Mammaglobin-A cDNA vaccination of breast cancer patients induces antigen-specific cytotoxic CD4+ICOShi T cells.

Mammaglobin-A (Mam-A) is a 10 kDa secretory protein that is overexpressed in 80 % of primary and metastatic human breast cancers. Previous studies from our laboratory demonstrated that Mam-A cDNA vaccine can induce Mam-A-specific CD8 T cell responses and mediate regression of human breast cancer xenografts in NOD/SCID mice. In this article, we present our results on a phase I clinical trial of a Mam-A cDNA vaccination in breast cancer patients with stage-IV metastatic disease, including the impact of vaccination on the expression of the inducible co-stimulator molecule (ICOS) on CD4 T cells. Specimens from seven patients with stage-IV metastatic cancer were available for these analyses. Patients were vaccinated with a Mam-A cDNA vaccine on days 0, 28, and 56, and immune responses were assessed at serial time points following vaccination. At 6 months following the first vaccination, flow cytometric analysis demonstrated a significant increase in the frequency of CD4+ICOS(hi) T cells from 5 ± 2 % pre-vaccination to 23 ± 4 % (p < 0.001), with a concomitant decrease in the frequency of CD4+FoxP3+ T cells (regulatory T cells [Treg]) from 19 ± 6 to 10 ± 5 % (p < 0.05). ELISpot analysis of CD4+ICOS(hi) sorted T cells demonstrated that following vaccination the cytokines produced by Mam-A-specific T cells switched from IL-10 (78 ± 21 spm pre-vaccination to 32 ± 14 spm 5 months post-vaccine p < 0.001) to IFN-γ (12 ± 6 spm pre-vaccination to 124 ± 31 spm 5 months post-vaccine p < 0.001). The ratio of CD4+ICOS(hi) T cells to CD4+FoxP3+ T cells increased from 0.37 ± 0.12 before vaccination to 2.3 ± 0.72 (p = 0.021) following vaccination. Further, these activated CD4+ICOS(hi) T cells induced preferential lysis of human breast cancer cells expressing Mam-A protein. We conclude that Mam-A cDNA vaccination is associated with specific expansion and activation of CD4+ICOS(hi) T cells, with a concomitant decrease in Treg frequency. These encouraging results strongly suggest that Mam-A cDNA vaccination can induce antitumor immunity in breast cancer patients.

Statistical methods for assays with limits of detection: Serum bile acid as a differentiator between patients with normal colons, adenomas, and colorectal cancer.

In analytic chemistry a detection limit (DL) is the lowest measurable amount of an analyte that can be distinguished from a blank; many biomedical measurement technologies exhibit this property. From a statistical perspective, these data present inferential challenges because instead of precise measures, one only has information that the value is somewhere between 0 and the DL (below detection limit, BDL). Substitution of BDL values, with 0 or the DL can lead to biased parameter estimates and a loss of statistical power. Statistical methods that make adjustments when dealing with these types of data, often called left-censored data, are available in many commercial statistical packages. Despite this availability, the use of these methods is still not widespread in biomedical literature. We have reviewed the statistical approaches of dealing with BDL values, and used simulations to examine the performance of the commonly used substitution methods and the most widely available statistical methods. We have illustrated these methods using a study undertaken at the Vanderbilt-Ingram Cancer Center, to examine the serum bile acid levels in patients with colorectal cancer and adenoma. We have found that the modern methods for BDL values identify disease-related differences that are often missed, with statistically naive approaches.

Vascular endothelial growth factor-trap overcomes defects in dendritic cell differentiation but does not improve antigen-specific immune responses.

PURPOSE: Induction of antitumor immune responses requires adequate function of dendritic cells. Dendritic cell defects in cancer patients have been implicated in tumor escape and the limited efficacy of cancer vaccines. Previous studies have shown that vascular endothelial growth factor (VEGF) plays a major role in abnormal dendritic cell differentiation and function in cancer. It has been proposed that inhibition of VEGF may result in improved immune responses. The goal of this study was to test this hypothesis. EXPERIMENTAL DESIGN: Fifteen patients with refractory solid tumors were enrolled into a phase I clinical trial of VEGF-Trap. Phenotype and function of different subsets of mononuclear cells were measured before and at different time points after the start of treatment. RESULTS: VEGF-Trap treatment did not affect the total population of dendritic cells, their myeloid or plasmacytoid subsets, myeloid-derived suppressor cells (MDSC), or regulatory T cells. It significantly increased the proportion of mature dendritic cells. However, that improvement was not associated with an overall increase in immune responses to various antigens and mitogens. A subset analysis revealed significant improvement in immune responses in patients who had no increase in the proportion of MDSC. An improvement in immune responses was absent in patients with an increase in the proportion of MDSC. CONCLUSIONS: Inhibition of VEGF signaling may improve differentiation of dendritic cells in cancer patients. However, it was not sufficient to improve immune responses. This shows multifaceted nature of immune deficiency and points out to the need for complex approach to modulation of immune reactivity in cancer.

