Faculty Bibliography

Frequent overexpression of programmed death-ligand 1 has recently been demonstrated in metaplastic breast cancer, which is a rare breast cancer subtype with limited treatment options. This report describes the clinical course of a patient with metastatic metaplastic breast cancer who had a remarkable response to anti-programmed death-1 therapy with pembrolizumab in combination with nab-paclitaxel. Tissue correlates are presented including tumor-infiltrating lymphocytes and high-programmed death-ligand 1 expression in the tumor.

Importance: The presence of tumor-infiltrating lymphocytes (TILs) is a favorable prognostic factor in breast cancer, and TILs may synergize with chemotherapy and immune checkpoint inhibitor therapy for improved clinical response. A more detailed understanding of the variation in lymphocytic infiltration in breast cancer may aid in identifying subtypes more amenable to immunomodulation. Objective: To determine the median percentage of patients with breast cancer with no, intermediate, or high levels of TIL and assess variations in lymphocytic cell subsets across breast cancer subtypes. Evidence Review: Eligible studies (PubMed, 1990-2015) analyzed tumor lymphocytic, CD8+, and FOXP3+ cellular infiltrates, and used multivariable analyses and quantitative methods for enumerating cell populations. Selection of of studies was performed in accordance with PRISMA guidelines and evaluated by 2 independent appraisers. Findings: Fifteen studies (n = 13914) met prespecified criteria and were reviewed in December 2015. A median of 11% (range, 5%-26%) of breast cancers demonstrate lymphocyte-predominant breast cancer (LPBC), with approximately 16% of cancers showing no evidence of TILs. Triple-negative (TN) breast cancers demonstrated the highest incidence of LPBC (20%; range, 4%-37%). This incidence is similar to that of breast cancers that are human epidermal growth factor 2 positive and either hormone receptor positive or negative (HER2+) at 16% (range 11%-24%). Hormone receptor positive/HER2- (HR+) breast cancer showed the lowest incidence of LPBC at 6% (range, 3%-12%). CD8+ T-cell infiltrates, indicative of type I immunity, were found in 48% of all breast cancers (range, 32%-80%) with similar levels observed in TN (60%; range, 40%-91%) and HER2+ disease (61%; range, 40%-83%). Fewer HR+ tumors demonstrated CD8+ TIL (43%; range, 30%-73%). The highest levels of FOXP3+ cells were observed in TN (70%; range, 65%-76%) and HER2+ disease (67%; range, 61%-74%). A minority of HR+ breast cancers demonstrated high levels of tumor-infiltrating FOXP3+ cells (38%; range, 35%-41%). Conclusions and Relevance: The magnitude of TIL is variable within and between breast cancer subtypes. Levels of lymphocytic subpopulations may identify breast cancers more amenable to immunomodulation and indicate additional strategies to enhance immunity in patients with low to moderate levels of TILs.

Breast cancer has the second highest death toll in women worldwide, despite significant progress in early diagnosis and treatments. The main cause of death is metastatic disease. Matrix metalloproteinases (MMPs) are required for the initial steps of metastasis, and have therefore been considered as ideal pharmacological targets for anti-metastatic therapy. However, clinical trials of MMP inhibitors were unsuccessful. These trials were conducted in patients with advanced disease, beyond the stage when these compounds could have been effective. We hypothesized that early treatment with a selective MMP inhibitor between the time of diagnosis and definitive surgery, the so-called "window-of-opportunity," can inhibit metastasis and thereby improve survival. To investigate our hypothesis we used the 4T1 mouse model of aggressive mammary carcinoma. We treated the animals with SD-7300, an oral inhibitor of MMP-2, -9 and -13, starting after the initial detection of the primary tumor. Seven days later the primary tumors were excised and analyzed for MMP activity, and the SD-7300 treatment was discontinued. After four weeks the animals were sacrificed and their lungs analyzed histologically for number of metastases and metastatic burden (metastases' area / lung section area). SD-7300 treatment inhibited 70-80% of tumor-associated MMP activity (P = 0.0003), reduced metastasis number and metastatic burden by 50-60% (P = 0.002; P = 0.0082, respectively), and increased survival (92% vs. 66.7%; P = 0.0409), relative to control vehicle. These results show that treatment of early invasive breast cancer with selective MMP inhibitors can lower the risk of recurrence and increase long-term disease-free survival.

The huge communities of residential microbes, including bacteria, viruses, Archaea, and Eukaryotes, that colonize humans are increasingly recognized as playing important roles in health and disease. A complex populous ecosystem, the human gastrointestinal (GI) tract harbors up to 1011 bacterial cells per gram of luminal content, whose collective genome, the gut metagenome, contains a vastly greater number of individual genes than the human genome. In health, the function of the microbiome might be considered to be in dynamic equilibrium with the host, exerting both local and distant effects. However, 'disequilibrium' may contribute to the emergence of disease, including malignancy. In this review, we discuss how the intestinal bacterial microbiome and in particular how an 'estrobolome,' the aggregate of enteric bacterial genes capable of metabolizing estrogens, might affect women's risk of developing postmenopausal estrogen receptor-positive breast cancer. Estrobolome composition is impacted by factors that modulate its functional activity. Exploring variations in the composition and activities of the estrobolome in healthy individuals and in women with estrogen-driven breast cancer may lead to development of microbiome-based biomarkers and future targeted interventions to attenuate cancer risk.

