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How Fast Does Cancer Grow?

Over the years, I've found that many people don't seem to realize that the vast majority of malignancies aren't palpable and don't create symptoms for several years and sometimes decades. This is a critical point to understand, as our choices today are unmistakeably what determine our risk for cancer and most chronic diseases in the years ahead - even thirty, forty, fifty years ahead.

When looking to understand the pace at which cancer grows and spreads, the main concept to consider is doubling time, which is the amount of time it takes for one cell to divide or for a group of cells (like a benign or malignant tumor) to double in size.

Doubling time is different for various tumours, but if you know the size of a tumor at two different points in its lifespan, you can calculate doubling time with the following online resource: Doubling Time.

To put this idea into numbers, let's say that a 1 millimeter mass is detected within lung tissue on a CT scan. If this same mass is measured to be 15 millimeters two years later, doubling time for this mass is 62 days.

Here's the take-home point: a 1 millimeter cluster of cancerous cells typically contains somewhere in the ball park of a million cells, and on average, takes about six years to get to this size. Generally, a tumor can't be detected until it reaches the 1 millimeter mark.

So to develop a mass that is likely to be problematic (say, about 5 centimeters to put a number to this example), make no mistake in understanding that this is a journey of many years.

To put it another way, a person doesn't go from being relatively healthy to having cancer suddenly appear and spread throughout his body within a few months or even a year. To have a growth that is visible to the eye or cancer that has metastasized, generally, it's scientifically sound to state that the cancerous mass began developing many years ago.

I like to share this information with clients because I find that it tends to heighten awareness of how important today's food and lifestyle choices are in determining our risk for disease in the future.

It's simple: what we do today determines our risk for disease tomorrow.

With this thought in mind, we can strive to apply the following guidelines to our daily choices to reduce risk of most chronic, degenerative conditions, including almost all types of cancer:

  1. Limit intake of refined sugar.

  2. Limit intake of unhealthy oils that are rich in polyunsaturated fatty acids.

  3. Limit exposure to ionizing radiation and electromagnetic fields.

  4. Avoid use of oral contraceptives and hormone replacement drugs whenever possible.

  5. Minimize exposure to exogenous toxins like pesticides, herbicides, heavy metals, dioxins, asbestos, volatile organic compounds, and polychlorinated biphenyls.

  6. Minimize or completely avoid use of recreational drugs.

  7. Optimize vitamin D status.

  8. Work at getting regular aerobic exercise and restful sleep.

  9. Strive to be emotionally balanced i.e. avoid living in a fight/flight state where sympathetic nervous system output dominates parasympathetic (rest/digest) tone.

I think it's worth noting that the concept of cancer growth happening at a predictable pace applies to all major types of chronic disease. Risk of a cerebrovascular accident (stroke) is determined by how healthy our blood vessels and blood pressure are over decades, not by a sudden transient spike in pressure. Risk of chronic obstructive pulmonary disease is determined by all of the substances that our lungs have been exposed to since day one. And so on and so forth.

Please consider sharing this post with family and friends who are under the illusion that cancer and other chronic diseases are mostly a matter of bad luck. Certainly, there are situations where genetic predispositions and environmental circumstances are not ideal, but in most cases, we can reduce overall risk by being mindful of our daily choices.


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Great topic! I would add the following significant risk factors: Smoking and exposure to smoke from other sources; excessive insulin exposure resulting from obesity and lack of exercise; sunburn; parabens in skin preparations; nitrates and nitrites in preserved meats; acrylamides from starch foods cooked at high temperatures, like chips and donuts; urethanes in fermented foods; a family of chemicals known as amines that form when fat drips off of meat and into a fire, such as a barbecue. On the positive side, there are many foods that protect against the damage leading to cancer, as well as minimizing the proliferation of blood vessels (angiogenesis) that feed the cancer and permit very high growth rates. There is an excellent talk on this topic by Dr. William Li on entitled "Can we Eat to Starve Cancer?"

