10 high-power fields) was directly associated with the presence of a BRCA1 mutation (odds ratio, 4.222; 95% confidence interval, 1.353-13.18; P=.013). The combination of estrogen receptor-negative phenotype and high mitotic rate had high specificity (99%; 95% confidence interval, 95%-100%) but low sensitivity (43%; 95% confidence interval, 26%-61%) for identifying a deleterious BRCA1 mutation. In patients with breast cancer at high risk for carrying a BRCA mutation, those with estrogen receptor-negative phenotype and high mitotic rate could be triaged specifically for BRCA1 testing instead of initially performing mutational analysis for both BRCA1 and BRCA2.

Prognostic significance of tumor grading and staging in mammary carcinomas with neuroendocrine differentiation

Invasive mammary carcinoma with neuroendocrine differentiation has been controversial in terms of its definition and clinical outcome. In 2003, the World Health Organization histologic classification of tumors designated this entity as neuroendocrine carcinoma of the breast and defined mammary neuroendocrine carcinoma as expression of neuroendocrine markers in more than 50% of tumor cells. It is an uncommon neoplasm. Our recent study showed that it is a unique clinicopathologic entity and has a poor clinical outcome compared with invasive mammary carcinoma with similar pathologic stage. Other investigators have also demonstrated a different molecular profile in this type of tumor from that of invasive ductal carcinoma. It is unknown whether the current prognostic markers for invasive mammary carcinoma are also applicable for neuroendocrine carcinoma of the breast. In the current study, we reviewed the clinicopathologic features and outcome data in 74 cases of mammary neuroendocrine carcinoma from the surgical pathology files at The University of Texas, MD Anderson Cancer Center, to identify relevant prognostic markers for this tumor type. As shown previously by univariate analysis, large tumor size, high nuclear grade, and presence of regional lymph node metastasis are adverse prognostic factors for overall survival and distant recurrence-free survival. In the current study, multivariate analysis revealed that overall survival was predicted by tumor size, lymph node status, and proliferation rate as judged by Ki-67 immunohistochemistry. Only nodal status proved to be a significant independent prognostic factor for distant recurrence-free survival. Neither mitosis score nor histologic grade predicted survival in mammary neuroendocrine carcinoma. Our data suggest that routine evaluation of Ki-67 proliferation index in these unusual tumors may provide more valuable information than mitotic count alone.

Histologic changes associated with false-negative sentinel lymph nodes after preoperative chemotherapy in patients with confirmed lymph node-positive breast cancer before treatment

BACKGROUND

A wide range of false-negative rates has been reported for sentinel lymph node (SLN) biopsy after preoperative chemotherapy. The purpose of this study was to determine whether histologic findings in negative SLNs after preoperative chemotherapy are helpful in assessing the accuracy of SLN biopsy in patients with confirmed lymph node-positive disease before treatment.

METHODS

Eighty-six patients with confirmed lymph node-positive disease at presentation underwent successful SLN biopsy and axillary dissection after preoperative chemotherapy at a single institution between 1994 and 2007. Available hematoxylin and eosin-stained sections from patients with negative SLNs were reviewed, and associations between histologic findings in the negative SLNs and SLN status (true negative vs false negative) were evaluated.

RESULTS

Forty-seven (55%) patients had at least 1 positive SLN, and 39 (45%) patients had negative SLNs. The false-negative rate was 22%, and the negative predictive value was 67%. The negative SLNs from 17 of 34 patients with available slides had focal areas of fibrosis, some with associated foamy parenchymal histiocytes, fat necrosis, or calcification. These histologic findings occurred in 15 (65%) of 23 patients with true-negative SLNs and in only 2 (18%) of 11 patients with false-negative SLNs (P = .03, Fisher exact test, 2-tailed). The lack of these histologic changes had a sensitivity and specificity for identifying a false-negative SLN of 82% and 65%, respectively.

CONCLUSIONS

Absence of treatment effect in SLNs after chemotherapy in patients with lymph node-positive disease at initial presentation has good sensitivity but low specificity for identifying a false-negative SLN.

Rosai-Dorfman disease confined to the breast

Rosai-Dorfman disease (also known as sinus histiocytosis with massive lymphadenopathy) is an uncommon, idiopathic, benign histiocytic lesion. It usually involves the cervical lymph nodes and, less commonly, extranodal sites. Involvement of the breast is rare, with only 17 cases reported in the English literature to date. Here we describe 3 new patients with extranodal Rosai-Dorfman disease in the breast. All 3 patients-aged 45, 53, and 54 years-presented with solid breast lesions that were detected on screening mammography and had no clinical history of Rosai-Dorfman disease or radiographic evidence of extramammary involvement. Initial diagnoses were accomplished by needle core biopsy in the one case and excisional biopsy in the other two. We present the histopathologic findings and follow-up of each patient and conduct a literature review of mammary Rosai-Dorfman disease with emphasis on its differential diagnosis. Because Rosai-Dorfman disease frequently mimics invasive breast carcinoma in its clinical presentation and radiographic appearance-and can mimic other benign or malignant histiocytic lesions microscopically-awareness and appropriate diagnosis of this entity are essential for proper treatment.

