Several cancers can lead to high protein levels in the blood. Multiple myeloma, a type of blood cancer, is characterized by abnormal plasma cells producing excessive proteins, leading to elevated levels in the bloodstream. Other cancers, such as lymphoma or leukemia, can also cause increased protein levels due to abnormal production by cancerous cells. Additionally, some solid tumors, like liver or kidney cancer, can contribute to high protein levels indirectly through their effects on liver or kidney function. However, it is important to note that high protein levels alone are not indicative of a specific cancer diagnosis, and further diagnostic tests are necessary for accurate evaluation. Consulting a healthcare professional is crucial for proper diagnosis and management.