Why it is performed
- Support monitoring of a diagnosed disease and response to treatment.
- Assist evaluation of a mass, symptoms or specific risk together with imaging and other tests.
- Use a marker in narrowly defined screening contexts when guidelines recommend it, not as an indiscriminate general panel.
How it is performed
The indicated sample is collected and analysed by immunoassay or another validated method. Diagnosis, treatment and previous results should be known; for monitoring, using the same method and laboratory is preferable when possible.
Preparation
- Provide the clinical reason and previous results; avoid broad panels without an indication.
- Report pregnancy, smoking, inflammation, liver/kidney disease or benign conditions that may alter some markers.
- Do not interpret an isolated rise as cancer or a normal result as excluding cancer.
How Askabide processes it
Combined pathway
Immunoassays or other techniques according to the requested AFP, CEA, CA-125, CA 19-9, PSA, hCG or other marker. On-site availability depends on active validated reagents; the remainder are processed by partner laboratories.
Part is performed at Askabide and another phase or confirmation is processed externally.
Results and indicative intervals
Intervals vary by method, analyser, reagent, units, age, sex, pregnancy, menstrual-cycle phase and reference population. The valid interval is the one printed on the laboratory report.
| Parameter or result | Indicative reference | How it is interpreted |
|---|---|---|
| Within interval | Específico del método | Does not exclude cancer and must be compared with the indication and prior results. |
| Raised | Específico del método | May reflect cancer, benign disease, inflammation, pregnancy, smoking or other causes depending on the marker. |
| Trend | Más útil en seguimiento | A serial change may be more informative than a single value when the method is consistent. |
Important limitations
- Most markers lack sufficient sensitivity and specificity for general screening of asymptomatic people.
- A rise does not confirm cancer; a normal value does not exclude it.
- Different methods may produce values that are not directly comparable.
- Indication and follow-up belong to the responsible clinician.