Trastuzumab Emtansine (T-DM1) and stereotactic radiation in the management of HER2+ breast cancer brain metastases

Background

Due to recent concerns about the toxicity of trastuzumab emtansine (T-DM1) with stereotactic radiation, we assessed our institutional outcomes treating HER2-positive breast cancer brain metastases (BCBM) with T-DM1 and stereotactic radiation.

Methods

This is a single institution series of 16 patients with HER2-positive breast cancer who underwent 18 stereotactic sessions to 40 BCBM from 2013 to 2019 with T-DM1 delivered within 6 months. The Kaplan-Meier method was used to calculate overall survival (OS), local control (LC), distant intracranial control (DIC), and systemic progression-free survival (sPFS) from the date of SRS. A neuro-radiologist independently reviewed follow-up imaging.

Results

One patient had invasive lobular carcinoma, and 15 patients had invasive ductal carcinoma. All cases were HER2-positive, while 10 were hormone receptor (HR) positive. Twenty-four lesions were treated with stereotactic radiosurgery (SRS) to a median dose of 21 Gy (14–24 Gy). Sixteen lesions were treated with fractionated stereotactic radiation (FSRT) with a median dose of 25 Gy (20-30Gy) delivered in 3 to 5 fractions. Stereotactic radiation was delivered concurrently with T-DM1 in 19 lesions (48%). Median follow up time was 13.2 months from stereotactic radiation. The 1-year LC, DIC, sPFS, and OS were 75, 50, 30, and 67%, respectively. There was 1 case of leptomeningeal progression and 1 case (3%) of symptomatic radionecrosis.

Conclusions

We demonstrate that stereotactic radiation and T-DM1 is well-tolerated and effective for patients with HER2-positive BCBM. An increased risk for symptomatic radiation necrosis was not noted in our series.

Targeted Therapy Given after Anti-PD-1 Leads to Prolonged Responses in Mouse Melanoma Models through Sustained Antitumor Immunity

Immunotherapy (IT) and targeted therapy (TT) are both effective against melanoma, but their combination is frequently toxic. Here, we investigated whether the sequence of IT (anti-PD-1)→ TT (ceritinib-trametinib or dabrafenib-trametinib) was associated with improved antitumor responses in mouse models of BRAF- and NRAS-mutant melanoma. Mice with NRAS-mutant (SW1) or BRAF-mutant (SM1) mouse melanomas were treated with either IT, TT, or the sequence of IT→TT. Tumor volumes were measured, and samples from the NRAS-mutant melanomas were collected for immune-cell analysis, single-cell RNA sequencing (scRNA-seq), and reverse phase protein analysis (RPPA). scRNA-seq demonstrated that the IT→TT sequence modulated the immune environment, leading to increased infiltration of T cells, monocytes, dendritic cells and natural killer cells, and decreased numbers of tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells. Durable responses to the IT→TT sequence were dependent on T-cell activity, with depletion of CD8⁺, but not CD4⁺, T cells abrogating the therapeutic response. An analysis of transcriptional heterogeneity in the melanoma compartment showed the sequence of IT→TT enriched for a population of melanoma cells with increased expression of MHC class I and melanoma antigens. RPPA analysis demonstrated that the sustained immune response induced by IT→TT suppressed tumor-intrinsic signaling pathways required for therapeutic escape. These studies establish that upfront IT improves the responses to TT in BRAF- and NRAS-mutant melanoma models.

Disseminated cancer cells in breast cancer: Mechanism of dissemination and dormancy and emerging insights on therapeutic opportunities

Metastatic spread in breast cancer patients is the major driver of cancer-related deaths. A unique subset of cells disseminated from pre-invasive or primary tumor lesions are recognized as the main seeds for metastatic outgrowth. Disseminated cancer cells (DCCs) can migrate to distant organs and settle in a dormant state for a prolonged period until they emerge to overt metastases. Understanding the biology of breast cancer cells dissemination, dormancy and reactivation to form overt metastases has become an important focus. In this review, we discuss the recent advancements of molecular pathways involving breast cancer cell dissemination, role of chemokine-chemokine receptor networks in DCCs migration, DCCs phenotypic heterogeneity and unique genes signatures in tumor dormancy, microenvironmental regulation and specific niches that favors DCCs homing and dormancy. In addition, we also discuss recent findings relating to the role of immune response on DCC dissemination and dormancy. With recent advances in the field of immunotherapy/targeted therapy and its beneficial effects in cancer treatment, this review will focus on their impact on DCCs, reversal of stemness, tumor dormancy and metastatic relapse.

