Importance of Prognosis With Cancer

Prognosis is a prediction or estimate of the chance of recovery or survival from a disease. Most healthcare providers give a prognosis based on statistics of how a disease acts in studies on the general population. What this means is that your prognosis is not something written in stone. It is an estimate or guesses about how you will do, but generally, some people will do much better and some people will do worse than what is "average." There are few people who are "average" when it comes to their health.

Prognosis with cancer can depend on several factors, such as the stage of disease at diagnosis, type, and subtype of cancer, the molecular profile of the tumor, and even gender. Let's talk about how prognosis is determined, and the limitation of the statistics used, especially in this era when treatments are improving.

doctor talking to patient about her prognosis with cancer

Prognosis Is a Statistic

Most information you will hear and read about the prognosis of your disease is based on statistics from studies looking at other people. It’s important to note that these numbers are only numbers, and do not look at individual variations. Most statistics are also somewhat dated. For example, statistics looking at the 5-year survival rate for a particular disease may be several years old—and since the time they were reported, newer and better treatments may have become available. Lung cancer is an example where the "prognosis" of the disease may not be very accurate. Many of the statistics we use that talk about survival are several years old. Yet, more new drugs have been approved for the treatment of lung cancer in the past five years than in the 40 years preceding that time.

A good example is lung cancer. The prognosis for someone with stage 4 lung cancer with one particular genetic mutation (an ALK rearrangement) would have been estimated as a year or less at best just a few years ago, with only 1 percent to 2 percent of people living 5 years. In 2019, the median survival with that particular molecular type of lung cancer is estimated to be 6.8 years with

Prognosis is Different for Everyone with Cancer

Every single cancer is different. If there are 200 people with stage 2A non-small cell lung cancer in a room, there are 200 cancers that differ in molecular profiles and other important variants. On top of this, every person has important differences that affect prognoses, such as age, general health, co-existing medical conditions, and ability to tolerate treatment. Look at some of the many factors that can affect the survival rate for people with lung cancer.

Terms Used to Describe Prognosis with Cancer

There are many terms that your healthcare provider may use in talking about your prognosis. Some of these are more likely to be used than others based on the expected survival with cancer. Other terms are used more often as parts of clinical trials. Some of these terms include:

Survival rate: The survival rate is the "average length of time someone is expected to survive cancer and is usually given based on a period of time, for example, “the 5-year survival rate.” 

Median survival rate: A median survival rate is a number which defines the time after which half of the people with a certain type and stage of cancer are alive, and 50 percent have died. With more aggressive tumors, such as lung cancer, the prognosis is often described in this way.

Progression-free survival: Progression-free survival or PFS is usually used to describe the response to treatment for cancer, and refers to the average amount of time during which cancer does not grow, or remains stable. For treatments that control cancer, rather than cure the disease, progression-free survival can be a measure to see how long a treatment may work (before cancer becomes resistant to the treatment). PFS is often used when describing treatments such as targeted therapies for cancer.

Disease-free survival: Disease-free survival refers to the length of time that someone remains free of detectable cancer.

Overall survival: Overall survival refers to the average length of time someone survives after a diagnosis of cancer before death from any cause including cancer.

Improving Your Prognosis

Aside from treatments your healthcare provider recommends, there are some things you can do yourself to improve your prognosis. Keep in mind that some people may succumb to the disease despite every effort to fight it, while others do well almost without trying. That said, there are some things individuals can do to raise their odds. Finding support from friends or in a cancer community or participating in regular exercise have both been found to improve survival for some people with some forms of cancer. 

A Word of Caution 

It's important to again point out what prognosis means. Since it is a statistic it is an estimate of how someone will do based on the average outcome of a group of people. Just as we know that everyone is not the same height and weight, we know that averages sometimes say little for an individual person. Yet with cancer, there are even more variables factored in than those that determine the height. It is also a statistic derived from past experience. Statistics may tell you how the "average" person did with cancer similar to yours (but of course molecularly different) at a time when treatments may be different than they are today.

If you have been diagnosed with cancer, after understanding the limitations in estimating prognosis, there is one more step that some people have found helpful. Try reframing the statistics in your mind. For example, instead of thinking that 40 percent of people do not survive for five years with particular cancer, realize that 60 percent of people do survive. And keep in mind that the statistics—those numbers we use to estimate prognosis—will look different five years from now than they do today.​​

A Word from Verywell

Some people find it helpful to be given a prognosis with their cancer. They find it urges them to look at their bullet list and do some of the things they have been putting off if their prognosis isn't what they hope, or to prepare for the well-being of loved ones who will remain when they are gone. Others do not want to hear their prognosis and find that it hurts them emotionally to be given an expected time life. There isn't a right or wrong, only what you prefer. If you're living with cancer, some family members or friends may disagree, but this isn't their decision. It's yours alone.

That said, with the advances in cancer treatment it's often hard to estimate prognosis. Even a 6 month time period can make the difference between a standard treatment that conferred one prognosis and the adoption of a new treatment that may offer a very different prognosis. This is a good time to be alive with cancer, but perhaps a poor time to trust what estimated prognosis may mean based on statistics.

Also Known As: survival rate 

Examples: Jill was given a good prognosis for recovery from her lung cancer since it was found at such an early stage

Frequently Asked Questions

  • What's the difference between prognosis and diagnosis?

    A diagnosis is a healthcare provider's determination of what condition a patient has. A prognosis is their educated prediction of the course of the disease and how a person may recover. For example, a cancer prognosis depends on multiple factors, such as the type of cancer and its stage.

  • What is a poor prognosis?

    A poor prognosis refers to an estimation that there is a low chance of recovery from a disease. For example, if a person's cancer is an aggressive type or has already metastasized to other areas, a doctor may give them a poor prognosis.

    In contrast, a good prognosis is a prediction that a person shows a good chance of recovering from a disease.

1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Cancer Institute. Understanding cancer prognosis. Reviewed June 17, 2019.

Additional Reading

By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."