Tumor Marker Tracking Calculator
Track serial tumor marker values (PSA, CEA, CA-125, etc.) to calculate doubling time, velocity, rate of change, and projected future values.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
Doubling time (days)
82.8
Velocity (units/month)
1.52
How to Use This Calculator
- Enter baseline tumor marker value (e.g., PSA, CEA, CA-125 in appropriate units) and date.
- Enter follow-up values and dates at each monitoring interval.
- Read percent change from baseline and doubling time calculation.
- Rising markers with shortening doubling time may indicate disease progression requiring evaluation.
- Use marker trends alongside imaging to guide treatment response assessment.
How the result changes with Second marker value
| Second marker value | Doubling time (days) | Velocity (units/month) |
|---|---|---|
| 10,000 | 8 | 3,380.87 |
| 35,000 | 6.9 | 11,836.42 |
| 65,000 | 6.4 | 21,983.09 |
| 90,000 | 6.2 | 30,438.65 |
What each input means
- First marker value
- First tumor marker measurement (ng/mL or U/mL).
- Second marker value
- Follow-up tumor marker measurement.
- Days between measurements
- Calendar days between the two marker draws.
- Projection forward (days)
- Project the marker value this many days into the future.
- Upper normal limit
- Lab reference upper limit of normal (e.g., PSA: 4.0 ng/mL, CEA: 5.0 ng/mL, CA-125: 35 U/mL).
What each result means
- Doubling time (days)
- Time for the marker to double. Negative = marker is declining (halving time). <90 days is concerning.
- Doubling time (months)
- Doubling time expressed in months.
- Velocity (units/month)
- Absolute marker change per month. For PSA, velocity >0.75 ng/mL/yr is a biopsy trigger.
- Rate of change (%/month)
- Percentage change per month from baseline.
- Projected future value
- Estimated marker value at the projection time point assuming exponential kinetics.
- Fold above normal
- Current marker value divided by the upper normal limit.
- Aggressive kinetics flag (0/1)
- 1 if doubling time < 3 months (90 days) while rising — concerning for aggressive disease.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersFirst marker value = 4, Second marker value = 8.5, Days between measurements = 90, Projection forward (days) = 180 = 5 input(s) provided
- Calculate Doubling timeDoubling time82.8 = 82.8
- Calculate VelocityVelocity = (marker2 - marker1) / monthsBetween1.52 = 1.52
- Calculate Doubling timeDoubling time = doublingTimeDays / 30.442.72 = 2.72
- Calculate Rate of changeRate of change = ((marker2 - marker1) / marker1) * 100 / monthsBetween38.1 = 38.1
Related Calculators
The questions that sit next to this one — chosen by subject, including calculators filed under a different category.
Tumor Doubling Time Calculator
Calculate tumor volume doubling time, specific growth rate, and projected size from serial imaging measurements. Includes RECIST-like diameter change assessment.
OncologyCancer Staging Calculator
Determine overall cancer stage from TNM descriptors, calculate lymph node ratio, assess nodal staging adequacy, and estimate tumor volume.
Pattern MakingPattern Marker Efficiency Calculator
Calculate fabric utilization percentage from marker layout dimensions and pattern piece areas.
OncologyChemotherapy Dose Calculator
Calculate BSA-based chemotherapy drug doses using the Mosteller formula with support for dose capping, renal/hepatic reductions, and cumulative cycle dosing.
More in Medical & Clinical.