Saturday, September 22, 2018

CANCER 101: The Essentials of How Cancer Happens (and Doesn't)

CANCER MADE EASY: GENETICS & MUTATIONS
By Dr. Patricia Clark

Our DNA and our genetic material is breaking and being damaged every single day. That's just the wear and tear of life. Our bodies have genes and mechanisms to repair broken DNA, and our immune systems have mechanisms to identify and destroy cancerous cells. With breast cancer, 5% to 10% of people have a genetic predisposition that raises their risk of development of breast cancer.

If we have a cell that can't be repaired, our immune system can recognize it and our natural killer cells can destroy it. So that's how things ought to work. Eventually, you accumulate MUTATIONS over a lifetime as more genes and genetic information are damaged and break down. Somebody like Angelina Jolie had a gene that predisposed her to get breast cancer. She had a gene called BRCA which is a DNA repair mechanism gene. She had one copy of that gene that did not work causing an 87% chance she was going to get breast cancer. She decided with a risk this high for the particular genetic mutation she had, she was going to get mastectomies and remove her ovaries, which were also at risk.

Genes are like a paragraph of instructions that tell a cell what it is supposed to do, such as what proteins it should make. If all the letters in the instructions are in the correct order, or the gene is “spelled’ correctly, the gene can be read by the cell and everything works. Pathologic mutations in genes have to occur in very specific locations for a cell to no longer be able to understand the instructions it carries. We have all read paragraphs where letters or words are left out, but we can understand the meaning of the paragraph. 

Changing the letters at a key location though, can change the entire meaning of the paragraph of instructions. For instance, If I have a sentence in that paragraph with the word CAR, and I change that "R" to a "T" it now reads CAT. That might change the entire meaning of the message to the cell, and it will no longer be able to carry out it’s functions. That would be a pathological mutation and raise the risk of inheriting cancer or of a cell becoming cancerous.  Had I changed the C to a K, and made the word 'KAR', the cell may have still been able to read and understood the word carrying that mutation and can happily continue making the proteins it was supposed to manufacture. This is why some mutations may cause no harm to the cell as long as the cell can still read and understand it’s instructions while other mutations can stop a gene in its tracks, being rendered pathologic. 

This is the simplest way to describe mutations.

A lot of mutations aren't going to matter. You have to mutate them in very specific spots before a cell cant read it. To get a cancer, it's not enough to have one mutation. You have to have one or more specific mutations to enable cells to divide uncontrollably. Then you've got to have a mutation that allows it to get out of the organ that it's in (such as a milk duct) and escape into the nearby adjacent tissues, forming a tumor. That's a whole other gene that has to be bad. You have to have a gene in there that allows those cells to bring in their own blood supply so they can keep the tumor fed and alive.. So that's yet another genetic mutation.

Like with breast cancer, people don’t die of the breast cancer in their breast. They die if it traveled into their entered their bloodstream and lodged in their lungs, it lodged in their liver, it lodged in their bones it lodged in their brain... if it had the mutations it needed to escape the breast and lodge in an organ system that you need. In order to do that it that takes a whole other set of genetic mutations. We can test the tumors for these mutations.  Putting a garden variety breast cancer cell in the lung (per se), may be sort of like putting a Palm tree in Alberta, Canada. You can put a Palm tree up there, unless it has a set of very specific genetic mutations, it's not going to survive the winter up there.

“IT’S NOT THAT EASY TO GET CANCER”:
So that's why all of us aren't running around with cancers. 1 in 8 women will develop breast cancer over their lifetimes. We have genetic mutations that we accumulate, a lot of them meaningless. Then the other thing is you've got to have the exact right mutations all lined up in a row for something to become cancerous. For the same reason not all firefighters in 9/11 die of cancer, it also depends on genetic predisposition and a person’s ability to protect from and heal environmental insults.  We see families where it seems everybody's getting cancer but we can't find a nice single smoking gun or a silver bullet that “caused” it. If cancer were a single process or silver bullet, we’d have it cured already. We're going to have cancer forever because you can't stop the body from mutating or accumulating genetic damage. If you could, we would all be immortal.

So that's the briefest of the basics. Understanding cancer from the angle of genetic mutation and  predisposition helps you see why some people get it, some people don't. Some people may not have the robust repair mechanisms or the lifestyle to fight it off.  Many are sedentary-- they don't exercise, they drink alcohol, or have other lifestyle risks that are another part of it. 

There are also a lot of environmental factors that can turn genes on and turn genes off. That’s a whole other layer. You can be predisposed because you carry a unique malfunctioning gene ... which carries a variable increase in somebody's risk.  They may have a 40% risk they're going to get cancer- or you can see it as that there's 60% risk they never will. We have proto-oncogenes that must be turned on to cause a tumor to form, and tumor suppressor genes that must be turned off to allow a cancer to form. We may or may not be exposed to the environment inside or outside the body that's going to turn it on - or off.



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ABOUT THE AUTHOR:
Awareness for a Cure welcomes our newest cancer expert, Dr. Patricia Clark- Breast and Oncoplastic Surgeon. Dr. Clark is a renowned speaker at the BC3 (National Breast Cancer Conferences) and is currently the medical director and surgical oncologist at the Ironwood Breast Cancer and Research Centers in Scottsdale, AZ. You can learn more about Dr. Clark at: www.drclarkmd.com


Eliminating Cancer is not enough:
A woman’s function and body image matter. For most women, there is no survival advantage to mastectomy. By using oncoplastic techniques such as breast reduction or mastopexy at the time of lumpectomy, selected women with larger tumors or more complex disease can now have complete removal of their cancer and still have a good cosmetic result. While Dr Clark personally performs oncoplastic procedures, high quality plastic surgery consultation is available for all women requiring reconstruction from mastectomy, and to optimize outcomes in selected women undergoing oncoplastic procedures.  Surgery can be performed on the other breast to provide symmetry. We don’t want the breast to be a reminder of cancer in years to come. www.drclarkmd.com


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CANCER 101: The Essentials of How Cancer Happens (and Doesn't)

CANCER MADE EASY: GENETICS & MUTATIONS By Dr. Patricia Clark Our DNA and our genetic material is breaking and being damaged ever...