A New Twist on a Classic: Enhancing Radioiodine Uptake in Advanced Thyroid Cancer

Advanced differentiated thyroid cancer that is resistant to radioactive iodine therapy may become responsive with a unique treatment combination of chloroquine and vorinostat. This treatment was demonstrated in cellular and animal models of thyroid cancer to inhibit endocytosis of the plasma membrane-bound iodine transporter, NIS, and restore iodine uptake. See related article by Read et al., p. 1352.

The Combined Effect of Immune Checkpoint Inhibitors and Tyrosine Kinase Inhibitors on Thyroid Function

Background: Recent successes with immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs) for the treatment of solid malignancies have paved the way for a new era of combined therapy. A common side effect seen with each of these classes of treatment is thyroid dysfunction, with rates estimated at 30-40% for TKI and 10-20% for ICI. However, little is known about the effect of combined ICI+TKI therapy on thyroid function. Therefore, this study evaluated the incidence, clinical features, and risk factors for developing thyroid abnormalities during ICI+TKI therapy and the relationship to cancer outcomes. Methods: We conducted a retrospective cohort study of patients treated with combination ICI+TKI cancer therapy at City of Hope Comprehensive Cancer Center from 2017 to 2023 who had pretreatment normal thyrotropin (TSH) levels. Primary analyses assessed the frequency, timing, and severity of thyroid function test abnormalities during ICI+TKI cancer therapy, and the requirement for thyroid hormone replacement. Secondary analyses evaluated risk factors for the development of thyroid dysfunction, including sex and drug regimen, and the association with cancer progression-free survival or overall survival. Univariable and multivariable models were used. Results: There were 106 patients who received ICI+TKI therapy with a median age of 63.5 years and a median follow-up of 12.8 months (interquartile range [IQR] 5.9-20.9). Notably, 63.2% (67/106) developed thyroid function abnormalities during ICI+TKI therapy, including 11 (10.4%) with hyperthyroidism, 42 (39.6%) with subclinical hypothyroidism (SCHypo), and 14 (13.2%) with overt hypothyroidism. The onset of thyroid dysfunction occurred at a median of 7 weeks (IQR 3.1-9.0) after start of ICI+TKI treatment for hyperthyroidism, 8.0 weeks (IQR 3.0-19.0) for SCHypo, and 8.1 weeks (IQR 5.9-9.1) for overt or worsening hypothyroidism. Hyperthyroidism resolved to hypothyroidism or normal TSH without intervention in all subjects, suggesting thyroiditis, and hypothyroidism was readily treated with thyroid hormone replacement. Conclusions: Thyroid dysfunction is a frequent adverse event in individuals treated with combination ICI+TKI therapy, with our data suggesting a rapid onset and higher incidence than previously seen with ICI or TKI therapy alone. Therefore, close monitoring of thyroid function during initial therapy and multidisciplinary care with endocrinology are recommended to facilitate early detection and initiation of thyroid hormone replacement in these patients.

A pathologically expanded, clonal lineage of IL-21 producing CD4+ T cells drives Inflammatory neuropathy

Inflammatory neuropathies, which include CIDP (chronic inflammatory demyelinating polyneuropathy) and GBS (Guillain Barre Syndrome), result from autoimmune destruction of the peripheral nervous system (PNS) and are characterized by progressive weakness and sensory loss. CD4+ T cells play a key role in the autoimmune destruction of the PNS. Yet, key properties of pathogenic CD4+ T cells remain incompletely understood. Here, we use paired scRNAseq and scTCRseq of peripheral nerves from an inflammatory neuropathy mouse model to identify IL-21 expressing CD4+ T cells that are clonally expanded and multifunctional. These IL-21-expressing CD4+ T cells are comprised of two transcriptionally distinct expanded populations, which express genes associated with Tfh and Tph subsets. Remarkably, TCR clonotypes are shared between these two IL-21-expressing populations, suggesting a common lineage differentiation pathway. Finally, we demonstrate that IL-21 signaling is required for neuropathy development and pathogenic T cell infiltration into peripheral nerves. IL-21 signaling upregulates CXCR6, a chemokine receptor that promotes CD4+ T cell localization in peripheral nerves. Together, these findings point to IL-21 signaling, Tfh/Tph differentiation, and CXCR6-mediated cellular localization as potential therapeutic targets in inflammatory neuropathies.

Safety and efficacy of immune checkpoint inhibitor cancer therapy in patients with preexisting type 1 diabetes mellitus

Introduction

Immune checkpoint inhibitors (ICI) produce dramatic tumor shrinkage and durable responses in many advanced malignancies, but their use is limited by the development of immune-related adverse events (IRAEs) that occur in up to 60% of patients and often affect endocrine organs. Concern for more severe IRAEs in patients with preexisting autoimmune diseases, including type 1 diabetes mellitus (T1DM), has led to the exclusion of such individuals from clinical trials of ICI therapy. As a result, little is known about the safety and efficacy of ICI in this population. Here, we report safety and treatments outcomes in ICI-treated patients with preexisting T1DM.

Methods

This retrospective case-controlled study evaluated adult patients with T1DM who received ICI therapy for solid malignancies from 2015 to 2021 at four academic medical centers. Patients with prior ICI therapy, bone marrow transplantation, or pregnancy were excluded. We collected data on demographics, cancer diagnosis and treatment, IRAE incidence and severity, and diabetes management. Controls were matched 2:1 by age, sex, cancer diagnosis, and ICI therapy class.

Results

Of 12,142 cancer patients treated with ICI therapy, we identified 11 with a preexisting confirmed diagnosis of T1DM prior to starting ICI therapy. Mean age was 50.6 years, 63.6% were women, and most received anti-PD1/PDL1 monotherapy (10/11) compared with combination therapy (1/11). Grade 3/4 IRAEs were seen in 3/11 subjects with preexisting T1DM and were hepatitis, myositis, and myasthenia gravis. All three cases had interruption of ICI therapy and administration of adjunct therapies, including steroids, IVIG, or mycophenolate mofetil with resolution of the IRAE. The odds of all-grade IRAEs and of severe IRAEs were comparable between cases and controls matched for age, sex, cancer type, and ICI therapy [OR 0.83 (95% CI 0.2-3.56), p = 0.81, and OR 1.69 (0.31-9.36), p = 0.55, respectively]. Overall survival was not different between patients with T1DM and controls (p = 0.54). No patients had hospitalizations for diabetes-related complications during therapy.

Discussion

These data suggest that ICI monotherapy can successfully be used in patients with preexisting T1DM, with IRAE rates comparable with individuals without preexisting T1DM. Larger, prospective studies of these potentially life-saving ICI therapies that include patients with preexisting autoimmunity are warranted.

Reduced Tumor Size of Untreated Papillary Thyroid Carcinoma After Immune Checkpoint Inhibitor-Induced Thyroiditis

Background/Objective

Immune checkpoint inhibitors (CPIs) activate antitumoral immune responses and are used to treat multiple types of primary and metastatic malignancies. Thyroid dysfunction is a known immune-related adverse event of CPI therapy. There are few data on the effect of CPI and CPI-induced thyroiditis on primary papillary thyroid carcinoma (PTC). We present a patient who developed CPI-induced thyroiditis during treatment for a nonthyroid malignancy and subsequent regression of a coexisting untreated primary PTC.

Case Report

A 49-year-old man with metastatic colon adenocarcinoma was found to have a large right thyroid nodule with biopsy confirmation of PTC. He did not have compressive symptoms or evidence of metastatic PTC. Resection was not performed because of colon cancer therapy. Treatment with CPI (ezabenlimab, an anti-programmed cell death protein 1 antibody) was initiated for the treatment of colon cancer. Four months after the initiation of CPI therapy, testing showed thyroid-stimulating hormone and free thyroxine levels of 174.9 (0.3-4.0 mIU/L) and 0.67 (0.93-1.70 ng/dL), respectively, consistent with CPI-induced hypothyroidism. Levothyroxine therapy was initiated. Repeat imaging 3 months later demonstrated a decrease in the tumor size to 4.1 × 4.9 × 4.2 cm (calculated volume change, -8.3% from baseline). At the last imaging, 1 year after the onset of CPI-induced thyroiditis, the PTC continued to decrease in size and measured 2.9 × 3.9 × 3.2 cm (volume change, -60.7% from baseline).

Discussion

CPI-induced thyroiditis suggests the development of an immune response against thyroid tissue and may reflect a similar increased immune response against PTC cells leading to tumor regression in this case.

Conclusion

Further research to assess the immunologic mechanism underlying this association is warranted to potentially develop improved immunotherapy for PTC.

Prognostic Value of Preoperative Molecular Testing and Implications for Initial Surgical Management in Thyroid Nodules Harboring Suspected (Bethesda V) or Known (Bethesda VI) Papillary Thyroid Cancer

Importance

Molecular testing is commonly used in the diagnosis of thyroid nodules with indeterminate cytology. The role of molecular testing in prognosticating oncologic outcomes in thyroid nodules with suspicious or malignant cytology is unclear.

Objective

To determine whether molecular profiling of Bethesda V (suspicious for thyroid cancer) and VI (thyroid cancer) nodules is associated with improved prognostication and whether it may inform initial treatment.

Design, Setting, and Participants

This retrospective cohort study included consecutive patients with Bethesda V or VI nodules who underwent surgery, with histopathology showing differentiated thyroid cancer, between May 1, 2016, and July 31, 2019 in the University of California, Los Angeles health system. Data were analyzed between April 2, 2021, and January 18, 2023.

Exposures

Masked ThyroSeq, version 3 molecular analysis after completion of initial treatment and acquisition of follow-up data.

Main Outcomes and Measures

Structural disease persistence or recurrence, distant metastasis, and recurrence-free survival were assessed using ThyroSeq Cancer Risk Classifier (CRC) molecular risk groups (low, RAS-like; intermediate, BRAF-like; high, combination of BRAF/RAS plus TERT or other high-risk alterations) using Cox proportional hazards regression models.

