Remission, Recurrence, Resistance
Educational orientation
Expanded educational edition: 2026-09-10. This page explains terms; it does not predict an individual course.
By the End of This Chapter
Read a timeline without confusing absent detection with biological absence.
Learning matrix and gaps in the short edition
Core Idea
Remission means cancer signs have decreased or are not detectable by the methods being used. Recurrence means disease has returned after a period of control. Resistance means disease does not respond, or stops responding, to a therapy. These words depend on test sensitivity, timing, cancer type, and response criteria.
Cancer can be controlled for long periods in some settings and difficult to control in others. The same word can carry different implications across diseases.
Step-by-Step Explanation
1. A result belongs to a time and a method
Response describes change under defined criteria. Remission may be partial or complete depending on what was assessed. No detectable disease is not the same claim as absence of every malignant cell: every method has limits. Recurrence describes disease returning after a period without detection; it should not automatically be confused with a new primary cancer.
2. Resistance is a biological explanation, not blame
A tumor population may contain differences before an intervention. If some cells survive better, their share may increase; other alterations may also arise during evolution. Resistance can involve the target, alternative pathways, cell state, or environment. It does not mean the tumor “decided to learn” or that the person caused the outcome.
3. Not responding and losing response are different situations
Intrinsic resistance describes lack of sensitivity from the outset within the assessed context. Acquired resistance describes loss of sensitivity after an initial response or control. In research, this distinction needs longitudinal assessments and clear criteria; one negative result does not necessarily reveal the mechanism. Exposure failure, measurement limitations, and heterogeneity may also influence observations. Chronology helps formulate hypotheses but does not alone prove which alteration caused a change. Avoid reconstructing an entire biological history from only two dates.
Supporting reading: NCI: Understanding Cancer Prognosis.
The Concept Illustrated
Worked Example
In an exercise, population A falls from 900 to 90 cells while B remains at 100. The total falls from 1,000 to 190, but B's share rises from 10% to about 53% without an absolute increase in B. This illustrates relative selection; it is not a clinical result or proof of a specific resistance mechanism.
Essential Vocabulary
- Complete response: no detectable disease by defined criteria.
- Partial response: measurable decrease.
- Progression: measurable worsening.
- Minimal residual disease: very low-level disease by sensitive methods.
What This Does Not Mean
"No evidence of disease" is not the same as proof that disease can never return.
Builder/Data Lens
Outcomes need timestamps, assessment method, criteria, and censoring. Response labels without dates are weak data.
Check Your Understanding
Does response at one assessment demonstrate that it will last?
Answer and reasoning
No. Magnitude and duration are different dimensions. Follow-up and explicit criteria are needed; today's observation cannot fill in the future.
Optional Deeper Exploration
For interventions, keep approved use, guidelines/clinical use, trial, translational, and preclinical status separate. In data, avoid using future recurrence information to predict baseline status: that is leakage; bias and external validation remain relevant, and performance does not establish clinical utility.
Go Deeper
References
- National Cancer Institute. NCI Dictionary of Cancer Terms
- National Cancer Institute. Cancer Clinical Trials Information