We present a quantum chemistry simulation to discuss the binding energy features of different methodologies in the fight against cancer. In the first one, selective estrogen receptor modulators used in breast cancer treatment are considered co-crystallized with estrogen receptors. Our theoretical binding energies and the experimental one are compared, and their features are discussed. Then, we investigate the importance of integrins in several cell types that affect tumor progression. In particula,r its binding energy features with cilengitide is investigated and proved to be an efficient alternative toward the development of new drugs. Finally, we discuss the efficiency of immunotherapy as a promising new cancer treatment. By reawakening and enhancing the immune system to fight cancer, this strategy has achieved impressive clinical responses. Much of them have been generated by the recognition that immune checkpoint proteins, like the PD-1 receptor, can be blocked by antibody-based drugs with profound effects.