Evidence and decision-making -- Evidence-based summary measures -- Making decisions when diagnosis is certain: Under expected utility theory -- Under regret theory -- Under dual processing theory -- Hybrid model -- Making decisions when diagnosis is uncertain: Under expected utility theory -- Under regret theory -- Under dual processing theory -- Hybrid model -- Using predictive modelling to tailor therapy -- Under expected utility theory -- Under regret theory -- Heuristic decision-making: fast-and-frugal tree -- Conclusions: future of decision-making in oncology and hematology -- Artificial intelligence vs standard decision theories.