How does cancer spread? What makes certain types of cancer different from others? Why do some treatments not work as effectively as others?
In: Biology
Cancer is termed as a rapid uncontrolled growth of abnormal cells. In patients, cancer cells will start moving towards nearby lymph nodes, tissue, organs, etc. The main difference in the types of cancer is the severity. For breast cancer patients, survival rates are very high compared to other forms of cancer because breasts aren’t necessary for survival, which is the reason why you see so many women get their breasts surgically removed to cut away the cancer completely
However, some cancers that attack more vital organs such as the lungs or liver are harder to overcome. The effectiveness of treatments largely depends upon the patient, major factors in a patients survival rate largely depends upon sex, age, when the cancer was discovered, previous health problems, genetic history, etc. These factors can either increase or decrease the effectiveness of certain drugs, radiation, or surgery.
Cancer basically spreads how you’d expect. It grows, parts break off, they move via your bloodstream or lymph system to other parts of your body, and then start growing again.
Different types of cancer are primarily about what parts of the body they’ve infected. Skin cancer is less dangerous than, say, brain cancer because it’s easier to remove part of your skin than part of your brain. Blood cancer (leukaemia) is particularly dangerous because it’s already spreading all around your body, and can affect your immune system, which is what would otherwise be fighting the cancer. The other main difference is how quickly it divides, which is caused by the details of the mutation that triggered the cancer; slower cancers are naturally less dangerous.
Treatments are varied, and do different things. The main three are surgery, radiotherapy, and chemotherapy. Surgery is effective at removing a tumor, but that will only stop the cancer if it hasn’t already begun to spread, and might not be possible if the tumor is on important parts of important organs. Radiotherapy means hitting the tumor from multiple angles using high spead particles, which damages the cancer, which again requires that it hasn’t already spread, and can cause radiation sickness or even more cancer if overdone. Chemotherapy is basically the only good option if the cancer is spreading, and essentially works by slowing down how quickly it can grow, but since this also slows down how quickly you can grow new cells elsewhere in the body, it causes harm and so can only be done to a certain extent. If any of these treatments can destroy cancer cells quicker than new ones appear, they will be effective, but if the cancer is too far progressed, too quick, or for the reasons listed above the treatments can only be carried out partially, they will not be as effective.
My condolences if anything besides curiosity triggered these questions.
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