Clinical T2N0 Esophageal Cancer: Identifying Pretreatment Characteristics Associated With Pathologic Upstaging and the Potential Role for Induction Therapy.

BACKGROUND: Although studies have suggested standard therapy for clinical T2N0 esophageal cancer should be primary surgery, we hypothesize there is a subgroup for whom induction therapy may result in improved overall survival. METHODS: Patients with cT2N0 esophageal cancer receiving induction therapy or upfront esophagectomy (UE) were identified in the National Cancer Data Base. The UE patients were dichotomized as (1) pathologically upstaged, or (2) same-staged or downstaged. Logistic regression models identified variables associated with upstaging, and Kaplan-Meier analysis compared median overall survival. RESULTS: From 2006 to 2012, 932 cT2N0 patients (52.2%) received UE, and 853 (47.8%) received induction therapy first. In all, 326 of 713 UE patients (45.7%) were upstaged: 87 of 326 (26.7%) had T upstaging; 98 of 326 (30.1%) had N upstaging; and 141 of 326 (43.3%) had both. Patients upstaged after UE had a higher tumor grade (35.1% versus 57.1% grade 3), and a higher rate of lymphovascular invasion (57.1% versus 17.7%; both p < 0.001). Variables associated with upstaging included lymphovascular invasion (odds ratio 6.0, 95% confidence interval: 2.9 to 12.5, p < 0.001) and tumor grade 3 (odds ratio 9.4, 95% confidence interval: 1.8 to 48.4, p = 0.007). Of upstaged UE patients, only 144 (44.2%) received adjuvant therapy. The median overall survival for cT2N0 patients upstaged after UE was 27.5 ± 2.5 months versus 43.9 ± 2.9 months for induction therapy patients (any resultant pathologic stage, p < 0.001). CONCLUSIONS: Half of all cT2N0 patients were pathologically upstaged after UE, with worse survival compared with patients receiving induction therapy. Refining an upstaging model would help select patients for induction therapy and increase the rate of chemotherapy in patients at risk for systemic disease.

A Phase I Trial of BKM120 (Buparlisib) in Combination with Fulvestrant in Postmenopausal Women with Estrogen Receptor-Positive Metastatic Breast Cancer.

PURPOSE: This trial was conducted to determine the maximum tolerated dose (MTD) and preliminary efficacy of buparlisib, an oral pan-class I PI3K inhibitor, plus fulvestrant in postmenopausal women with metastatic estrogen receptor positive (ER(+)) breast cancer. EXPERIMENTAL DESIGN: Phase IA employed a 3+3 design to determine the MTD of buparlisib daily plus fulvestrant. Subsequent cohorts (phase IB and cohort C) evaluated intermittent (5/7-day) and continuous dosing of buparlisib (100 mg daily). No more than 3 prior systemic treatments in the metastatic setting were allowed in these subsequent cohorts. RESULTS: Thirty-one patients were enrolled. MTD was defined as buparlisib 100 mg daily plus fulvestrant. Common adverse events (AE) included fatigue (38.7%), transaminases elevation (35.5%), rash (29%), and diarrhea (19.4%). C-peptide was significantly increased during treatment, consistent with on-target effect of buparlisib. Compared with intermittent dosing, daily buparlisib was associated with more frequent early onset AEs and higher buparlisib plasma concentrations. Among the 29 evaluable patients, the clinical benefit rate was 58.6% (95% CI, 40.7%-74.5%). Response was not associated with PIK3CA mutation or treatment cohort; however, loss of PTEN, progesterone receptor (PgR) expression, or mutation in TP53 was most common in resistant cases, and mutations inAKT1 and ESR1 did not exclude treatment response. CONCLUSIONS: Buparlisib plus fulvestrant is clinically active with manageable AEs in patients with metastatic ER(+)breast cancer. Weekend breaks in buparlisib dosing reduced toxicity. Patients with PgR negative and TP53 mutation did poorly, suggesting buparlisib plus fulvestrant may not be adequately effective against tumors with these poor prognostic molecular features.

The epidermal growth factor receptor as a target for colorectal cancer therapy.

The epidermal growth factor receptor (EGFR) is the prototypical member of the erbB receptor family. The EGFR axis is activated by a variety of ligands that are crucial in the formation and propagation of many tumors, including colorectal cancer, through their effects on cell signaling pathways, cellular proliferation, control of apoptosis, and angiogenesis. The importance of the EGFR axis in tumorigenesis and tumor progression makes it an attractive target for the development of anticancer therapies. A variety of targeting strategies to exploit the role of EGFR in tumors have been employed. The most highly developed of these anti-EGFR approaches are the monoclonal antibodies and the tyrosine kinase inhibitors (TKIs). Clinical evaluations of these compounds have yielded some promising results. The role of the EGFR axis in colorectal cancer formation and progression is reviewed and the clinical development of these anticancer EGFR-targeted drugs is reviewed and updated.