Researchers at the Dana-Farber Cancer Institute in Boston say exercise helps combat breast cancer. Not the first time we've heard this fact. But these same researchers have something new to say -- about the reason physical activity lowers the risk of breast cancer recurrence.

Jennifer Ligibel, MD, of Dana-Farber, reports that exercise lowers levels of the hormone insulin in the bloodstream. This is significant because there appears to be an association between relatively high levels of insulin, seen in obese and sedentary people, and an increased risk of breast cancer recurrence and breast cancer-related death.

"We know that women who are overweight at the time of breast cancer diagnosis have a higher risk of recurrence than lean women, but the reasons for this have not been clear," said Ligibel.

White House Press Secretary Tony Snow popped in for an unexpected visit on Bill O'Reilly's Radio Factor on Wednesday with the purpose of clearing up a certain cancer matter.

"Some of this has been misreported," Snow told O'Reilly in reference to his recent cancer recurrence.

"I do not have liver cancer," Snow said. "There are a number of small tumors that are in my abdominal cavity; they have not hit any other organs."

Snow, 51, said there is also no cancer traveling through his bloodstream and that he plans to return to work after recovering from the surgery he had two weeks ago to remove tumors from his abdomen.

Although his cancer is not threatening his life -- he says if the tumors didn't grow from now until the time he died, he would be absolutely fine -- Snow will still receive chemotherapy to "drive this sucker into remission," he said.

Snow began battling cancer in 2005 when he was diagnosed with colon cancer, had his colon removed, and underwent several months of chemotherapy.

I never would have predicted it -- that a tooth could become a tool for dispensing medication. But the refinement of such a creation is actually in the works and before long, you may be asking not for a gold or decorative tooth but for one capable of doling out your drugs in the exact doses and at the right times.

Think about this:

Researchers from Europe and Israel are working right now on a tiny dispensing system called IntelliDrug. Their goal is to create parts small enough they can fit into a false tooth placed in the back of the mouth. The device will release a specific amount of medication at certain intervals so patients receive the proper dosage right on schedule.

This invention, crafted by an Israeli dentist, could pick up the slack for people who forget to take medicine and could save lives for those whose lives depend on scheduled drug therapy. It could also allow for better absorption of medication into the body.

The IntelliDrug device will deliver medicine directly into the bloodstream through the lining of the cheek around the mouth. Saliva, meanwhile, mixes with the drug and carries it throughout they body in a manner more efficient than just swallowing a pill every few hours.

While researchers hope to one day turn their device into a replacement tooth, the apparatus -- consisting of a stainless steel housing, a pump, custom valves, a microprocessor, batteries, and a reservoir for the drug pill -- currently comes in the form of a block the size of two teeth. It is strapped to the the side of teeth and hugs the inside of the cheek. The unit can be removed, and a technician can refill the drug reservoir, clean the unit, and change batteries when necessary.

Clinical trials on pigs are ongoing. Human testing is expected to begin by the end of the year.

Lung cancer tumors in mice are shrinking -- with the help of a hormone important in the control of blood pressure.

This new discovery, led by scientists at Wake University School of Medicine, suggests some drugs used to manage blood pressure might also prevent or treat lung cancer.

This all came about when it was noticed that lung cancer rates were lower among those treated for high blood pressure with angiotensin-converting enzyme, or ACE, inhibitors. These drugs, including Capoten and Lotensin, increase levels of angiotensin-(1-7) in the bloodstream.

In studies, the angiotensin-(1-7) hormone caused a 30 percent decrease in tumor volume in mice. Tumors in mice not treated with the hormone more than doubled.

This study, published in the journal Cancer Research, is the first demonstration of the effect in animals.

Environmental groups claim some children's bath products contain a suspected cancer-causing chemical in amounts that reach or exceed safe limits. The chemical in question -- 1,4-dioxane -- is found in products made by companies such as Johnson and Johnson, Disney, Kimberly-Clark, and Gerber, says David Steinman, head of the environmental publishing company Freedom Press.

The Environmental Protection Agency (EPA) calls this chemical, already known to cause cancer in animals, a probable human carcinogen. But there is no real regulation on the petroleum-derived chemical and the Food and Drug Administration (FDA) only recommends cosmetic companies limit the concentration of 1,4-dioxane to 10 parts per million (ppm).

