What happened when dermal and subcutaneous MCTs were analyzed as separate groups?

• A. Statistical significance was achieved
• B. Beclin-1 remained non-predictive
• C. The sample sizes were too small to reach statistical significance, but most deaths occurred in the high Beclin-1 group
• D. Beclin-1 predicted recurrence

Answer: (C)

When you analyze dermal and subcutaneous mast cell tumors as separate groups, the numbers in each subgroup become smaller, which lowers the statistical power to detect real differences. In this case, the separate analyses did not reach statistical significance, but there was a clear pattern: most deaths occurred in the group with high Beclin-1 expression. This suggests a possible association between high Beclin-1 and worse outcome that the small sample sizes couldn’t confirm with statistical significance. It highlights how subgroup analyses can reveal trends that are masked in the overall dataset, while also illustrating the risk of underpowered results when groups are too small.