The war against cancer: A complete cure or live with control?

Cancer is not one disease, but a collection of many diseases. It threatens patients’ lives and reduces their life quality. As scientific research on cancer advances and technology improves, more and more cancers are being cured. For example, 70% cancers in children are cured. In adults, most types of skin cancer, thyroid cancer, laryngocarcinoma, testis carcinoma, Hodgkin lymphoma and some forms of leukemia are cured. This is largely due to the constantly improved and innovated treatments and therapies. Current treatments for cancer mainly include surgical therapy, chemistry therapy, radiation therapy, targeted therapy and immunotherapy. Immunotherapy is the most innovative one. After being treated with immunotherapy, patients with malignant melanoma, which was once believed to be incurable can now reach ten-year survival rate. This means “curing cancer” is possible. However, because of the complexity of cancer, no single method can prevent all cancers and no single treatment can cure all cancers. Most importantly, cancer cells can easily become resistant to current treatments. This resistance can arouse from environmental adaptation, tumor heterogeneous, and the physical position of cells within the tumor. Cancer cells in area where blood supply is poor may survive from treatments which require blood circulation to transport drugs or immune cells to target area for killing. Tumor heterogeneous means other than the fast dividing cancer cells in the tumor, there are also quiescent cells which do not respond to therapies aiming at dividing cells, and there may also present a small number of cells which originally bear resistance. Based on this original heterogeneity plus the different micro physical positions within the tumor, the diversity of the genome composition and the phenotype of these cancer cells are further increased. Under prolonged pressure from host, drug maintenance, host immune response and the non-permissive environment, most of the cancer cells may have been killed, but some cancer cells may get adapted to the environment thus producing cancers that are even more resistant, resilient and malignant. Therefore, we cannot say we can cure all types of cancers. In fact, we are still long way off from curing all the cancers. Currently we can control cancer by allowing patients to live with a balanced small amount of cancer cells, which seem to give longer survival rate than trying to get rid of all the cancer cells. As our knowledge accumulates and treatments improve, we will have more and more control over cancer and in the end we will solve all these problems and finally cure all cancers.