Alpha6beta4 integrin crosslinking induces EGFR clustering and promotes EGF-mediated Rho activation in breast cancer

Background

The α6β4 integrin is overexpressed in the basal subtype of breast cancer and plays an important role in tumor cell motility and invasion. EGFR is also overexpressed in the basal subtype of breast cancer, and crosstalk between α6β4 integrin and EGFR appears to be important in tumor progression.

Methods

We evaluated the effects of α6β4 crosslinking on the distribution and function of EGFR in breast carcinoma cell line MDA-MB-231. Receptor distribution was evaluated by fluorescence microscopy and multispectral imaging flow cytometry, and ligand-mediated EGFR signaling was evaluated using Western blots and a Rho pull-down assay.

Results

Antibody-mediated crosslinking of α6β4 integrin was sufficient to induce cell-surface clustering of not only α6β4 but also EGFR in nonadherent cells. The induced clustering of EGFR was observed minimally after 5 min of integrin crosslinking but was more prominent after 15 min. EGFR clustering had minimal effect on the phosphorylation of Akt or Erk1,2 in response to EGF in suspended cells or in response to HB-EGF in adherent cells. However, EGFR clustering induced by crosslinking α6β4 had a marked effect on Rho activation in response to EGF.

Conclusion

Crosslinking α6β4 integrin in breast carcinoma cells induces EGFR clustering and preferentially promotes Rho activation in response to EGF. We hypothesize that this integrin-EGFR crosstalk may facilitate tumor cell cytoskeletal rearrangements important for tumor progression.

Characterization of a naturally occurring breast cancer subset enriched in epithelial-to-mesenchymal transition and stem cell characteristics

Metaplastic breast cancers (MBC) are aggressive, chemoresistant tumors characterized by lineage plasticity. To advance understanding of their pathogenesis and relatedness to other breast cancer subtypes, 28 MBCs were compared with common breast cancers using comparative genomic hybridization, transcriptional profiling, and reverse-phase protein arrays and by sequencing for common breast cancer mutations. MBCs showed unique DNA copy number aberrations compared with common breast cancers. PIK3CA mutations were detected in 9 of 19 MBCs (47.4%) versus 80 of 232 hormone receptor-positive cancers (34.5%; P = 0.32), 17 of 75 HER-2-positive samples (22.7%; P = 0.04), 20 of 240 basal-like cancers (8.3%; P < 0.0001), and 0 of 14 claudin-low tumors (P = 0.004). Of 7 phosphatidylinositol 3-kinase/AKT pathway phosphorylation sites, 6 were more highly phosphorylated in MBCs than in other breast tumor subtypes. The majority of MBCs displayed mRNA profiles different from those of the most common, including basal-like cancers. By transcriptional profiling, MBCs and the recently identified claudin-low breast cancer subset constitute related receptor-negative subgroups characterized by low expression of GATA3-regulated genes and of genes responsible for cell-cell adhesion with enrichment for markers linked to stem cell function and epithelial-to-mesenchymal transition (EMT). In contrast to other breast cancers, claudin-low tumors and most MBCs showed a significant similarity to a "tumorigenic" signature defined using CD44(+)/CD24(-) breast tumor-initiating stem cell-like cells. MBCs and claudin-low tumors are thus enriched in EMT and stem cell-like features, and may arise from an earlier, more chemoresistant breast epithelial precursor than basal-like or luminal cancers. PIK3CA mutations, EMT, and stem cell-like characteristics likely contribute to the poor outcomes of MBC and suggest novel therapeutic targets.

