Cancer: What You Need to Know, by Stephen Rosenberg
Introduction
Dr. Stephen Rosenberg spoke at our CTAC 2019 event and wrote this very informative book that we help all of us cope with cancer. I am going to try to summarize it.
Chapter 1: Cancer. Millions of Diseases
Cancer is millions of diseases. It varies from person to person and even within the same person. The range of prognosis and patient survival times varies dramatically.
Overall, cancer death rates have declined, and the number of cancer survivors has increased.
Where in the Body Does Cancer Come From?
Cancer comes from almost anywhere in the body. No organ or cell is immune from turning into cancer. Cancer, at its core, comes from cells, the building blocs of your body. The average human body is made up of 30-40 trillion cells. Each cell has a nucleus, which you can think of as the control center or brain of the cell.
Stored in the nucleus is the DNA. DNA contains the genes that make up who and what you are. Cancer comes from mistakes made in copying the DNA.
Cancer Cells Grow like Weeds: The definition of cancer is a disease caused by the unchecked growth of cells in the body. Unlimited Growth in the Garden. Errors in DNA can cause cells to behave selfishly. The faulty DNA tells the rest of the cancer cell to divide into two cells. Two cells become four cells, etc.
Like weeds in the garden, cancer cells take up valuable space and resources in organs, leading to abnormal function of the normal cells of that organ.
Solid Tumors: In general we split cancers into two types: liquid tumors and solid tumors.
Solid tumors are cancers that originate in any solid organ or structure in the body. (lung, liver, heart, etc.) Solid tumors can be cut out with surgery, treated with radiation, chemotherapy.
Metastasis: when cancer cells move from one part of the body to another.
Liquid tumors: cancers that make their home in the bloodstream. These cancers include many types of leukemia.
The cells in your blood come from the bone marrow. Bone marrow makes up the inside of large bones such as the pelvis or spine. These cells are vital for normal functions of the human body.
The cells include red blood cells, which carry oxygen throughout the body. The white blood cells, which are the immune cells that fight infections. Platelets are cells that allow the blood to clot.
Because blood moves throughout the body, the cells travel anywhere blood goes
How Does Cancer Decide Where to Go?
Cancer spreads anywhere it needs to go to find an environment with resources to help it grow. Different types of cancer tend to spread to certain parts of the body. Prostate cancer tends to spread to the bone. Breast cancer spreads to the armpit region. Lung cancers often spread in the chest or brain.
Where has all the Progress Gone?
Progress against cancer has been uncertain. Cancer spreads to different parts of the body and it keeps on changing. As cancer cells grow, new changes in DNA allow them to grow faster. Cancer cell will use any competitive edge for resources in the body. Cancer cells will try to steal the nutrients normal organs and cells need to survive. The change cancer cells go through to be more resistant to chemotherapy, radiation or immunotherapy.
Getting Back to the Basics
We can use cancer’s desire to divide against it.
Chapter 2: The Biology of Cancer
How a Normal Cell Behaves
Cells are the building blocks of our bodies. Each cell has a nucleus that stores the DNA, “the brain of the cell.” The DNA gives orders.
DNA instructions are rewritten as RNA. The RNA exits the nucleus and its instructions are used to build proteins in the rest of the cell. Proteins perform the actions of the cell. These instructions are to grow, divide, sleep, or anything in between.
Each cell has a program to tell it to stop growing and die when too much damage occurs to the genetic code (DNA). Cancer cells lack the normal signals telling them to self-destruct.
My Mom Had Cancer will I get Cancer
Most cancers come from a mix of risk factors, like age and exposures to things like smoking.
There are genetic syndromes, passed own, from parents that increase the risk of getting cancer. An example is a mutation in the genes, BRCA1/2 that increases the risk for breast cancer and other cancers.
A patient should work out a complete family history before meeting with a cancer doctor.
The Cancer Cell Making Crazy Decisions
Mutations are what drive cancer. Mutation in the DNA gives inappropriate instructions to the RNA, which uses them to make the proteins that act throughout the cell.
There are checks and balances in a cell. For example, tumor suppressors stop the cell’s signal to keep growing. The most well-known tumor suppressor is called p53–it is known as the “guardian of the genome.”
If cancer cell gets rid of tumor suppressors, it is free to do what it wants. This allows the cancer cell to focus on growing and dividing.
Cancer Orders in Gorging on Sugar
For cancer cells to keep on growing, they need nutrients: sugar and oxygen just like the rest of us. To help bring in extra supplies, cancer cells demand that the body form new blood vessels, directed to the cancer.
When looking for cancer cells we use the need of cancer cells for sugar. A PET scan uses a labeled sugar that is taken up by cancer cells. The labeled sugar shows up on our scans, helping us see where the cancer is located.
A cancer cell continues to divide at all costs. A cancer cells mutation gives cells more advantages to grow over time.
Metastasis
The movement of cancer to other parts of the body.
Cancer Cells Do Not AGE
Cancer cells can invade our organs and use our resources indefinitely.
In normal cells DNA has some scrap material; however, these protective ends get shorter with age.
By contrast cancer cell’s mutated DNA produces a protein knows as telomerase. This protein repairs the protective end, allowing cancer cells to avoid the aging process and keep growing.