Results

In 105 patients with papillary thyroid cancer (median [IQR] follow-up, 3.8 [3.0-4.7] years), ThyroSeq identified genomic alterations in 100 (95%) samples (6 [6%] low risk, 88 [88%] intermediate risk, and 6 [6%] high risk; median [IQR] age, 44 [34-56] years; 68 [68%] female and 32 [32%] male). No patients with low-risk or negative results experienced recurrence. Of the 88 patients with intermediate risk, 6 (7%) experienced local recurrence, with 1 of them also developing distant metastasis. The 6 patients with high risk (all with BRAF V600E plus TERT mutation) underwent total thyroidectomy followed by radioactive iodine (RAI) ablation. Four patients with high risk (67%) experienced local recurrence, with 3 of them also developing distant metastasis. Thus, patients with high-risk alterations were more likely to experience persistence or recurrence and distant metastasis than patients with intermediate risk. In a multivariable analysis incorporating patient age, sex, cancer size, ThyroSeq molecular risk group, extrathyroidal extension, lymph node positivity, American Thyroid Association risk, and RAI ablation, only cancer size (hazard ratio, 1.36; 95% CI, 1.02-1.80) and ThyroSeq CRC molecular risk group (high vs intermediate and low: hazard ratio, 6.22; 95% CI, 1.04-37.36) were associated with structural recurrence.

Conclusions and Relevance

Among the 6% of patients with high-risk ThyroSeq CRC alterations in this cohort study, the majority experienced recurrence or distant metastasis despite initial treatment with total thyroidectomy and RAI ablation. In contrast, patients with low- and intermediate-risk alterations had a low recurrence rate. Preoperative knowledge of molecular alteration status at diagnosis may allow for deescalation of initial surgery and refining of the intensity of postoperative surveillance in patients presenting with Bethesda V and VI thyroid nodules.

Safety and Activity of Immune Checkpoint Inhibitors in People Living With HIV and Cancer: A Real-World Report From the Cancer Therapy Using Checkpoint Inhibitors in People Living With HIV-International (CATCH-IT) Consortium

PURPOSE

Compared with people living without HIV (PWOH), people living with HIV (PWH) and cancer have traditionally been excluded from immune checkpoint inhibitor (ICI) trials. Furthermore, there is a paucity of real-world data on the use of ICIs in PWH and cancer.

METHODS

This retrospective study included PWH treated with anti-PD-1- or anti-PD-L1-based therapies for advanced cancers. Kaplan-Meier method was used to estimate overall survival (OS) and progression-free survival (PFS). Objective response rates (ORRs) were measured per RECIST 1.1 or other tumor-specific criteria, whenever feasible. Restricted mean survival time (RMST) was used to compare OS and PFS between matched PWH and PWOH with metastatic NSCLC (mNSCLC).

RESULTS

Among 390 PWH, median age was 58 years, 85% (n = 331) were males, 36% (n = 138) were Black; 70% (n = 274) received anti-PD-1/anti-PD-L1 monotherapy. Most common cancers were NSCLC (28%, n = 111), hepatocellular carcinoma ([HCC]; 11%, n = 44), and head and neck squamous cell carcinoma (HNSCC; 10%, n = 39). Seventy percent (152/216) had CD4+ T cell counts ≥200 cells/µL, and 94% (179/190) had HIV viral load <400 copies/mL. Twenty percent (79/390) had any grade immune-related adverse events (irAEs) and 7.7% (30/390) had grade ≥3 irAEs. ORRs were 69% (nonmelanoma skin cancer), 31% (NSCLC), 16% (HCC), and 11% (HNSCC). In the matched mNSCLC cohort (61 PWH v 110 PWOH), 20% (12/61) PWH and 22% (24/110) PWOH had irAEs. Adjusted 42-month RMST difference was -0.06 months (95% CI, -5.49 to 5.37; P = .98) for PFS and 2.23 months (95% CI, -4.02 to 8.48; P = .48) for OS.

CONCLUSION

Among PWH, ICIs demonstrated differential activity across cancer types with no excess toxicity. Safety and activity of ICIs were similar between matched cohorts of PWH and PWOH with mNSCLC.

Antigen presentation by clonally diverse CXCR5+ B cells to CD4 and CD8 T cells is associated with durable response to immune checkpoint inhibitors

Introduction

Increased T cell infiltration and interferon gamma (IFNγ) pathway activation are seen in tumors of melanoma patients who respond to ICI (immune checkpoint inhibitor) or MAPK pathway inhibitor (MAPKi) therapies. Yet, the rate of durable tumor control after ICI is almost twice that of MAPKi, suggesting that additional mechanisms may be present in patients responding to ICI therapy that are beneficial for anti-tumor immunity.

Methods

We used transcriptional analysis and clinical outcomes from patients treated with ICI or MAPKi therapies to delineate immune mechanisms driving tumor response.

Results

We discovered response to ICI is associated with CXCL13-driven recruitment of CXCR5+ B cells with significantly higher clonal diversity than MAPKi. Our in vitro data indicate that CXCL13 production was increased in human peripheral blood mononuclear cells by anti-PD1, but not MAPKi, treatment. Higher B cell infiltration and B cell receptor (BCR) diversity allows presentation of diverse tumor antigens by B cells, resulting in activation of follicular helper CD4 T cells (Tfh) and tumor reactive CD8 T cells after ICI therapy. Higher BCR diversity and IFNγ pathway score post-ICI are associated with significantly longer patient survival compared to those with either one or none.

Conclusions

Response to ICI, but not to MAPKi, depends on the recruitment of CXCR5+ B cells into the tumor microenvironment and their productive tumor antigen presentation to follicular helper and cytotoxic, tumor reactive T cells. Our study highlights the potential of CXCL13 and B cell based strategies to enhance the rate of durable response in melanoma patients treated with ICI.

Clonally expanded, thyrotoxic effector CD8+ T cells driven by IL-21 contribute to checkpoint inhibitor thyroiditis

Autoimmune toxicity occurs in up to 60% of patients treated with immune checkpoint inhibitor (ICI) therapy for cancer and represents an increasing clinical challenge for expanding the use of these treatments. To date, human immunopathogenic studies of immune-related adverse events (IRAEs) have relied on sampling of circulating peripheral blood cells rather than affected tissues. Here, we directly obtained thyroid specimens from individuals with ICI-thyroiditis, one of the most common IRAEs, and compared immune infiltrates with those from individuals with spontaneous autoimmune Hashimoto's thyroiditis (HT) or no thyroid disease. Single-cell RNA sequencing revealed a dominant, clonally expanded population of thyroid-infiltrating cytotoxic CXCR6+ CD8+ T cells (effector CD8+ T cells) present in ICI-thyroiditis but not HT or healthy controls. Furthermore, we identified a crucial role for interleukin-21 (IL-21), a cytokine secreted by intrathyroidal T follicular (TFH) and T peripheral helper (TPH) cells, as a driver of these thyrotoxic effector CD8+ T cells. In the presence of IL-21, human CD8+ T cells acquired the activated effector phenotype with up-regulation of the cytotoxic molecules interferon-γ (IFN-γ) and granzyme B, increased expression of the chemokine receptor CXCR6, and thyrotoxic capacity. We validated these findings in vivo using a mouse model of IRAEs and further demonstrated that genetic deletion of IL-21 signaling protected ICI-treated mice from thyroid immune infiltration. Together, these studies reveal mechanisms and candidate therapeutic targets for individuals who develop IRAEs.

Spectrum of Clinical Presentations, Imaging Findings, and HLA Types in Immune Checkpoint Inhibitor-Induced Hypophysitis

Context

Hypophysitis is a known immune-related adverse event (irAE) of immune checkpoint inhibitors (CPIs), commonly associated with CTLA-4 inhibitors and less often with PD-1/PD-L1 inhibitors.

Objective

We aimed to determine clinical, imaging, and HLA characteristics of CPI-induced hypophysitis (CPI-hypophysitis).

Methods

We examined the clinical and biochemical characteristics, magnetic resonance imaging (MRI) of the pituitary, and association with HLA type in patients with CPI-hypophysitis.

Results

Forty-nine patients were identified. Mean age was 61.3 years, 61.2% were men, 81.6% were Caucasian, 38.8% had melanoma, and 44.5% received PD-1/PD-L1 inhibitor monotherapy while the remainder received CTLA-4 inhibitor monotherapy or CTLA-4/PD-1 inhibitor combination therapy. A comparison of CTLA-4 inhibitor exposure vs PD-1/PD-L1 inhibitor monotherapy revealed faster time to CPI-hypophysitis (median 84 vs 185 days, P < .01) and abnormal pituitary appearance on MRI (odds ratio 7.00, P = .03). We observed effect modification by sex in the association between CPI type and time to CPI-hypophysitis. In particular, anti-CTLA-4 exposed men had a shorter time to onset than women. MRI changes of the pituitary were most common at the time of hypophysitis diagnosis (55.6% enlarged, 37.0% normal, 7.4% empty or partially empty) but persisted in follow-up (23.8% enlarged, 57.1% normal, 19.1% empty or partially empty). HLA typing was done on 55 subjects; HLA type DQ0602 was over-represented in CPI-hypophysitis relative to the Caucasian American population (39.4% vs 21.5%, P = 0.01) and CPI population.

Conclusion

The association of CPI-hypophysitis with HLA DQ0602 suggests a genetic risk for its development. The clinical phenotype of hypophysitis appears heterogenous, with differences in timing of onset, changes in thyroid function tests, MRI changes, and possibly sex related to CPI type. These factors may play an important role in our mechanistic understanding of CPI-hypophysitis.