Coexpression of alpha6beta4 integrin and guanine nucleotide exchange factor Net1 identifies node-positive breast cancer patients at high risk for distant metastasis

Preclinical data indicate that alpha6beta4 integrin signaling through Ras homolog gene family, member A, plays an important role in tumor cell motility. The objective of this study was to determine whether the combined expression of alpha6beta4 integrin and neuroepithelioma transforming gene 1 (Net1), a guanine nucleotide exchange factor specific for Ras homolog gene family member A, is associated with adverse clinical outcome in breast cancer patients. Immunohistochemical expression of each protein was evaluated in a tumor tissue microarray prepared from the primary tumors of 94 node-positive patients with invasive breast carcinoma treated with total mastectomy and doxorubicin-based chemotherapy without radiation with a median follow-up of 12.5 years. Associations between staining results and multiple clinicopathologic variables were investigated. Although there was no significant association between alpha6beta4 integrin or Net1 expression and clinical outcome when each marker was considered individually, coexpression of alpha6beta4 and Net1 was associated with decreased distant metastasis-free survival (P = 0.030). In the subset of patients with hormone receptor-positive tumors, coexpression of alpha6beta4 and Net1 was associated with a decrease in distant metastasis-free and overall survival (P < 0.001 and P = 0.006, respectively). Although an association between human epidermal growth factor receptor 2 expression and coexpression of alpha6beta4 and Net1 (P = 0.008) was observed, coexpression of alpha6beta4 and Net1 (hazard ratio, 1.63; P = 0.02) and lymphovascular invasion (hazard ratio, 2.35; P = 0.02) were the only factors independently associated with the development of distant metastasis in multivariate analysis. These findings suggest that coexpression of alpha6beta4 integrin and Net1 could be a useful biomarker for aggressive disease in node-positive breast cancer patients.

How many sentinel lymph nodes are enough during sentinel lymph node dissection for breast cancer?

BACKGROUND

: It remains unclear how many sentinel lymph nodes (SLNs) must be removed to accurately predict lymph node status during SLN dissection in breast cancer. The objective of this study was to determine how many SLNs need to be removed for accurate lymph node staging and which patient and tumor characteristics influence this number.

METHODS

: The authors reviewed data for all patients in their prospective database with clinical tumor, lymph node, metastasis (TNM) T1 through T3, N0, M0 breast cancer who underwent lymphatic mapping at their institution during the years 1994 through 2006. There were 777 patients who had at least 1 SLN that was positive for cancer. Simple and multiple quantile regression analyses were used to determine which patient and tumor characteristics were associated with the number of positive SLNs. The baseline number of SLNs that needed to be dissected for detection of 99% of positive SLNs in the total group of patients also was determined.

RESULTS

: The mean number of SLNs removed in the 777 lymph node-positive patients was 2.9 (range, 1-13 SLNs). Greater than 99% of positive SLNs were identified in the first 5 lymph nodes removed. On univariate analysis, tumor histology, patient race, tumor location, and tumor size significantly affected the number of SLNs that needed to be removed to identify 99% of all positive SLNs. On multivariate analysis, mixed ductal and lobular histology, Caucasian race, inner quadrant tumor location, and T1 tumor classification significantly increased the number of SLNs that needed to be removed to achieve 99% recovery of all positive SLNs.

CONCLUSIONS

: In general, the removal of a maximum of 5 SLNs at surgery allowed for the recovery of >99% of positive SLNs in patients with breast cancer. The current findings indicated that tumor histology, patient race, and tumor size and location may influence this number.

How many sentinel lymph nodes are enough during sentinel lymph node dissection for breast cancer?

BACKGROUND

: It remains unclear how many sentinel lymph nodes (SLNs) must be removed to accurately predict lymph node status during SLN dissection in breast cancer. The objective of this study was to determine how many SLNs need to be removed for accurate lymph node staging and which patient and tumor characteristics influence this number.

METHODS

: The authors reviewed data for all patients in their prospective database with clinical tumor, lymph node, metastasis (TNM) T1 through T3, N0, M0 breast cancer who underwent lymphatic mapping at their institution during the years 1994 through 2006. There were 777 patients who had at least 1 SLN that was positive for cancer. Simple and multiple quantile regression analyses were used to determine which patient and tumor characteristics were associated with the number of positive SLNs. The baseline number of SLNs that needed to be dissected for detection of 99% of positive SLNs in the total group of patients also was determined.

RESULTS

: The mean number of SLNs removed in the 777 lymph node-positive patients was 2.9 (range, 1-13 SLNs). Greater than 99% of positive SLNs were identified in the first 5 lymph nodes removed. On univariate analysis, tumor histology, patient race, tumor location, and tumor size significantly affected the number of SLNs that needed to be removed to identify 99% of all positive SLNs. On multivariate analysis, mixed ductal and lobular histology, Caucasian race, inner quadrant tumor location, and T1 tumor classification significantly increased the number of SLNs that needed to be removed to achieve 99% recovery of all positive SLNs.

CONCLUSIONS

: In general, the removal of a maximum of 5 SLNs at surgery allowed for the recovery of >99% of positive SLNs in patients with breast cancer. The current findings indicated that tumor histology, patient race, and tumor size and location may influence this number.

