Rita A. Mukhtar

Tumor-associated macrophages in breast cancer as potential biomarkers for new treatments and diagnostics

While several inflammatory cell types participate in cancer development, macrophages specifically play a key role in breast cancer, where they appear to be part of the pathogenesis of high-grade tumors. Tumor-associated macrophages (TAMs) produce factors that promote angiogenesis, remodel tissue and dampen the immune response to tumors. Specific macrophage types contribute to increased metastases in animal models, while human studies show an association between TAMs and tumors with poor prognostic features. Macrophages display a spectrum of phenotypic states, with the tumor microenvironment skewing TAMs towards a ‘nonclassical’ activation state, known as the M2, or wound healing/regulatory state. These TAMs are found in high-risk breast cancers, making them an important therapeutic target to explore. Improved techniques for identifying TAMs should translate into clinical applications for prognosis and treatment.

Elevated Levels of Proliferating and Recently Migrated Tumor-associated Macrophages Confer Increased Aggressiveness and Worse Outcomes in Breast Cancer

PurposeMacrophages play a major role in inflammatory processes and have been associated with poor prognosis in a variety of cancers, including breast cancer. Previously, we investigated the relationship of a subset of tumor-associated macrophages (PCNA+ TAMs) with clinicopathologic characteristics of breast cancer. We reported that high PCNA+ TAM counts were associated with hormone receptor (HR)-negative, high-grade tumors and early recurrence. To further understand the significance of elevated PCNA+ TAMs and the functionality of TAMs, we examined the expression of S100A8/S100A9 with the antibody Mac387. The heterodimeric S100A8/S100A9 complex plays a role in inflammation and is increased in several cancer types.MethodsWe performed immunohistochemistry using the Mac387 antibody on 367 invasive human breast cancer cases. Results were compared to previous PCNA+ TAM counts and were correlated with patient outcomes adjusting for HR status and histologic grade.ResultsLike PCNA+ TAMs, high Mac387 counts were associated with HR negativity, high tumor grade, younger age, and decreased recurrence-free survival. Mac387, however, appears to identify both a subset of macrophages and a subset of tumor cells. The concordance between Mac387 and PCNA+ TAM counts was low and cases that had both high Mac387 and high PCNA+ TAMs counts had a stronger association with early recurrence.ConclusionsThe presence of high numbers of PCNA+ TAMs and Mac387-positive cells in breast cancers with poor outcomes may implicate a subset of TAMs in breast cancer pathogenesis, and may ultimately serve to develop potential cellular targets for therapeutic interventions.

Biology of breast cancer in Nigerian women: a pilot study.

BACKGROUND Compared to the developed world, there are relatively few studies that describe the tumor biology of breast cancer in African women. While little is known about the tumor biology, clinical and epidemiologic studies suggest that breast cancer in African women are characterized by presentation at late stage and poor clinical outcomes. Analysis of the biological features of breast cancers in Nigerian women was designed to bring additional insight to better understand the spectrum of disease, the phenotypes that present, and the types of interventions that might improve outcomes. MATERIALS AND METHODS We performed histological analyses for hormone receptors (estrogen and progesterone receptors), HER2, and tumor infiltrating macrophages (TAM) on 17 breast cancers, obtained from Abia State University Teaching Hospital (Aba, Nigeria), between November 2008 and October 2009. On a subset of these cases, we investigated the potential role of a virus in the etiology of these aggressive cancers. RESULTS The majority of cases in this cohort were characterized as high grade (100% were grade III), triple-negative (65%), and occur in young women (mean age 47 years). We observed high infiltration of TAMs in these tumors, but no evidence of a viral etiology. CONCLUSION Our findings indicate that breast cancers in Nigerian women have a highly aggressive phenotype (high grade, hormone receptor negative), which is similar to other studies from Africa and other developing nations, as well as from African American women, but is significantly different from Caucasian women in the developed world. The presence of high numbers of TAMs in these tumors raises the possibility of targeting the immune microenvironment for therapeutic interventions.

Characterizing the immune microenvironment in high-risk ductal carcinoma in situ of the breast.

PurposeThe recent increase in the incidence of ductal carcinoma in situ (DCIS) has sparked debate over the classification and treatment of this disease. Although DCIS is considered a precursor lesion to invasive breast cancer, some DCIS may have more or less risk than is realized. In this study, we characterized the immune microenvironment in DCIS to determine if immune infiltrates are predictive of recurrence.MethodsFifty-two cases of high-grade DCIS (HG-DCIS), enriched for large lesions and a history of recurrence, were age matched with 65 cases of non-high-grade DCIS (nHG-DCIS). Immune infiltrates were characterized by single- or dual-color staining of FFPE sections for the following antigens: CD4, CD8, CD20, FoxP3, CD68, CD115, Mac387, MRC1, HLA-DR, and PCNA. Nuance multispectral imaging software was used for image acquisition. Protocols for automated image analysis were developed using CellProfiler. Immune cell populations associated with risk of recurrence were identified using classification and regression tree analysis.ResultsHG-DCIS had significantly higher percentages of FoxP3+ cells, CD68+ and CD68+PCNA+ macrophages, HLA-DR+ cells, CD4+ T cells, CD20+ B cells, and total tumor infiltrating lymphocytes compared to nHG-DCIS. A classification tree, generated from 16 immune cell populations and 8 clinical parameters, identified three immune cell populations associated with risk of recurrence: CD8+HLADR+ T cells, CD8+HLADR− T cells, and CD115+ cells.ConclusionThese findings suggest that the tumor immune microenvironment is an important factor in identifying DCIS cases with the highest risk for recurrence and that manipulating the immune microenvironment may be an efficacious strategy to alter or prevent disease progression.