Immune System Evasion Hiding in Plain Sight
Part of the immune system’s job is to look for any new cancers and destroy them. Cancer cells avoid the immune system by throwing up smoke screens.
Biology: The Big Picture
To summarize, cancer cells are just reflections of our normal cells. They use sugar and oxygen and avoid our immune system. Abnormal cell “thinking: leads to strange instructions being sent throughout the cell. A cancer cell’s only concern is getting enough oxygen and sugar to go on to its next cell division.
Immune System Evasion: Hiding in Plane Sight
Our immune system is always looking for new cancers and pre-cancerous cells and destroys them. Cancer cells avoid the immune system from recognizing them. The cancer cell tricks another type of immune cell that was going to destroy the cancer.
How Cancer is diagnosed
Because many of the symptoms of cancer point to a lot of different diseases, it is hard to know whether cancer is the cause of a particular symptom.
To understand each patient’s cancer, doctors use information from biopsies, scans, and clinical exams. Doctors then stage a patient’s tumor.
There are lots of screening tests for various cancers. Breast cancer screening is recommended. Prostate screening is controversial. The USPSTF website provides a list of screening tests.
Why the glands are swollen
A swollen gland comes from lymph nodes, which are spread throughout the body. Many cancers take over the lymph node and the immune system does not recognize them.
Red Flags: Symptoms that call for a closer look
Doctors take a special notice of red flags such as headaches, unexplained night sweats, weight loss, etc.
If doctors suspect a certain type of cancer, they may order a test for tumor markers–proteins that leak out into the blood from tumors. Doctors may use tumor markers to narrow down the possible types of cancer.
Getting a biopsy
If a doctor identifies a suspicious mass or growth, a biopsy is often performed. It tells the doctor whether it is just an infection, cancer, or something else.
A doctor can use a needle or ultrasound or CAT scan to help guide the biopsy.
While there is a small chance that a biopsy can lead to a cancer spreading, it is still important to have a biopsy.
After the Biopsy: Cancer Under the Microscope
Pathologists are doctors who specialize in diagnosing or identifying tissue. They solve the mystery of “what is the mass?”
Pathologists comment on how abnormal the cell looks. An example of tumor grading in prostate cancer is called the Gleason score. The more abnormal the cell, the higher the score. High-grade tumors behave more aggressively and metastasize more often.
Genetic analysis helps doctors determine what will make the cancer vulnerable.
The Purpose of Scans
Scans are done for one of three reasons:
Check how big the mass is and see whether it is directly invading different organ structures
Help decide whether the cancer can be cut out in an operation
Figure out whether the cancer has spread to other parts of the body.
Limits of Imaging
If scans are less than 1 centimeter (.4 inches) scans cannot reliably separate cancer from normal masses. Once a cancer has 1-centimeter mass, that mass already has 100 million to a billion cells.
Can a Scan Tell If My Cancer Treatment is working?
Why do not doctors order scans during cancer treatment: 1) Inability to see a single cancer cells on scans. We need to see millions of cells 2) There is a time span between the death of a cancer cell and what we see on the scan.
Choosing the Right Scan
Most common scans are CAT scans, MRI scans, bone scans, and PET/CT scans
CT scans are helpful for seeing the details of organs, lymph nodes, and other parts of the body very clearly.
MRI uses magnetic fields to help us peer inside a person. MRI is best at looking at soft tissues–like the normal folds of the brain, soft tissue of the arm. Downside of MRI include time and patient comfort.
Nuclear medicine tests sue radioactive substance or material (called a tracer) placed in the body. If an area takes up too much or too little tracer, it may imply there is a cancer.
PET/CT scan is used across a variety of cancers.
PET/CT Teaming up to Find High Sugar Consumption.
PET/CT involves injecting a labeled sugar. We can then see sugar on the scanner. Cancer cells use up lots of sugar quickly and inefficiently so we can see cancer cells light up. However, not all cancers reliably take up the labeled cancer. Also, because the brain uses a lot of sugar, PET/CT scans are not effective.
The lighting up is called activity. This indicates how much sugar a part of the body has taken up, which causes a glow. The more glow, the faster the cells are using sugar and more them
there are means cancer. To pinpoint the image we need a CT scan, which is clear vs. PET, which is grainy.
TNM: A secret language for stages of cancer.
We generally define staging in two areas.
Clinical stage uses information from a physical exam and scans for staging. A pathological stage is determined after surgery.
Biopsy confirms what type of cancer a person has. A pathological stage is reserved for after surgical procedure on the cancer.
First part of diagnosis is clinical stage (TNM). The clinical stage is broken into 3 parts: T (tumor); N (lymph nodes) and M (metastasis).
T takes into account the size of the tumor
N looks at the number of lymph nodes the cancer has spread to
M looks at whether the cancer has spread to other organs
Doctors do not generally discuss TNM but just tell people the stage.
Staging: Grouping Patients
We generally just give a person a stage. Instead of T2N1M0, we just say stage 2.
Stage 1 is the cancer is local
Stage 4 means that it has spread to other parts of the body.
Originally published in the Sarasota Herald-Tribune