Breast carcinoma with neuroendocrine differentiation and myocardial metastases

A 63-year-old Japanese woman was diagnosed with metastatic well-differentiated neuroendocrine carcinoma presenting as a perianal mass without an obvious primary site. Two years later, she presented with a breast mass determined on histologic examination to be the primary neuroendocrine carcinoma. The tumor was weakly positive for estrogen receptor and clearly originated in multifocal ductal carcinoma in situ. At the same time, she was found to have multiple metastases in bone and liver and, later, heart. Most studies report a relatively poor prognosis and limited treatment responsiveness for neuroendocrine breast carcinoma. Better understanding of the cellular origin and molecular pathogenesis of this relatively enigmatic rare disease is required.

Loss of myoepithelium is variable in solid papillary carcinoma of the breast

AIMS

Reports on the frequency of myoepithelial loss in solid papillary carcinoma (SPC) of the breast, an unusual variant of papillary carcinoma with a solid pattern of expansile growth, have been strikingly contradictory. The aim was to clarify the frequency of myoepithelial loss in cases of SPC diagnosed at our institution.

METHODS AND RESULTS

Eleven cases of SPC with available blocks or unstained slides were retrieved from the M. D. Anderson archives or obtained from outside contributors. Immunohistochemistry for smooth muscle actin (SMA) and p63 was evaluated on the circumscribed nests that appeared to be non-invasive by haematoxylin and eosin morphology. Three of the 11 cases (27%) were positive for both SMA and p63 at the periphery of all such foci, whereas eight cases (73%) lacked staining for both myoepithelial markers in at least one focus. Of these eight cases, one was diagnosed with only microinvasion, yet metastatic tumour resembling the circumscribed primary SPC was identified in two ipsilateral axillary lymph nodes.

CONCLUSIONS

SPC of the breast frequently lacks myoepithelial markers at the tumour-stromal interface in spite of a circumscribed non-invasive appearance. Metastases from such tumours are infrequent, but can occur in cases that lack myoepithelial marker expression by immunohistochemistry.

Feasibility and accuracy of sentinel lymph node biopsy after preoperative chemotherapy in breast cancer patients with documented axillary metastases

BACKGROUND

The feasibility and accuracy of sentinel lymph node (SLN) biopsy in patients with breast cancer after preoperative chemotherapy has been demonstrated in a number of large, single-institution studies. However, a relative contraindication to SLN biopsy after preoperative chemotherapy is the presence of axillary metastases at initial diagnosis. The objective of this study was to determine the feasibility and accuracy of SLN biopsy after preoperative chemotherapy in patients with documented axillary metastases at presentation.

METHODS

Between 1994 and 2002, 69 patients who had axillary metastases identified by ultrasound-guided, fine-needle aspiration underwent SLN biopsy after treatment on prospective, preoperative chemotherapy protocols. All but 8 patients underwent axillary lymph node dissection (ALND). Those 8 patients either declined additional surgery or were offered enrollment in other institutional protocols.

RESULTS

The median patient age was 49 years, and the median primary tumor size was 4 cm. The SLN identification rate was 92.8%. Thirty-one of 64 patients (48.4%) had successfully mapped, positive SLNs. Sixty-one patients underwent ALND, including 5 patients who did not have an SLN identified. In the 56 patients in whom a SLN was identified and an ALND was performed, 10 patients had a false-negative SLN (25%).

CONCLUSIONS

SLN biopsy was feasible after preoperative chemotherapy, even in patients who initially presented with cytologically proven, lymph node-positive disease. However, the false-negative rate of SLN biopsy in this group of patients was much higher than that observed in clinically lymph node-negative patients. Based on the current results, the status of the SLN cannot be used as a reliable indicator of the presence or absence of residual disease in the axilla in this patient population.

Phosphorylated galectin-3 mediates tumor necrosis factor-related apoptosis-inducing ligand signaling by regulating phosphatase and tensin homologue deleted on chromosome 10 in human breast carcinoma cells

Galectin-3 (GAL3), a beta-galactoside-binding lectin, confers chemoresistance to a wide variety of cancer cell types. It may exhibit anti- or pro-apoptotic activity depending on the nature of the stimulus. We report here that introducing phosphorylated galectin-3 (P-GAL3) into GAL3-null, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant human breast carcinoma cells promotes TRAIL-induced apoptotic cell death by stimulating the phosphorylation/inactivation of the pro-apoptotic molecule Bad resulting in the inhibition of mitochondrial depolarization and the release of cytochrome c. Exposure of the transfectant cells to TRAIL leads to the recruitment of the initiator capase-8 followed by activation of the effector caspase-9, independent of cytochrome c, and subsequently the processing of the executioner caspase-3. P-GAL3 and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) were coordinately expressed, with concomitant dephosphorylation of Akt in TRAIL-sensitive cells. In contrast, overexpression of phospho-mutant GAL3 (incapable of phosphorylation) failed to elicit similar responses. Depletion of PTEN using small interference RNAs reinstated Akt phosphorylation and conferred TRAIL resistance. In addition phosphatidylinositol 3-kinase inhibitors rendered the phospho-mutant GAL3-resistant cells sensitive to TRAIL. These findings suggest a pivotal role for P-GAL3 in promoting TRAIL sensitivity through activation of a nonclassic apoptotic pathway and identify P-GAL3 as a novel regulator of PTEN.