Abstract PS14-19: Characteristics of breast cancer brain metastases presentation by subtype and validation of the modified breast graded prognostic assessment

Purpose: Breast cancer brain metastases (BCBM) diagnosis is increasing in frequency due to improved systemic control and imaging techniques. Differences have been noted in rates of central nervous system (CNS) relapse and biologic subtype. The modified breast graded prognostic assessment (breast-GPA) was initially validated in patients treated between 1996-2013 and considers biologic subtype. In this study, we characterize patients diagnosed with BCBM by subtype and validate the breast-GPA in a modern cohort of patients.

Methods: All patients with BCBM treated at our institution with radiotherapy between 2016 and 2019 were identified. Characteristics of patients’ initial brain metastasis diagnosis were retrieved from the clinical chart and radiologic examinations. To test differences between cohorts, the Kruskal-Wallis and Pearson’s chi-square tests were used when appropriate. Overall survival (OS) was calculated from the date of brain metastasis diagnosis to the date of death using the Kaplan-Meier (KM) method, with the log-rank test used to examine differences between groups.

Results: A total of 122 BCBM patients were identified. Breast cancer subtypes included hormone receptor (HR)+/HER2- (45%), triple negative (TN) (25%), HR-/HER2+ (16%), and HR+/HER2+ (14%). The first treatment for BCBM patients following diagnosis was whole brain radiation (51%), surgery followed by stereotactic radiation (28%), and stereotactic radiation (21%). The interval between breast cancer diagnosis and diagnosis of BCBM was longest for HR+/HER2- 4.5 years, followed by TN 2.8 years, HR+/HER2+ 2.3 years, HR-/HER2+ 1.9 years, p=0.003. The interval from systemic metastases to BCBM diagnosis trended towards the shortest for TN patients 6.6 months, p=0.15. A total of 34 patients (28%) were diagnosed with leptomeningeal disease (LMD) at initial brain metastases presentation. LMD was diagnosed most commonly at presentation in HR+/HER2- (36%) followed by , TN (26%), HR-/HER2+ (26%), and HR+/HER2+ (6%), p=0.06. No differences were noted based on receptor typessubtype and age, symptomatic intracranial disease, number of brain metastases, type of first intracranial treatment or concurrent systemic metastases at initial BCBM presentation, all p > 0.05. Twenty-four month KM OS rates following diagnosis of brain metastasis for breast-GPA 0-1, 1.5-2, 2.5-3, and 3.5-4 groups were 14%, 27%, 33%, and 86% (p=0.0005), respectively.

Conclusions: In our institutional analysis, similarities were noted in the initial presentation of BCBM based on receptor typesubtype. Significant differences were noted in OS based on the modified breast-GPA. Further investigation is needed to determine which subtypes of asymptomatic breast cancer patients are at sufficient risk to warrant brain MRI screening.

Citation Format: Yuki Kawahara, Matthew Fahey, Thrisha K Potluri, Matthew N Mills, Nicholas B Figura, Iman R Washington, Roberto Diaz, Timothy J Robinson, Hsiang-Hsuan M Yu, Arnold B Etame, James Liu, Michael A Vogelbaum, Brian J Czerniecki, Peter A Forsyth, Hatem H Soliman, Hyo S Han, Kamran A Ahmed. Characteristics of breast cancer brain metastases presentation by subtype and validation of the modified breast graded prognostic assessment [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS14-19.

