Other parameters include age, gender, and location of lesion (spot). Older patients (greater than 65 years) tend to have larger and thicker lesions leading to a poorer prognosis. Females have greater survival rates than males. Lesions located on the arms and legs have a better prognosis than those on the head, neck or torso. This may partially explain the better female survival rate as 45% of melanomas grow on the trunk in males and 42% of melanomas arise on the legs in women (Balch,1992).
Chest x-rays are performed to check for the possibility of melanoma tumors in the lung since this is the most frequent site of metastasis (spread). Computerized tomography (CT) and Magnetic Resonance Imaging (MRI) scans are done to locate possible tumors in the rest of the body. “Whole-body MR imaging has been proposed for evaluation of the presence of metastases and/or for the evaluation of primary cancers” (Langley, 2004). This type of MRI covers the entire body and not just a section so it is more definitive for locating metastases. Spiral CT scans take hundreds of pictures of slices of the internal body organs and therefore will often show small tumors. PET scans are done to locate glucose changes that accompany tumor growth. A combination of both a CT and PET scan are often used to locate any systemic tumors.
Blood that is commonly drawn for testing is for LDH, CBC, and liver function tests. Lactic dehydrogenase (LDH) is a chemical released by the body when tumors are growing and increases with cancer. A Complete Blood Count (CBC) will show a low hemoglobin and hematocrit which are reflective of the blood loss associated with gastrointestinal tumors. Liver function tests will be elevated with tumor extension to the liver.
Currently, chest x-rays and LDH tests are no longer being recommended as part of routine melanoma care in patients with clinically localized melanoma. Low yield of finding new melanomas, high rate of false-positive tests and the lack of early detection of metastases on survival are the reasons (Wang, 2004). For patients with a more advanced stage of melanoma, chest x-rays and LDH are still useful.