Learning about the meanings of frequently used cancer terms

6 Frequently Used Cancer Terms: What Do They Actually Mean?

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When I read news articles about cancer research, I often find myself annoyed by the confusing way in which terminology about cancer and cancer research in used.

In cancer language, it’s not unusual for the medical or scientific meaning of a word to be different from the way the same word is understood in everyday language.

Sometimes the difference reflects a focus on populations vs. individuals, and in that case the context in which the term is used is critical. Media reports sometimes add to the confusion by failing to clarify these differences.

Here are six terms that are frequently used in reporting about cancer research and treatment, and some observations on what they actually mean.


The term breakthrough is often used in reporting about cancer research. There’s a story almost every week it seems, claiming a new breakthrough.

The Oxford Dictionary defines breakthrough as “a sudden, dramatic and important discovery or development.” And the Free Dictionary by Farlex defines a medical breakthrough as “a significant step forward in theory development or research.”

Scientific or medical breakthroughs do occur, but they are pretty rare. They’re certainly not happening every week. As I understand it, that is just not the way science works the vast majority of the time. Research into new cancer therapies is a process that develops over many years or decades. If and when there is success, it is very rarely sudden or dramatic.


In stories about celebrity experiences with cancer, the celebrities sometimes claim that they are “cancer free” after treatment. But is it really possible to know that? Is it possible to totally eliminate or “cure” a person’s cancer?

At scientific meetings, physician speakers occasionally comment that many patients being treated for breast cancer today are being “cured”. They apparently mean this on a population level, i.e. with treatment, fewer overall will die from breast cancer than otherwise would.

But the catch is that for an individual early stage patient, even when the intent of treatment is to remove any microscopic cancer cells still in the body after surgery, there is no way today to verify that the cancer has been fully eliminated.  Certainly that’s the case with breast cancer and that seems to be the case with most types of cancer. Even the term “no evidence of disease” does not rule out the possible presence of microscopic disease that we can’t detect with any test available today.

Palliative Care

Palliative care is often confused with end-of-life care, including in some reporting about cancer. This can be a disservice to patients, who may be reluctant to access care that could be very helpful for them because of this misunderstanding.

Mayo Clinic defines palliative care as “specialized medical care that focuses on providing patients relief from pain and other symptoms of a serious illness, no matter the diagnosis or stage of disease.”

Some have suggested that a better term is needed. It might help to have a term that stresses the specialist nature of this care, which can be a valuable way to address particularly problematic symptoms, bringing in knowledge and expertise beyond what the main physician treating the individual might be able to offer.

Patient-Centered Care

When I first heard this term it really had me scratching my head. What kind of quality health care wouldn’t be considered patient-centered and why would anyone want it? A related concept is patient-centered outcomes.

Yet, these terms do represent an evolution that may be underway/has been underway for a while in the thinking about health care. As I understand it, the difference if we had truly patient-centered care would be a shift in medical decision-making from a focus on populations to a focus on the individuals being cared for. This definition from NEJM Catalyst sums up the goals of patient-centered care:

In patient-centered care, an individual’s specific health needs and desired health outcomes are the driving force behind all health care decisions and quality measurements. Patients are partners with their health care providers, and providers treat patients not only from a clinical perspective, but also from an emotional, mental, spiritual, social, and financial perspective.

These certainly seem like desirable goals. Sometimes the whole concept pushes too far and becomes more about marketing than caring for people, but this basic definition seems to represent very important goals worth striving for.


Cancer prevention is another term that is meaningful and important in talking about populations, but does not translate to individuals. At the population level, we can take measures such as regulating environmental contaminants that result in fewer people getting cancer. In that scenario, the regulatory measures “prevent” some cases of cancer–it just isn’t possible to know which individuals would have gotten cancer and now did not as a result of the preventive action.

For individuals, we can only take actions that reduce our risk for cancer. As an example, cigarette smoking is known to increase risk for a number of types of cancer. Not smoking, therefore, is a very important way to reduce our risk. However, not smoking does not guarantee that we won’t still get cancer.


The term “survival” in the context of cancer can be especially confusing.

The concept of “relative survival”, usually referring to 5-year survival, is often used to provide a general benchmark of life expectancy after a diagnosis of a particular type of cancer. This concept simply refers to being alive after a cancer diagnosis, whatever the stage of the cancer. It doesn’t mean that an individual is “cancer free” or even that they’ve completed treatment, if their diagnosis was early stage disease.

Relative survival can be helpful in tracking progress at the population level over years or decades, but for many reasons it may not have a lot of relevance for one person being treated today.

One of the reasons an individual today may have a different outcome is that these statistics usually are based on people who were treated a number of years ago, and there may be better treatment options available now. In addition, factors specific to the individual, such as other health conditions or differences in access to timely care, can have a significant impact.

So, there are six of the cancer terms that are very frequently used and have different meanings in the medical or scientific context than they do in everyday language. A lot of confusion or misunderstanding can arise when we don’t understand what these terms actually mean in the context in which they’re being used.

Related Post
Making Sense of Cancer Research News in the Media

Image Credit: plutmaverick via Shutterstock


  1. Excellent post. I remember sitting in on a ‘media’ briefing years ago. The speaker said the drug had 12 % advantage. The audience yawned. He then said: “No in oncology, that’s BIG”! Uh oh because WE live in the real world.

  2. Excellent. I would add to this the two most deceptive and misunderstood words in research, “well tolerated”.

    1. Oh yes, that’s a good one. As I’m learning, it’s pretty amazing the extent of side effects a drug can have and still be considered well tolerated. Quite a disconnect from the way most of us would probably understand those words.

    1. When words mean something different to different people or in different contexts it makes communicating pretty difficult, doesn’t it? Thanks for your comment!

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