Abstract PS3-09: The use of magnetic resonance imaging (MRI) in predicting pathological complete response(pCR) in the breast and axilla after the addition of immunotherapy to neoadjuvant systemic therapy (NST)

Introduction: Immunotherapy use is increasing as an adjunct to current NST for breast cancer treatment with the goals of increasing pCR and down staging tumors. In this study, we assessed the effectiveness of MRI in the evaluation of tumor response after neoadjuvant immunotherapy in combination with NST. Methods: We retrospectively reviewed the clinicopathological data of 105 women undergoing Immunotherapy in conjunction with NST at a single institution. All patients had been enrolled in IRB approved protocols and had undergone definitive surgery. Patients were excluded for: failure to complete at least two thirds of treatment, no pre or post treatment MRI, or surgery in an outside institution. We analyzed 73 patients from 5 distinct treatment protocols including: (1) 24 Triple negative breast cancer (TNBC) patients (pts) treated with Intratumoral Talimogene laherparepvec (TVEC) in combination with weekly paclitaxel followed by dose dense Adriamycin and Cytoxan (ddAC); (2) 19 HER2/Neu positive (HER2+) pts treated with subcutaneous interferon gamma (IFN-γ) in combination with weekly paclitaxel with trastuzumab and pertuzumab (HP); (3), 7 HER2+ pts treated with 3 weeks of HER2 pulsed dendritic cell vaccines (DC1) followed by Taxotere, Carboplatin, and HP; (4), 14 pts on the ISPY2 trial: 8 TNBC and 4 Hormone receptor positive, HER2/Neu negative (HR+) pts randomized to treatment with pembrolizumab with weekly paclitaxel followed by ddAC (2 also received additional SD101), and 2 TNBC pts treated with Durvalumab, Olaparib and Paclitaxel, followed by ddAC and (5) 9 HR+ pts on neoadjuvant Durvalumab and an Aromatase Inhibitor for 6 cycles. Results: A total of 73 patients were included in the study. Median age was 51 years (range 27-76); 46.6% of patients had TNBC, 35.6% had HER2+ and the remaining 17.8% were HR+ HER2-. The median clinical tumor size was 3.4cm (range 1.3-10.6) pre therapy and 1cm (range 0-10.1) post therapy. The pCR was 38.2%, 57.7%, and 0% respectively for TNBC, HER2+, HR+ tumors. Complete radiological response (rCR) of both the axilla and breast was 41.2%, 61.5% and 7.7%, for TNBC, HER2+ and HR+ tumors. The sensitivity of MRI to detect in breast pCR was 65.6% with a specificity of 81%, NPV and PPV of 75% and 73.3% respectively. MRI identified 37 pts with suspicious axillary nodes on pretreatment MRI; of these 30 had fine needle aspiration (FNA) confirmed metastatic disease. Post treatment, 70.3% (26/37) had normalized axillary nodes. Of those with normalized nodes, 26.9% (7/26) had residual cancer on final pathology. Of the patients with confirmed FNA lymph node metastasis, axillary pCR of 63.3% was achieved. The sensitivity and specificity of MRI to detect pCR within the axilla was 87% and 50% and NPV and PPV 70% and 74.1%, respectively. 3 patients had axillary disease on final pathology but no suspicious imaging and a benign FNA. Conclusion: The addition of immunotherapy to current NST strategies can improve pCR and decrease residual cancer burden. The PPV and NPV of MRI to predict pCR in patients undergoing immunotherapy in combination with NST remains within the ranges described in patients undergoing NST alone. MRI remains a useful tool to guide surgical management but is not accurate enough to replace pathological evaluation.

Citation Format: Noeline Rajarajan, Daniel Segarra, Robert J Weinfurtner, Adrian A Lopez, M Catherine Lee, John Kiluk, Hatem Soliman, Hung Khong, Han S Hyo, Marilin Rosa, Brian J Czerniecki, Nazanin Khakpour. The use of magnetic resonance imaging (MRI) in predicting pathological complete response(pCR) in the breast and axilla after the addition of immunotherapy to neoadjuvant systemic therapy (NST) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-09.

Feasibility of Axillary Lymph Node Localization and Excision Using Radar Reflector Localization

INTRODUCTION

Neoadjuvant chemotherapy (NAC) is commonly used for patients with clinically detected nodal metastases. Sentinel lymph node biopsy (SLNB) after NAC is feasible. Excision of biopsy-proven positive lymph nodes in addition to SLNB, termed targeted axillary dissection (TAD), decreases the false-negative rate of SLNB alone. Positive nodes can be marked with radar reflector-localization (RRL) clips. We report our institutional experience with RRL-guided TAD and demonstrate its safety and feasibility.