Hi, all the foods mentioned that feed cancer are basically all the food being served normally today. What else can I eat? :(

Today food companies are well aware that people are becoming more concerned about choosing clean foods that do not cause several serious illnesses to develop. There are better choices of the processed foods we love to eat without additives we want to avoid. Read the labels where it shows what is in the product you are buying. Also call the brands you like to ask customer service if they are considering offering foods you like minus the bad ingredients. Actually the best diet is choosing your own ingredients which are as close to the way they look when growing and making your own recipes for everything you like to eat. The only reason so many of us with hectic lifestyles eat fast food and junk is that we fall for the advertisements making products look exciting, appetizing, and fast and easy to get. This makes lots of money for the manufacturing companies and for the medical field, too! It is not really time consuming to pack your own meals and snacks if we simplify our choices and experiment with the myriads of interesting fruits, vegies and condiments that are healthy but not familiar to us. I myself have been trying to clean up my diet and experimenting with mixing different basic ingredients to form the most delicious, quick and easy recipes that have stopped my cravings for junk. One favorite of mine is mashed tofu mixed with ripe mashed banana, slivered almonds, pumpkin pie spice, chia seeds, monk fruit powder and a bit of oat milk to soften the seeds. Stay away from fried foods and anything so much processed that you can't recognize the original ingredients it comes from. Drink more plain water and no soda or juice. Eliminate foods with a lot of added sweetener of any kind. Watch the amount of saturated fat and sodium in processed foods that drive up your cholesterol and blood pressure. Make better choices!

How far can you reverse the effects of poor previous choices? I am 36 and I was on the pill from age 16 to 32. I've also had a bad diet for some of those years - lots of sugar and fats and processed meat, not enough veg - and not got enough exercise. I've not had enough sleep and been very stressed.

How much damage will I already have done and how far can I reverse this by making lifestyle changes?

Re: your recommendation that a person get regular aerobic exercise, a recent newsletter from Yoga Journal magazine claims that yoga in itself is sufficient for an individual's exercise and fitness needs, including aerobic. I would have trouble fitting both yoga (to which I'm committed) AND aerobic exercise, e.g. on my elliptical crosstrainer, into my daily routine. Most of the yoga I do, who am an overweight 65 year old male, is not very demanding--more low-key stretching. If I had to choose, which one is more likely to keep me healthy and fit over the long term?

Here's the link:

Any thoughts?

A dime (Canadian) is 18 millimeters in diameter, so one fifth of this would be 3.6 millimeters. This is quite a lot more than 1 millimeter. Maybe what is meant is that a tumor of 1 millimeter is roughly equal to the thickness of a dime, which is 1.22 millimeters, and one at 15 millimeters roughly equal to the diameter of a dime. Still not perfect, but easier to visualize at least for me.

I am from India, and in a developing ountry like India, there is a widespread lack of personal hygiene. This has nothing to do with poverty or so, as even people who are highly paid are very low in hygiene. And i belive that this is one of the causes of cancer in india, may be some microbes entering the body through unclean hands/food/air are producing some toxins, which over the period is causing cancerous. Most of the health/cancer studies are conducted in the West where personal hygiene can be taken for granted and hence the after effects of long term lack of hygiene is never considered.

We are all entitled to our opinions, but there was lack of hygiene back in the dark ages also and I don't think people were coming down with cancer because of that. From what I have read, India and China especially, are very polluted countries. They have many chemical factories there and well those factories don't practice "good hygiene". The waters and the soils are very contaminated.

This really bothers me a lot because all the waters of the world are connected. I could go on and on, but I don't want to bore anybody, just wanted to mention that I don't think the cancer is from bad hygiene, just my opinion, I am not a professional. :-)

People in the Dark Ages usually didn't make it past 30 years old. Naturally-occurring cancers (not from excessive chemical/radiation exposure) rarely occur in teenagers and young adults, meaning that they would die before the cancer could kill them. Cancer can, in fact, be caused by bacteria and viruses that are present in places where good hygiene isn't practiced. However, sanitation isn't the primary factor of cancer occurrence, but it may lead to the spread of other diseases.

It is completely un-true that people in the ancient past did not "make it past 30 years old." Many infants died of infections, and many others died before the age of five also of infection. This caused an imbalance in life-expentency tables. But once a person became an adult there was no reason not to expect a long life. Cancer, heart attacks and strokes, as well as diabetes, were relatively rare in all ancient/dark age people.

So Seinfeld was right?

My aunt was feeling ill and went to the doctor. I'm not sure what she was told but she went home. Within about 10 days later she went to the ER and was admitted to the hospital. By that evening she was dead.
They did an autopsy and found cancer all over her body. How could it have gone undetected for so long for it to spread that much.

Hi Laura, My mother also died from cancer. Her story is almost identical to your aunt's except that she lived a couple of weeks after diagnosis. My understanding is that many cancers do not cause pain or other symptoms particularly in the early days. Even when advanced, the cancer may only produce a vague feeling of being unwell that could be attributed to age or tiredness, so it is easy for a cancer not to be diagnosed.