Inhibition of IL-17A Protects against Thyroid Immune-Related Adverse Events while Preserving Checkpoint Inhibitor Antitumor Efficacy

Immune checkpoint inhibitor (ICI) immunotherapy leverages the body's own immune system to attack cancer cells but leads to unwanted autoimmune side effects in up to 60% of patients. Such immune-related adverse events (IrAEs) may lead to treatment interruption, permanent organ dysfunction, hospitalization, and premature death. Thyroiditis is one of the most common IrAEs, but the cause of thyroid IrAEs remains unknown. In this study, we use a new, physiologically relevant mouse model of ICI-associated autoimmunity to identify a key role for type 3 immune cells in the development of thyroid IrAEs. Multiple lineages of IL-17A-producing T cells expand in thyroid tissue with ICI treatment. Intrathyroidal IL-17A-producing innate-like γδT17 cells were increased in tumor-free mice, whereas adaptive Th17 cells were also prominent in tumor-bearing mice, following ICI treatment. Furthermore, Ab-based inhibition of IL-17A, a clinically available therapy, significantly reduced thyroid IrAE development in ICI-treated mice with and without tumor challenge. Finally, combination of IL-17A neutralization with ICI treatment in multiple tumor models did not reduce ICI antitumor efficacy. These studies suggest that targeting Th17 and γδT17 cell function via the IL-17A axis may reduce IrAEs without impairing ICI antitumor efficacy and may be a generalizable strategy to address type 3 immune-mediated IrAEs.

Factors Associated With Hospitalization Among Breast Cancer Patients With COVID-19: A Diverse Multi-Center Los Angeles Cohort Study

BACKGROUND

The SARS-CoV-2 virus has infected and killed millions of people worldwide. Breast cancer is the most prevalent cancer in women and few studies have investigated the outcomes of patients with a history of breast cancer and COVID-19. We report the clinical outcomes of patients with invasive breast cancer who tested positive for SARS-CoV-2, including hospitalization and death, and evaluate demographic and cancer-related factors associated with these outcomes.

PATIENTS

Patients with a history of invasive breast cancer and positive SARS-CoV-2 test from January 1 to December 31, 2020 at two large, academic Los Angeles health systems were included.

METHODS

Retrospective chart review of the electronic medical record was performed. Data for demographic and cancer-related factors were manually abstracted. Relationships between outcomes and clinical variables were evaluated using Fisher's exact test and linear regression analysis.

RESULTS

Among a total of 132 patients, 40 (30.3%) were hospitalized, while 11 (8.3%) required intensive care support, and 8 patients (6.1%) died. Older age and presence of one or more additional comorbidities were associated with hospitalization and death (P = .010, P = .003, P = .034, P < .001). Hispanic/Latinx ethnicity was associated with hospitalization (P = .047). Cancer treatment was not associated with hospitalization or death.

CONCLUSION

In our diverse, multi-center, breast cancer cohort, Hispanic/Latinx ethnicity, older age and presence of other comorbidities were associated with worse outcomes from COVID-19. Breast cancer treatment, including surgery, radiation, systemic therapy, and endocrine therapy, was not associated with hospitalization in our cohort. Further studies are needed to explore the relationship between breast cancer and COVID-19 outcomes.

Optimal Thyroid Hormone Replacement Dose in Immune Checkpoint Inhibitor-Associated Hypothyroidism Is Distinct from Hashimoto's Thyroiditis

Background: Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many advanced cancers but are recognized to cause treatment-limiting immune-related adverse events (IrAE). ICI-associated thyroiditis is the most common endocrine IrAE and usually resolves to permanent hypothyroidism. Optimal thyroid hormone replacement in these patients remains unclear. We report the levothyroxine (LT4) dose needed to achieve stable euthyroid state in patients with hypothyroidism from ICI-associated thyroiditis, with comparison to patients with Hashimoto's thyroiditis (HT) and athyreotic state. Methods: We conducted a retrospective study of adults with ICI-associated hypothyroidism treated with LT4 at an academic medical center. Patient data were collected from the electronic medical record. Cases had ICI exposure followed first by hyperthyroidism and then subsequent hypothyroidism. Controls were HT (positive thyroid autoantibodies, requiring LT4) and athyreotic (total thyroidectomy or radioiodine ablation, requiring LT4) patients. Patients with central hypothyroidism, thyroid cancer, pregnancy, gastrointestinal stromal tumors, and use of L-triiodothyronine were excluded. Our primary outcome compared LT4 dose needed to achieve euthyroid state (thyrotropin 0.3-4.7 mIU/L over >6 consecutive weeks) for ICI-associated hypothyroidism, HT, and athyreotic patients, considering the impact of age and possible interfering medications by linear regression modeling. Secondary analysis considered the impact of endocrine specialty care on the time to euthyroid state. Results: One hundred three patients with ICI-associated thyroiditis were identified. Sixty-six of the 103 patients achieved euthyroid state; 2 with intrinsic thyroid gland function recovery and 64 on LT4. The mean LT4 dose achieving stable euthyroid state was 1.45 ± standard deviation (SD) 0.47 mcg/[kg·day] in ICI-associated hypothyroidism, 1.25 ± SD 0.49 mcg/[kg·day] in HT, and 1.54 ± SD 0.38 mcg/[kg·day] in athyreotic patients, using actual body weight. The difference in dose between ICI-associated hypothyroidism and HT was statistically significant (p = 0.0093). Dosing differences were not explained by age or use of interfering medications. Conclusions: ICI-associated thyroiditis represents an increasingly recognized cause of hypothyroidism. Our study demonstrates that patients with ICI-associated hypothyroidism have different thyroid hormone dosing requirements than patients with HT. Based on our findings and prior reports, we recommend that in patients with ICI-associated thyroiditis LT4 therapy be started at an initial weight-based dose of 1.45 mcg/[kg·day] once serum free thyroxine levels fall below the reference range.

Sex Differences in Immunity

Strong epidemiological evidence now exists that sex is an important biologic variable in immunity. Recent studies, for example, have revealed that sex differences are associated with the severity of symptoms and mortality due to coronavirus disease 2019 (COVID-19). Despite this evidence, much remains to be learned about the mechanisms underlying associations between sex differences and immune-mediated conditions. A growing body of experimental data has made significant inroads into understanding sex-influenced immune responses. As physicians seek to provide more targeted patient care, it is critical to understand how sex-defining factors (e.g., chromosomes, gonadal hormones) alter immune responses in health and disease. In this review, we highlight recent insights into sex differences in autoimmunity; virus infection, specifically severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; and cancer immunotherapy. A deeper understanding of underlying mechanisms will allow the development of a sex-based approach to disease screening and treatment.

Management of Immunotherapy-Related Toxicities, Version 1.2022, NCCN Clinical Practice Guidelines in Oncology

The aim of the NCCN Guidelines for Management of Immunotherapy-Related Toxicities is to provide guidance on the management of immune-related adverse events resulting from cancer immunotherapy. The NCCN Management of Immunotherapy-Related Toxicities Panel is an interdisciplinary group of representatives from NCCN Member Institutions, consisting of medical and hematologic oncologists with expertise across a wide range of disease sites, and experts from the areas of dermatology, gastroenterology, endocrinology, neurooncology, nephrology, cardio-oncology, ophthalmology, pulmonary medicine, and oncology nursing. The content featured in this issue is an excerpt of the recommendations for managing toxicities related to CAR T-cell therapies and a review of existing evidence. For the full version of the NCCN Guidelines, including recommendations for managing toxicities related to immune checkpoint inhibitors, visit NCCN.org.

Polyendocrine Autoimmunity and Diabetic Ketoacidosis Following Anti-PD-1 and Interferon α

Immune checkpoint inhibitor (ICI) therapies are now first-line therapy for many advanced malignancies in adults, with emerging use in children. With increasing ICI use, prompt recognition and optimal management of ICI-associated immune-related adverse events (IRAEs) are critical. Nearly 60% of ICI-treated adults develop IRAEs, which commonly manifest as autoimmune skin, gastrointestinal, and endocrine disease and can be life-threatening. The incidence, presentation, and disease course of spontaneous autoimmune diseases differ between adults and children, but the pattern of pediatric IRAEs is currently unclear. We report a case of a pediatric patient presenting with new onset autoimmune diabetes mellitus and diabetic ketoacidosis during ICI treatment of fibrolamellar hepatocellular carcinoma (FLC). Distinct from spontaneous type 1 diabetes mellitus (T1DM), this patient progressed rapidly and was negative for known β cell autoantibodies. Additionally, the patient was positive for 21-hydroxylase autoantibodies, suggesting development of concomitant adrenal autoimmunity. Current guidelines for the management of IRAEs in adults may not be appropriate for the management of pediatric patients, who may have different autoimmune risks in a developmental context.

COVID-19 outcomes in patients with a history of breast cancer: A diverse multicenter Los Angeles cohort study

e12544

Background: Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has affected over 100 million individuals during the current pandemic. Cancer is a reported risk factor for worse outcomes from SARS-CoV-2 infection and its clinical syndrome COVID-19. However, risk associated with specific cancer subtypes, extent of disease, and treatment history remains unclear. Breast cancer is the most common cancer in women and is treated with multiple modalities that may affect COVID-19 severity and outcomes, including surgery, radiation (RT), hormone therapy (HT), and chemotherapy (CT). Methods: We conducted a retrospective cohort study of patients with SARS-CoV-2 and history of breast cancer at two academic centers in Los Angeles, CA between January – September, 2020. Demographic information, cancer diagnosis, treatment history, comorbid conditions, and clinical outcomes of COVID-19 were reviewed. The primary outcome was rate of hospitalization for COVID-19. Associations were evaluated for significance by chi-square test or Student’s T test, with a = 0.05. Results: Our cohort included 61 patients with history of breast cancer. 19 (31.1%) required hospitalization and 3 (4.9%) died from COVID-19. Median age was 61 years. 44% of patients were White/Caucasian, 37.7% Hispanic/Latinx, 8% Black/African American, 5% Asian, and 5% were of another race. 87% of patients had local or regional disease and 13% had distant metastases. 53% of patients had ever received CT historically, 66% HT, and 53% RT. 25% of patients received cancer treatment (surgery, CT, or RT) within 90 days of COVID-19 diagnosis. 38% were on HT at time of COVID-19 diagnosis. Patients with prior RT were more likely to be hospitalized from COVID-19 than those with no prior RT (44% vs 14%, p = 0.02), as were patients with 2 or more comorbidities (p = 0.01). In addition, there was a trend toward lower hospitalization rates for patients on HT [24% vs. 42% (p = 0.17)] and a trend toward higher hospitalization rate for non-white ethnicity [35% vs. 25% (p = ns)]. Extent of disease, history of CT, or receipt of any cancer treatment (e.g. surgery, RT, CT) within 90 days of COVID-19 diagnosis were not associated with hospitalization rate. Conclusions: In our diverse cohort of breast cancer patients with COVID-19 a history of RT and presence of multiple comorbidities were both associated with increased risk of hospitalization, while a history of HT was not. Further investigation is needed to validate these findings in larger cohorts. These findings may inform recommendations for breast cancer patients during the ongoing SARS-CoV-2 pandemic.