PATIENTS AND METHODS

We performed an institutional review board-approved retrospective review of consecutive clinically node-positive female patients with breast cancer treated with NAC and RRL-guided TAD between January 2017 and September 2019. Clinicopathologic and treatment data were collected; descriptive statistics are reported.

RESULTS

Forty-five patients were analyzed; the median age was 55 years (range, 20-72 years), and the median body mass index was 27.2 kg/m² (range, 16.5-40.4 kg/m²). All patients received NAC, primary breast surgery, and TAD. All clinically detected nodal metastases were confirmed with percutaneous biopsy and marked with a biopsy clip. RRL clips were implanted a median of 8 days (range, 1-167 days) prior to surgery; all were retrieved without complications. The RRL node was identified as the sentinel lymph node in 36 (80%) patients. Twenty-five patients had positive nodes, of which 24 were identified by RRL node excision, and 1 (4%) patient had a positive node identified by SLNB but not RRL. Over a median follow-up time of 29.6 months, 5 patients recurred (1 local, 4 distant).

CONCLUSIONS

RRL-guided TAD after NAC is safe and feasible. This technique allows for adequate assessment of the nodal basin and helps confirm excision of the previously biopsied positive axillary node.

Th1 cytokines in conjunction with pharmacological Akt inhibition potentiate apoptosis of breast cancer cells in vitro and suppress tumor growth in vivo

Targeted drug approaches have been a major focus for developing new anticancer therapies. Although many such agents approved in the last 20 years have improved outcomes, almost all have underperformed expectations. The full potential of such agents may yet be obtained through novel combinations. Previously, we showed that anti-estrogen drugs combined with a dendritic cell-based anti-HER-2 vaccine known to induce strong Th1-polarized immunity dramatically improved clinical response rates in patients with HER-2^pos/ER^pos early breast cancer. Here, we show that the small molecule Akt antagonist MK-2206, when combined with the Th1 cytokines IFN-gamma and TNF-alpha, maximize indicators of apoptotic cell death in a panel of phenotypically-diverse human breast cancer lines. These findings were mirrored by other, structurally-unrelated Akt-targeting drugs that work through different mechanisms. Interestingly, we found that MK-2206, as well as the other Akt antagonist drugs, also had a tendency to suppress Th1 cytokine expression in stimulated human and murine lymphocytes, potentially complicating their use in conjunction with active immunotherapy. After verifying that MK-2206 plus IFN-gamma could show similar combined effects against breast cancer lines, even in the absence of TNF-alpha, we tested in a rodent HER-2^pos breast cancer model either a HER-2-based DC vaccine, or recombinant IFN-gamma with or without MK-2206 administration. We found that for MK-2206, co-administration of recombinant IFN-gamma outperformed co-administration of DC vaccination for slowing tumor growth kinetics. These findings suggest a combined therapy approach for Akt-targeting drugs that incorporates recombinant Interferon-gamma and is potentially translatable to humans.

Clinical development of immunotherapies for HER2+ breast cancer: a review of HER2-directed monoclonal antibodies and beyond

Human epidermal growth factor receptor 2-positive (HER2⁺) breast cancer accounts for ~25% of breast cancer cases. Monoclonal antibodies (mAbs) against HER2 have led to unparalleled clinical benefit for a subset of patients with HER2⁺ breast cancer. In this narrative review, we summarize advances in the understanding of immune system interactions, examine clinical developments, and suggest rationales for future investigation of immunotherapies for HER2⁺ breast cancer. Complex interactions have been found between different branches of the immune system, HER2⁺ breast cancer, and targeted treatments (approved and under investigation). A new wave of immunotherapies, such as novel HER2-directed mAbs, antibody drug conjugates, vaccines, and adoptive T-cell therapies, are being studied in a broad population of patients with HER2-expressing tumors. The development of immunotherapies for HER2⁺ breast cancer represents an evolving field that should take into account interactions between different components of the immune system.

