In late March, Zoran Lasic, an interventional cardiologist at Jamaica Hospital Medical Center and Lenox Hill Hospital in New York, was finishing afternoon clinic when he was approached by a nurse colleague seeking his advice. Her husband — a 56-year-old whose father died of sudden cardiac arrest at 55 — had been feeling chest pressure. The pressure radiated down his arms and occasionally to his neck and, the previous day, had been accompanied by dyspnea and diaphoresis, making him worried enough to call an ambulance. The emergency medical technicians did an electrocardiogram, said it looked OK, and told him to call his primary care doctor. He did, and he was advised that given New York’s Covid-19 outbreak, it was not a good time to go to the hospital. Now, a day later, his colleague asked Lasic, what should they do?

Nearly apoplectic, Lasic advised urgent coronary angiography, which he performed a few hours later. The man had a thrombus extending from his proximal-to-midleft anterior descending artery and became hemodynamically unstable during the procedure. Nevertheless, revascularization was successful, and he was discharged the following day with preserved left ventricular function. Lasic, describing a precipitous decline across the New York region in patients presenting with acute coronary syndromes, worries that others won’t be so lucky. “I think the toll on non-Covid patients will be much greater than Covid deaths,” he said.

As the coronavirus pandemic focuses medical attention on treating affected patients and protecting others from infection, how do we best care for people with non–Covid-related disease? For some, new risks may warrant reconsideration of usual standards of care. For others, the need to protect caregivers and preserve critical care capacity may factor into decisions. And for everyone, radical transformation of the health care system will affect our ability to maintain high-quality care. As Michael Grossbard, chief of hematology at New York University’s Langone Hospital, told me, “Our practice of medicine has changed more in 1 week than in my previous 28 years combined.”

Cancer care, which often involves immunosuppressive therapy, tumor resection, and inpatient treatment, has been disproportionately affected by Covid-19. Like other oncologists I spoke with, Grossbard, who primarily treats lymphoma, has been tasked with revising chemotherapy protocols to minimize both the frequency of chemotherapy visits and the degree of immunosuppression. For example, though patients with low-grade lymphoma typically receive maintenance therapy, it will not be recommended for now because it requires an office visit, worsens immunosuppression, and improves progression-free but not overall survival. Other protocol modifications have arisen because of cancellations of elective surgeries. For instance, some patients with solid tumors, such as breast and rectal cancers, are being offered systemic therapy before, rather than after, surgery.

Many modifications may not affect long-term outcomes. Eric Winer, a breast oncologist at Dana-Farber Cancer Institute, believes, for instance, that giving antihormonal therapy to women with hormone-receptor–positive breast tumors and delaying surgery probably won’t alter overall survival, though this approach hasn’t been formally tested in Stage I disease. But even when there’s greater uncertainty about treatment modifications, Winer has been impressed by many patients’ graceful acceptance.

I spoke to Ms. C., a 40-year-old patient of Winer who was recently diagnosed with inflammatory breast cancer. Treatment typically involves 4 to 6 months of chemotherapy followed by surgical excision, though as Ms. C. said, “When you have cancer, your first reaction is ‘Just get it out of my body now.’” But as she and Winer watched Covid-19 decimate Italy, they began discussing what the evolving situation would mean for her. She’d started receiving an anthracycline, which heightened her risk of infection, and was supposed to have surgery in May. When we spoke, it wasn’t clear whether or when her surgery would proceed, but she and Winer had agreed that if it was postponed, she would resume targeted systemic therapy. She seemed to take this uncertainty in stride, partly because the hallmark rash of inflammatory breast cancer disappeared after she began receiving Herceptin (trastuzumab) a few months ago. “I literally saw my cancer shrink,” she told me, “and I’m so thankful we are where we are now, as opposed to 25 years ago.”

Suspending other aspects of cancer care will have graver consequences. David Ryan, chief of oncology at Massachusetts General Hospital (MGH), told me that three patient groups worry him most. The first are the subgroup of patients with lymphoma for whom CAR-T therapy is potentially curative. More than half these patients receive therapy in clinical trials, many of which have been paused amid society-wide shutdowns; even if enrollment could continue, there’s concern about the need for ICU care in a resource-constrained system. A related concern is for patients requiring bone marrow transplants, given their high risk of infection and potential need for ICU care.

Finally, and most wrenching to Ryan, are patients with refractory tumors who are nearing the end of life, but for whom an experimental targeted therapy may hold promise; Ryan would otherwise offer these patients enrollment in an early-phase trial. One recent analysis suggests that such enrollment is associated with clinical benefit in nearly 20% of patients,1 and participation allows patients to have some hope in their dying days and to feel like they’re “giving back” to the scientific community.

The individual toll, as clinical trials slow to a crawl, is mirrored by a societal one. As Ryan, who sent me an email message while serving a volunteer shift in the hospital’s Covid unit, lamented, “There’s no question that clinical research in cancer will be set back by at least a year as we all drop what we’re doing to take care of the surge of patients.”