Survival and Prognosis in Cancer
When a cancer is diagnosed, the first question on the mind is “how long will I live”? The doctor will be able to tell whether the cancer is curable or not depending on the stage of cancer.
Is the cancer curable?
A curable cancer is one where treatment will be able to get rid of the cancer completely without it ever coming back. If the cancer is curable the doctor can give an approximate percentage chance of cure in most situations.
What if the cancer is not curable?
If the cancer is not curable, treatment options will still be available but the intention here will be to control any symptoms that the cancer is causing and to prolong life.
What kind of figures can the Oncologist give when talking about survival and prognosis?
Usually Oncologists quote figures regarding the benefits of treatment in terms of cure and survival and some of the common ones are given below.
This is the rate at which people respond to treatment. For example, if the response rate is 40%, it means that the cancer will be stable or improve in 40% of patients who have that treatment.
Progression Free Survival
Here, the doctor can tell as to how long the patient is well before the cancer starts to grow again after treatment. For example, in a patient with stage 4 cancer if the progression free survival of a particular chemotherapy drug is 6 months, it means that the patient can be expected to be well for up to 6 months after treatment before the cancer starts to grow again.
This is a figure that is commonly quoted by Oncologists to patients particularly in stage 4 cancer patients. Again, citing an example, if the median survival for a patient is 11 months, it means that 50% of patients are expected to survive or live that long from a point in time. It is important to understand that a median survival figure is the average of similar patients and is a rough guide. As it is an average, there will be some patients whose survival is below 11 months in this example and some whose survival is more than 11 months.
5 Year survival
Most cancers that recur after treatment recur within 5 years. Hence 5-year survival figures are used as a guide to inform patients about long term survival from cancer. Sometimes 10-year survival figures are also used.
The doctor’s survival figure did not match with the patient’s true survival?
Doctors will never be able to give a very accurate estimate of patient’s survival with cancer. Most of the figures quoted are average figures which apply to a group of patients with a particular cancer but not a single patient. In each patient, the survival depends on the type of cancer, the response had with treatment and many other factors. These figures should therefore only be used as a guide and not as absolute ones.