The Prognostic Implications of Macrophages Expressing Proliferating Cell Nuclear Antigen in Breast Cancer Depend on Immune Context

Tumor associated macrophages (TAMs) are recruited from the circulation to the tumor site, and can undergo a spectrum of phenotypic changes, with two contrasting activation states described in the literature: the M1 and M2 phenotypes. We previously identified a population of TAMs that express proliferating cell nuclear antigen (PCNA) and are associated with high grade, hormone receptor negative breast cancers and poor outcomes. In the present exploratory study we again found that high PCNA+ TAM counts in pre-treatment tumor biopsies (102 invasive breast cancer cases from the I-SPY 1 Trial, a prospective neoadjuvant trial with serial core biopsies and gene array data) were associated with high grade, hormone receptor negativity, and decreased recurrence free survival. We explored the association of these PCNA+ TAMs with the expression of M1 and M2 related genes and, contrary to expectation, observed that high PCNA+ TAM levels were associated with more M1- than M2-related genes. An immune gene signature, derived from cytotoxic T cell and MHC Class II genes (Tc/ClassII), was developed and we found that high PCNA+ TAM counts, in the context of a low Tc/ClassII signature score, were associated with significantly worse recurrence free survival in all cases and in hormone receptor negative only cases. We observed similar results using a gene signature-proxy for PCNA+ TAMs in a larger independent set of 425 neoadjuvant-treated breast cancer cases. The results of this exploratory study indicate that high numbers of PCNA+ TAMs, in the absence of an anti-tumor immune microenvironment (as indicated by a low Tc/ClassII signature score), are associated with poor outcomes in breast cancer patients treated with neoadjuvant chemotherapy. This, along with the observation that PCNA+ TAMs were associated predominantly with M1-related genes, may provide new insights into the role of the immune microenvironment in breast cancer.

How to use magnetic resonance imaging following neoadjuvant chemotherapy in locally advanced breast cancer

Magnetic resonance imaging (MRI) is highly sensitive in identifying residual breast cancer following neoadjuvant chemotherapy (NAC), and consequently is a commonly used imaging modality in locally advanced breast cancer patients. In these patients, tumor response is an important prognostic indicator. However, discrepancies between MRI findings and surgical pathology are well documented. Overestimation of residual disease by MRI may result in greater surgery than is actually required while underestimation may result in insufficient surgery. Thus, it is important to understand when MRI findings are reliable and when they are less accurate. MRI most accurately predicts pathology in triple negative, Her2 positive and hormone receptor negative tumors, especially if they are of a solid imaging phenotype. In these cases, post-NAC MRI is highly reliable for surgical planning. Hormone receptor positive cancers and those demonstrating non mass enhancement show lower concordance with surgical pathology, making surgical guidance more nebulous in these cases. Radiologists and surgeons must assess MRI response to NAC in the context of tumor subtype. Indiscriminate interpretations will prevent MRI from achieving its maximum potential in the pre-operative setting.

Long-term survival and renal transplantation in a monozygotic twin with cloacal dysgenesis sequence

Cloacal dysgenesis sequence (CDS) is a severe hindgut malformation occurring in 1:50,000 to 250,000 live births (Qureshi et al. Prenatal diagnosis of cloacal dysgenesis sequence: differential diagnosis from other forms of fetal obstructive uropathy. Fetal Diagn Ther 1998;13:69-74; Bargaje et al. Cloacal dysgenesis sequence. Ann Diagn Pathol 2008;12:62-66). It is characterized by a smooth perineum with no urethral, vaginal, or anal openings, and lack of labioscrotal development. Typically, the bladder, vagina, and colon each end blindly, although persistent cloaca without perineal orifice can be seen. With no egress for urine, infants have renal insufficiency and pulmonary hypoplasia, usually making CDS lethal (Sahinoglu Z et al. The prenatal diagnosis of cloacal dysgenesis in six cases: can the termination of pregnancy always be the first choice? Prenat Diagn 2004;24:10-16). Reported survivors have had a persistent urachus or have been spared the effects of oligohydramnios by the presence of a twin (Liang X. Cloacal dysgenesis sequence: observations in four patients, including three fetuses of second trimester gestation. Pediatr Dev Pathol 1998;1:281-288). We report a case of long-term survival, currently to 25 months of age, and renal transplantation in a monochorionic, diamniotic twin girl with CDS.

