Beclin-1 predictive effect is concentrated in which Kiupel grade MCTs?

• A. Kiupel HIGH-grade MCTs
• B. Kiupel LOW-grade MCTs
• C. All grades
• D. Recurrent tumors only

Answer: (A)

Beclin-1 is tied to autophagy, a cellular process that helps tumor cells endure stress. In canine mast cell tumors, the Kiupel grading system separates tumors into low- and high-grade groups, with high-grade tumors being more biologically aggressive and more reliant on survival pathways like autophagy. Because of this greater dependence on autophagy in high-grade tumors, Beclin-1 levels or autophagic activity tend to provide more information about prognosis in these cases. In low-grade tumors, the disease course is typically favorable and autophagy plays a less decisive role in outcomes, so Beclin-1 adds little predictive value there. Recurrent tumors aren’t the focus here since the strongest, most consistent predictive signal comes from high-grade MCTs.