DOG-1 (Discovered on GIST-1)

DOG‑1 (Discovered on GIST‑1) is a highly sensitive and specific IHC marker for gastrointestinal stromal tumours (GISTs). It detects TMEM16A/ANO1, a chloride channel protein encoded on chromosome 11q13, and shows membranous and cytoplasmic staining. DOG‑1 is especially valuable because it remains positive in many KIT‑negative and PDGFRA‑mutant GISTs, making it one of the most reliable markers for confirming GIST. Although DOG‑1 is most strongly associated with GIST, it is also naturally expressed in several normal tissues, including gastric mucosa, salivary glands, pancreatic acini, bile ducts, and myoepithelial/basal cells of the breast and prostate (1).

Recommended Controls

Criteria for acceptable staining is a membranous and cytoplasmic staining pattern. The recommended control to include a gastrointestinal tumour (GIST) which is a high expressor that will stain all tumour cells and an appendix, for both negative and positive control. A moderate staining pattern should be seen in the Cajal cells and no staining should be seen in the mast cells and smooth muscle cells.

Expected staining pattern

Appendix

GIST

Disclaimer

These methods are intended as a guide only. Laboratories that wish to implement these methods should perform internal validation/verification prior to use. The RCPAQAP does not make any claim or warranty for the accuracy or performance of these methods.