Integrin signaling in epithelial cells

Although most cells of adult mammals express multiple different integrins, particular types of cells have a characteristic repertoire of integrin expression. Benign and malignant epithelial cells use specific integrins to allow the epithelial microenvironment to modulate a wide variety of cell functions, including cell survival, proliferation, morphogenesis, differentiation, motility, invasion and metastasis. An important concept emerging from the data on integrin signal transduction is that integrin signaling impinges on pathways downstream of other receptors, creating elaborate intracellular signaling networks. This review highlights signal transduction functions of epithelial integrins, with particular emphasis on signaling pathways underlying some of the most important functions of epithelium.

Pathological evaluation of axillary sentinel lymph nodes in breast cancer

Nodal staging is the most important prognostic factor in the management of patients with breast cancer. Sentinel lymph node (SLN) procedure enables selective targeting of the first lymph node that drains the tumor when the initial metastases occur. A negative sentinel node predicts the absence of tumor mestastases in the other regional lymph nodes with high accuracy. Thorough histopathological evaluation of SLNs important for accurate assessment. In this chapter, we discuss the histopathological evaluation of SLNs.

Metaplastic Sarcomatoid Carcinoma of the Breast With Absent or Minimal Overt Invasive Carcinomatous Component

Metaplastic carcinomas of the breast are a heterogeneous group of neoplasms ranging from tumors with a predominant component of overt carcinoma and focal mesenchymal differentiation to keratin-positive tumors with pure sarcomatoid morphology. We examined the clinicopathologic features of 22 patients previously diagnosed at M.D. Anderson Cancer Center with metaplastic carcinoma of the breast with pure or almost pure sarcomatoid morphology. Patients were included in the study if their tumors had sarcomatoid morphology and: 1) an invasive carcinomatous component identifiable on hematoxylin and eosin stains comprising less than 5% of the invasive tumor; or 2) associated ductal carcinoma in situ; or 3) immunohistochemical expression of keratin in the sarcomatoid areas. Patients with low-grade fibromatosis-like metaplastic tumors and those who received neoadjuvant chemotherapy were excluded. Axillary lymph node dissection or limited axillary node excision was performed in 17 patients, including 1 patient who had a sentinel lymph node biopsy. Lymph node involvement occurred in only 1 patient and consisted of a single 3.5-mm metastasis. Clinical follow-up was available for 21 patients and ranged from 4 months to 155 months (median follow-up, 35 months). Ten patients experienced local relapse, including 7 of 11 patients treated with breast-conserving surgery, and 9 developed distant metastases, most frequently to the lungs. These findings suggest that metaplastic sarcomatoid carcinomas that lack or have only a minimal overt invasive carcinomatous component have a biologic behavior similar to that of sarcomas. In addition to systemic treatment, early aggressive local therapy is recommended, as these patients have a high rate of local relapse.

Tumor cavitation in stage I non-small cell lung cancer: epidermal growth factor receptor expression and prediction of poor outcome

PURPOSE

To retrospectively identify radiographic characteristics of stage I non-small cell lung cancer (NSCLC) that may correlate with epidermal growth factor receptor (EGFR) or HER2 expression or with prognosis.

MATERIALS AND METHODS

This study was approved by the institutional review board, with waiver of informed consent, and was in compliance with HIPAA regulations. Findings of chest computed tomography (CT) were retrospectively evaluated in 72 patients who underwent resection of pathologic stage I NSCLC; tumor diameter, presence of calcifications, type of contour, type of margins, attenuation of the nodule, presence of a halo, presence of cavitation, and tumor location were documented. Immunohistochemical studies were performed in surgical specimens. Imaging and molecular data were correlated with patient outcome. Cox proportional hazards regression models were used to correlate biologic and radiographic variates with clinical outcome.

