Test Catalog

Test ID: COX2    
COX-2 Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Identifying normal and neoplastic cells expressing cyclooxygenase-2 (COX-2)

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Cyclooxygenase 2 (COX-2) is an inducible enzyme involved in production of prostaglandins in inflammatory processes. It is involved in the response of cells to growth factors, tumor promoters, and cytokines that induce its expression. There is increased evidence that expression of COX-2 plays a role in development and progression of malignant epithelial tumors. Eighty five to 90% of colon cancers show over-expression of COX-2. COX-2 positivity has been correlated with a poor response to treatment and shorter overall survival.

Interpretation Provides information to assist in interpretation of the test results

This test does not include pathologist interpretation; only technical performance of the stain is performed. If an interpretation is required, order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request, call 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut fresh.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Deng L, Liang H, Han Y: Cyclooxygenase-2 and beta-catenin as potential diagnostic and prognostic markers in endometrial cancer. Front Oncol. 2020;10:582704

2. Salem AM, Elfeky MA, Nawar N, Alattar AZ, Atef Elekiabi O, Elaidy MM: Prognostic value of combined; Cox-2, cyclin D1 and P21 expression in colorectal cancer (CRC) patients: An immunohistochemical study. Open J Pathol.2018;8(3):106-121

3. Sano Y, Kogashiwa Y, Araki R, et al: Correlation of inflammatory markers, survival, and COX2 expression in oral cancer and implications for prognosis. Otolaryngol Head Neck Surg. 2018 Apr;158(4):667-676