Identification of RORg+T Cells as Key Players in Thyroid Autoimmunity From Checkpoint Immunotherapy

Purpose: Immune checkpoint inhibitors (ICI) are powerful new cancer therapies that leverage the body’s own immune system to attack cancer cells. Unfortunately, their use may be limited by the development of immune-related adverse events (IrAE) in up to 60% of patients. Thyroiditis is a common IrAE, with shared and distinct features from spontaneous thyroid autoimmunity, i.e. Hashimoto thyroiditis (HT). The cause of IrAE remains unknown, however, recent data suggest that toxicity can be uncoupled from anti-tumor effects.

Methods: We developed a novel mouse model to study mechanisms of IrAE, in which ICI (anti-PD-1 and/or anti-CTLA-4) treatment leads to multi-organ immune infiltrates, including thyroiditis. To understand immune changes occurring with ICI-autoimmunity, we first evaluated changes in the frequency and activation status of different immune cells in our mice using immunohistochemistry (IHC) and flow cytometry. Then we confirmed these findings in peripheral blood and thyroid fine needle aspiration (FNA) specimens from patients with ICI-thyroiditis, HT, or no IrAE, using flow cytometry and single cell RNA sequencing (scRNAseq) techniques.

Results: In our mouse model, ICI treatment of autoimmune-prone non-obese diabetic mice induces multi-organ autoimmunity. Modeling ICI-IrAE observed in humans, our mice developed increased immune infiltrates in multiple tissues (e.g. thyroid, colon, liver, lung), autoantibodies, and acceleration of underlying autoimmune risk (i.e. diabetes). Increased frequency of autoimmune disease was seen with combination (anti-PD-1 + anti-CTLA-4) vs. single agent ICI. We found increased IL-17A⁺ T cells in secondary lymphoid tissues of ICI-treated mice, a cytokine produced by RORγ ⁺ Th17 and Tc17 cells and associated with autoimmunity. IHC studies on thyroid infiltrates showed accumulation of CD4⁺ and CD8⁺ T cells and macrophages in ICI-treated vs. isotype control mice. This finding was confirmed by flow cytometry analyses of thyroid-infiltrating leukocytes in ICI-thyroiditis mice, which showed significantly increased T cells, specifically RORγ ⁺ T cells, and rare B220⁺ B, CD11b⁺ myeloid, or NKp46⁺ NK cells. In patients with ICI-thyroiditis, thyroid FNA showed that thyroid immune infiltrates were predominately T cells. scRNAseq studies in patients with ICI-thyroiditis showed enrichment of Th17 and Tc17 (RORγ ⁺ IL23R⁺ CD161⁺) T cells, compared to ICI-treated patients without IrAE.

Conclusion: We have identified a role for RORγ ⁺ Th17 and Tc17 cells in thyroid autoimmunity from ICI using a newly developed mouse model of ICI-associated IrAE and translational studies in patients with ICI-thyroiditis. Th17 and Tc17 cells have previously been associated with spontaneous autoimmune disease, including HT, but have not yet been characterized in IrAE. These cells provide a potential therapeutic target for prevention of endocrine IrAE from ICI.

Frequency of Thyroid Hormone Replacement After Lobectomy for Differentiated Thyroid Cancer

OBJECTIVE

To determine the frequency of levothyroxine (LT4) supplementation after therapeutic lobectomy for low-risk differentiated thyroid cancer (DTC).

METHODS

This retrospective cohort study enrolled adult patients with low-risk DTC confirmed using surgical pathology who underwent therapeutic lobectomy at a single institution from January 2016 through May 2020. The outcome measures were postoperative serum thyroid-stimulating hormone (TSH) levels and the initiation of LT4. The predictors of a postoperative TSH level of >2 mU/L and initiation of LT4 were evaluated using Cox proportional hazards models.

RESULTS

Postoperative TSH levels were available for 115 patients (91%), of whom 97 (84%) had TSH levels >2 mU/L after thyroid lobectomy. Over a median follow-up of 2.6 years, a postoperative TSH level of >2 mU/L was associated with older age (median 52 vs 37 years; P = .01), higher preoperative TSH level (1.7 vs 0.85 mU/L; P < .001), and primary tumor size of <1 cm (38% vs 11%, P = .03). Multivariate analysis revealed that only preoperative TSH level was an independent predictor of a postoperative TSH level of >2 mU/L (hazard ratio [HR] 1.53, P = .003). Among patients with a postoperative TSH level of >2 mU/L, 66 (68%) were started on LT4 at a median of 74 days (interquartile range 41-126) after lobectomy, with 51 (77%) undergoing at least 1 subsequent dose adjustment to maintain compliance with current guidelines.

CONCLUSION

More than 80% of the patients who underwent therapeutic lobectomy for DTC developed TSH levels that were elevated beyond the recommended range, and most of these patients were prescribed LT4 soon after the surgery.

COVID-19 Outcomes of Patients With Differentiated Thyroid Cancer: A Multicenter Los Angeles Cohort Study

Objective

Cancer may be a risk factor for worse outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infections. However, there is a significant variability across cancer types in the extent of disease burden and modalities of cancer treatment that may impact morbidity and mortality from coronavirus disease-19 (COVID-19). Therefore, we evaluated COVID-19 outcomes in patients with a differentiated thyroid cancer (DTC) history.

Methods

This is a retrospective cohort study of patients with a history of DTC and SARS-CoV2 infection from 2 academic Los Angeles healthcare systems. Demographic, thyroid cancer, and treatment data were analyzed for associations with COVID-19 outcomes.

Results

Of 21 patients with DTC and COVID-19, 8 (38.1%) were hospitalized and 2 (9.5%) died from COVID-19. Thyroid cancer initial disease burden and extent, treatment, or current response to therapy (eg, excellent vs incomplete) were not associated with COVID-19 severity in DTC patients. However, older age and the presence of a comorbidity other than DTC were significantly associated with COVID-19 hospitalization (P = .047 and P = .024, respectively). COVID-19–attributed hospitalization and mortality in DTC patients was lower than that previously reported in cancer patients, although similar to patients with nonthyroid malignancies in these centers.

Conclusion

These data suggest that among patients with DTC, advanced age and comorbid conditions are significant contributors to the risk of hospitalization from SARS-CoV2 infection, rather than factors associated with thyroid cancer diagnosis, treatment, or disease burden. This multicenter report of clinical outcomes provides additional data to providers to inform DTC patients regarding their risk of COVID-19.

Changes in Stage Distribution and Disease-Specific Survival in Differentiated Thyroid Cancer with Transition to American Joint Committee on Cancer 8th Edition: A Systematic Review and Meta-Analysis

BACKGROUND

Recent revision significantly changed the American Joint Committee on Cancer (AJCC) staging criteria for differentiated thyroid cancer (DTC). To quantitatively evaluate resulting changes in patient stage distribution and the associated disease-specific survival (DSS) incorporating diverse populations, we performed a meta-analysis of studies comparing the AJCC 7th edition (AJCC-7) with 8th edition (AJCC-8) staging for DTC.

MATERIALS AND METHODS

After PROSPERO registration (#CRD42019123657), publications in English reporting DSS of DTC with AJCC-7 and AJCC-8 from inception to June 2019 were identified by search of MEDLINE and PubMed. Random-effects meta-analyses were conducted to compare differences in survival between AJCC-7 and AJCC-8. Pooled hazard ratios, 10-year DSS, and corresponding interval estimates were calculated for AJCC subgroups. Differences in survival between editions were assessed using subgroup analysis with nonoverlapping confidence intervals indicating statistical significance.

RESULTS

Final analysis included six studies with 10,850 subjects and median follow-up from 55 to 148 months. Use of AJCC-8 shifted classification to earlier stages: stage I, from 60% to 81%; stage II, from 5% to 13%; stage III, from 21% to 2%; stage IV, from 10% to 3%. Ten-year DSS was significantly lower in AJCC-8 versus AJCC-7 in patients with stage II (88.6%, 95% confidence interval [CI] 82.7-94.6% vs. 98.1%, 95% CI 96.6-99.6%, respectively) and stage III disease (70.5%, 95% CI 59.1-83.9% vs. 96.8%, 95% CI 94.1-99.64%, respectively).

CONCLUSION

Meta-analysis of revised AJCC staging for DTC, incorporating diverse populations, demonstrates redistribution of patients toward earlier clinical stages and better stratification of disease-specific mortality risk, specifically among patients now classified with stage II and III disease.

IMPLICATIONS FOR PRACTICE

This study provides updated estimates of disease-specific survival for patients with differentiated thyroid cancer determined by the American Joint Committee on Cancer staging system that are generalizable to broader populations and support improved stratification using the recently revised criteria.

Treatment of Differentiated Thyroid Carcinomas

Differentiated thyroid cancer (DTC) is the most common thyroid cancer and is frequently encountered in clinical practice. The incidence of DTC has increased significantly over the past three decades. Surgical resection, radioactive iodine (RAI), and levothyroxine suppression therapy remain the primary modalities for DTC treatment. Active surveillance for low-risk thyroid cancer may be an alternative to immediate surgery for appropriately selected patients. Patient characteristics influence treatment selection and intensity. In the subset of patients with progressive distant metastatic disease, not amenable to treatment with surgery or RAI, novel agents, including targeted therapies and immunotherapy, should be considered.

