Cancer might be a third category of cell type, thinks clinician Doru Paul. He discusses the continuous interaction and communication between tumor cells versus normal cells that make cancer a disease of the macro environment. Listen and learn

• Why cancer is a multi-level disease, with influences beyond the cancer and genetics connection,
• What is known and unknown about the first cells that make cancer,
• How the metastatic process is primarily an epigenetic process and why that's significant, and
• What makes the role of cell metabolism and energy fundamental in understanding cancer.

Doru Paul is an associate professor of Clinical Medicine at Weill Cornell Medical College. He brings a vivid understanding of the process of cancer cells in the human body as the disease grows and transforms.

He adds that "the organism itself is giving, in a sense, birth to cancer," and compares the area of cancer growth as akin to placenta, altering to provide a suitable environment for cancer cells. But he sees it not just as a disease of the tissue, but rather a combination of factors at the cellular, genetic and epigenetic, and tissue levels.

Key to this combination and fundamental to cancer growth is the metabolic process. Metabolism is essential for cancer cell activity, for division, invasion, growth, and spread. "So, to me," he adds, "cancer is a disease of energy and a disease of communication."

He also lets listeners in on what researchers know about why cancer progresses differently, as with lung cancer stages, and what he's witnessed about the unpredictable speed of growth under the chemotherapy process.

Finally, he offers promising glimpses into the future of cancer treatment along the lines of immunotherapy combinations and ways to make, for example, the liver less conducive to cancer growth. In other words, researchers are finding ways to make our bodies less comfortable hosts.