Medicine is the science of statistics, and now it is more appropriate than in the treatment of cancer.
Here is a guide to understanding some of the legal terms you will come across when discussing cancer treatment.
First, you need to know that no one can predict with certainty the exact outcome of a patient. Instead, cancer mortality rates are based on the consequences of a large number of people having the same disease. In other words, the statistics that will be indicated for you are only probabilities.
The second thing to know is that not all cancers have the same results. In other words - some types of cancer are more lethal than others.
And the third thing to understand is that the likelihood of a cure depends very much on the stage of your cancer.
For example, in all cancers in patients with a stage disease, the survival rate is higher than in patients with stage 2. And in patients with stage 2, the disease is higher than in patients with stage 3. Patients in the 3rd stage have a higher survival rate than in patients with stage 2. patients of the 4th stage.
That is why it is so important for you to find out at what stage of the disease you have.
What is 5-year survival?
When doctors cite the likelihood of survival, they do not tell you that you must live for 3 years and 3 months. Instead, they quote you a figure called the 5-year survival rate. This number represents the probability that someone with your illness will be alive at the end of 5 years.
For example, if the 5-year survival rate is 25%, this means that the chances of being alive after 5 years are 25%. It is important to look at a specific group of patients for citing 5-year survival. For example, it may include all patients with a certain type of cancer, or it may include only patients with a specific stage of this cancer.
For example, 49 percent, or about half, of people diagnosed with early stage lung cancer live for at least five years after diagnosis. Thus, the five-year survival rate of the early stage of lung cancer is 49%. Compare this with a five-year survival rate for people diagnosed with lung cancer, which has spread (metastasized) to other areas of the body, which is only 3 percent.
So, as you can see, you want to find out what is the survival rate of patients with the same disease stage.
What is remission?
Remission refers to the reduction of cancer. Remissions can be complete or partial depending on the presence or absence of any evidence of cancer. Obviously, if cancer is not detected after treatment, the remission will be complete.
If the cancer is smaller, but it has not completely disappeared, the patient experiences a partial remission.
Complete remission can be a medicine. But there is still a chance that the cancer will return depending on the type of cancer. In people who achieve only partial remissions, cancer almost always regresses.
Are there any other statistical terms that I should know about?
The 5-year survival rate tells you how many people live at the end of 5 years, but this does not tell you how many of these people are in complete remission at the end of 5 years (in other words, how many people have lived for 5 years and have no evidence of cancer) .
So, here are two more specific conditions:
Relapse-free 5-year survival. This is the percentage of people who not only live in 5 years, but are in complete remission.
5 progression-free survival. This is the percentage of people who live after 5 years, but who still have evidence of cancer, although the cancer is not progressing. This includes people who may have had some success in treatment, but not enough to completely eradicate their cancer.
Two other statistical terms that you should be aware of are relative risk and absolute risk:
Absolute risk reduction or benefit. This is the absolute difference in results between alternatives. For example, if treatment A increased survival by 22%, and treatment B increased survival by 20%, then treatment A was rejected in absolute terms (22% -20%) = 2%.
Relative risk reduction or benefit. This is a relative difference in results between alternatives. Thus, in the example above, the relative advantage (22-20%) / 20% = 10%. This number is calculated by taking into account the difference in output as a percentage.
You should beware that results are often presented as relative risk reduction or benefit, because the numbers sound more impressive. For example, in the example above, the relative advantage of 10% seems more impressive than the absolute advantage of 2%.
I hope you can now learn a little about cancer statistics.
