Tumor and Host—Seeds and Soil

For decades, cancer scientists and oncologists have focused more on what type of ‘disease’ a person has, as opposed to what type of ‘person’ has a disease. Every individual has a unique biological environment within.

Zeroing in on the cancer burden—the tumors—and decimating rogue cancer cells, has comprised a single-minded approach to wiping this insidious disease off the face of the planet.

Siddhartha Mukherjee’s excellent and extensive piece in the New Yorker, titled The Invasion Equation, opens with a challenging dilemma: “We can detect tumors earlier than ever before. Can we predict whether they’re going to be dangerous?”

The vexing fact is that people can have a similar tumor type, stage and grade, receive similar treatment, and then go on to have much different journeys. One may achieve a durable, long-term remission, while another person relapses with metastatic disease and dies within six months.

With few exceptions, we simply don’t know with exactitude which patients might fall into the categories of overdiagnosed or overtreated. We are not yet skilled at pinpointing whether some early cancers may never pose a problem, and should simply be monitored. Nor are we confidently and thoroughly able to evaluate and plot that a specific patient with localized cancer will gain no further benefit after surgery by going through chemotherapy or radiation.

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Primary solid tumors, the original site of a new cancer, do not tend to kill. It’s disease that has spread, becoming metastatic, that typically hastens death. Despite this, and as an example of overtreatment, current clinical guidelines recommend women receive chemotherapy after surgery for certain local breast cancers, as if all are at risk for metastasis.

Essentially, we currently risk adding more physical, emotional, and financial stressors by unnecessarily adding toxic therapies for many patients who do not require them.


Mukherjee is a practicing oncologist and author best known for his 2010 Pulitzer Prize-winning book, The Emperor of All Maladies. In 2015 the book was made into a Ken Burns-directed, six-hour television documentary of the same name. I reviewed Emperor here.

In his New Yorker piece, Mukherjee shares a story of Lake Michigan, which became overwhelmed by mollusks thought to have originated in Ukraine. “In the late nineteen-eighties, cargo ships traveling from the Black Sea and Caspian Sea had dumped their ballast water into the Great Lakes, contaminating them with foreign organisms.”

By the mid nineteen-nineties these hearty mollusks—zebra and quagga mussels—began covering beaches, coating docks and piers, and clogging water pipes and sanitation systems.

By 2012 these bedeviling bivalves had propagated in such a profound way that Lake Michigan was estimated to contain nine-hundred-and-fifty-trillion mussels—more mussels in weight than all of the fish in the Great Lakes combined. These invasive species caused billions of dollars in damage.

Mukherjee asks: “What made these mussels such malignant invaders?” After all, in their Native Ukraine—living in the deltas and basins—these world-class breeders, known to produce one million eggs per year, only reach a fraction of their concentration as compared to what happened in the Great Lakes.

The author reasons that multiple factors may have been at play in the Lake Michigan mussel takeover, including water quality, water depths, pathogens, and natural predators.

And this phenomenon is not limited to mollusks. Other foreign species, such as the Asian carp, are also incredibly virulent in U.S. waters as compared to their native lands. The Japanese knotweed, while tame at home, is hostile in its destructive growth in the gardens of England.

“We want to know which mollusk we’re dealing with; we also need to know which lake”, writes Mukherjee.

Tumor and Host, Seeds and Soil

I have written about the host environment here.

Seeds and Soil is how Mukherjee analogizes mollusks and lakes when describing the relationship between cancer cells and tumors—the ‘seeds’—within the host environment’s normal tissue and cells comprising the ‘soil’.  This is a different approach than just looking at cancer as a genetic disease and mutating tumors.

I like the seeds and soil metaphor. My colleague Keith I. Block, MD, arguably the father of modern integrative oncology, refers to the host or soil as ‘terrain’. My colleague Donald I. Abrams, MD, a leading integrative oncologist, refers to it as ‘the garden’, and emphasizes the need for it to be nurtured and weeded regularly.

Modern oncology is still utilizing mostly anticancer agents like chemotherapy, but with use of more targeted therapies, including monoclonal antibodies, kinase inhibitors, and hormone blockers. These agents home in on specific molecules associated with disease growth pathways.

But more recently a number of immunotherapies, including a novel gene therapy, CAR-T, are ushering in a whole new understanding and approach to the unique biology of the host and soil.

These advancements will come from new tests and assays that will be more predictive. The next generation of diagnostics will better differentiate which patient should undergo, say, chemotherapy (or any type of chemical therapy) and/or radiation therapy after surgery; or who should get surgery alone because the risk of metastasis is quite low.

Critically, we will also gain a much clearer idea as to who might simply need monitoring without treatment. Currently, many people are overtreated; we just cannot define exactly who. With few exceptions, we do not have the prognostication tools to reliably tell which patients should skip what is now part of standard care as captured in the clinical guidelines that inform treatment protocols.

This means, sadly, only a fraction of those receiving chemotherapy and radiation therapy for, as an example, non-metastatic breast cancer, are receiving a clear benefit.

As depressing as this is, it is my view that, even without more precise predictive tests, most patients should follow the current clinical treatment guidelines, as opposed to gambling with surgery only, or pursuing alternative cancer care in lieu of conventional treatment altogether.

Modern oncology—commercial interests, scientists, and clinicians—will continue its focus on predictive assays and more targeted chemical therapies, aimed at both tumors and the host environment (also known as: seeds and soil).

But while the arsenal of predictive prognostication tools are still in development, you can take smart steps now to positively affect your underlying health and become more ‘cancer-proof’.

It has never been more important to focus on the host and soil for those looking to:

(1) prevent cancer;

(2) get through active treatment in the best potential physical and emotional shape;

(3) establish a more durable, long-term remission.

Our genes, including harmful oncogenes, are continuously expressed, switching on and off. This is called epigenetics. Our everyday lifestyle and choices control how our genes are expressed.

Healthy eating, daily exercise, stress reduction techniques, plentiful sleep, and abundant filtered water are critical habits that we must adopt to influence a healthier host and soil environment.  These habits modulate our gene expression. Sensible decisions comprise the core tenets of lifestyle medicine and integrative oncology and, vitally, the medical literature unequivocally supports these approaches for cancer prevention.

Novel, patented medicines and tests are on the horizon, arriving soon to support new approaches to better predict and treat cancer with more precision. But we live in the here and now—and there is plenty, right now, that can be done to tend to your own host, soil, and garden… to avoid tumors, seeds, and mollusks.