How Does Cancer Kill You?

Hearing the unfortunate news about Mr. Rogers, who died of stomach cancer, made me wonder just what the mechanics of dying of cancer are. I realize they’re probably variable according to the type of cancer, but how does a tumor in your stomach kill you? Also, why isn’t there heart cancer (or at least, why do you never hear of it if such a disease exists)?

Partly it’s due to the cancerous cells sapping your body of nutrients, but doing nothing with them that benefits the body. Cancerous cells proliferate rapidly, using energy in the process. Terming a cancer after the organ it begins in is somewhat misleading, since the worst damage occurs whent he cancer spreads to other organs (metastasizes). The other thing cancerous cells do is replace healthy cells in an organ, reducing it’s effectiveness as it spreads. They do this largely by hijacking the blood supply to feed themslevs, starving nearby healthy cells.

A tumor in your stomach generally won’t kill you; it’s possible to starve if the tumor grows large enough to interfere with digestion, and it’s possible to bleed to death if the tumor is of the right type, but most people who die of stomach cancer do so because the cancer metastasizes to other tissues, where the cells grow unrestrained and undetected until they completely shut down a vital organ system or two.

The Master had a column about heart cancer you should be able to find.

As for cancer, it kills in many ways.

My mother had colon cancer. Ultimately, she starved to death. She could no longer get any nutrition out of any food she ate.

My father had pancreatic cancer. He died of a pulmonary embolism. However, we didn’t know he had pancreatic cancer until after he died because the first symptom of the disease was the embolism.

I’m no doctor, but I think the ulimate cause of death can be quite different. Sherwin Nuland’s “How We Die” is a great book explaining just what happens to the body when you die. He has a chapter on congestive heart failure, two different ones on cancer I believe, AIDS, and other diseases.

I would assume that a cancer would have to be of a fairly significant size to interfere with digestion, and that it would have caused some sore of symptom before it reached that stage (my grandfather, for instance, also died of stomach cancer in the early 1950s - he had a number of symptoms before he was diagnosed and actually drank teaspoonfuls of kerosene to ease the pains in his stomach).

Pancreatic cancer has a reputation for being nearly always fatal because by the time the cancer itself is diagnosed it has metastisized to other organs (which happened to my other grandfather - given my family history I’m willing to bet that the Big C will be the cause of my demise).

Thanks for the answers so far - we’ll see if Q the M chimes in tomorrow.

Mi0nor nitpick, but pancreatic cancer is a digestive system cancer. The pancreas sectretes enzymes into the small intestine that are important in the digestive process, in addition to producing insulin which helps regulate sugar metabolism.

To clarify, my mother’s colon cancer was diagnosed and she had definite symptoms and went through treatments. They just didn’t work as she had an extremely aggressive form of cancer.

My father’s pancreatic cancer did not manifest itself in any digestive problems. He wasn’t losing weight or getting jaundiced. He just had a bad cough. Then he felt weak and then died en route to the hospital to get fully checked out from stem to stern.

Cancer kills in many ways. Depending on the specific type, all or some of the following may apply:

  1. Cancer, at its primary site can cause lethal problems eg. lung cancer blocking a bronchus (breathing tube) leading to pneumonia, eg. cancer of the bile ducts blocking off the liver

  2. Cancer can spread locally and kill, eg. a lung tumor that eats it way into a blood vessel or into the heart lining

  3. Cancer can spread far beyond its primary site and do damage there, eg. breast cancer spreading to the liver and causing liver failure, or eg. breast cancer spreading diffusely through the lungs, or eg. lung cancer spreading to the brain

  4. Cancer weakens the body, sometimes in obvious ways such as malnutrition, and sometimes in subtler ways such as inhibiting the immune system. In either case, infections result and are much more severe than in “normal” individuals.

  5. Cancer makes the blood clot more readily. Blood clots kill. (The association between cancer and clots is quite common but not generally appreciated, IMO, by lay people)

(N.B. Both #5 and #6 are made worse by the immobility of advanced cancer patients)

  1. Cancer replaces the bone marrow causing fewer white blood cells and/or platelets to be produced. Infection and/or bleeding results.

  2. Cancer can leads to bizarre, unpredictable, and sometimes mysterious effects in the body, eg. lung cancer causing “Lou Gehrig’s Disease”, eg. kidney cancer causing high blood calcium levels, eg. myeloma (a type of bone marrow cancer) causing breakdown of the nerves in the body (neuropathy), eg. lymph cancer leading to kidney failure

I’m sure there are even more mechanisms.

Slight typo above.