The Novel Application of Genomic Profiling Assays to Shorten Inactive Status for Potential Kidney Transplant Recipients With Breast Cancer.

The concern about cancer recurrence has traditionally resulted in delaying kidney transplantation for 2–5 years after a cancer diagnosis in patients who are otherwise eligible for transplant. This period of inactive status to observe the tumor biology can result in significant morbidity and decreased quality of life for patients with end‐stage renal disease (ESRD). We reported the novel application of genomic profiling assays in breast cancer to identify low‐risk cancers in two patients with ESRD who were able to have the mandatory inactive status eliminated prior to kidney transplantation.

Variation in Annual Volume at a University Hospital Does Not Predict Mortality for Pancreatic Resections

Annual volume of pancreatic resections has been shown to affect mortality rates, prompting recommendations to regionalize these procedures to high-volume hospitals. Implementation has been difficult, given the paucity of high-volume centers and the logistical hardships facing patients. Some studies have shown that low-volume hospitals achieve good outcomes as well, suggesting that other factors are involved. We sought to determine whether variations in annual volume affected patient outcomes in 511 patients who underwent pancreatic resections at the University of California, San Francisco between 1990 and 2005. We compared postoperative mortality and complication rates between low, medium, or high volume years, designated by the number of resections performed, adjusting for patient characteristics. Postoperative mortality rates did not differ between high volume years and medium/low volume years. As annual hospital volume of pancreatic resections may not predict outcome, identification of actual predictive factors may allow low-volume centers to achieve excellent outcomes.

Functional Status and Survival After Breast Cancer Surgery in Nursing Home Residents

Importance Breast cancer surgery, the most common cancer operation performed in nursing home residents, is viewed as a low-risk surgical intervention. However, outcomes in patients with high functional dependence and limited life expectancy are poorly understood. Objective To assess the overall survival and functional status changes after breast cancer surgery in female nursing home residents stratified by surgery type. Design, Setting, and Participants This study used Medicare claims from 2003 to 2013 to identify 5969 US nursing home residents who underwent inpatient breast cancer surgery. Using the Minimum Data Set Activities of Daily Living (MDS-ADL) summary score, this study examined preoperative and postoperative function and identified patient characteristics associated with 30-day and 1-year mortality and 1-year functional decline after surgery. Cox proportional hazards regression was used to estimate unadjusted and adjusted hazard ratios (HRs) of mortality. Fine-Gray competing risks regression was used to estimate unadjusted and adjusted subhazard ratios (sHRs) of functional decline. Statistical analysis was performed from January 2016 to January 2018. Main Outcomes and Measures Functional status and death. Results From 2003 to 2013, a total of 5969 female nursing home residents (mean [SD] age, 82 [7] years; 4960 [83.1%] white) underwent breast cancer surgery: 666 (11.2%) underwent lumpectomy, 1642 (27.5%) underwent mastectomy, and 3661 (61.3%) underwent lumpectomy or mastectomy with axillary lymph node dissection (ALND). The 30-day mortality rates were 8% after lumpectomy, 4% after mastectomy, and 2% after ALND. The 1-year mortality rates were 41% after lumpectomy, 30% after mastectomy, and 29% after ALND. Among 1-year survivors, the functional decline rate was 56% to 60%. The mean MDS-ADL score increased (signifying greater dependency) by 3 points for lumpectomy, 4 points for mastectomy, and 5 points for ALND. In multivariate analysis, poor baseline MDS-ADL score (range, 20-28) was associated with a higher 1-year mortality risk (lumpectomy: HR, 1.92 [95% CI, 1.23-3.00], P = .004; mastectomy: HR, 1.80 [95% CI, 1.35-2.39], P < .001; and ALND: HR, 1.77 [95% CI, 1.46-2.15], P < .001). After multivariate adjustment, preoperative decline in MDS-ADL score (lumpectomy: sHR, 1.59 [95% CI, 1.25-2.03], P < .001; mastectomy: sHR, 1.79; [95% CI, 1.52-2.09], P < .001; and ALND: sHR, 1.72 [95% CI, 1.56-1.91], P < .001) and cognitive impairment (lumpectomy: sHR, 1.27 [95% CI, 1.03-1.56], P = .02; mastectomy: sHR, 1.26 [95% CI, 1.09-1.45], P = .002; and ALND: sHR, 1.14 [95% CI, 1.04-1.24], P = .003) were significantly associated with 1-year functional decline across all breast cancer surgery groups. Conclusions and Relevance For female nursing home residents who underwent breast cancer surgery, 30-day mortality and survival as well as 1-year mortality and functional decline were high. The 1-year survivors had significant functional decline. This study’s findings suggest that this information should be incorporated into collaborative surgical decision-making processes.