Cancer. A simple word that can cause enormous damage and pain. Humanity's achievements have been impressive, but we have not yet been able to completely break the resistance of this disease, or rather, this group of diseases. What makes cancer so complicated to cure? The factors are many, but at the top of the list we find limitations in studies, and a chilling capacity for adaptation on the part of tumors.
In one way or another, cancer is a disease that remains on our radar. Sometimes it affects us directly, and at times it strikes friends, family, neighbors. We have been researching the multiple forms of cancer for decades. Several diseases have been completely eradicated, however, cancer resists. Oncologist and Pulitzer Prize winner Siddhartha Mukherjee called cancer "The Emperor of All Maladies". One in six deaths worldwide is linked to cancer, and it is expected that the number of new cases will grow by 70 percent in the next two decades. That brings us to "the" question:
Why is it so difficult to cure cancer?
It all starts with its nature: Cancer is mutation, chaos, loss of control. The scientific term is "abnormal cell growth", although that does not necessarily make a tissue cancerous (hyperplasia is a good example). In a normal situation, cells detect these mutations, correct them or eliminate them.
The problem arises when a mutation enables the multiplication and spread of cancer cells, which opens the possibility of invasion into nearby tissues, and in the worst case, metastasis. Surgery, chemotherapy, radiation, immunotherapy, hormone therapy, and localized treatments are some of the weapons at our disposal to fight cancer, however, their effectiveness is not 100 percent.
Unfortunately, our studies on cancer have limits. Many things work wonderfully in the laboratory, but once we translate those discoveries into a treatment, we find that it has no effect. Then there is the detail of subcloning, multiple populations of cancer cells with small differences that arise from the same tumor. A treatment can be very effective at eradicating one type of subclone, and ignore others.
To this we must add the complex and delicate connection that tumors maintain with healthy tissue, their ability to suppress the action of the immune system (thus blocking cancer recognition), the presence of so-called cancer stem cells that remain alive beyond traditional detection, and their adaptation at the molecular level to survive under stress. Cancer changes, but so do we, and the future anticipates extraordinary resources, including nanotechnology.
