There are some types of cancer cells that favor to produce lots of fluid. Thus, it will cause effusions. This is their specific property. If you have this kind of cancer, you will have it and it will change.
By blood transfusion, do you mean by using globulin? Since globulin can increase the osmotic pressure, which will absorb more water in the blood, decreasing the exudation. This will also help to decrease the production of the effusions.