In multivariable analysis, which biomarker was the only significant independent predictor of survival?

• A. Kiupel grade
• B. Beclin-1 immunolabeling
• C. Mitotic count
• D. KIT immunolabeling pattern

Answer: (B)

In multivariable analysis, you’re looking for predictors that provide information about outcome that isn’t already captured by other factors. Beclin-1 immunolabeling stood out because, after including Kiupel grade, mitotic count, and KIT immunolabeling pattern in the model, it remained the only biomarker with a statistically significant association with survival. This means Beclin-1 adds independent prognostic information beyond those standard histologic and KIT measures. The other markers may relate to prognosis in a univariate sense or correlate with Beclin-1, but they do not provide additional predictive value once Beclin-1 is accounted for. Beclin-1 reflects autophagy activity, a process that can influence tumor cell survival under stress, and its expression level thus offers unique prognostic insight in this context.