RESULTS

There were 38 men (53%) and 34 women (47%) (median age, 65.5 years). Median follow-up was 56.3 months; median overall survival, 76.3 months. A strong correlation was found between tumor diameter measured by radiologists and that measured by pathologists (P < .001; Pearson correlation coefficient, 0.81). EGFR overexpression was found in 48 (67%) tumors; significantly more was found in squamous cell carcinomas than was found in adenocarcinomas (P = .028), and more was found in T2 tumors than was found in T1 tumors (P = .001). HER2 overexpression was found in 13 (18%) tumors; cavitation, in 16 (22%) tumors. Cavitary lesions were significantly more common in squamous cell carcinomas than were in adenocarcinomas (P = .013) and in EGFR-overexpressing tumors (P = .012) than in tumors that did not overexpress EGFR. Cavitary lesions were significantly associated with shorter disease-free survival time (P = .01) and shorter overall survival time (P < .007).

CONCLUSION

Patients who have stage I NSCLC with cavitary lesions have an adverse prognosis and are likely to have tumor EGFR overexpression.

Beta4 integrin subunit gene expression correlates with tumor size and nuclear grade in early breast cancer

In vitro data support a role for the alpha6beta4 integrin in tumor cell migration and invasion, particularly in breast carcinoma cells, but clinical data on this potentially important integrin are limited. The beta4 integrin subunit has been shown to cluster with genes characteristic of basal/myoepithelial cells in cDNA microarray analyses of breast cancer, and the subset of breast cancers with increased expression of genes characteristic of basal/myoepithelial cells appears to be particularly aggressive. The purpose of this study was to determine whether alpha6beta4 integrin expression correlates with aggressive clinicopathologic features of breast cancer and whether expression of this integrin has prognostic significance in early breast cancer. We evaluated tumor expression of the beta4 integrin subunit gene in a cohort of patients with early invasive breast carcinoma by in situ hybridization and correlated expression levels with multiple clinicopathologic characteristics. We also evaluated expression of laminin-5 protein, the principal ligand of alpha6beta4, in this patient cohort. Although we observed a slight trend towards decreased disease-free survival for patients whose tumors had high beta4 gene expression and coexpression of laminin-5, this did not reach statistical significance (P=0.11). However, we did observe a correlation between beta4 mRNA expression and both tumor size (P=0.01) and tumor nuclear grade (P<0.01). These results do not demonstrate prognostic significance for beta4 gene expression and/or laminin-5 protein expression in early breast cancer, but increased beta4 gene expression in larger tumors and in higher grade tumors does support a potential role for the alpha6beta4 integrin in tumor progression.

CD44 expression is associated with increased survival in node-negative invasive breast carcinoma

PURPOSE

CD44 is a multifunctional cell surface receptor with many known splice variants, some of which have been reported to play a role in tumor progression. The purpose of this study was to evaluate the prognostic significance of CD44 isoforms in early-stage, lymph node-negative invasive breast carcinoma.

EXPERIMENTAL DESIGN

Immunohistochemical staining for CD44 isoforms was done on archival paraffin tissue sections of invasive breast carcinoma from a cohort of lymph node-negative patients who received no adjuvant tamoxifen or chemotherapy and who had a mean clinical follow-up period of 15 years. Immunohistochemical staining was done with antibodies to CD44s, the standard isoform of CD44, and to isoforms containing variant exon 6 (CD44v6); levels of staining were correlated with clinical outcome data.

RESULTS

There was a trend towards increased disease-free survival for patients whose tumors had high anti-CD44s positivity (P = 0.05), and a significant association was observed between anti-CD44s positivity and disease-related survival (P = 0.04). Expression of CD44v6 isoforms did not correlate with clinical outcome.

CONCLUSION

CD44 expression, as assessed by immunohistochemical staining with anti-CD44s, may be a favorable prognostic factor in patients with node-negative invasive breast carcinoma.

Adhesion-independent alpha6beta4 integrin clustering is mediated by phosphatidylinositol 3-kinase

Clustering of cell-surface integrins is known to augment integrin-mediated signal transduction, but mechanisms of integrin clustering are poorly understood. Here we report that adhesion-independent clustering of alpha6beta4 integrin, known to be important in mediating tumor cell motility, is driven by phosphatidylinositol 3-kinase (PI3K) but does not require activation of the PI3K-Akt pathway. We observed clustering of alpha6beta4 in breast carcinoma cells after adhesion-independent cross-linking of the beta4 integrin subunit. Clustering was significantly blocked when cross-linking was performed in the presence of PI3K inhibitors LY294002 and wortmannin. In contrast, no significant inhibition of clustering was observed with protein kinase C inhibitor GF109203X, rapamycin, or heparin. Although alpha6beta4 clustering was blocked by PI3K inhibitors, clustering was not associated with increased PI3K lipid kinase activity or increased phosphorylation of Akt. A novel role for PI3K in alpha6beta4 integrin clustering is proposed.

