Labwork shows high rdw-cv (16.1) mcv normal, low plt (116) everything else normal. what could this be? anemia? i have metastatic breast cancer?

For determining if you have or not anemia, a hemoglobin (Hb) or a hematocrit (Hct) will be needed. Your platelet count is borderline low. Most common causes for anemia ( if you indeed have anemia) and/or low platelets are related to either the main disease or treatment received, with other causes still possible, less likely. Your oncologist remains your best reference at this point.