Identification of Racial Inequities in Access to Specialized Inpatient Heart Failure Care at an Academic Medical Center

BACKGROUND

Racial inequities for patients with heart failure (HF) have been widely documented. HF patients who receive cardiology care during a hospital admission have better outcomes. It is unknown whether there are differences in admission to a cardiology or general medicine service by race. This study examined the relationship between race and admission service, and its effect on 30-day readmission and mortality Methods: We performed a retrospective cohort study from September 2008 to November 2017 at a single large urban academic referral center of all patients self-referred to the emergency department and admitted to either the cardiology or general medicine service with a principal diagnosis of HF, who self-identified as white, black, or Latinx. We used multivariable generalized estimating equation models to assess the relationship between race and admission to the cardiology service. We used Cox regression to assess the association between race, admission service, and 30-day readmission and mortality.

RESULTS

Among 1967 unique patients (66.7% white, 23.6% black, and 9.7% Latinx), black and Latinx patients had lower rates of admission to the cardiology service than white patients (adjusted rate ratio, 0.91; 95% CI, 0.84-0.98, for black; adjusted rate ratio, 0.83; 95% CI, 0.72-0.97 for Latinx). Female sex and age >75 years were also independently associated with lower rates of admission to the cardiology service. Admission to the cardiology service was independently associated with decreased readmission within 30 days, independent of race.

CONCLUSIONS

Black and Latinx patients were less likely to be admitted to cardiology for HF care. This inequity may, in part, drive racial inequities in HF outcomes.

Risk Factors for New Hypothyroidism During Tyrosine Kinase Inhibitor Therapy in Advanced Nonthyroidal Cancer Patients

BACKGROUND

Thyroid dysfunction during tyrosine kinase inhibitor (TKI) cancer treatment is common, but predisposing risk factors have not been determined. Recommendations for monitoring patients treated with one or multiple TKI and in conjunction with other relevant cancer therapies could be improved. The study objective was to assess the risk factors for new thyroid dysfunction in TKI-treated previously euthyroid cancer patients.

METHODS

A retrospective cohort study of patients with advanced nonthyroidal cancer treated with TKI from 2000 to 2017, having available thyroid function tests showing initial euthyroid status, excluding patients with preexisting thyroid disease or lack of follow-up thyroid function tests. During TKI treatment, patients were classified as euthyroid (thyrotropin [TSH] normal), subclinical hypothyroidism (TSH 5-10 mIU/L, or higher TSH if free thyroxine normal), or overt hypothyroidism (TSH >10 mIU/L, low free thyroxine, or requiring thyroid hormone replacement). The timing of thyroid dysfunction and TKI used were assessed. Risk factors for incident hypothyroidism were evaluated using multivariate models.

RESULTS

In 538 adult patients included, subclinical hypothyroidism occurred in 71 (13.2%) and overt hypothyroidism occurred in 144 (26.8%) patients with TKI therapy, following a median cumulative TKI exposure of 196 days (interquartile range [IQR] 63.5-518.5 days). The odds of hypothyroidism were greatest during the first six months on a TKI. Median exposure time on the TKI concurrent with thyroid dysfunction in patients treated with only one TKI was 85 days (IQR 38-293.5 days) and was similar to the 74 days (IQR 38-133.3 days) in patients treated previously with other TKI (p = 0.41). Patients who developed hypothyroidism compared to those who remained euthyroid had greater odds of being female (odds ratio = 1.99 [confidence interval 1.35-2.93], p < 0.01), but greater cumulative TKI exposure and greater number of TKI received were not associated with thyroid dysfunction.

CONCLUSIONS

Thyroid dysfunction occurred in 40% of euthyroid patients. Monitoring thyroid function in TKI-treated patients is recommended, with particular attention to female patients and within the first six months of exposure to a new TKI.

Hypothyroidism During Tyrosine Kinase Inhibitor Therapy Is Associated with Longer Survival in Patients with Advanced Nonthyroidal Cancers

BACKGROUND

Tyrosine kinase inhibitor (TKI)-induced thyroid dysfunction is recognized as a common adverse effect of treatment, but the importance of incident hypothyroidism during TKI therapy remains unclear. This study analyzed the prognostic significance of hypothyroidism during TKI therapy in cancer patients.

METHODS

This was a retrospective cohort study of adult patients with advanced nonthyroidal cancer treated with TKI and available thyroid function testing at three affiliated academic hospitals from 2000 to 2017. Patients with preexisting thyroid disease were excluded. Demographic, clinical, and cancer treatment data were collected. Thyroid status with TKI treatment was determined from thyroid function testing and initiation of thyroid medication, and classified as euthyroid (thyrotropin [TSH] normal), subclinical hypothyroidism (SCH; TSH 5-10 mIU/L, or higher TSH if free thyroxine normal), or overt hypothyroidism (OH; TSH >10 mIU/L, low free thyroxine, or requiring replacement). Multivariate models were used to evaluate the effect of TKI-related hypothyroidism on overall survival (OS).

RESULTS

Of 1120 initial patients, 538 remained after exclusion criteria. SCH occurred in 72 (13%) and OH in 144 (27%) patients with TKI therapy. Patients with hypothyroidism had significantly longer OS, with median OS in euthyroid patients of 685 days [confidence interval (CI) 523-851] compared to 1005 days [CI 634-1528] in SCH and 1643 days [CI 1215-1991] in OH patients (p < 0.0001). After adjustment for age, sex, race/ethnicity, cancer type, cancer stage, ECOG performance status, and checkpoint inhibitor therapy, OH remained significantly associated with OS (hazard ratio = 0.561; p < 0.0001), whereas SCH did not (hazard ratio = 0.796; p = 0.165). Analysis of hypothyroid patients (SCH and OH) with TSH >5 and <10 mIU/L stratified by hormone replacement status showed improved survival associated with hormone replacement.

CONCLUSIONS

New hypothyroidism in cancer patients treated with TKI is associated with significantly improved OS, should not necessitate TKI dose reduction or discontinuation, and may provide independent prognostic information.

Circulating Myeloid-Derived Suppressor Cells Predict Differentiated Thyroid Cancer Diagnosis and Extent

BACKGROUND

Establishing the preoperative diagnosis and long-term prognosis of differentiated thyroid cancer (DTC) remain challenging in some patients. Myeloid-derived suppressor cells (MDSC) are tumor-induced cells mediating immune tolerance that are detectable in the peripheral blood of cancer patients. The authors previously developed a novel clinical assay to detect the phenotypes of two human MDSC subsets in peripheral blood, and hypothesize that higher MDSC levels measured by this assay correlate positively with both malignancy and worse patient outcomes.

METHODS

A prospective observational pilot study was performed of patients undergoing thyroidectomy for a solitary thyroid nodule. The presence of a thyroid nodule >1 cm was confirmed sonographically, and fine-needle aspiration biopsy performed prior to surgery in all cases. Peripheral blood collected preoperatively was analyzed using a novel flow cytometry-based immunoassay to detect and quantify two subsets of human MDSC. Circulating MDSC levels were compared by histopathologic diagnosis, stage, and presence of persistent disease after treatment.

RESULTS

Of 50 patients included in this study, MDSC measurement was successful in 47 (94%). One patient was found to have a concurrent cancer, leaving 46 patients for primary analysis. The cytologic diagnoses were benign in five (10.8%), atypia or follicular lesion of undetermined significance in five (10.8%), suspicious for follicular neoplasm in five (10.8%), suspicious for malignant in three (6.5%), and malignant in 28 (60.1%) of the 46 nodules. Final histopathology was benign in 11 (24%) and DTC in 35 (76%), encompassing 34 PTC cases and one follicular thyroid carcinoma. Mean percentages of CD11b(+)HLA-DR(low)HIF1a(+) MDSC (CD11b(+)MDSC) were 14.0 ± 6.2% and 7.9 ± 3.6% in DTC versus benign nodules, respectively (p < 0.005). A cutoff of 12% yielded a specificity of 0.91, a sensitivity of 0.72, and a likelihood ratio of 7.9. Mean CD11b(+)MDSC levels increased linearly with higher TNM stage (p < 0.01), and were 19.4 ± 5.4 in patients with persistent cancer after surgery compared with 13.2 ± 6.8 in those without evidence of disease (p < 0.05).

CONCLUSION

MDSC measurement using this flow cytometry-based assay represents a novel approach for preoperatively assessing malignancy risk and cancer extent in patients with thyroid nodules. While further validation is needed, these data suggest that MDSC assessment may serve as a useful adjunct when cytology is indeterminate, and predict tumor stage and recurrence risk in cases of thyroid cancer.

Clinical features and hospital outcomes in thyroid storm: a retrospective cohort study

CONTEXT

Thyroid storm (TS) is a rare but life-threatening manifestation of thyrotoxicosis. Predictive features and outcomes remain incompletely understood, in part because studies comparing TS with hospitalized thyrotoxic patients have rarely been performed.

OBJECTIVES

Our objectives were to compare the diagnosis and outcomes in TS versus hospitalized compensated thyrotoxic (CT) patients and to assess differences in diagnostic classification using the Burch-Wartofsky scores (BWSs) or Akamizu (Ak) criteria for identifying TS.

DESIGN, SETTING, AND PATIENTS

This was a retrospective cohort study of hospitalized patients during a 6-year period at an academic tertiary hospital, with age ≥ 18 years, TSH <0.01 mIU/L, and clinically diagnosed TS or CT.

OUTCOME MEASURES

In-patient mortality, hospital and intensive care unit length of stay, intubation, and ventilator duration were assessed.

