Cancer

Is the home-screening test for colon cancer effective?

DEAR DOCTOR K: I heard about a new home test that detects colon cancer. Is it a good alternative to colonoscopy?

DEAR READER: The new test appears to be an advance, but I don't think it's as good as colonoscopy. Particularly for people who are at higher risk for colon cancer, I regard colonoscopy as the best test. Colon (or colorectal) cancer lies in the wall of the colon. It can cause painless bleeding. The amount of blood can be so small ("occult blood") that it isn't visible in the bowel movement, but it can be detected by chemical tests.

How does chemotherapy fight cancer?

DEAR DOCTOR K: My mother was diagnosed with cancer and will soon begin chemotherapy. I'd like to understand how chemotherapy is given, and how it fights cancer.

DEAR READER: Chemotherapy uses drugs that kill cancerous cells, but only injure healthy cells. To understand chemotherapy, you need to understand what cancer is and what is different about cancer cells.

Can an alkaline diet help prevent cancer?

DEAR DOCTOR K: I've heard that an alkaline diet can help prevent cancer. Is this true?

DEAR READER: I wish it were, but it's not. So-called alkaline diets do not fend off cancer. That's because it's nearly impossible to change your body's pH by changing what you eat. Let me back up for a minute. Every day our bodies perform any number of intricate balancing acts. One of them is to make sure the body's fluids, tissues and cells don't get too acidic or, at the other extreme, too alkaline. As you may remember from high school chemistry, acidity and alkalinity are measured as pH.

Should I have a mammogram and a MRI if I’m at high risk for breast cancer?

DEAR DOCTOR K: I'm at high risk for breast cancer. Should I have screening mammograms, MRIs or both?

DEAR READER: Many factors can put a woman at high risk for breast cancer. The most common and important are these: (1) inheriting certain high-risk genes from one of your parents; (2) having a parent, sibling or child with breast cancer; and (3) having received radiation treatment to the chest (usually for some type of cancer) before age 30.

Is it possible to prevent or reduce your risk of cancer?

DEAR DOCTOR K: Is it possible to prevent, or at least reduce, your risk of cancer?

DEAR READER: Absolutely, it is. It is possible both to reduce the risk that your cells will turn cancerous, and to catch cancer early and prevent it from causing suffering. But first let's define some terms. What does it mean to say that a "cell turns cancerous"? Cancer is uncontrolled cell growth. Most cells "grow" not by becoming larger, but from dividing. (An exception: Fat cells grow not only by dividing, but also by becoming larger.) One cell becomes two, two become four, four become eight, and so on.

Do you suggest HPV testing or Pap smears for cervical cancer screenings?

DEAR DOCTOR K: I am 31 years old and have always had normal Pap smears. I just read that HPV testing might be better. What do you suggest?

DEAR READER: Screening for cervical cancer has led to a dramatic decrease in the disease. Until fairly recently, all cervical cancer screening was done by Pap smear. But the FDA recently approved the use of a new screening tool -- the HPV DNA test -- that may eventually take its place.

Why delay treatment for slow-growing prostate cancer?

DEAR DOCTOR K: I was recently diagnosed with prostate cancer. My doctor says my cancer is slow-growing and that we should just monitor it for now. Why not treat it right away?

DEAR READER: I know this will sound odd, but cancer is not always bad for your health. There are types of cancer that can cause no symptoms, that grow slowly (if at all) and that are unlikely to spread. There are types of cancer that you will never know you had. You will die with these cancers, but you won't die from them.

What are pulmonary nodules — can they cause lung cancer?

DEAR DOCTOR K:I saw my doctor because I've been getting short of breath. He did an X-ray and CT scan that found three small "pulmonary nodules." Do I have lung cancer?

DEAR READER: There are few things more frustrating, for both you and your doctor, than when the doctor says: "Well, it's almost surely nothing to worry about ... but there is a small possibility that it's bad." How often does that happen? Pretty much every day, in my experience.

Does eating fish help prevent prostate cancer?

DEAR DOCTOR K: Does eating fish help prevent prostate cancer?

DEAR READER: You've certainly heard me encourage readers to eat plenty of fish, particularly fatty fish such as salmon and mackerel. That's because many good studies have found that people who eat fish frequently have lower rates of many serious diseases, including heart disease and several types of cancer. A recently published study from the Prostate Cancer Prevention Trial (PCPT) was described in the media as coming to the opposite conclusion. I don't agree, but to explain why, I first need to talk about the substances in fish that are thought to be beneficial for humans.