Paclitaxel is a widely used chemotherapy agent that has rarely been associated with ophthalmic toxicities. Cystoid macular edema is one such rare side effect of paclitaxel therapy. Its pathophysiology remains poorly understood. Here, we report on a 69-year-old woman who developed cystoid macular edema associated with the albumin-bound formulation of paclitaxel after several months of therapy for breast cancer. After 2 months of drug withdrawal, her vision improved and there was a significant improvement in the macular edema by imaging with spectral-domain optical coherence tomography. Oncologists using taxane agents should be aware of this rare adverse outcome for timely patient referral to an ophthalmologist and appropriate treatment to preserve a patient's visual acuity.

Upon analysis of archived primary tumors of 482 patients with triple negative breast cancer (TNBC) enrolled in two randomized Phase III adjuvant chemotherapy trials, we have found that tumor infiltrating lymphocytes (TILs), as assessed and quantified by hematoxylin and eosin (H&E) staining are a robust and independent predictor of disease-free survival (DFS), distant recurrence-free interval (DRFI) and overall survival (OS).1 Our findings provide confirmation of results observed in TNBC in a European adjuvant chemotherapy dataset and therefore elevate TILs as prognostic biomarker for operable TNBC to level I evidence.

BACKGROUND: An abscopal response describes radiotherapy-induced immune-mediated tumour regression at sites distant to the irradiated field. Granulocyte-macrophage colony-stimulating factor is a potent stimulator of dendritic cell maturation. We postulated that the exploitation of the pro-immunogenic effects of radiotherapy with granulocyte-macrophage colony-stimulating factor might result in abscopal responses among patients with metastatic cancer. METHODS: Patients with stable or progressing metastatic solid tumours, on single-agent chemotherapy or hormonal therapy, with at least three distinct measurable sites of disease, were treated with concurrent radiotherapy (35 Gy in ten fractions, over 2 weeks) to one metastatic site and granulocyte-macrophage colony-stimulating factor (125 mug/m2 subcutaneously injected daily for 2 weeks, starting during the second week of radiotherapy). This course was repeated, targeting a second metastatic site. A Simon's optimal two-stage design was chosen for this trial: an additional 19 patients could be enrolled in stage 2 only if at least one patient among the first ten had an abscopal response. If no abscopal responses were seen among the first ten patients, the study would be deemed futile and terminated. The primary endpoint was the proportion of patients with an abscopal response (defined as at least a 30% decrease in the longest diameter of the best responding abscopal lesion). Secondary endpoints were safety and survival. Analyses were done based on intention to treat. The trial has concluded accrual, and is registered with ClinicalTrials.gov, number NCT02474186. FINDINGS: From April 7, 2003, to April 3, 2012, 41 patients with metastatic cancer were enrolled. In stage 1 of the Simon's two-stage design, ten patients were enrolled: four of the first ten patients had abscopal responses. Thus, the trial proceeded to stage 2, as planned, and an additional 19 patients were enrolled. Due to protocol amendments 12 further patients were enrolled. Abscopal responses occurred in eight (27.6%, 95% CI 12.7-47.2) of the first 29 patients, and 11 (26.8%, 95% CI 14.2-42.9) of 41 accrued patients (specifically in four patients with non-small-cell lung cancer, five with breast cancer, and two with thymic cancer). The most common grade 3-4 adverse events were fatigue (six patients) and haematological (ten patients). Additionally, a serious adverse event of grade 4 pulmonary embolism occurred in one patient. INTERPRETATION: The combination of radiotherapy with granulocyte-macrophage colony-stimulating factor produced objective abscopal responses in some patients with metastatic solid tumours. This finding represents a promising approach to establish an in-situ anti-tumour vaccine. Further research is warranted in this area. FUNDING: New York University School of Medicine's Department of Radiation Oncology and Cancer Institute.

Large cell neuroendocrine carcinoma of the breast (NECB) is an extremely rare type of breast cancer; little is known about effective chemotherapies, and data on pathologic response to treatment are unavailable. We report the case of a 34-years-old woman with large cell NECB with initial clinical and pathologic evidence of treatment response to anthracycline-containing neo-adjuvant therapy. Histologic reassessment early during anthracycline chemotherapy revealed cell death with necrosis of 50% of the tumor cells seen in the biopsy specimen. After completing neo-adjuvant chemotherapy, the patient underwent breast-conserving surgery. Pathologic evaluation of the surgical specimen showed a partial response but margins were positive for residual carcinoma. Despite repeated neo-adjuvant chemotherapy, radiotherapy, and surgical resection, the tumor grew rapidly between surgeries and recurred systemically. Therefore, we review the literature on large cell NECB and its treatment options.