My partner had chemo and had a scan and 6 weeks later had another scan. Doctors said the tumours where stable but would they have grown or changed in 6 weeks?

I remember seeing a doctor several years ago and she thought she felt a lump in my stomach. Then she told me to flex, and then decided it was only muscle. My twin was diagnosed with leiomyosarcoma in November 2018. She died in August 2020. I started worrying about my own health because one has a 48% chance getting cancer if their twin had it. Then, one day, I was leaning over to get something from the fridge and it seemed like there was a ball rolling around in my stomach. I called my Dr immediately and she sent me for an ultrasound but they found nothing. So I thought that I was only constipated. But after a cleanse, it was still there. So I bugged my Dr for a CT but she hhesitated and sent for another utrasound. Still nothing. Then I demanded an MRI or CT scan and my dr requested both which I went to in August 2020. They only found a 1 cm nodule on my lower colon and rectal area which they identified as endometreosis. Since. Ive gone through about 6 months of buffoonary with my Dr referring me to different specialists who referred without notifying her of the referrals. I basically had to set things up since they each rejected me because they thought the other dr was taking me. I finally got an appointment, but not until January of 2022! Lastmonth, I decide that I'm goin to Europe to have exploritory surgery. I wss doing the planning and ordered my records from my Dr, when last week I noticed an odorous liquid seeping out of my bellybutton. I thought it was a blister from the button on my jeans, so switched to elastic pants. But still, after a week it was still running and my whole stomach started swelling. I had just spoken to my Dr about the trip to Europe a couple weeks and did mention the 'ball' in my stomach and that my stool was becoming thinner. She basically laughed it off yet again saying if 4 out 5 drs think it's endometriouses then it probably is. But what about my CA125 test being at 51? Again, she said that's average. Anyway, my daughter suggested I really go to emergency since no doctor has physically looked at it because of Covid restrictions. So, the day before yesterday, I went early in the morning to ER, knowing it would be busy. They saw me fairly soon and the doctor said it was probably an infection. Or endometriosis. I'm 'okay good, I'll be out by noon.' Well, they did an ultrasound and the radiogist actually came into the room to see some things on the screen. He said 'look for vascularization'. That's when I knew something was wrong. Then, they sent me to a CT scan and found 5 tumours in my stomach including a large one that turned out to be 'the ball'. I was right. For over a year I knew something was wrong but nobody took me seriously. Now, it's ulcerating and becoming painful. It's not only difficult to shower but frankly, I'm grossed out from the smell and fluid emminating from what I thought was a healthy stomach. I've always been athletic and healthy. I've never been the type to complain about injuries even with the few I've had. But this, this is different. I could barely move yesterday. It also hurt because the er dr kept poking me with the biopsy needle and didn't get enough anyway. It's 'Suspicious for Malignancy' but it was affected by air-dry so inadequate for results. I have an appointment with a oncology surgeon on Wednesday. I'm really frightened but I'm hopeful I can dissolve away thsee tumours.

I am so sorry to hear about the delay in getting help. I will be praying for you.

Hi Cheryl,
I'm still here. I cut out all sugar and fat. For years I have been eating organic only anyway so I think it was mostly stress and negativity that contributed to my cancer. I try to get as much exercise as possible. I went in for Taxol chemo in May but it damaged my stomach lining and caused neuropathy in my limbs. I didn't go back and am now looking for other types of treatment besides Taxol. It may work for some people but, for me, it was detrimental to my health since I cannot stomach (literally) solid foods any longer. I'm on a regiment of b12 and other supplements that heal the stomach lining so I can get back to eating solid food. I have been trying to stay stress-free by meditating and cutting out all toxic people from my life. I think I'll be okay.

Thanks this is ver informative.

stage 4 lung cancer spread all over body. Husband diagnosed 5/4/2017, passed away 5/27/2017.How long had this cancer been there.

Wow. Who knows! So fast. I was diagnosed with stage 4 metastatic breast cancer that traveled to the bone throughout my body except my skull and

I fell down stairs from having a seizure and upon scanning my neck for damage, doctor found stage 4 Cancer in almost all my bones. Cancer had metastasized from a lump in my breast....god knows when. I'm still kicking over 2 years later. It could have gone both ways. I could have not responded to the first drug they offered me and the Cancer could have eaten me up in 2 months tops OR it could go like it did and my body responded to the 1st drug and nothing has spread in 2 years. It's bearable...mostly.

Congratulations. What a miracle! May I ask which drug you took to recover?