CA 15-3 levels can be higher than usual with conditions that are cancerous and non-cancerous as well. Usually, an increase in the CA 15-3 occurs in breast cancer that has metastasized and spread to other body regions.
The higher the CA 15-3 in the blood would consequently mean the presence of more cancerous cells. When breast cancer metastasizes to the liver or bones, the highest levels become. If the treatment turns out to be effective, the level of CA 15-3 reduces and returns to normal. Sometimes the CA 15-3 levels may increase over time. This may be an indication that the treatment is not effective and the cancer is not responding to it. It may also mean that the cancer is recurring or returning after the treatment.
Apart from breast cancers, CA 15-3 may also be higher than usual in the case of cancers of the prostate, ovary, pancreas, liver, colon, endometrial and lung regions. However, these levels do not go as high as breast cancer.
Kindly note that elevation of CA 15-3 levels can also be seen in healthy individuals in benign conditions, but they tend to remain stable over time in mild conditions, unlike in malignancy, where levels rise quickly. Other benign causes of elevated CA 15-3 levels are liver cirrhosis, tuberculosis, sarcoidosis, pelvic inflammatory disease, SLE, endometriosis.
Disclaimer: Please consult with your doctor for interpreting the test reports.