This indicates that they are stimulated by elevated levels of female hormones prior to her period and then regress when hormone levels fall. Cancers are unlikely to respond this way. Simple cysts are often compressible and feel relatively soft . As the amount of fluid in the cyst increases it can get quite firm. Fibroadenomas often have a rubbery feel to them.
Cancers usually feel quite hard.
Breast cancers are rarely tender to touch . Sometimes they may seem tender but this is really due to tender overlying breast tissue. Cancers are often irregular in shape while benign lesions tend to be round or oval. The surface of a cancer often feels irregular while benign lesions are often smooth or lobulated. When they are pressed the surrounding tissue can be felt to move with the lump as it is dragged along.