RESULTS

Twenty-five TS and 125 CT patients were identified and analyzed. All but 1 TS patient received thionamides, β-blockade, glucocorticoids, and iodides within 24 hours of diagnosis. CT patients received thionamides and β-blockade alone. In the acute hospital setting, rates of fever (>100.4 °F), heart rate (>100 beats/min), altered mentation, and a precipitating event were all higher for TS than for CT patients. Altered mentation was the only clinical feature significantly different between TS and the subset of CT patients defined as TS by BWS or Ak criteria (P < .001). TS patients had greater in-patient mortality, hospital and intensive care unit length of stay, and ventilation requirements than CT patients.

CONCLUSIONS

In acutely hospitalized thyrotoxic patients, the presence of central nervous system dysfunction distinguished clinically diagnosed TS from patients with BWS- or Ak-defined TS. Because TS patients had significantly worse outcomes in this study, thyrotoxic patients with possible TS and central nervous system dysfunction may derive the greatest benefit from aggressive supportive and TS-specific treatments.

MHC class I loss is a frequent mechanism of immune escape in papillary thyroid cancer that is reversed by interferon and selumetinib treatment in vitro

PURPOSE

To evaluate MHC class I expression on papillary thyroid cancer (PTC) and analyze changes in MHC expression and associated immune activation with current and experimental treatments for thyroid cancer using in vitro PTC cell lines.

EXPERIMENTAL DESIGN

MHC class I expression and assessment of tumor-infiltrating leukocyte populations were evaluated by immunohistochemistry. PTC cell lines were analyzed for HLA-ABC expression by flow cytometry following tyrosine kinase inhibitor, IFNα or IFNγ, or radiation treatment. Functional changes in antigenicity were assessed by coculture of allogeneic donor peripheral blood leukocytes (PBL) with pretreated or untreated PTC cell lines and measurement of T-cell activation and cytokine production.

RESULTS

Both MHC class I and β2-microglobulin expression was reduced or absent in 76% of PTC specimens and was associated with reduced tumor-infiltrating immune cells, including effector (CD3(+), CD8(+), CD16(+)) and suppressor (FoxP3(+)) populations. Treatment of PTC cell lines with the MEK1/2 inhibitor selumetinib or IFN increased HLA-ABC expression. This phenotypic change was associated with increased T-cell activation (%CD25(+) of CD3(+)) and IL2 production by PBL cocultured with treated PTC cell lines. Additive effects were seen with combination selumetinib and IFN treatment.

CONCLUSIONS

MHC class I expression loss is frequent in human PTC specimens and represents a significant mechanism of immune escape. Increased antigenicity following selumetinib and IFN treatment warrants further study for immunotherapy of progressive PTC.

Adenosine A1 receptor antagonist, L-97-1, improves survival and protects the kidney in a rat model of cecal ligation and puncture induced sepsis

Previously it was reported that combining antibiotics with L-97-1, an adenosine A1 receptor antagonist, significantly improves survival and blocks acute lung injury induced by Yersinia pestis CO 99 in a rat model of pneumonic plague. In the current studies using a conscious rat model of cecal ligation and puncture (CLP) sepsis, L-97-1 was administered in daily intravenous infusions in combination with antibiotics to simulate the use of L-97-1 as an anti-sepsis therapeutic in the clinical setting. In these studies, when administered at 12 h following CLP, in combination with broad spectrum antibiotics, ceftriaxone and clindamycin, L-97-1 improves 7 day (d) survival [25%, 35%, and 75% for L-97-1 (10 mg/kg/h, 12.5 mg/kg/h, and 15 mg/kg/h, respectively) versus (vs.) 25% for antibiotics alone] in a dose-dependent manner. The addition of L-97-1, 15 mg/kg/h to antibiotics significantly increased 7 d survival following CLP compared to therapy with either antibiotics alone (P=0.002) or L-97-1 at 15 mg/kg/h alone (P<0.001) and was not significantly different than survival in sham CLP animals (Log-rank (Mantel-Cox) test with Bonferroni׳s correction for multiple comparisons). Moreover, in these studies, in combination with antibiotics L-97-1 dose-dependently protects the kidney, significantly improving renal function at 24 h post CLP at 10 mg/kg/h (P<0.001), 12.5 mg/kg/h (P<0.0001), and 15 mg/kg/h (P<0.0001) vs. antibiotics alone (ANOVA followed by Tukey׳s post-hoc test for pair-wise comparisons). The results of these studies support efficacy for L-97-1 as an anti-sepsis therapeutic.

BRAF V600E in papillary thyroid carcinoma is associated with increased programmed death ligand 1 expression and suppressive immune cell infiltration

BACKGROUND

There remain a small number of patients with papillary thyroid cancer (PTC) who suffer recurrence, metastases, or death. While mutation of the BRAF gene, corresponding to the constitutively active BRAF(V600E) protein, has been associated with worse clinical outcomes in thyroid cancer, the reasons underlying this observation are presently unknown. Disruption of endogenous host immune surveillance and promotion of tumor immune escape is one mechanism by which BRAF(V600E) tumors may achieve more aggressive behavior. This study evaluated the relationship between BRAF(V600E) status and known strategies of tumor-mediated immune suppression.

METHODS

Tissue sections of PTC tumors from 33 patients were evaluated by immunohistochemistry for tumor-expressed suppressive ligands and enzymes and effector and suppressor populations of tumor-infiltrating immune cells. Presence of BRAF(V600E) was evaluated by direct DNA sequencing of PTC specimens and the results correlated with tumor-expressed molecules and tumor-infiltrating immune cell populations, as well as patient characteristics and pathologic findings.

RESULTS

BRAF(V600E) tumors more often express high levels of immunosuppressive ligands programmed death ligand 1 (53% vs. 12.5%) and human leukocyte antigen G (41% vs. 12.5%) compared to BRAF wild-type tumors. There was no association between indoleamine 2,3-dioxygenase 1 expression and BRAF(V600E) status. Furthermore, BRAF(V600E) tumors demonstrate both lower CD8(+) effector to FoxP3(+) regulatory T cell, and CD68(+) pan-macrophage to CD163(+) M2 macrophage ratios, indicating relative increases in suppressive T cell and macrophage components, respectively.

CONCLUSIONS

Overall, BRAF(V600E) PTC tumors display a broadly immunosuppressive profile and evidence of disturbed host tumor immune surveillance that may contribute to the poorer outcomes observed in this subset of patients with thyroid cancer.

Establishment and characterization of a new human extragonadal germ cell line, SEM-1, and its comparison with TCam-2 and JKT-1

OBJECTIVE

To describe the establishment and characterization of a human cell line, SEM-1, from a patient diagnosed with a mediastinal seminoma.

METHODS

A small percentage of germ cell tumors develop as primary lesions in extragonadal sites, and the etiology of these tumors is poorly understood. Currently, only 2 cell lines from seminoma patients have been reported, JKT-1 and TCam-2, both derived from the testis. The cell line was characterized by heterotransplantation in Nude mice, cytogenetic studies, immunohistochemical and flow cytometry staining for germ cell tumor biomarkers, quantitative reverse-transcription polymerase chain reaction for cancer testis antigen expression, and BRAF mutation screening with quantitative polymerase chain reaction.

RESULTS

Characterization studies confirmed the human extragonadal seminoma origin of SEM-1 and demonstrated that it had more features in common with TCam-2 than JKT-1. Specifically, SEM-1 was positive for Sal-like protein 4 (SALL-4), activator protein-2γ (AP-2γ), and cytokeratin CAM5.2, and demonstrated heterogeneous expression of stem cell markers octamer-binding transcription factor 3/4, NANOG, c-KIT, SOX17, and SOX2. Cytogenetic analysis revealed a hypotriploid chromosome number, with multiple copies of 12p, but isochromosome 12p and the BRAF mutation V600E were not identified. The cell lines also did not contain the BRD4/NUT gene rearrangement [t(15,19)] seen in midline carcinomas nor did they contain overexpressed nuclear protein in testis (NUT) genes.

CONCLUSION

SEM-1 is the first cell line derived from an extragonadal germ cell tumor showing intermediate characteristics between seminoma and nonseminoma, and as such, is an important model to study the molecular pathogenesis of this malignancy.

Immune cell infiltration patterns and survival in head and neck squamous cell carcinoma

PURPOSE

This study examines the tumour-host immune interactions in head and neck squamous cell carcinoma (HNSCC) and their relationship to human papillomavirus (HPV) infectivity and patient survival.

METHODS

The adaptive and innate immune profile of surgical tumour specimens obtained from HNSCC patients was determined using qRT-PCR and immunohistochemistry. Intratumoural and invading margin leukocyte populations (CD3, CD8, CD16, CD20, CD68, FoxP3 and HLA-DR) were quantified and compared with patient disease-specific survival. Additionally, the expression of 41 immune activation- and suppression-related genes was evaluated in the tumour microenvironment. Tumour cells were also assessed for expression of HLA-A, HLA-G and HLA-DR. HPV infectivity of tumour biopsies was determined using HPV consensus primers (MY09/MY11 and GP5+/GP6+) and confirmed with p16 immunohistochemistry.

RESULTS

HPV+ patient samples showed a significantly increased infiltration by intratumoural CD20+ B cells, as well as by invasive margin FoxP3+Treg, compared with HPV- patient samples. There was also a trend towards increased intratumoural CD8+ T cells and HLA-G expression on tumour cells in HPV+ samples. qRT-PCR data demonstrated a general pattern of increased immune activation and suppression mechanisms in HPV+ samples. Additionally, a combined score of intratumoural and invasive margin FoxP3 infiltration was significantly associated with disease-specific survival (P < 0.05).

CONCLUSIONS

These data demonstrate significant differences in the immune cell profile of HPV+ and HPV- HNSCC. This study identifies several possible targets for immunotherapy and possible prognostic markers (FoxP3 and HLA-G) that may be specific to HNSCC.

