What a Five-Year Cancer Survival Rate Actually Means

This page is for anyone who has been given, or has looked up, a five-year survival rate. It explains what the number counts, why it is often out of date, and why it cannot predict what will happen to one person.

A five-year survival rate is a backward-looking count. It answers one question. Of the people diagnosed with this cancer during a past period, what share were still alive five years later? It is not a prediction. It is not a countdown. Five years is the period most often used, but the number does not mean anything changes on its own at year five.

Most published figures are relative survival, not overall survival. SEER defines relative survival as "an estimate of the percentage of patients who would be expected to survive the effects of their cancer," and adds that "it excludes the risk of dying from other causes."

NCI describes relative survival as a comparison of people with cancer to people who do not have cancer. This is why a relative survival figure can reach 100 percent. SEER's current figure for localized female breast cancer is 100.0 percent. That means those women were about as likely to be alive five years later as women without breast cancer. It does not mean none of them died.

Across all cancer types combined, SEER reports 70.5 percent five-year relative survival for people diagnosed in 2016 to 2022.

Survival statistics need follow-up time before they can exist. To know who was alive five years after diagnosis, five years have to pass. Then the registry data are compiled, cleaned and published. So any figure you read describes people diagnosed years earlier. SEER's current figures are for people diagnosed in 2016 to 2022. They were treated with the drugs, radiation techniques and surgery of that period.

NCI says it takes years to see the benefit of new treatments. So the statistics your doctor uses may not be based on treatments used today. Ask your oncologist whether treatment for your cancer has changed since then. It is one of the more useful questions available.

A headline figure pools every stage, age, tumor subtype, molecular profile and level of background health. It includes someone diagnosed at 85 with heart failure and someone diagnosed at 40 with no other illness. It includes someone whose tumor was found on a screening test and someone who arrived in an emergency department with widespread disease.

SEER states the limitation plainly: "because survival statistics are based on large groups of people, they cannot be used to predict exactly what will happen to an individual patient." An average cannot tell you which side of it you are on. It describes a crowd, and you are not a crowd.

Registries group the extent of disease as localized, regional or distant. The gaps are enormous, and the headline figure hides them.

Female breast cancer (2016-2022): 91.9 percent overall — but 100.0 percent localized, 87.5 percent regional, 33.8 percent distant.

Pancreatic cancer (2016-2022): 13.7 percent overall — but 43.6 percent localized, 17.0 percent regional, 3.4 percent distant.

Someone with localized pancreatic cancer who reads "13.7 percent" is reading a number weighted toward the 79 percent of cases found at the regional or distant stage. Someone with distant breast cancer who reads "91.9 percent" is reading a number dominated by the 64 percent of cases found at the localized stage. In both directions, the headline is the wrong figure for the individual.

Survival statistics are usually quoted from the day of diagnosis. SEER*Explorer also publishes conditional survival: five-year relative survival rates "conditioned on the patient having already survived 0, 1, 3, or 5 years since the cancer diagnosis." That answers a different question. What is the outlook now, given how far I have already come? It is a fair question to ask at follow-up appointments.

NCI also says that for cancers that return, most do so within the first 5 years after treatment. But there is a chance that cancer will come back later.

Statistics are useful for choosing between treatments and for planning. They are poor at telling you what will happen to you. Ask for figures specific to your stage and your subtype. Ask how old the underlying data are. Ask about validated prediction tools that take your own features into account. And ask how the picture changes with time survived.

For stage-by-stage SEER figures broken out by cancer type — localized, regional, and distant, for 22 cancers — see Understanding Cancer Survival Statistics, which links out to each cancer-specific survival and outlook page.

• SEER*Explorer — survival and conditional survival statistics
• SEER Cancer Stat Facts — Female Breast Cancer
• SEER Cancer Stat Facts — Pancreatic Cancer
• NCI — Understanding Cancer Statistics
• NCI — Understanding Prognosis (survival statistics, cure and remission)
• SEER Cancer Stat Facts — Cancer of Any Site
• SEER — Types of cancer statistics