Abstract OT3-10-01: Phase Ib study of stereotactic radiation and nivolumab in the management of metastatic breast cancer with brain metastases

Background:Patients with breast cancer brain metastases represent a poor prognosis cohort with a high unmet clinical need. Standard-of-care treatments for patients with breast cancer brain metastases include local treatments, such as surgical resection and radiation treatment modalities that include stereotactic radiosurgery (SRS) or whole brain radiotherapy. Numerous pre-clinical studies have provided evidence to combine radiation therapy with immune checkpoint inhibition to improve response rates. The evidence is strongest for short course, hypofractionated radiation regimens. We hypothesize treatment with nivolumab and SRS will be feasible and well tolerated and may improve intracranial tumor control rates compared to SRS alone. Trial Design:The study is designed as a prospective, single-arm, nonrandomized, open-label, phase Ib trial of nivolumab and SRS among patients with metastatic breast cancer brain metastases. Treatment will be initiated with a dose of nivolumab (480 mg IV) that will be repeated every 4 weeks. The initial dose of nivolumab will be followed 1 week later by SRS at sites of brain metastases or post-operative cavities. Patients will be allowed to continue endocrine and HER2-targeted therapies if brain metastases progression was noted on these agents.Eligibility:Eligible patients include those ≥18, ECOG ≤2 with ≤10 breast cancer brain metastases of all subtypes eligible for stereotactic radiation. Specific Aims:The primary objective is to evaluate the safety and feasibility of nivolumab and SRS to sites of brain metastases. Secondary objectives include evaluation of intracranial progression free survival (PFS), extracranial PFS, overall survival, local control, and distant brain control. Correlative aims include assessing blood and tissue biomarkers (i.e. PD-L1, mutation burden, TCR repertoire etc.) for association with clinical benefit.Statistical Methods:Safety and feasibility will be monitored by a 3 + 3 design followed by a dose expansion phase. Patient Accrual:This study is open with 4 patients enrolled at the time of submission. A total of 12 patients will be enrolled.Contact Information:Kamran A. Ahmed MD, Moffitt Cancer Center, email: kamran.ahmed@moffitt.org, Clinical trial information: NCT03807765.

Citation Format: Kamran A Ahmed, Youngchul Kim, Avan J. Armaghani, John A. Arrington, Jimmy J. Caudell, Ricardo L. Costa, Brian J. Czerniecki, Arnold B. Etame, Peter A. Forsyth, Hung T. Khong, Sungjune Kim, Loretta Loftus, Timothy J. Robinson, Marilin Rosa, Solmaz Sahebjam, Hatem H. Soliman, Aixa E. Soyano, Nam D. Tran, H. Michael Yu, Hyo S. Han. Phase Ib study of stereotactic radiation and nivolumab in the management of metastatic breast cancer with brain metastases [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-10-01.

Management of brain metastases in breast cancer: a review of current practices and emerging treatments

PURPOSE

Breast cancer brain metastases (BCBM) are becoming an increasingly common diagnosis due to improved systemic control and more routine surveillance imaging. Treatment continues to require a multidisciplinary approach managing systemic and intracranial disease burden. Although, improvements have been made in the diagnosis and management of BCBM, brain metastasis patients continue to pose a challenge for practitioners.

METHODS

In this review, a group of medical oncologists, radiation oncologists, radiologists, breast surgeons, and neurosurgeons specializing in the treatment of breast cancer reviewed the available published literature and compiled a comprehensive review on the current state of BCBM.

RESULTS

We discuss the pathogenesis, epidemiology, diagnosis, treatment options (including systemic, surgical, and radiotherapy treatment modalities), and treatment response evaluation for BCBM. Furthermore, we discuss the ongoing prospective trials enrolling BCBM patients and their biologic rationale.

CONCLUSIONS

BCBM management is an increasing clinical concern. Multidisciplinary management combining the strengths of surgical, systemic, and radiation treatment modalities with prospective trials incorporating knowledge from the basic and translational sciences will ultimately lead to improved clinical outcomes for BCBM patients.

Implant-sparing Mastectomy: An Alternative for Women Undergoing Mastectomy With Retropectoral Implants

INTRODUCTION

Implant-sparing mastectomy (ISM) is a skin-sparing mastectomy that preserves a retropectoral implant and potentially eliminates the need for tissue expansion or complex reconstruction. This study aimed to determine oncologic and surgical outcomes and reconstructive patterns in patients undergoing ISM.

PATIENTS AND METHODS

A single-institution, retrospective review of patients undergoing ISM from 2006 to 2018 was performed. Patient/tumor characteristics, stage, adjuvant therapy use, 90-day complication rates, reconstruction type, and disease recurrence were collected.