With respect to immobility and item #6, I meant to say that immobility increases the likelihood of infections in cancer patients (eg. if you don’t move around, you get pneumonia). Immobility has no effect on the marrow directly.

KarlGauss has provided an excellent explanation, yet it does not touch on the total damage done by the disease, the family and lovers being so close that a part of them slowly dies, too.

Carol was young-in her early 30’s when first diagnosed with an ovarian lump. Surgery and treatment indicated that all was well for a few years. Then a routine follow up indicated that problems had returned. Worse yet, the problems had grown. A lengthy operation followed.

Together with a morphine pump, Carol clung to life in the hospice until she could be no more.

I just wish that her doctors had let her pass with dignity and did not extend her suffering, knowing that there was no hope of remediation.

Also to expand on KarlGauss’s stuff – #5 and #7 are basically the same. Cancers, by producing certain hormones or other kinds of molecules, or by initiating bizarre immune reactions, cause what are known as paraneoplastic syndromes. These can include neurologic disease. What BobT’s father had was called Trosseau’s Syndrome – hypercoagulabilty associated with adenocarcinoma, especially of the pancreas.

Basically, cancer can invade, impinge, or interfere.

Er, Trousseau’s. Also I’d just like to add that stomach cancer like that of Fred Rogers often causes a wasting called cachexia, not necessarily by obstruction but by what is thought to be paraneoplastic. Cachexia can be seen in other cancers too.

Pancreatic cancer has an extremely high mortality rate because there is no effective treatment for it. Several types of cancer now have effective treatments with a good prognosis. But the treatments for pancreatic cancer are not effective for most folks who have it at this time, and as the organ itself is crucial to life processes, death is usually fairly rapid. Of course, the rapidity of death after diagnosis also has to do with the fact that it normally is diagnosed as a well advanced tumor.

The SDMB, where you learn more by accident than in school by choice.

Do cancerous cells release any kind of poisons? I seem to remember my biology professor saying so in college.

I was also told that pancreatic cancer is mildly familial - by the oncologist attending my grandmother shortly before she died of it. :frowning:

Is that true?


I suppose it depends on what you mean by poisons. You could call some of their chemical “waste” poisons, eg. urate, phosphate, lactate. Some cancer cells can release mucin, which may contribute to the cancer’s ability to promote clots.

Of more importance, I think, is that the body’s response to many cancers includes the production of substances that have fairly severe and detrimental effects, i.e. cytokines which cause the cachexia referred to above by edwino, as well as fevers and even the high blood calcium I mentioned.

As another layperson, I second the recommendation.

Again to add to KarlGauss
Cancers of tissues which produce things (like glands) can continue to make their enzymes even when they have distantly spread. So those can be toxins as well. There was a case presentation in NEJM a few months ago of a man with pancreatic cancer who presented with fat necrosis on his legs. Basically, the pancreas releases lipase which breaks up fats in the intestine. The pancreatic cancer was releasing buckets of lipase (it was an acinar not a ductal carcinoma), and this was eating up his fat in his legs and in his retroperitoneum.

Also, pancreatic cancer is difficult to treat because it usually shows up late. There are no signs of it early, like there would be of other adenocarcinomas (like thyroid or breast cancers). It is a similar problem with lung adenocarcinomas, and partly explains why they are so fatal. Virtually the only survivable pancreatic cancer is cancers near or on the ampulla of Vater (where the common bile duct empties into the duodenum), which present earlier. And those require a massive, invasive surgery called a Whipple procedure, as well as your standard heavy chemo and radiation. In the Whipple, you take out the distal stomach, the gall bladder and most of the bile duct system, most of the duodenum, and about half of the pancreas. Correct me if I’m wrong, Karl, because I’m in the latter graduate school part of an MD/PhD.

Yes, pancreatic cancers tend to become symptomatic only after they’re far advanced. I think you’re right edwino - they kill not because they’re inherently aggressive, but that they’re found out too late.

One exception to this “rule” that pancreatic cancers come to attention only late in their course (in addition to what edwino said about the occasional pancreatic tumours that cause jaundice early, and are thus detected early) are islet cell tumours of the pancreas. Even small islet cell tumours may become manifest because of their tendency to secrete hormones with fairly dramatic effects (eg. insulin, ACTH, etc.)

As an aside, some cancers are clearly aggressive from day 1. A good example of this is small cell carcinoma of the lung where even small primary tumours tend to have (micro)-metastasized by the time they’re found. Breast cancer also tends to metastasize early on, but may not exhibit other lethal characteristics for a long while. This is why “cure” for breast cancer (if that even exists) is defined as a least 10 years disease free survival, as opposed to 5 year survival for most other cancers.