Today, the cost of treating cancer is very high, so early detection of cancer is essential, and one of the possible ways to diagnose cancer in the early stages is to use sensors that are made in the terahertz area. The proposed structure is a multilayer structure in which graphene is used in the upper and middle layer and the middle layer has a ribbon form. A disk form element is used in the upper layer. Finally, a ring is added to the structure. In the final structure of the ring, it actually inhibits the field, and this will increase the Q-factor at 6.7 THz. The interaction of layers on each other and their effect on reflection is studied to modify the final structure by variation of the chemical potential of the graphene layer in the range of 0.2 to 0.6 eV. Finally, the proposed absorber is used to discriminate cancer and healthy breast tissue. The effect of the thickness and distance of the tissue from the absorber are examined to realize the material effect on sensitivity and figure of merit (FOM) as two main factors for detecting the cancer tissue.