RESULTS

A total of 121 ISMs in 73 women were performed. Seventy (57.9%) ISMs were for breast cancer (BC) treatment and 51 (42.1%) for prophylaxis. Among BC cases, 72.3% were cT1/cT2 and 73.8% were cN0; 72.3% received systemic therapy and 33.8% received radiation therapy. There were 3 deaths owing to BC at the median follow-up of 35 months. Among 5 recurrences, only 1 was local. There was no BC identified after prophylactic ISM. Total 90-day complication rate per ISM was 15.7%. Rates were 0.8% for both seroma and wound infection, 2.5% for wound dehiscence, 3.3% for hematoma, and 8.2% for skin necrosis. The majority (72.6%) of patients required only implant exchange for reconstruction. Overall use of autologous reconstruction was low (12.3%); 77.8% of flaps were performed in patients receiving radiation therapy.

CONCLUSION

ISM is a unique approach for patients pursuing mastectomy for BC treatment or prevention with equivalent oncologic outcomes and complication rates to mastectomy with reconstruction. Reconstruction for the majority was markedly simplified by elimination of tissue expansion while maintaining a low rate of flap reconstruction.

T-helper 1-type cytokines induce apoptosis and loss of HER-family oncodriver expression in murine and human breast cancer cells

A recent neoadjuvant vaccine trial for early breast cancer induced strong Th1 immunity against the HER-2 oncodriver, complete pathologic responses in 18% of subjects, and for many individuals, dramatically reduced HER-2 expression on residual disease. To explain these observations, we investigated actions of Th1 cytokines (TNF-α and IFN-γ) on murine and human breast cancer cell lines that varied in the surface expression of HER-family receptor tyrosine kinases. Breast cancer lines were broadly sensitive to the combination of IFN-γ and TNF-α, as evidenced by lower metabolic activity, lower proliferation, and enhanced apoptosis, and in some cases a reversible inhibition of surface expression of HER proteins. Apoptosis was accompanied by caspase-3 activation. Furthermore, the pharmacologic caspase-3 activator PAC-1 mimicked both the killing effects and HER-2-suppressive activities of Th1 cytokines, while a caspase 3/7 inhibitor could prevent cytokine-induced HER-2 loss. These studies demonstrate that many in vivo effects of vaccination (apparent tumor cell death and loss of HER-2 expression) could be replicated in vitro using only the principle Th1 cytokines. These results are consistent with the notion that IFN-γ and TNF-α work in concert to mediate many biological effects of therapeutic vaccination through the induction of a caspase 3-associated cellular death mechanism.

Sequential Anti-PD1 Therapy Following Dendritic Cell Vaccination Improves Survival in a HER2 Mammary Carcinoma Model and Identifies a Critical Role for CD4 T Cells in Mediating the Response

Patients with metastatic HER2 breast cancer (MBC) often become resistant to HER 2 targeted therapy and have recurrence of disease. The Panacea trial suggested that HER2 MBC patients were more likely to respond to checkpoint therapy if TIL were present or if tumor expressed PD-L1. We assessed whether type I polarized dendritic cells (DC1) could improve checkpoint therapy in a preclinical model of HER2+ breast cancer. TUBO bearing mice were vaccinated with either MHC class I or class II HER2 peptide pulsed DC1 (class I or class II HER2-DC1) concurrently or sequentially with administration of anti-PD-1 or anti-PDL1. Infiltration of tumors by immune cells, induction of anti-HER2 immunity and response to therapy was evaluated. Class I or class II HER2-DC1 vaccinated mice generated anti-HER2 CD8 or CD4+ T cell immune responses and demonstrated delayed tumor growth. Combining both MHC class I and II HER2-pulsed DC1 did not further result in inhibition of tumor growth or enhanced survival compared to individual administration. Interestingly class II HER2-DC1 led to both increased CD4 and CD8 T cells in the tumor microenvironment while class I peptides typically resulted in only increased CD8 T cells. Anti-PD-1 but not anti-PD-L1 administered sequentially with class I or class II HER2-DC1 vaccine could improve the efficacy of HER2-DC1 vaccine as measured by tumor growth, survival, infiltration of tumors by T cells and increase in systemic anti-HER2 immune responses. Depletion of CD4+ T cells abrogated the anti-tumor efficacy of combination therapy with class II HER2-DC1 and anti-PD-1, suggesting that tumor regression was CD4 dependent. Since class II HER2-DC1 was as effective as class I, we combined class II HER2-DC1 vaccine with anti-rat neu antibodies and anti-PD-1 therapy. Combination therapy demonstrated further delay in tumor growth, and enhanced survival compared to control mice. In summary, Class II HER2-DC1 drives both a CD4 and CD8 T cell tumor infiltration that leads to increased survival, and in combination with anti-HER2 therapy and checkpoint blockade can improve survival in preclinical models of HER2 positive breast cancer and warrants exploration in patients with HER2 MBC.

