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What are we learning and why are we learning this? Content, procedures, or skills.

Vocabulary objective

Tier II: High frequency words used across content areas. Key to understanding directions & relationships, and for making inferences.

Tier III: Low frequency, domain specific terms.

Building on what we already know

Make connections to prior knowledge. This is where we build from.


There is no single disease called ‘cancer’. Rather, cancer is a general name for over a hundred different diseases. These diseases have some superficial similarities:

* mutations in oncogenes – genes that control cell growth
* Leads to a loss of control over their growth
* These cells are not well differentiated (not formed correctly)
* cells don’t perform their intended job properly
* The line of cells becomes immortal, and cannabilize the body’s resources
* The cells metastasize – move into other tissues

Causes of cancers

* mutation in a gene, inherited from a parent
* spontaneous gene mutation in a gene
* damage to gene from ionizing radiation (ultra-violet light, nuclear radiation)
* damage to gene from a chemical (carcinogen)
* damage to gene from a virus

Process by which cells become cancerous


{ image from http://cisncancer.org/research/what_we_know/advances/oncogenes.html }

Tumor suppressor genes in normal cells normally act as braking signals, during phase G1 of the cell cycle

They stop or slow the cell cycle before S phase.

If the tumor-suppressor genes are mutated, then the normal brake mechanism will be disabled, resulting in uncontrolled growth, i.e. cancer.

Many mutations are needed to transform normal cells into cancer cells:

Why is it so hard to cure a cancer?

“Cancer cells evolve. With each cell division, cancer cells accumulate mutations that cause variations. These variations allow cancer cells to change and adapt to survive within the complex ecosystem that is our body. In this schematic, the original cancer cell type shown in beige is no more; its descendants have all mutated and diverged, adapting and surviving with each cell division.”

Image credit: Buddhini Samarasinghe

How subsequent gene mutations lead to an out-of-control cell

Oncogenes tumor supressor


Tumor –

benign tumor –

malignant tumor –

Treating cancer

There is no such thing as a “cure” for “cancer” because there is no such thing as a specific disease called “cancer”. Rather, there are over a hundreds of different cancers, each with a different molecular cause, therefore each responds to a different treatment.

targeted therapy – http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted

Conventional surgery –

Cryosurgery –

Radiation therapy-

Chemotherapy –

cancer immunotherapy uses parts of one’s immune system to fight the cancer

The Toxins of William B. Coley and the Treatment of Bone and Soft-Tissue Sarcomas

Edward F McCarthy, MD, writes:

In 1891, William B. Coley injected streptococcal organisms into a patient with inoperable cancer. He thought that the infection he produced would have the side effect of shrinking the malignant tumor. He was successful, and this was one of the first examples of immunotherapy. Over the next forty years, as head of the Bone Tumor Service at Memorial Hospital in New York, Coley injected more than 1000 cancer patients with bacteria or bacterial products. These products became known as Coley’s Toxins. He and other doctors who used them reported excellent results, especially in bone and soft-tissue sarcomas.

Despite his reported good results, Coley’s Toxins came under a great deal of criticism because many doctors did not believe his results. This criticism, along with the development of radiation therapy and chemotherapy, caused Coley’s Toxins to gradually disappear from use. However, the modern science of immunology has shown that Coley’s principles were correct and that some cancers are sensitive to an enhanced immune system. Because research is very active in this field, William B. Coley, a bone sarcoma surgeon, deserves the title “Father of Immunotherapy.”

Vaccines against cancer-causing-viruses

Cell phones and cancer

Decades ago, a few small, preliminary studies suggested that the microwave radiation emitted from cell phones might cause cancer.  Since then, no further studies have shown this. In fact, although the use of cell phones went up by a factor of 100%, then 1000%, and then 10,000% percent, the number of cancers has not changed. If there truly was a connection between cell phone microwave radiation and cancer, then these changes in cell phone use would have caused a noticeable rise in cancers, which did not occur.

Can You Hear Me Now? The Truth about Cell Phones and Cancer: Physics shows that cell phones cannot cause cancer. By Michael Shermer on October 1, 2010

… Cell phones cannot cause cancer, because they do not emit enough energy to break the molecular bonds inside cells. Some forms of electromagnetic radiation, such as x-rays, gamma rays and ultraviolet (UV) radiation, are energetic enough to break the bonds in key molecules such as DNA and thereby generate mutations that lead to cancer. Electromagnetic radiation in the form of infrared light, microwaves, television and radio signals, and AC power is too weak to break those bonds, so we don’t worry about radios, televisions, microwave ovens and power outlets causing cancer.

Where do cell phones fall on this spectrum? According to phys­i­­cist Bernard Leikind in a technical article in Skeptic magazine (Vol. 15, No. 4), known carcinogens such as x-rays, gamma rays and UV rays have energies greater than 480 kilojoules per mole (kJ/mole), which is enough to break chemical bonds. Green-light photons hold 240 kJ/mole of energy, which is enough to bend (but not break) the rhodopsin molecules in our retinas that trigger our photosensitive rod cells to fire. A cell phone generates radiation of less than 0.001 kJ/mole. That is 480,000 times weaker than UV rays and 240,000 times weaker than green light!

