The definition I choose for this regret is based on decision theory. In this sense I define regret as the possible opportunity cost or loss resulting from a decision. That is the difference between the actual payoff of the path taken, versus what might have been gained if the alternative choice had been made. See the following link for more background: en.wikipedia.org/wiki/Regret.
The side effects and trade offs of cancer treatments [ as a negative ] are balanced against the [ possible positive ] future gains. I simplify this important dialogue with the following "regret matrix":

The side effects and trade offs of cancer treatments [ as a negative ] are balanced against the [ possible positive ] future gains. I simplify this important dialogue with the following "regret matrix":

- The lesson: make sure you have an honest conversation with your medical team. Ensure you understand both sides of the equation; both the advantages and the "cost".
- Know that all the "forecasting and probability" data is based on the average for a group of people. Review the statistics module in my companion website.
- I suggest a simple model to help decision making in the companion website - click on the ADJUVANT DECISIONS tab in that section.