Chromogenic in situ hybridization for alpha6beta4 integrin in breast cancer: correlation with protein expression

The alpha6beta4 integrin is the receptor for the basement membrane protein laminin-5. Recent studies suggest that alpha6beta4 integrin expression in invasive breast carcinomas may be a poor prognostic factor. Because we have not had reliable results with commercially available antibodies for the immunohistochemical detection of alpha6beta4 integrin in archival paraffin-embedded tissues, we designed a probe to detect beta4 integrin subunit mRNA in paraffin sections. In situ hybridization for beta4 mRNA was performed on paraffin-embedded tissue sections of 25 invasive breast carcinomas using a hyperbiotinylated oligonucleotide DNA probe. Immunohistochemical staining was performed on corresponding frozen tumor sections using two commercially available antibodies to the beta4 integrin subunit. All cases positive for beta4 protein by one or both antibodies were also positive for beta4 mRNA by in situ hybridization, but three cases with beta4 mRNA expression were negative by immunohistochemistry with both antibodies. These findings suggest that in situ hybridization appears to be a sensitive method for detecting beta4 integrin mRNA, but it appears to identify some cases that either lack beta4 protein or express variants not recognized with commercial antibodies directed to particular extracellular or cytoplasmic domains.

Jun activation domain binding protein 1 expression is associated with low p27(Kip1)levels in node-negative breast cancer

PURPOSE

The purpose is to evaluate expression levels of Jun activation domain-binding protein 1 (JAB1) in breast cancer tissue and adjacent normal tissue, to determine whether JAB1 expression is associated with p27(Kip1) expression in invasive breast carcinomas, and to evaluate the prognostic significance of JAB1 and p27(Kip1) in node-negative breast cancer.

EXPERIMENTAL DESIGN

JAB1 levels were measured in 10 matched pairs of invasive breast tumor tissue and adjacent normal tissue using Western blot analysis. We also investigated the immunoreactivity of JAB1 and p27(Kip1) levels in paraffin-embedded tissue specimens from 220 patients with node-negative breast cancer who had not received adjuvant systemic therapy. The median follow-up was 15 years.

RESULTS

JAB1 was expressed at higher levels in invasive tumors than in adjacent normal tissue (P = 0.01). JAB1 overexpression was observed in 57% of invasive breast cancers. Low levels of p27(Kip1) were noted in 70% of the tumor specimens. We found an inverse correlation between JAB1 and p27(Kip1) expression levels (P = 0.01). JAB1 overexpression was associated with patient age of at least 50 years (P = 0.03) and tumor size of </=2 cm (P = 0.01). Elevated levels of p27(Kip1) were associated with low nuclear grade (P = 0.01). At 5 years of follow-up, neither JAB1 nor p27(Kip1) expression was related to disease-free survival.

CONCLUSIONS

These data indicate that JAB1 is commonly overexpressed in invasive breast carcinomas. JAB1 overexpression is associated with low levels of p27(Kip1) in node-negative breast cancer. In this study, JAB1 and p27(Kip1) were not independent prognostic factors.

Histologic localization of sentinel lymph node metastases in breast cancer

Data from a recent study support the hypothesis that axillary lymph node metastases frequently localize near the inflow junction of the afferent lymphatic vessel. Our goal was to evaluate the microscopic location of axillary sentinel lymph node metastases in a prospective study of breast cancer patients. A total of 305 axillary sentinel lymph nodes from 213 breast cancer patients undergoing surgery at our institution were evaluated. Preoperative lymphoscintigraphy using technetium-labeled sulfur colloid and intraoperative isosulfan blue dye injection were used for identifying the sentinel lymph node. Intraoperatively, the surgeon placed a suture either at the point of entry of isosulfan blue dye or at the area with the highest radioactive counts, and this area was inked at the grossing bench before processing. Metastases were identified in 55 of the 305 lymph nodes examined. Thirty-four nodes contained metastases in both the inked half and the opposite half. Metastatic tumor was identified in the inked half alone in 18 lymph nodes. Only three nodes contained metastatic tumor in the opposite half with no tumor in the inked half (p <0.001). Similar results were found when nodes tagged at the point of blue dye entry and nodes tagged at the area with the highest radioactive counts were analyzed separately. Our findings suggest that metastatic tumor has a higher probability of being present in the region of the inflow junction of the afferent lymphatic vessel. This information may be useful in determining the optimal method for evaluating axillary sentinel lymph node specimens from breast cancer patients.