Even making the cell phone ra­di­a­tion more intense just means that there are more photons of that energy, not stronger photons. Cell phone photons cannot add up to become UV photons or have their effect any more than microwave or radio-wave photons can. In fact, if the bonds holding the key mole­cules of life together could be broken at the energy levels of cell phones, there would be no life at all because the various natural sources of energy from the environment would prevent such bonds from ever forming in the first place.


“Oh no! My cell phone’s going to kill me!” by Orac on May 19, 2010

… there has not been a large increase in brain cancer or other cancers claimed to be due to cell phone radiation in the 15 to 20 years since the use of cell phones took off back in the 1990’s, nor has any study shown a convincing correlation between cell phone use and brain cancer.

Of course, one would not expect a priori, based on what is known about basic science, that cell phone radiation would cause cancer. After all, the development of cancer in general ultimately requires mutations in critical genes regulating cell growth and development. For an outside treatment to cause such mutations, as far as we know, requires the ability to cause DNA damage through the breaking of chemical bonds. Ionizing radiation can do this, as can certain cehmicals and chemotherapeutic agents. Indeed, that’s how these agents work against cancer because cancer cells tend to be more sensitive to DNA damaging agents than normal cells due to defective DNA repair mechanisms.

Thus, it is highly implausible based on basic science that cell phone radiation could cause cancer. It’s not homeopathy level-implausible, but it’s pretty implausible. Nor is it impossible, as has been claimed, because there may be biological mechanisms behind cancer that we do not yet understand, and it’s almost always physicists with little knowledge of epigenetics and other mechanisms of cancer development who make such dogmatic claims. Still, such physicists are not too far off; if cell phones could cause cancer, it would have to be through a previously unknown physiological or genetic mechanism. Absent compelling evidence of a link between cell phones and cancer, then, it is not unreasonable to rely on the basic science and consider the possibility of such a link to be remote.

Still, anything having to do with “radiation” causes fear, because most people don’t understand the different wavelengths and varieties of radiation. There’s also a cottage industry that’s sprung up to take advantage of people’s lack of knowledge about basic physics and chemistry by selling useless “cell phone radiation shields.” Much like research into various highly implausible forms of “alternative medicine,” though, research into a possible link between cell phone use and brain cancer continues unaffected by considerations of prior plausibility. So does the hysteria, sometimes even infecting prominent, high-ranking cancer researchers who really, really should know better.


Nuclear power and cancer

In theory, during an accident, radiation released from nuclear power plants can increase the background rates of cancer, perhaps dramatically. It has long been expected by opponents of nuclear power that it’s use would be highly dangerous. Yet in the 60 years of it’s use, the number of actual accidents, Soviet designed tragedies like Chernobyl (an event in a class by itself, due to deliberate malfeasance), and even Fukushima Daiichi, the tsunami-damaged nuclear reactor site, have caused far less damage and death than coal, oil and other sources of power.

Surprisingly, simply burning coal releases more radiation into the environment than running a nuclear reaction. Similarly, getting into an airplace to fly away from Fukushima Daiichi caused thousands of Japanese citizens to be exposed to even more ionizing radiation than if they had simply stayed at home – as airplane flights make one rise above most of the atmopshere, thereby increasing one’s exposire to natural background radiation from space.

There is also the intriguing phenomenon of radiation hormesis:

Radiation hormesis is the hypothesis that low doses of ionizing radiation (just above natural background levels) are beneficial. Low level radiation apparently activates repair mechanisms that protect against disease, that are not activated in absence of ionizing radiation. The reserve repair mechanisms are hypothesized to be sufficiently effective as to not only cancel the detrimental effects of ionizing radiation – but also inhibit disease not related to radiation exposure. This counter-intuitive hypothesis has captured the attention of scientists and public alike in recent years.

Radiation hormesis. (2016, December 10). In Wikipedia, The Free Encyclopedia. Retrieved 18:44, February 2, 2017
Radiation hormesis (Wikipedia)

There is no environment without some level of background radioactivity. What society needs to do is become familiar with the statistics, so it can make informed choices on how much power to generate/consume, and where this power should come from.

Coal releases more radioactivity than nuclear power


What kinds of radiation cause cancer?

Conspiracy theories abound online

Many people are convinced that a “cure for cancer” is being suppressed. Not so.  I have friends who work in bioscience companies. The labs they worked in can’t keep a secret about which employee is going out with whom, or who’s getting a promotion. And there are thousands of competing companies, all across the planet, with tens of thousands of employees. On top of that, they build all of their research on the work of thousands of other post-docs and biochemistry professors, from many different colleges and universities. It would be impossible for these thousands of people to hold such a conspiracy.


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What kinds of radiation cause cancer?

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