Cancer is when a single normal cell in whatever body organ somehow becomes altered, & acquires an ability to multiply uncontrollably. Over many years, a lump (“tumor” in Latin) forms and grows. Tumor cells may get into the blood and spread to other organs (“metastasis”). Cancer takes over the body, and the person dies. By the way, most “tumors” aren’t cancer, although patients get scared when they hear the word.
Nobody knows what causes cancer to develop, but 1 out of 4 people will die of one kind or another. It’s more common as we get older, since it takes so many years to evolve. We know some things that can be involved, like smoking, radiation, etc., but we don’t know why some smokers get cancer and others don’t. Genetics and heredity certainly involved, since some cancers run in families, but the majority don’t.
It’s impossible to talk about cancer in general, since every kind is so different. Even in a specific organ, there are many kinds of cancer. Some grow and kill quickly, others linger so long that nothing ever happens.
We suspect cancer by certain symptoms (see below). The first step in diagnosis is usually some kind of “image,” like x-ray, ultrasound, CT scan, MRI. But then to be sure, and to know what kind of cancer it is, we need a biopsy — a sample of tissue examined under a microscope. This can be complicated; for example, we might see lung cancer on an x-ray, but to get the biopsy, sometimes we can find it in sputum (phlegm), often a pulmonologist needs to enter the lung by tube (bronchoscopy), and sometimes a surgeon needs to open the lung & go in directly.
The main symptoms that lead us to suspect cancer include:
- A sore that doesn’t heal; a new change in a wart or mole
- Unusual bleeding (coughing, peeing, vomiting, pooping blood; vaginal spotting)
- A lump that doesn’t go away or gets bigger (usually doesn’t hurt)
- Difficulty in swallowing for 2 weeks (like food almost gets stuck)
- Nagging cough for over 3 weeks
- Hoarseness for 2 weeks
- Weight loss for a few weeks (without trying)
- Fevers or drenching sweats for over a week
- New diarrhea or constipation, or both (alternating), for 1-2 months
If a patient has any of the above, we aim for the relevant organ. For example, “hoarseness” gets referred to an Ear-Nose-Throat Specialist (ENT; Otolaryngologist) to examine the larynx (voice box). Swallowing difficulty gets referred to Gastroenterology for endoscopy. Coughing up blood gets a chest x-ray, and maybe a chest CT scan. Etc.
Metastatic cancer means the disease has spread from its original organ to other parts of the body. When this happens, cure is impossible, but long-term control can still be achieved (so patients live longer, sometimes lots longer). The most common organs for metastasis are bone, liver, lung, and brain. Note that there’s an enormous difference between cancers which originate in those organs, and those that metastasize to them.
So, for example, primary bone cancer involves a single location, while metastases affect many bones. Primary liver cancer virtually only happens among patients with liver cirrhosis, or those with Hepatitis B or sometimes C, but many other cancers spread to the liver. Brain and lung cancer is treated completely differently depending upon whether it’s primary or metastatic.
Each kind of cancer requires its own type of treatment. Cancer therapy is so complex, that most institutions don’t begin it until a monthly “Tumor Board,” comprised of many different experts, meets to agree on the best option. Some cancers can be cured, especially if they’re discovered before they metastasize. Some can be held under control for a long time. Treatments for some cancers only help people live a few months longer. Some don’t work at all.
Especially for cancer, but as for all life-threatening diseases, it’s important to ask your specialist for numbers, in terms of probabilities, which may be only general estimates. In terms of how long patients live, they’re usually given in numbers like “30% survive 5 years.” Ask about:
- How long will I live if I don’t do anything?
- What’s the chance that Treatment X will help me live ____ years longer?
- What are the worst side effects of Treatment X? What’s the chance I’ll get them?
- What are the minor side effects of Treatment X? What’s the chance I’ll get them?
Preventing Cancer (& Preventing Death from it)
Cancer Prevention would be ideal, but unfortunately rarely works. We should certainly screen for Colon Cancer (large intestine & rectum) for anybody:
- Over 50 years-old (or now some say >45)
- Had a parent or sibling who had colon cancer at an age 10-years-or less older than patient
- Persons with Inflammatory Bowel Disease or some uncommon conditions
Screening can be done by colonoscopy, by stool testing in various ways, or by “virtual colonoscopy” (special CT Scan; see colonoscopy link). The latter two require subsequent colonoscopy if abnormal. Colonoscopy doesn’t only diagnose cancer, but actually prevents it, by removing polyps which could potentially evolve into cancer in the future.
Cervical Cancer of the Uterus is detected by Papanicolaou (Pap) tests. But, as for colonoscopies above, Pap tests can detect non-cancerous but nonetheless high-risk cell changes which could evolve into cancer. Treatment would then be preventive. Death rates from Cervical Cancer are very high in poorer countries without capacity for widespread Pap testing.
Unfortunately, not many other types of Cancer are amenable to screening. Breast Cancer (by mammogram) and Prostate Cancer (by blood test) are two, but the concept is controversial (may not save lives, may do more harm than good, but maybe useful). There’s a special low-radiation CT Scan for anyone who ever smoked much, for Lung Cancer, but the number of lives saved is relatively small.
Ovarian Cancer and Pancreatic Cancer are common, but attempts to screen successfully have failed, even among persons with strong family histories of disease. That’s because the cancer advances so rapidly, that even if you’re negative today, in a short time it could develop and progress too far.
I tried teaching my middle-school daughter about probabilities once, and told her, “The risk of dying from cancer ‘just by getting out of bed in the morning’ is 1 in 4.” She replied, “Then I’m not getting out of bed.”