Breast leptomeningeal disease: a review of current practices and updates on management

PURPOSE

Leptomeningeal disease (LMD) is an advanced metastatic disease presentation portending a poor prognosis with minimal treatment options. The advent and widespread use of new systemic therapies for metastatic breast cancer has improved systemic disease control and extended survival; however, as patients live longer, the rates of breast cancer LMD are increasing.

METHODS

In this review, a group of medical oncologists, radiation oncologists, radiologists, breast surgeons, and neurosurgeons specializing in treatment of breast cancer reviewed the available published literature and compiled a comprehensive review on the current state of breast cancer LMD.

RESULTS

We discuss the pathogenesis, epidemiology, diagnosis, treatment options (including systemic, intrathecal, surgical, and radiotherapy treatment modalities), and treatment response evaluation specific to breast cancer patients. Furthermore, we discuss the controversies within this unique clinical setting and identify potential clinical opportunities to improve upon the diagnosis, treatment, and treatment response evaluation in the management of breast LMD.

CONCLUSIONS

We recognize the shortcomings in our current understanding of the disease and explore the future role of genomic/molecular disease characterization, technological innovations, and ongoing clinical trials attempting to improve the prognosis for this advanced disease state.

Immunotherapy in breast cancer: Current status and future directions

Breast cancer, one of the leading causes of death in women in the United States, challenges therapeutic success in patients due to tumor heterogeneity, treatment resistance, metastasis and disease recurrence. Knowledge of immune system involvement in normal breast development and breast cancer has led to extensive research into the immune landscape of breast cancer and multiple immunotherapy clinical trials in breast cancer patients. However, poor immunogenicity and T-cell infiltration along with heightened immunosuppression in the tumor microenvironment have been identified as potential challenges to the success of immunotherapy in breast cancer. Oncodrivers, owing to their enhanced expression and stimulation of tumor cell proliferation and survival, present an excellent choice for targeted immunotherapy development in breast cancer. Loss of anti-tumor immune response specific to oncodrivers has been reported in breast cancer patients as well. Dendritic cell vaccines have been tested for their efficacy in generating anti-tumor T-cell response against specific tumor-associated antigens and oncodrivers and have shown improved survival outcome in patients. Here, we review the current status of immunotherapy in breast cancer, focusing on dendritic cell vaccines and their therapeutic application in breast cancer. We further discuss future directions of breast cancer immunotherapy and potential combination strategies involving dendritic cell vaccines and existing chemotherapeutics for improved efficacy and better survival outcome in breast cancer.

