Aug. 21, 2008 - The FDA is reviewing the safety of Vytorin, which combines the cholesterol-lowering drugs Zocor and Zetia, after a clinical trial linked the drug to cancer risk.

In the trial, called SEAS, 4.1% of patients taking Vytorin died of some form of cancer - more than the 2.5% of patients who received an inactive placebo.

A recent statement issued by the study investigators noted that these differences "are small and could have occurred as a result of chance."

While other clinical trial data do not indicate an increase in cancer risk, the FDA is alerting doctors and patients now while it awaits further data from the manufacturers, which they should receive in about three months. After that point, the FDA says it'll take an additional six months for a complete evaluation of the data.

Based on all available data on the link between Vytorin and cancer risk, the FDA says patients should not stop taking Vytorin or any other cholesterol drug.

The American Heart Association says the same thing, recommending that patients taking prescribed cholesterol-lowering drugs should not stop taking them without talking with their doctor. Patients who stop taking prescribed cholesterol medications increase their risk of having a heart attack or other cardiovascular event.

Vytorin is jointly marketed by Merck and Schering-Plough. Schering-Plough tells WebMD it is cooperating with the FDA.

"We believe that the findings in SEAS on cancer are likely to be an anomaly," Schering-Plough's Mary-Fran Faraji tells WebMD. "We don't believe, in light of all the data, that there's an association [of cancer] with Vytorin."

A recent study reviewing cancer risk from Zocor and other cholesterol-lowering statin drugs found no link between statin use and cancer, contradicting its own preliminary findings that did suggest such a link.

"When you put all of the information together, there is no evidence that statins increase the risk of cancer," researcher Richard Karas, MD, says in a news release in response to those study findings.

In addition, interim data from two ongoing trials of Vytorin show no increased risk of cancer in patients receiving the drug. The first of these trials (the SHARP study) won't be finished until 2010; the second (the IMPROVE-IT study) will end in 2012.

In a separate development, the U.S. House Energy and Commerce Committee is investigating the SEAS study and today asked Merck and Schering-Plough for details.

Faraji says both companies are cooperating with that investigation.

Earlier this year, Vytorin suffered another setback when a clinical trial showed that Vytorin did not reduce artery-clogging plaque better than Zocor alone.

About Cancer

Cancer (medical term: malignant neoplasm) is the general name for a group of more than 100 diseases in which a group of cells display uncontrolled growth (division beyond the normal limits), invasion (intrusion on and destruction of adjacent tissues), and sometimes metastasis (spread to other locations in the body via lymph or blood). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited, do not invade or metastasize. Most cancers form a tumor but some, like leukemia, do not. The branch of medicine concerned with the study, diagnosis, treatment, and prevention of cancer is oncology.

Cancer cells can spread to other parts of the body through the blood and lymph systems. Most cancers are named for the organ or type of cell in which they start - for example, cancer that begins in the colon is called colon cancer; cancer that begins in basal cells of the skin is called basal cell carcinoma.

Cancer types can be grouped into broader categories. The main categories of cancer include:

• Carcinoma - a cancer which is derived from the lining cells, or epithelium, of an organ. There are 4 major types of epithelium in the body (Glandular, squamous, transitional, and pseudostratified). Some types are only found in a few select organs such as the lung (pseudostratified) or urinary bladder (transitional).  Carcinomas can arise from any of these epithelial types. For example, breast carcinoma is most commonly derived from the lining cells of the milk producing glands. A carcinoma with a glandular growth pattern is an adenocarcinoma.  Common adenocarcinomas include prostate, colon, and breast.  A carcinoma with a growth pattern resembling the squamous lining cells is termed a squamous cell carcinoma.  Common squamous cell carcinomas are found in the esophagus and skin.  However, any of these organs may have either type of carcinoma arising from it, although these latter diagnoses are exceedingly rare.
• Central nervous system cancers - cancers that begin in the tissues of the brain and spinal cord.
• Leukemia - cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of abnormal blood cells to be produced and enter the blood.
• Lymphoma - a cancer derived from the white blood cells that are present in the lymphoid tissues of the body.  These sites most commonly include the lymph nodes and spleen. However, lymphomas may arise from any organ and body site.
• Sarcoma - cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.

Today, millions of people are living with cancer or have had cancer. The risk of developing most types of cancer can be reduced by changes in a person's lifestyle, for example, by quitting smoking, limiting time in the sun, being physically active, and eating a better diet. Half of all men and one-third of all women in the US will develop cancer during their lifetimes.

Although doctors often cannot explain why one person develops cancer and another does not, research shows that certain risk factors increase the chance that a person will develop cancer. Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or viruses, bacteria, and certain hormones. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth.  Other common risk factors for cancer include:

• Growing Older
• Family history of cancer
• Poor diet, lack of physical activity, or being overweight
• Alcohol