Mackenzie Alleman doesn’t like to take chances.

At age 28, Alleman had a preventive double mastectomy. She’d recently learned she is a carrier of the BRCA1 gene mutation and had an 87% chance of developing the disease that had taken her mother’s life years earlier.

“I didn’t want to go through that,” Alleman, now 31, said of her mother’s cancer experience. “More than that, I didn’t want any of my family to go through that.”

Although the surgery dramatically reduced Alleman’s risk of developing breast cancer, the Old City resident wasn’t entirely at ease. She’d also found out she had a 53% chance of developing ovarian cancer — which is much more difficult to detect in its early stages and for which preventive surgery is not recommended until a woman is at least 35.

So instead, every spring, Alleman gets an ultrasound and blood test that, although less-than-ideal screening tools, help her believe that she is doing something to monitor her risk of ovarian cancer.

“It’s not an appointment you’re looking forward to, by any means; it’s just a little peace of mind,” she said. “These surveillance tests are something you rely on to keep going.”

Except this year, when she called to schedule her appointment for April or May, she was told she’d have to wait.

Mammograms, colonoscopies and other routine cancer screenings are among the dozens of procedures put on hold as health systems look to preserve resources for critical coronavirus patients.

In Pennsylvania, Gov. Tom Wolf recently authorized hospitals to resume elective and non-urgent procedures, assuming they have sufficient protective equipment, staff and capacity to treat patients who are positive for COVID-19 as well as those who aren’t. Still, even as many health systems begin to reopen shuttered services, delays could linger for several more months as they see new cases and address a backlog of patients whose procedures were delayed.

Preventive screenings for cervical, colon and breast cancer plummeted 86% to 96% in March, compared with previous years, according to a new report by Epic, an electronic medical records company that analyzed 2.7 million patient records across 23 states.

“On a global scale, it’s a lot of screening procedures being deferred — and maybe some cancers that could develop in this time, as well,” said Austin Chiang, a gastroenterologist in Philadelphia.

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Hospitals have remained open for people with urgent health needs, including cancer treatment, and have encouraged patients whose procedures have been delayed to seek help if their medical condition worsens.

In most cases, especially for those of average risk, delaying a mammogram or colonoscopy by a month or so is safe. But, Epic cautioned in its white paper, “If the trend continues and centers are not able to resume testing, cancer cases could go undiagnosed for prolonged periods of time, which may lead to tumor detection at a later stage.”

Overall, visits to outpatient offices declined 60% between mid-March and mid-April, according to a report from Harvard Medical School researchers, who analyzed provider data from Phreesia, a health-care technology firm used by ambulatory-care centers.

That kind of cut to services — and revenue — has put enormous financial strain on many practices, said Michael Chernew, a professor of health-care policy at Harvard and one of the report’s authors. Some practices may not be able to rebound quickly, which could exacerbate delays, he said. The hardest-hit practices may not be able to reopen at all.

“It’s not a medical problem to delay a month or two on your colonoscopy … but the concern is as the capacity to deliver those services gets strained, people will say, ‘You know what? Skip it,’” Chernew said.

It’s unclear how eager patients will be to reschedule postponed screening tests if they do not have a history of cancer or an elevated risk.

Some people may be reluctant to return to the doctor’s office for fear of contracting the virus, and others may have been laid off and lost their insurance coverage. Between 25 million and 43 million people could lose their employer-sponsored health insurance as unemployment soars, according to a report by the Urban Institute and the Robert Wood Johnson Foundation.

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Anjali Malik, a breast radiologist in Washington, D.C., is worried that people who were told it was OK to delay a mammogram or colonoscopy during the pandemic may question whether they need to do the procedure at all.

“Just from the messaging alone that these can be delayed, it gives people one more reason to put these things off,” she said.

But, she emphasized, it is important to stay current with routine mammograms and colonoscopies because the cancers they detect are treatable and have a high survival rate if detected early.

Alleman is eager to get back to her doctor’s office, but will have to wait a while longer — her ultrasound and blood test are currently scheduled for the fall.

As an organizer with the local chapter of The Breasties, a breast cancer patient group, Alleman understands the reason for the delays and doesn’t mind waiting if it means others who are at higher risk for cancer than she is can be seen sooner.

Still, she’ll be counting down the days until she can get the all-clear from her screenings and breathe easier again.