In trying to discover the primary site, there are two important considerations.
1. Some primary cancers are much more treatable than others. These include cancers of the
    breast, prostate, thyroid and ovary, lymphomas (including Hodgkin's disease), as well as
    germ cell tumors similar to those that develop in the testes. Great efforts are made to determine if one of these
    is the primary site. Not only is the prognosis much better with these types of cancer, but the treatment has to
    be specific for that cancer. The usual non-specific combination chemotherapy programs for CUPS have a low
    rate of response.
2. There are important clues your doctor can use to discover the primary site.
    • One clue is the location of the metastases. A woman with a tumor that develops in glands (adenocarcinoma)
      and is found in the lymph nodes of the armpit, for example, is more likely to have carcinoma of the breast. A
      woman who develops fluid in the abdomen (ascites) or has a tumor involving the lining of the abdominal
      cavity (peritoneum) should be suspected of having ovarian cancer.
    • The most common sites of CUPS are metastases to the lung, lymph nodes, bones and liver. When CUPS is
      found in the upper part of the body (above the diaphragm), the most common source is the lung. When it
      appears in the liver, the usual primary site is the gastrointestinal tract, including the pancreas.