A Positron Emission Tomography (PET) scan helps doctors determine the presence of cancer, how advanced it is, and whether it has spread. Cancer cells use more glucose, or sugar, than healthy cells. Your doctor delivers harmless radioactive sugar into your bloodstream and uses a camera to observe the movement of the sugar throughout your body. Your doctor can see which cells take in larger amounts of sugar, indicating possible areas of cancer.

A second opinion

Even if you’re confident that your doctor has made an accurate diagnosis, it’s a good idea to look for a second opinion to explore all your treatment options. Loyalty isn’t something you should be concerned about. Your doctor will understand that your diagnosis is important enough to deserve a second opinion. In fact, he or she may be a valuable resource as you consider where you should go for additional tests and opinions.

Your diagnosis

An accurate diagnosis is the first step in creating a plan of action.

A cancer diagnosis is a life-changing experience. To make the critically important decisions about your treatment, you need the most accurate information that’s available about your particular situation. The place to start is asking the cancer specialists you consult with about what they uncovered during the diagnostic process and the variety of treatment options that may be available to you based on that information.

Diagnostic tests

Because the initial symptoms of cancer can be vague or inconclusive, your doctor may perform several tests to determine whether you have cancer and, if that’s the case, the precise location, type, and extent of the disease. This information is essential for you and your doctor to determine which therapies are likely to be the most effective.

Blood tests can detect substances that are produced by certain cancers

Endoscopes use a small camera to see inside the body

Scans such as mammograms, computed tomography (CT) scans, and magnetic resonance imaging (MRI) use radiation or magnetic waves to create pictures of internal organs

Biopsies are the surgical removal of tissue for examination under a microscope

Tumor markers

As genetic research and other scientific advances yield a deeper understanding of cancer, increasingly sophisticated diagnostic tools are enabling more individualized diagnosis and treatment. For example, certain kinds of cancers release proteins, hormones, and other substances into your blood, or cause your body to produce certain substances called tumor markers. By testing your blood, urine, or a tumor sample to measure the levels of these markers, doctors are able to diagnose and track cancer and even, in some cases, predict how it might respond to certain therapies.

One example of the critical information that tumor markers can yield is the diagnostic test immunohistochemistry (IHC). Oncologists use this process to identify cell types based on how color-stained antibodies bind to different molecular markers in a cell. For some metastatic tumors, it may be difficult to determine where the cancer originated. Since it’s important to know the cancer’s primary site to treat it effectively, doctors may use IHC to identify the cell type — for instance liver or pancreatic cells pinpoint the origin of the tumor.

In some cases, a person’s IHC results can also help oncologists determine whether specific therapies are likely to be effective. Women with breast or ovarian cancer, for instance, whose IHC results indicate high levels of the HER2 protein, may be good candidates for certain biotherapies, such as monoclonal antibodies.

Cancer statistics

No one can tell you how long you will live, or how well you will respond to treatment. The only information your doctor can give you is the statistical average for a large and diverse group of people with a similar diagnosis and stage.

If you ask for this information, your doctor will probably tell you the five-year survival rate — the percentage of people who are cancer free after five years.

But keep in mind that these statistics include people who had other health problems, those who refused treatment, and those who were treated 10 or 20 years ago, without today’s advanced therapies. In fact, recent studies indicate that cancer survival statistics may be too pessimistic. In other words, survival rates may be inaccurate and misleading. Equally important, since statistics apply to groups, not individuals, they don’t translate into a personal prognosis.