Generation of tumor-targeted antibody-CpG conjugates

A number of monoclonal antibodies against tumor-associated antigens have been developed for the treatment of cancer. The anti-tumor effects of such antibodies can be enhanced by conjugation to immune stimulatory ligands, such as the toll-like receptor 9 agonist CpG oligodeoxynucleotides (CpG). The present study describes methods for the conjugation of CpG to two clinically approved monoclonal antibodies (rituximab and trastuzumab) via a Sulfo-EMCS maleimide linker. This conjugation method yielded stable joining of CpG and antibody (molar range 2.2-4.3:1). Immunofluorescence studies showed intact antigen-specific antibody binding of the immunoconjugates, that were comparable to unmodified antibody. Furthermore, antibody-CpG conjugates demonstrated improved (rituximab) or equivalent (trastuzumab) immune stimulatory activity compared to free CpG in vitro. These studies demonstrate the feasibility of antibody-CpG immunoconjugates and provide the foundation for future in vivo immunotherapy evaluation.

An in vivo immunotherapy screen of costimulatory molecules identifies Fc-OX40L as a potent reagent for the treatment of established murine gliomas

PURPOSE

We tested the combination of a tumor lysate vaccine with a panel of costimulatory molecules to identify an immunotherapeutic approach capable of curing established murine gliomas.

EXPERIMENTAL DESIGN

Glioma-bearing mice were primed with a tumor lysate vaccine, followed by systemic administration of the following costimulatory ligands: OX40L, CD80, 4-1BBL, and GITRL, which were fused to the Fc portion of human immunoglobulin. Lymphocytes and mRNA were purified from the brain tumor site for immune monitoring studies. Numerous variations of the vaccine and Fc-OX40L regimen were tested alone or in combination with temozolomide.

RESULTS

Lysate vaccinations combined with Fc-OX40L led to the best overall survival, yielding cure rates of 50% to 100% depending on the timing, regimen, and combination with temozolomide. Cured mice that were rechallenged with glioma cells rejected the challenge, showing immunologic memory. Lymphocytes isolated from the draining lymph nodes of vaccine/Fc-OX40L-treated mice had superior tumoricidal function relative to all other groups. Vaccine/Fc-OX40L-treated mice exhibited a significant increase in proliferation of brain-infiltrating CD4 and CD8 T cells, as indicated by Ki67 staining. Fc-OX40L had single-agent activity in transplanted and spontaneous glioma models, and the pattern of inflammatory gene expression in the tumor predicted the degree of therapeutic response.

CONCLUSIONS

These data show that Fc-OX40L has unique and potent activity against experimental gliomas and warrants further testing.

Abstract 3669: Autocrine interleukin/STAT3 signaling in breast implant-associated T cell anaplastic large cell lymphoma cell lines suggests a mechanism for tumor progression and effective therapy

Recently, over 80 cases of anaplastic large-cell kinase (ALK)-negative, T-cell, anaplastic, non-Hodgkin lymphomas (T-ALCL) have been identified worldwide in patients with textured saline and silicone breast implants. These breast implant-associated T-ALCL cases are striking for their homogeneous clinical presentation and pathology that is distinct from established classes of ALCL. In order to understand the nature of this newly emerged clinical entity, we have established three new cell lines, designated T cell Breast Lymphoma (TLBR) -1, -2, and -3, from patient primary tumor biopsy specimens. Characterization of these pre-clinical models confirmed fidelity to the original tumor biopsy specimens and highlighted unique features that may aid the development of effective treatments for these cancers. Gene expression analysis demonstrated significant up-regulation of survivin and down-regulation of pro-apoptotic genes (BID, BAK, BBC3) by all TLBR cell lines relative to healthy donor T cells. This preliminary finding prompted examination of upstream regulators of cell survival in T cells, namely the interleukin signaling associated with the JAK/STAT pathway. TLBR cell lines were found to secrete high levels of IL-6 and IL-10, and were strongly positive for the cognate receptors. The TLBR cell lines also showed elevated levels of STAT3 and pSTAT3 by immunoblotting techniques, along with a simultaneous reduction in expression of the pSTAT3 phosphatase, SHP-1. These results implicate an unregulated autocrine STAT3 pathway present in the TLBR cell lines that strongly contributes to their tumorigenesis. Assays of various inhibitors of this pathway support this hypothesis since targeting of STAT3 with the tyrosine kinase inhibitor, Sunitinib, led to dramatic in vitro cell death in all TLBR cell lines. More specific inhibition of STAT3 with S3I-201 had comparable results with Sunitinib. Furthermore, IL-6 neutralization by a monoclonal antibody or SHP-1 restoration by 5-azacytidine treatment also demonstrated moderate efficacy in inhibiting TLBR cell line growth in vitro. These discoveries strongly suggest the use of these reagents in the clinical treatment of Breast Implant Associated T-ALCL. The TLBR cell lines closely resemble the primary breast implant-associated lymphomas from which they were derived, and as such provide valuable preclinical models to study the unique biology and provide clinicians with improved knowledge for treatment and diagnosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3669. doi:1538-7445.AM2012-3669

Abstract 3550: Differences in immune escape in HPV+ versus HPV- head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and has not seen an improvement in survival in decades. Current standard-of-care treatments including surgical resection, chemotherapy and radiation still lead to high rates of recurrence and loco-regional metastasis contributing to the poor prognosis in these patients. It is well established that HNSCC are highly immune-modulatory tumors and may therefore benefit from immunotherapy treatment regimens. Better methods are therefore needed to match patients with the appropriate immunotherapy. Recently, human papillomavirus (HPV) was implicated in the etiology of a subset of HNSCC arising in younger patients without a history of alcohol and tobacco use. Approximately 30% of HNSCC tumors are HPV+ and despite late stage presentation, often have a better prognosis and response to therapy. This study examines how host immune recognition and response varies between HPV+ and HPV- HNSCC, with the goal of identifying new targets for immunotherapy. The immune profile and HPV infection status of 41 HNSCC patient tumor samples obtained from surgical resection was characterized by qRT-PCR, PCR, and IHC techniques. Tumor samples were analyzed for the expression of 40 genes involved in immune activation and suppression in the tumor microenvironment to generate an immune profile. Gene expression levels were normalized to GAPDH and compared across HPV+, HPV- and normal tissue groups by ANOVA and post-test pairwise analysis. HPV infectivity of tumor biopsies was determined using HPV consensus primers (MY09/MY11 and GP5+/GP6+) and confirmed with p16 immunohistochemistry. From these studies, eight of 41 (20%) HNSCC biopsies were HPV+ by PCR and IHC analysis. HPV+ tumors demonstrated statistically significant increased expression of genes related to immunosuppression including regulatory T (CD4, FoxP3, CTLA-4, and FasL) and myeloid suppressor cell markers (CD11b and IL-6, an inducer of these suppressor cells), as well as negative-regulators (SOCS1) (p&lt;0.05). These tumors also demonstrated an increase in markers of immune activation and infiltration, including evidence of T cells (CD4, Fas-L), antigen presenting cells (CD80, CD83, CD1c), and inflammatory cytokines and co-stimulatory molecules (IL-2, IL-12, IFN- γ, and OX40L) (p&lt;0.05). There were no statistically significant differences in gene expression found between normal tissue and HPV- HNSCC tumors. These studies demonstrate a general pattern of increased immunogenicity and concurrent immunosuppression in patients with HPV+ versus HPV- HNSCC that could potentially be used to inform immunotherapy treatment of HNSCC patients. HPV+ tumors may be more effectively treated with a regimen that employs a combination of immune stimulation and reversal of immune tolerance mechanisms, while HPV- tumors may require greater immune stimulation to activate endogenous anti-tumor immune responses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3550. doi:1538-7445.AM2012-3550

Abstract 1553: Key determinants of immunotherapy success in frequently-used murine tumor models

Cancer immunotherapy uses a patient's own immune system to recognize and eliminate malignant cells. The potential advantages of this approach over conventional treatments include the systemic trafficking of immune cells to treat primary and metastatic disease, inherent antigen-specificity of adaptive immunity to minimize collateral damage, and the induction of immunological memory to prevent recurrent disease. While many acknowledge the promise of immunotherapy, its translation to the clinic has been slow and only occasionally successful. In the more than 3 decades of experience of our laboratory in developing and testing immunotherapy reagents for cancer, we observed that a given set of reagents can produce complete regressions in some but not all tumor models. We hypothesized that a major contributor to this variability was underlying differences in the immune escape strategies utilized by different tumors. Our hypothesis was supported with data from a series of immunotherapy experiments on a panel of experimental murine solid tumor models. Comprehensive immune profiles were generated for each by measuring tumor infiltrating leukocytes (TIL), immune activation, and immune suppression present in the tumor microenvironment using qRT-PCR, immunohistochemistry staining, and flow cytometry techniques. Key differences emerged amongst models in the extent of immune activation that correlated directly with TIL and immunosuppression. From these data, it appears that some tumors are more “visible” to the immune system and have active countermeasures to survive, while others use immune evasion strategies to persist in the host. To classify tumor models along this spectrum, ten immune-related genes and cell markers showing significant change across the models were selected to generate an immunogenicity score for each model: CD40, 41BBL, OX40L, CD80, CD86, CD11c, CD45, BM-2 (PMN marker), Granzyme B, and CD8. Importantly, we observed that MHC class I mouse equivalent H2-D correlated with this immunogenicity level for each tumor. Secondly, Treg and MDSC were measured in the tumor microenvironment and draining lymphoid tissues using immunohistochemical and flow cytometry techniques to determine the dominant suppressor cell population(s) present. Immunotherapy regimens were then developed to match each tumor model using immunogenicity to indicate the level of immune stimulation needed and suppressor cell component to indicate targets for reversing tumor tolerance. These regimens were used to treat established solid tumors in mice and demonstrated that two features of a tumor's immune profile, namely immunogenicity level and dominant suppressor cell component, are the key determinants of immunotherapy success in vivo. Viewed in this way, the tumor/host relationship becomes the overriding feature for determining optimal treatment for patients based upon immune profiling data obtained at the time of biopsy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1553. doi:1538-7445.AM2012-1553

Chemokines, costimulatory molecules and fusion proteins for the immunotherapy of solid tumors

In this article, the role of chemokines and costimulatory molecules in the immunotherapy of experimental murine solid tumors and immunotherapy used in ongoing clinical trials are presented. Chemokine networks regulate physiologic cell migration that may be disrupted to inhibit antitumor immune responses or co-opted to promote tumor growth and metastasis in cancer. Recent studies highlight the potential use of chemokines in cancer immunotherapy to improve innate and adaptive cell interactions and to recruit immune effector cells into the tumor microenvironment. Another critical component of antitumor immune responses is antigen priming and activation of effector cells. Reciprocal expression and binding of costimulatory molecules and their ligands by antigen-presenting cells and naive lymphocytes ensures robust expansion, activity and survival of tumor-specific effector cells in vivo. Immunotherapy approaches using agonist antibodies or fusion proteins of immunomodulatory molecules significantly inhibit tumor growth and boost cell-mediated immunity. To localize immune stimulation to the tumor site, a series of fusion proteins consisting of a tumor-targeting monoclonal antibody directed against tumor necrosis and chemokines or costimulatory molecules were generated and tested in tumor-bearing mice. While several of these reagents were initially shown to have therapeutic value, combination therapies with methods to delete suppressor cells had the greatest effect on tumor growth. In conclusion, a key conclusion that has emerged from these studies is that successful immunotherapy will require both advanced methods of immunostimulation and the removal of immunosuppression in the host.

