Some cancer surgeries are being delayed, many stent procedures for clogged arteries have been pushed back and infertility specialists were asked to postpone helping patients get pregnant. Doctors in virtually every field are scrambling to alter care as the new coronavirus spreads. Medical groups issued advice this week on how hospitals and doctors should adapt as beds and supplies are pinched and worries rise about exposing patients to possible infection. That includes canceling elective surgeries, including many for slow-growing or early-stage cancers, which many people would consider not elective at all.