ON THIS PAGE: You will read about the scientific research being done now to learn more about this type of cancer and how to treat it. To see other pages, use the menu.
Doctors are working to learn more about CUP, ways to prevent cancer, how to best treat CUP, and how to provide the best care to people diagnosed with this disease. The following areas of research may include new options for patients through clinical trials. Always talk with your doctor about the diagnostic and treatment options best for you.
Using tumor genetics to diagnose the primary site. Different tissues within the body make different proteins, depending on which genes are active. This is called gene expression. For example, some of the genes expressed by healthy lung cells are different from those expressed by healthy colon cells. When cancer develops in these organs, it usually has the same organ-specific pattern of gene expression. It is now possible to analyze a tumor sample from a biopsy to figure out which genes are being expressed. This usually can predict the location where the cancer began.
As mentioned in the Treatment Options  section, site-specific treatment based on gene expression profiling prediction is replacing empiric chemotherapy as the standard treatment for patients with CUP who do not fit into any of the specific subgroups. Ongoing clinical trials continue to look at the outcomes of assay-directed treatment in order to better define its role in treating CUP.
Targeted therapy. As outlined in the Treatment Options  section, targeted therapy is directed at specific molecular abnormalities within the cancer cell or the surrounding tissue environment that contributes to cancer growth and spread. These abnormalities include gene mutations in the tumor and abnormal activity of various signaling proteins within cancer cells. Learn more about the basics of targeted treatments .
Several targeted therapies are approved by the FDA for specific cancers, either used alone or with chemotherapy. Examples of these targeted treatments include HER2 targeted therapy for HER2-positive breast cancer, BRAF inhibitors for BRAF-mutated melanoma, and EGFR inhibitors for EGFR-mutated non-small cell lung cancer. However, no targeted therapies are currently approved to treat CUP specifically, and the targeted drugs approved for other cancers have not been tested for CUP.
Since CUP actually covers many tumor types, it is likely that some patients would benefit from the targeted therapies already proven to treat specific tumor types. For example, therapies targeting HER2, which is a molecular abnormality found in about 1 of every 5 breast cancers, have dramatically improved treatment results for these patients.
Could a patient with CUP who is predicted to have breast cancer by gene expression profiling have an abnormality in HER2? If so, would treatment with a therapy targeting HER2 benefit this patient? The answer to both questions is likely to be “yes,” but no clinical trials have addressed this issue for HER2 or any other molecular abnormalities. In fact, tumors from patients with CUP are not routinely tested for HER2 abnormalities or for any of the other molecular abnormalities for which targeted treatments exist.
A recent study found that the incidence of potentially treatable molecular abnormalities (using targeted treatments already approved for other cancers) is approximately 25% in CUP. In ongoing clinical trials, people with CUP whose tumors have specific molecular abnormalities are being treated with drugs targeted against the abnormality. It is likely that these clinical trials will identify additional effective treatment options for specific patient groups.
New types of treatment. Patients with CUP that no longer responds to standard treatment may want to consider clinical trials that test new types of treatment. Of particular interest are drugs that induce the immune system to fight cancer, such as anti-PD-1 and anti-PD-L1 agents, because these drugs have already been proven effective against a variety of cancer types. In addition, many new drugs are being tested for the first time in studies called phase I clinical trials . The goals of these studies are to identify the side effects and best doses for these new drugs, as well as to learn if they are effective against cancer.
Palliative care. Clinical trials are underway to find better ways of reducing symptoms and side effects of current cancer treatments to improve patients’ comfort and quality of life.
Looking for More About the Latest Research?
If you would like additional information about the latest areas of research regarding CUP, explore these related items that take you outside of this guide:
To find clinical trials specific to your diagnosis, talk with your doctor or search online clinical trial databases now .
Visit the website of the Conquer Cancer Foundation  to find out how to help support research for every cancer type. Please note that this link takes you to a separate ASCO website.
The next section in this guide is Coping with Treatment . It offers some guidance in how to cope with the physical, emotional, and social changes that cancer and its treatment can bring. Or, use the menu to choose another section to continue reading this guide.