Which statement best describes Beclin-1's prognostic value across all primary MCTs not treated with adjunctive therapy?

• A. It was a strong predictor of MCT-specific survival
• B. It was not a significant prognostic marker for survival or DFI
• C. It predicted DFI but not survival
• D. It predicted KIT pattern

Answer: (B)

Beclin-1 acts as a regulator of autophagy, a process cells use to recycle components under stress. In prognostic studies for canine mast cell tumors, researchers look for biomarkers whose expression levels help predict outcomes like survival or recurrence. When looking across all primary MCTs that were not treated with adjunctive therapy (i.e., managed with surgery alone), Beclin-1 expression did not show a statistically meaningful association with the outcomes of interest. In practical terms, its level could not reliably distinguish dogs that would have longer or shorter MCT-specific survival, nor those with longer or shorter disease-free intervals. So, Beclin-1 isn’t a useful prognostic marker in this untreated, broad MCT population. It also didn’t provide a reliable signal about KIT pattern in this context, and the main takeaway is the lack of predictive value for survival and DFI in this setting.