The 7 Most Misunderstood Medical Terms in Cancer
In this article
Why Is There So Much Confusion?
Many terms used in oncology are based on imaging measures (CT/PET) and standardized assessment criteria. From a patient's perspective, however, these words often get reduced to good news versus bad news. Yet in clinical practice, some expressions can have a neutral or even positive meaning.
A Quick Map to Help You Read
- Is there a measurable change?
- Is the disease under control?
- Should the current treatment plan continue?
- Is another assessment or test needed?
- “It is over / completely gone.”
- “Everything is getting worse.”
- “The treatment was wasted.”
- “They have given up.”
The 7 Most Commonly Confused Terms
For each term, the cards below provide: the patient's common interpretation, the medical meaning and the best question to ask when you hear the term .
1) Progression
The patient's common interpretation: “Everything is getting worse.”
Medical meaning: The disease has advanced compared with the previous assessment according to standard criteria, such as growth of some lesions or the appearance of a new site.
Often misunderstood2) Stable Disease
The patient's common interpretation: “The treatment is not working.”
Medical meaning: The disease has not shrunk substantially, but it has not progressed either; in other words, it is under control.
Often good news3) Partial Response
The patient's common interpretation: “I have not fully recovered.”
Medical meaning: The tumor burden has decreased substantially, but it has not disappeared completely.
A positive response4) Complete Response
The patient's common interpretation: “The cancer is completely gone.”
Medical meaning: Measurable disease cannot be detected through imaging or clinical findings.
Confused with a cure5) Remission
The patient's common interpretation: “There is none left at all.”
Medical meaning: Signs of the disease have substantially decreased or become undetectable. Remission can be complete or partial.
Not equivalent to being cured6) Recurrence
The patient's common interpretation: “The treatment was wasted.”
Medical meaning: The disease reappears after being under control for a period of time.
A new plan is made7) A Treatment Break
The patient's common interpretation: “They have given up.”
Medical meaning: A planned or unplanned pause to manage side effects, protect organs, allow recovery, or strategically reassess the situation.
It does not mean it is overWhat Most Often Leads to Misinterpreting These Terms?
Two people looking at the same report may think different things. Common pitfalls that increase misinterpretation include:
- Differences between imaging methods: CT and PET do not answer the same question. CT mainly shows size; PET provides clues about metabolic activity.
- Measurement error: Millimeter-scale differences can sometimes arise from the equipment or scanning technique and may sometimes be clinically insignificant.
- The possibility of pseudoprogression during immunotherapy: Although rare, immune cells entering the tumor can make it appear temporarily larger on imaging. Doctors evaluate this using separate assessment criteria.
- A change in treatment goals: For some cancers, the goal is long-term control rather than complete disappearance. Stable disease can therefore be very valuable.
- “Is this term considered good or bad in my disease?”
- “Is the goal of treatment to shrink the disease or to control it?”
- “What criteria were used for this assessment? CT/PET, measurement criteria, and so on?”
- “What exactly is our next step?”
Scientific References
- Eisenhauer EA, et al. New response evaluation criteria in solid tumours: Revised RECIST guideline (version 1.1). European Journal of Cancer. 2009.
- Seymour L, et al. iRECIST: guidelines for response criteria for use in trials testing immunotherapeutics. The Lancet Oncology. 2017.
- National Cancer Institute (NCI). Dictionary of Cancer Terms: Remission, Recurrence, Progression, Response. (Patient dictionary/terminology guide).
- ASCO (American Society of Clinical Oncology) Patient Information. “Understanding scans and treatment response”. (Patient information materials).
- ESMO (European Society for Medical Oncology) Patient Guides. “How to understand treatment outcomes and follow-up”.
- Street RL Jr, et al. Patient-centered communication in cancer care: promoting healing and reducing suffering. (Literature on communication in cancer care).
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A misunderstanding can even affect treatment.
This is something we frequently see in oncology practice: patients assume stable is bad and lose hope, interpret complete response as no risk remaining and become less diligent with follow-up, or understand a treatment break as giving up.
The right question, however, is: “What does this term mean for my cancer and my treatment goal?” Simply asking this at an appointment can dramatically improve communication.
Note: This article provides general information. Assessment methods and clinical meaning can differ for each patient. Always interpret your own report together with your treating oncology team.