A lymph node metastatic mouse model reveals alterations of metastasis-related gene expression in metastatic human oral carcinoma sublines selected from a poorly metastatic parental cell line

BACKGROUND

Greater than 40% of patients with squamous cell carcinoma (SCC) of the oral cavity have lymph node metastasis at the time of diagnosis and a 5-year survival rate of less than 50%. Changes in gene expression that regulate metastasis of SCC to lymph nodes have not been identified.

METHODS

To study metastasis of oral SCC, highly metastatic oral SCC cell lines from a poorly metastatic oral SCC cell line were established by in vivo selection using a lymph node metastatic mouse model. The metastatic potential of the cells was studied using Matrigel invasion and cell surface protein adhesion assays. mRNA and protein encoded from metastasis-related genes in the metastatic derivatives and in their parental cells were examined using Northern blot analysis, immunoblotting, rapid analysis of gene expression, and a cDNA microarray technique.

RESULTS

The in vivo selected metastatic cells showed much higher Matrigel invasion capability than the parental cells. They also showed alterations in their adhesion properties to three cell surface proteins. Comparison of metastatic and nonmetastatic cells revealed several significant alterations in the expression of metastasis-related genes, including up-regulation of the urokinase-type plasminogen activator receptor, integrin beta1, membrane type 1-matrix metalloproteinase, and down-regulation of protease-activated receptor-1.

CONCLUSIONS

To the authors' knowledge, the current study is the first to report on gene expression analysis using a lymph node metastatic mouse model of human oral SCC. The data suggest that certain alterations of metastasis-related gene expression favor invasion of oral SCC and that cell surface proteins may play major roles in the metastasis of oral SCC to the lymph nodes.

Expression of protease-activated receptor 1 in oral squamous cell carcinoma

Protease-activated receptor 1 (PAR-1) is a G-coupled membrane protein. In this study, we analyzed the expression of PAR-1 in oral squamous cell carcinomas (SCCs). PAR-1 was expressed in oral SCCs, but the level of PAR-1 protein was lower in non-metastatic cells than in metastatic cells. Thrombin stimulated the growth of metastatic cells, and both thrombin and thrombin receptor activation peptide (TRP) enhanced the adhesion of these cells to fibronectin, but had no effect on non-metastatic cells. Thrombin and TRP also induced matrix metalloproteinase (MMP)-2 and MMP-9 activities in metastatic cells. These results suggest that PAR-1 may contribute to the growth and invasive potential of oral SCC.

Adhesion of aspirated tumor cells to extracellular matrix proteins: a new methodology utilizing fine-needle aspiration

BACKGROUND

Cell adhesion molecules mediate the interactions of cells with other cells and with extracellular matrix components. Such interactions may be important in the development of tumor invasion and metastasis. This article describes a new approach to the evaluation of tumor cell-matrix interactions by utilizing fine-needle aspiration of resected tumors.

METHODS

Fine-needle aspiration was performed on 15 fresh surgical specimens of various types of carcinomas. After partial purification by isotonic Percoll centrifugation, tumor cell adhesion to collagen Type IV, laminin, and fibronectin was evaluated by counting cytologically malignant cells adhering to matrix-coated plastic substrates. Frozen tissue sections of the corresponding tumors were studied simultaneously for immunohistochemical expression of alpha-2, alpha-3, alpha-4, and alpha-5 integrin subunit expression. Results of the immunohistochemical staining then were compared with the adhesion data for particular tumors.

RESULTS

In general, the majority of the tumors exhibited little or no adhesion to collagen or laminin, but several tumors showed marked adhesion to fibronectin. Striking differences were noted between some tumors of the same histologic subtype. Competitive inhibition studies performed with two of the tumors (a large cell carcinoma and a renal cell carcinoma) showed decreased adhesion to fibronectin in the presence of anti-alpha-5, suggesting at least a partial role for the alpha-5-beta 1 fibronectin receptor in mediating the adhesion of these tumors to fibronectin. All the tumors examined exhibited strong immunohistochemical expression of the alpha-2 and alpha-3 integrin subunits, and all were negative for alpha-4. Three of the tumors showed weak expression of alpha-5, two of which (a squamous cell carcinoma and a renal cell carcinoma) were the tumors that showed the greatest adhesion to fibronectin.

CONCLUSIONS

Quantitative adhesion data can be obtained using cell suspensions prepared from fine-needle aspirates, and there are marked differences in adhesive properties between particular tumors. Although two of the tumors showed a correlation between adhesion to fibronectin and immunohistochemical expression of the alpha-5 integrin subunit, matrix adhesion does not necessarily correlate with immunohistochemical expression of adhesion molecule receptors. In the future, this methodology potentially could be of value in determining which patients may benefit from therapies aimed at modifying tumor cell-matrix interactions.