Involve. Supporting you. Supporting your patients with cancer
General Terms
- Test Group – The group being given the investigational treatment or therapy.
- Control Group – The group being given the standard treatment that is already approved and in use or a placebo.
- Superiority Trial – A superiority trial is designed to detect a difference between treatments. These trials generally are designed to show a statistical difference in endpoints if the differences between arms demonstrate a P value of 0.05 or less.
- Independent Radiology Review (IRR) – Assessment of radiographic data by a blinded radiology panel. The Response Evaluation Criteria in Solid Tumors (RECIST) guidelines suggest that all responses should be reviewed by independent experts when evaluating response rates as a primary endpoint. Independent review of radiologic data ensures that bias does not affect the interpretation of radiographic images.
- Investigator-assessed Radiology Review – Assessment of radiographic data by the investigators conducting the study.
Response Criteria Definitions
- Clinical Benefit Response – An endpoint that measures the improvement in at least 1 parameter (eg, pain, functional impairment, weight changes). The assessment of clinical benefit response varies from trial to trial.
- Complete Response (CR) – The disappearance of all target lesions.
- Disease-free Survival (DFS) – The length of time after treatment during which no cancer is found. Disease-free survival can be reported for an individual patient or for a study population.
- Duration of Response – Measured from the time measurement criteria are met for CR or PR (whichever status is recorded first) until the first date that recurrence or progressive disease (PD) is objectively documented, taking as reference for PD the smallest measurements recorded since treatment was started.
- Overall Survival (OS) – The percentage of subjects in a study who have survived for a defined period of time. Overall survival is usually reported as time since diagnosis or initial treatment and is often called the survival rate.
- Partial Response (PR) – At least a 50% decrease in the sum of the longest diameter (LD) of target lesions, taking as reference the baseline sum LD.
- Progression-free Survival (PFS) – Progression-free survival is similar to time to progression (TTP), but with an important difference: PFS means the time from the beginning of treatment until progression or death from any cause. Thus, a person who dies of another cause BEFORE progression of disease would be counted in PFS, but not in TTP.
- Progressive Disease (PD) – At least a 20% increase in the sum of the LD of target lesions, taking as reference the smallest sum LD recorded since treatment was started, or the appearance of 1 or more new lesions.
- Relative Risk Reduction (RRR) – The measurement of risk reduced in one arm of a study compared with another arm of the study. For example, if 60% of patients in group A died and 30% of patients in group B died, the treatment in group B would have a relative risk reduction of 0.5 or 50% (ie, the rate of death in group B is half of that in group A).
- Response Rate/Overall Response Rate (RR/ORR) – Response recorded from the start of treatment until disease progression/recurrence (taking as reference for progressive disease the smallest measurements recorded since the treatment was started).
- Stable Disease (SD) – Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum LD recorded since treatment was started.
- Time to Progression (TTP) – The time from diagnosis (or treatment) until the disease starts to get worse.
- Time to Treatment Failure (TTF) – The time calculated from the date of randomization until the date of disease progression.
Statistical Definitions
- Confidence Interval (CI) – A confidence interval is a range of plausible values that accounts for uncertainty in a statistical estimate. A narrow confidence interval implies high precision; a wide interval implies poor precision. When you see a confidence interval in a published medical report, you should look for 2 things:
- Does the interval contain a value that implies no change or no effect?
- Does the confidence interval lie partly or entirely within a range of clinical indifference?
- Hazard Ratio (HR) – Hazard ratio is the probability of one group of patients experiencing a particular event (eg, relapse or death) relative to another group. A number less than 1 indicates decreased risk, while a number greater than 1 indicates increased risk.
- Mean – The mean is the mathematical average of all the values and is calculated by adding up all the values in a dataset and dividing by the number of values. For instance, in the series of numbers: 1, 2, 3, 4, 5, the mean is 3 (1+2+3+4+5=15; 15/5=3).
- Median – The median is essentially the midpoint of the data points in a set, the value at which as many numbers in the group are larger as are smaller. In this series: 4, 5, 6, 9, 13, 14, 19, the median is 9 since 3 numbers are larger and 3 are smaller. When there is an even quantity of numbers in the group, the median is usually defined as the mean of the 2 numbers in the middle.
- Mode – The mode of a data sample is the element that occurs most often in the series. For example, the mode of the sample [1, 3, 6, 6, 6, 6, 7, 7, 12, 12, 17] is 6.
- N-value – The number of patients in a particular study or assigned to a specific test group (the larger the n-value, the more credible the results may be as more people have been included in the study).
- P-value – The P value is a statistical value that measures the probability that the difference between groups during a trial occurred by chance. For example, a P value of 0.05 (or 1 chance in every 20 tries) indicates that there is only a 5% probability that the results observed between treatments in the sample happened by chance. The P value is the key defining point of clinical trials, its value determining whether one treatment can be considered to have a statistically significant advantage over another. In general, clinical trials are powered to show statistical significance between treatments when 1 treatment shows a P value of 0.05 or less.
Take the Cancer IQ Quiz!