Studies show Johnson's Kids Shampoo Watermelon Explosion contains the maximum recommended level of 10 ppm. They also reveal that Kid Care's Hello Kitty Bubble Bath contains 12.3 ppm of the chemical. And two adult shampoos have been found to have twice the recommended level of this chemical that is typically a manufacturing by-product.

It's been reported that nearly 57 percent of all baby soaps contain 1,4-dioxane. But Iris Grossman, director of communications at Johnson and Johnson, stresses that all of her products are within FDA limits.

Cancer is not the only risky link to children's bath products. It seems these items are also linked to early puberty development. And this is concerning because a fast-paced growth rate combined with children's porous skin increases susceptibility to toxins that can enter the bloodstream. One breast cancer expert says an increase in breast cancer risk is linked to toxic exposures during the formative years of life.

Cancer cells sometimes secrete specialized proteins into the bloodstream that serve as indicators of tumor growth. These tumor markers are often distinctly associated with a particular type of cancer. Like prostate cancer.

The most well-known tumor marker today is the PSA -- the prostate-specific antigen. PSA is a highly specific protein that is secreted only by cells of the prostate gland. It is one of the most widely used -- and the only widely accepted -- screening test for cancer.

There's also the tumor marker CA-125, used in the diagnosis of ovarian cancer and in the monitoring of response to treatment for the same disease. There's CEA for colon cancer, CA-19-9 for pancreatic cancer, AFP for liver and testicular cancer, beta-HCG for testicular cancer, and CA 15-3 for breast cancer. And research is under way on newer, more useful tumor markers. This is a good thing -- because some tumor markers are not specific enough or sensitive enough to accurately predict tumor growth.

This is why my oncologist does not recommend I enter the world of tumor markers, despite my status as a breast cancer survivor. He suggests I rely simply on how I feel for monitoring my chances for cancer recurrence. If I experience any worrisome symptoms, he will be the first to wage an all-out assessment of my health. But without symptoms, tumor markers are not likely to help me at all.

A peek at my breast cancer tumor markers would likely be hazy, inconclusive, and not all that helpful. Examination of tumor markers can lead to false positives. It can lead to expensive and often unnecessary follow-up testing. It can lead to worry and panic and even alarm if the numbers are not in the hoped-for range.

Although an abnormal tumor marker level may suggest cancer, this alone is typically not enough to diagnose the disease. Measurements of tumor markers are usually combined with other tests, such as a biopsy, to confirm cancer. So what would I do with an abnormal number and nothing suspicious to biopsy? I would worry. I would panic. Perhaps unnecessarily.

My doctor suggests I refrain from a wild cancer chase. And I am happy with his suggestion. Between my own awareness, follow-up oncology appointments, mammograms, annual OB/GYN check-ups, and more, I am confident any health issues that come my way will be detected early -- and can be resolved in good time. I have no need for confusing tumor marker details. Unless they are conclusively recommended, I will survive without them. More important, I will survive without worry.

The detection of prostate cancer in the United States changed dramatically with the discovery of a screening technique based on a blood test for PSA. PSA stands for prostate specific antigen.

This is a simple and inexpensive test that measures the amount of prostate specific antigen in your bloodstream. PSA is a protein made only by the prostate. Generally when a test shows higher than normal PSA levels, there's a greater chance of having prostate cancer.

Eye cancer in most adults is a secondary cancer spread from tumors of the breast, lung, kidneys and prostate glands via the bloodstream or the lymphatic system. Yearly eye exams are the best way to screen for eye cancer or Intraocular lymphoma.

Often melanomas of the eye are found during a routine eye exam. When the doctor looks through the pupil at the back of the eye, they may be able to see a dark spot that may indicate an early melanoma. Because they are rare, there is no screening test for them other than routine eye exams. People who find a dark spot on their iris (colored part of the eye) that is enlarging should have a doctor look at it. The first symptom of this disease is usually trouble with vision. Pain is rare. Intraocular lymphoma most often affects both eyes.

Examination of the eye by an ophthalmologist is the most important step in diagnosing melanoma of the eye. The doctor will look for enlarged blood vessels on the outside of the eye, which can indicate a tumor inside the eye. Using an ophthalmoscope, the ophthalmologist can get a very good look inside the eye and detect a tumor or other abnormality. Most of the time, this examination alone can make the diagnosis. To confirm the diagnosis, imaging tests such as ultrasound or angiography may be required. Angiography is a procedure done with a fluorescent dye that is injected into the bloodstream through a vein in the arm and will travel to the veins in the eye for examination. Very rarely will a biopsy also be needed.