Solid cancer refers to cancer that originates in a solid organ or tissue of the body, such as the lung, breast, prostate, or colon. In contrast, cancers that originate in blood cells or lymphatic tissues, such as leukemia or lymphoma, are considered hematologic or liquid cancers. Solid cancers can be classified by the type of tissue they arise from, their location in the body, and their behavior (whether they are benign or malignant, and how aggressive they are). Treatment options for solid cancers depend on the type, stage, and location of cancer, and may include surgery, radiation therapy, chemotherapy, targeted therapy, or immunotherapy.