Th1 cytokines sensitize HER-expressing breast cancer cells to lapatinib

The HER family of receptor tyrosine kinases has been linked to deregulation of growth and proliferation for multiple types of cancer. Members have therefore become thefocus of many drug and immune-based therapy innovations. The targeted anti-cancer agent, lapatinib, is a small molecule inhibitor that directly interferes with EGFR (HER-1)and HER-2 signaling, and indirectly reduces HER-3 signaling, thus suppressing important downstream events. A recently-developed dendritic cell-based vaccine against early breast cancer (ductal carcinoma in situ; DCIS) that generates strong Th1-dominated immunity against HER-2 has induced pathologic complete response in about one-third of immunized individuals. In vitro studies suggested cytokines secreted by Th1 cells could be major contributors to the vaccine effects including induction of apoptosis and suppression of HER expression. With a view toward improving complete response rates, we investigated whether the principle Th1 cytokines (IFN-γ and TNF-α) could act in concert with lapatinib to suppress activity of breast cancer lines in vitro. Lapatinib-sensitive SKBR3, MDA-MB-468 and BT474 cells were incubated with Th1 cytokines, lapatinib, or both. It was found that combined treatment maximized metabolic suppression(Alamar Blue assay), as well as cell death (Trypan Blue) and apoptosis(Annexin V/Propidium Iodide and TMRE staining). Combined drug plus cytokine treatment also maximized suppression of both total and phosphorylated forms of HER-2 and HER-3. Interestingly, when lapatinib resistant lines MDA-MB-453 and JIMT-1 were tested, it was found that the presence of Th1 cytokines appeared to enhance sensitivity for lapatinib-induced metabolic suppression and induction of apoptotic cell death, nearly abrogating drug resistance. These studies provide pre-clinical data suggesting the possibility that targeted drug therapy may be combined with vaccination to enhance anti-cancer effects, and furthermore that robust immunity in the form of secreted Th1 cytokines may have the capacity to mitigate resistance to targeted drugs.

Immune interconnectivity of anatomically distant tumors as a potential mediator of systemic responses to local therapy

Complex interactions occur between tumor and host immune system at each site in the metastatic setting, the outcome of which can determine behavior ranging from dormancy to rapid growth. An additional layer of complexity arises from the understanding that cytotoxic T cells can traffic through the host circulatory system. Coupling mathematical models of local tumor-immune dynamics and systemic T cell trafficking allows us to simulate the evolution of tumor and immune cell populations in anatomically distant sites following local therapy and thus computationally evaluate immune interconnectivity. Results suggest that the presence of a secondary site may either inhibit or promote growth of the primary, depending on the capacity for immune recruitment of each tumor and the resulting systemic redistribution of T cells. Treatment such as surgical resection and radiotherapy can be simulated to estimate both the decrease in tumor volume at the local treatment-targeted site, and the change in overall tumor burden and tumor growth trajectories across all sites. Qualitatively similar responses of distant tumors to local therapy (positive and negative abscopal effects) to those reported in the clinical setting were observed. Such findings may facilitate an improved understanding of general disease kinetics in the metastatic setting: if metastatic sites are interconnected through the immune system, truly local therapy does not exist.

Histological immune response patterns in sentinel lymph nodes involved by metastatic melanoma and prognostic significance

BACKGROUND

To further characterize the micromorphometric immunological pattern to metastatic melanoma in sentinel lymph node (SLN) biopsies and completion lymph node (CLN) dissections and their relation to 5-year overall survival (OS).

METHODS

Retrospective cohort of 49 patients from 1996 to 2005 with a positive SLN who underwent CLN dissection (CLD) was studied. Micromorphometric characteristics included follicular center count (FCC)/profile, sinus histiocytosis, metastatic size, tumor infiltrating lymphocytes (intranodal), paracortical dendritic cells, germinal center reaction and morphology. Comparison of Kaplan-Meier survival curves used the exact log-rank statistic.

RESULTS

In the high-FCC (n = 5-51) vs the low-FCC (n < 5) lymph nodes, a delayed separation occurred at 3 years, with 5-year OS rates being 73% vs 54% in the high- and low-FCC groups, respectively. Improved survival up to 3 years was also noted in CLDs that showed a higher FCC when compared to the prior SLN. Patients with metastatic deposits >2 mm had significantly lower 5-year survival (both <.001).

CONCLUSIONS

Nodal micromorphometric features (ie, FCC) are probably related to host immune response to metastasis. Quantitative evaluation of lymphoid follicular centers could provide valuable prognostic information to help to stratify patients.

Oncoplastic Surgery: Keeping It Simple With 5 Essential Volume Displacement Techniques for Breast Conservation in a Patient With Moderate- to Large-Sized Breasts

Oncoplastic surgery is an evolving field in breast surgery combining the strengths of breast surgical oncology with plastic surgery. It provides the surgeon the ability to excise large areas of the breast in the oncologic resection without compromising, and possibly improving, its aesthetic appearance. The purpose of this review is to provide a guide that could help a breast surgeon excise breast cancer in most areas of the breast using 5 oncoplastic techniques. These techniques would be used depending primarily on the location of the cancer in the breast and also on the size of the tumor.