Angiogenesis: Cause or Effect?

Companion Diagnostics and Surrogate Markers for a Novel Antiangiogenic Therapy Multitargeted Epigenetic therapies (MTET)

by M. A. Nezami, MD; Daniel E. Stobbe, MD; and Aron Gould-Simon, MD

Patients with cancer are evaluated through different oncology laboratory markers, aiming at translation to clinical findings, both to evaluate progression of disease as well as translating to overall survival, as surrogate markers. This effort has been revolutionized as the traditional measurements of the tumor size in CT scans, and identifying cancer response by Response Evaluation Criteria in Solid Tumors (RECIST), has failed to effectively translate into patient survival. Therefore establishing the prognosis in majority of patients, especially with heterogeneous tumors, has been extremely challenging.

One area of most recent attention in identifying surrogate markers has been the vasculogenesis and its related serum markers. Different stages of carcinogenesis and metastasis is greatly dependent on tumor angiogenesis, as a result of vascular endothelial dysfunction. Novel ways to assess vascular function in cancer include measuring levels of circulating endothelial cells (CEC) or circulatory tumor cells (CTCs). The presence of CEC has recently been recognized as a useful marker of vascular damage. CTCs can induce endothelial colonies and may contribute toward vasculogenesis. Increased vasculogenesis increases CTC viability, in a vicious cycle. Also, as the circulatory tumor cells transition to mesenchymal cells, their tendency towards vasculogenesis increases. Such transition appears to be dynamic and under the influence of stroma.

Secondly, there have been efforts to correlate FDG-PET scan findings with patients’ prognosis. That said, unfortunately there is no direct translation to survival, especially in heterogeneous tumors.

The current understanding of the previously described Warburg effect suggests increased hypoxia as a driver for tumor growth, as a common signature of highly malignant tumors with capacity to metabolize glucose quickly, to lactic acid. This pattern can be related to increased glycolytic enzymes activity. One recent finding was that activated hypoxia response elements (HRE) by hypoxia can activate hexokinases. This phenomenon could potentially translate into increased SUV findings at FDG-PET scan.

Our understanding of heterogeneity of tumors has led us to look more in depth at cancer stem cells and epidermomesenchymal transition (EMT). Logically, the tumors which have higher heterogeneity have higher stem cell potentials and increased EMT transition. Here again, hypoxia and related hypoxia induced factor (HIF-1) can also be a the promoter or origin of such increased activity in downstream targets, through Wnt, Snail, and Slug pathways increasing the tendency of tumors to show more heterogeneity.

That said, as of today, there is not a single biomarker used clinically for assessing vasculogenesis, or intratumoral hypoxia and the correlation between FDG-PET findings and survival has not been strong, especially in more heterogeneous cancers (such as breast and lung cancer). Several studies have failed to show direct harmony in CTC findings and FDG-PET (although in breast cancer some studies have shown some but not strong relationship between progression of disease in PET and increased CTC, when CTC has been less than 5). The same is true for NSCLC. In NSCLC (due to heterogenic features), we see discordant relationships, between CTC and FDG-PET findings, described in the literature as the more aggressive cases, can have less CTC readings, and vice versa, and there is very poor correlation of CTC with PET findings.

Here we hypothesize that serum/plasma vascular endothelial growth factor (VEGF) measurements, as a biomarker for vasculogenesis (and possible intratumoral hypoxia), before and after therapy independently, or in addition to, circulatory tumor cells assay, can be used as a prognostic marker correlating with FDG-PET findings. This could become a meaningful companion diagnostic tool to translate to clinical outcome, and overall survival.

This is also important in therapeutic areas, as traditional chemotherapies in general (all anthracyclines, alkylators, platinum-based chemotherapies, etc.) increase the serum circulatory tumor cells, as well as serum VEGF, by several mechanisms, including pro-inflammatory cytokines, disrupting the tumor vessels by disrupting endothelial dysfunction and causing tumor cell leaks. This necessitates new tools to overcome such negative measurable impact on potential survival.

Accordingly, here, we present a summary of 100 cases of advanced disease, and we present in detail three cases of patients with heterogeneous stage IV breast cancer who had failed several lines of chemotherapy and were treated using a novel antiangiogenic therapy consisting of natural and off-label drugs. These are known to inhibit hypoxia-induced pathways, in a protocol called multitargeted epigenetic therapy (MTET), resulting in independent and synergistic response identified by serum VEGF/CTC/ and FDG-PET combo findings, and translated to improved progression-free or overall survival.

We conclude that this sample presents considerable effect size and can affect the current practice of oncology by providing better prognostic and therapeutic tools targeting angiogenesis in refractory heterogeneous disease.

• As of November 2014, 100 patient charts were selected and reviewed retrospectively. The inclusion criteria were diagnosis of cancer, and receiving minimum of 2 weeks of treatments per protocol. No patients were excluded. Patients were aged 18 to 83 years. All were diagnosed by their oncologist/physician and were offered standard conventional treatment of surgery, traditional chemotherapy, or radiation. Out of 100 patients, for 62 patients (62%) there were no actual treatment options available for them (except palliative care) due to severity of the disease and failure to respond to the standard of care, including chemotherapy.
• These people had stage four disease with multiple micro- or macrometastatic disease or had relapsed after unsuccessful therapies. Progression or recurrence of disease was manifested by their tumor markers and scans.

The following results were obtained during or after completing the course of therapy:

Imaging response (PET), decreased metabolic activity: 58 patients had imaging reports to follow for their condition. The other 42 had no imaging or it was not applicable or relevant. Out of 58 patients, 36 patients (62%) had positive response in their scans after the treatments. In 17 patients the results were mixed or improved initially, or the tumor was stabilized (total response of 91%). Five cases (8%) continued to progress.

Decrease in VEGF/FGF-2/IL-8: 37 patients had increased VEGF, correlating with higher risk of metastasis. 34 patients had decreased VEGF after the treatments (92%). Three patients progressed despite therapy (8%).

Twenty patients had increased CTC. Sixteen patients had positive circulatory tumor cells response by lowered CTC, which correlates with both disease-free and overall survival posttreatment. One patient got worse and 3 had mixed responses (initially improved then progressed).

Since patients with cancer may have significant stratifying confounders in selecting their control group, we used each patients preinterventional status as the control arm. Patients’ other stratifying confounders did not change during the study.

1. These data reveal superior response in the group of patients compared to the controls (conventional therapies). In 62% of patients treated, there was no conventional treatment option available at the time of referral. In this group results were far better compared with conventional modalities of treatment.

2. Patients with stage four terminal disease receiving the above program, improved beyond the standard-of-care expectations, and the patients who did receive chemotherapy concurrently with above targeted therapies had significant improvement in quality of life and chemotherapy response.

M.A. Nezami, MD
Director of Pacific Medical Center of Hope1680 E. Herndon Ave., Suite #102
Fresno, CA 93720
559-439-5393; fax: 559-439-5828
amnezami@yahoo.com
www.allcancercare.com

Daniel E. Stobbe, MDValley Metabolic Imaging
6121 N. Thesta Ave., Suite 207
Fresno, CA 93710
559-449-2640; fax: 559-432-7020

Aron Gould-Simon, MD
Valley Metabolic Imaging
6121 N. Thesta Ave., Suite 207
Fresno, CA 93710
559-449-2640; fax: 559-432-7020