Compared with Patterns I and II, Pattern III in KIT pattern carries what approximate HR for survival and DFI?

• A. HR 1.0
• B. HR 2.0
• C. HR 4.5
• D. HR 3.0–3.6

Answer: (D)

In survival analysis, the hazard ratio measures how much more (or less) quickly events occur in one group compared with another. In the KIT pattern, Pattern III shows far more disorganized KIT localization, which is linked to more aggressive tumor behavior. Compared with Patterns I and II, Pattern III carries a substantially higher risk of death or loss of disease-free interval, quantified as about a 3.0 to 3.6 times higher hazard. So the approximate HR for survival and DFI with Pattern III is in the 3.0–3.6 range. This reflects the markedly worse prognosis associated with Pattern III, whereas Patterns I and II have relatively lower risk.