USC-HN2, a new model cell line for recurrent oral cavity squamous cell carcinoma with immunosuppressive characteristics

Head and neck squamous cell carcinomas (HNSCC) are common and aggressive tumors that have not seen an improvement in survival rates in decades. These tumors are believed to evade the immune system through a variety of mechanisms and are therefore highly immune modulatory. In order to elucidate their interaction with the immune system and develop new therapies targeting immune escape, new pre-clinical models are needed. A novel human cell line, USC-HN2, was established from a patient biopsy specimen of invasive, recurrent buccal HNSCC and characterized by morphology, heterotransplantation, cytogenetics, phenotype, gene expression, and immune modulation studies and compared to a similar HNSCC cell line; SCCL-MT1. Characterization studies confirmed the HNSCC origin of USC-HN2 and demonstrated a phenotype similar to the original tumor and typical of aggressive oral cavity HNSCC (EGFR(+)CD44v6(+)FABP5(+)Keratin(+) and HPV(-)). Gene and protein expression studies revealed USC-HN2 to have highly immune-modulatory cytokine production (IL-1β, IL-6, IL-8, GM-CSF, and VEGF) and strong regulatory T and myeloid derived suppressor cell (MDSC) induction capacity in vitro. Of note, both USC-HN2 and SCCL-MT1 were found to have a more robust cytokine profile and MDSC induction capacity when compared to seven previously established HNSCC cell lines. Additionally, microarray gene expression profiling of both cell lines demonstrate up-regulation of antigen presenting genes. Because USC-HN2 is therefore highly immunogenic, it also induces strong immune suppression to evade immunologic destruction. Based upon these results, both cell lines provide an excellent model for the development of new suppressor cell-targeted immunotherapies.

Functional characterization of human Cd33+ and Cd11b+ myeloid-derived suppressor cell subsets induced from peripheral blood mononuclear cells co-cultured with a diverse set of human tumor cell lines

Background

Tumor immune tolerance can derive from the recruitment of suppressor cell populations, including myeloid-derived suppressor cells (MDSC). In cancer patients, MDSC accumulation correlates with increased tumor burden, but the mechanisms of MDSC induction remain poorly understood.

Methods

This study examined the ability of human tumor cell lines to induce MDSC from healthy donor PBMC using in vitro co-culture methods. These human MDSC were then characterized for morphology, phenotype, gene expression, and function.

Results

Of over 100 tumor cell lines examined, 45 generated canonical CD33⁺HLA-DR^lowLineage^- MDSC, with high frequency of induction by cervical, ovarian, colorectal, renal cell, and head and neck carcinoma cell lines. CD33⁺ MDSC could be induced by cancer cell lines from all tumor types with the notable exception of those derived from breast cancer (0/9, regardless of hormone and HER2 status). Upon further examination, these and others with infrequent CD33⁺ MDSC generation were found to induce a second subset characterized as CD11b⁺CD33^lowHLA-DR^lowLineage^-. Gene and protein expression, antibody neutralization, and cytokine-induction studies determined that the induction of CD33⁺ MDSC depended upon over-expression of IL-1β, IL-6, TNFα, VEGF, and GM-CSF, while CD11b⁺ MDSC induction correlated with over-expression of FLT3L and TGFβ. Morphologically, both CD33⁺ and CD11b⁺ MDSC subsets appeared as immature myeloid cells and had significantly up-regulated expression of iNOS, NADPH oxidase, and arginase-1 genes. Furthermore, increased expression of transcription factors HIF1α, STAT3, and C/EBPβ distinguished MDSC from normal counterparts.

Conclusions

These studies demonstrate the universal nature of MDSC induction by human solid tumors and characterize two distinct MDSC subsets: CD33⁺HLA-DR^lowHIF1α⁺/STAT3⁺ and CD11b⁺HLA-DR^lowC/EBPβ⁺, which should enable the development of novel diagnostic and therapeutic reagents for cancer immunotherapy.

A new mechanism for blocking myeloid-derived suppressor cells by CpG

In this issue of Clinical Cancer Research, Zoglmeier and colleagues show that CpG, via the induction of IFN-α, matures myeloid-derived suppressor cells to abrogate immune suppression in 2 murine solid tumor models.

Breast implant-associated, ALK-negative, T-cell, anaplastic, large-cell lymphoma: establishment and characterization of a model cell line (TLBR-1) for this newly emerging clinical entity

BACKGROUND

Primary lymphomas of the breast are very rare (0.2-1.5% of breast malignancies) and the vast majority (95%) are of B-cell origin. Recently, 40 cases of clinically indolent anaplastic large-cell kinase (ALK)-negative, T-cell, anaplastic, non-Hodgkin lymphomas (T-ALCL) have been reported worldwide.

METHODS

A tumor biopsy specimen from a patient in this series was obtained for characterization. By using a human stromal feeder layer and IL-2, a novel cell line, TLBR-1, was established from this biopsy and investigated by using cytogenetics and various biomolecular methods.

RESULTS

Immunoperoxidase staining of the tumor biopsy showed a CD30/CD8/CD4 coexpressing T-cell population that was epithelial membrane antigen (EMA)(+) and perforin(+) . Multiplex polymerase chain reaction (PCR) of TCRγ genes showed monoclonality that suggested a T-cell origin, yet pan-T markers CD2/5/7, anaplastic large-cell kinase (ALK)-1, pancytokeratins, CD20, CD56, and Epstein-Barr virus (EBV) by in situ hybridization (ISH) were negative. TLBR-1 is IL-2 dependent, has a relatively long doubling time (55 hours), and displays different cellular shapes in culture. Cytogenetic analysis of tumor and TLBR-1 cells confirmed a highly anaplastic cell population with a modal number of 47 chromosomes lacking t(2;5). PCR screens for EBV and human T-lymphotropic virus types 1 and 2 (HTLV-1/2) were negative. Fluorescence-activated cell-sorting (FACS) analysis showed strong positivity for CD4/8, CD30, CD71, and CD26 expression, and antigen presentation (HLA-DR(+) CD80(+) CD86(+) ), IL-2 signaling (CD25(+) CD122(+) ), and NK (CD56(+) ) markers, and Western blots demonstrated strong Notch1 expression. Severe combined immunodeficiency (SCID) mouse TLBR-1 heterotransplants recapitulated the histology and marker characteristics of the original tumor.

CONCLUSIONS

TLBR-1, a novel ALK-negative, T-cell, anaplastic, large-cell lymphoma, closely resembles the original biopsy and represents an important tool for studying this newly recognized disease entity.

Characterization of cytokine-induced myeloid-derived suppressor cells from normal human peripheral blood mononuclear cells

Tumor immune tolerance can derive from the recruitment of suppressor cell populations, including myeloid-derived suppressor cells (MDSCs). In cancer patients, increased MDSCs correlate with more aggressive disease and a poor prognosis. Expression of 15 immune factors (TGFbeta, IL-1beta, IL-4, IL-6, IL-10, GM-CSF, M-CSF, IDO, fms-related tyrosine kinase 3 ligand, c-kit ligand, inducible NO synthase, arginase-1, TNF-alpha, cyclo-oxygenase 2, vascular endothelial growth factor [VEGF]) by MDSC-inducing human solid tumor cell lines was evaluated by RT-PCR. Based upon these data, cytokine mixtures were then tested for their ability to generate suppressive CD33(+) cells from healthy donor PBMCs in vitro by measuring their ability to inhibit the proliferation of, and IFN-gamma production by, fresh autologous human T cells after CD3/CD28 stimulation. Induced MDSCs were characterized with respect to their morphology, surface phenotype, and gene expression profile. MDSC-inducing cancer cell lines demonstrated multiple pathways for MDSC generation, including overexpression of IL-6, IL-1beta, cyclo-oxygenase 2, M-CSF, and IDO. CD33(+) cells with potent suppressive capacity were best generated in vitro by GM-CSF and IL-6, and secondarily by GM-CSF + IL-1beta, PGE(2), TNF-alpha, or VEGF. Characterization studies of cytokine-induced suppressive cells revealed CD33(+)CD11b(+)CD66b(+)HLA-DR(low)IL-13R alpha2(int) large mononuclear cells with abundant basophilic cytoplasm. Expression of inducible NO synthase, TGFbeta, NADPH oxidase, VEGF, and/or arginase-1 was also upregulated, and Transwell studies showed suppression of autologous T cells to be contact dependent. Suppressive CD33(+) cells generated from PBMCs by GM-CSF and IL-6 were consistent with human MDSCs. This study suggests that these cytokines are potential therapeutic targets for the inhibition of MDSC induction in cancer patients.