Nineteen years ago, Elyce Cardonick got a call about a newly diagnosed lymphoma patient whose fast-growing chest tumor was causing severe breathing problems.

The cancer patient was 13 weeks pregnant and had rejected her oncologist's advice to abort before starting toxic chemotherapy.

Cardonick, a young maternal-fetal medicine specialist then at Jefferson University Hospital, discovered that little was known about treating cancer during pregnancy. The issue became her calling, inspiring her to create the Pregnancy and Cancer Registry to collect data about treatment and long-term results for both mothers and children.

Today, the registry includes nearly 400 women who battled 23 types of malignancy, including colon, ovarian, and lung cancer. Ninety-five percent of them gave birth and, as Cardonick has published, the results are both reassuring and surprising: Effective cancer treatment need not compromise the health of the unborn child.

A wall of her office at Rowan University's Cooper Medical School in Camden is crammed with photographs of smiling families who turned to her for guidance, some from as far away as Thailand. The gallery includes the lymphoma patient, Patty Sosnader of Worcester, and her son, Brenden, who will soon be in college.

"This wall inspires me every day," said Cardonick, now 50, who has two children of her own.

Thankfully uncommon

Based on the few epidemiological studies of cancer in pregnancy, it is thankfully uncommon - 1 in 1,000 to 2,000 births, affecting perhaps 4,000 women a year in the United States. Obstetricians and oncologists may see only a case or two in a career, which is one reason Cardonick's pre-Internet idea for a registry faced considerable skepticism.

Logically, she says, cancer treatment seems "in conflict with the interest of the developing fetus." Traditional chemotherapy attacks fast-multiplying cells, a characteristic of both cancer and a fetus. Radiation damages cellular DNA; for the fetus, ionizing rays could mean deformity, brain damage, or an increased risk of leukemia.

Even so, when Cardonick scoured the medical literature in 1997, she found a small but heartening trove of data: Agustin Aviles, an oncologist in Mexico City, had treated dozens of pregnant women for blood cancers, with remarkably good outcomes. Cardonick also spent a month studying with a University of Pennsylvania breast cancer specialist, because breast cancer is the most common malignancy in pregnancy. Not only has it affected more than half the registry patients, but the incidence also is expected to increase as more women delay childbirth.

Cardonick deduced that judicious use of chemotherapy, and even of low-dose diagnostic radiation, was relatively safe. The risks depended on many factors. Were the drug molecules small enough to penetrate the placenta? How did the drug work? Could the fetus be shielded from the maternal radiation? And, most of all, what was the stage of pregnancy? A fetus is most vulnerable in the first 14 weeks, when the organs are forming, so the first trimester was the riskiest.

"One drug we tend to avoid is methotrexate," Cardonick said, explaining that it interferes with a vitamin vital to brain and spinal cord formation. "But even that has been safely used in the second trimester."

Newer drugs that target a specific molecular driver of cancer pose particular dilemmas. Some are so novel that their fetal effects can't be predicted, while others are clearly too risky. Avastin, for example, disrupts the formation of blood vessels, which is vital to placental and fetal development.

But again, timing is key. After consulting with Cardonick, Phyllis Markoff of Cherry Hill treated her aggressive form of breast cancer with traditional chemotherapy, then delivered her son. Next came even more chemo and Herceptin, a targeted drug that has dramatically improved survival for women like her - but can harm fetal kidneys.

"My son is a completely normal 9-year-old," said Markoff, now 46. "He plays trombone, and soccer, and video games. He reads books. . . . Cancer treatment is not a death sentence for women or their babies."

Science, not fear

In 2000, Cardonick discovered a unique ally, Hope for Two. The online support group had recently been founded by Patty Murray of suburban Buffalo, who battled breast cancer before delivering a healthy son. The Hope for Two website became a source of referrals to the Pregnancy and Cancer Registry.

No matter how patients wind up turning to Cardonick, she focuses on science, not fear.

She firmly believes that abortion is the woman's choice. Of 90 women in the registry whose doctors recommended termination, 20 took that option, in most cases because first-trimester treatment was deemed essential for the woman and too perilous for the fetus.

For women who plan to proceed with treatment, Cardonick stresses that the data show they should tailor it - not lessen or postpone it until delivery - to protect their offspring. While treatment doesn't guarantee long-term survival (several women in the registry have died of their cancer), she has found no evidence that it impairs children's cognitive or general development.

Amy Hansen, 31, of Fort Collins, Colo., called Cardonick in 2013 after being diagnosed with a rare form of ovarian cancer. Hansen was 12 weeks pregnant and refused to undergo the standard surgery - a total hysterectomy. Instead, she decided to have the diseased ovary removed, followed by a grueling chemo regimen.

"Elyce said, 'Amy, I have research that says it's safe to do chemotherapy during pregnancy. Make sure they are not giving you a weaker dose just because you're pregnant,' " Hansen recalls. "It was what I needed to hear."

Gavin Michael Hansen is now 2 and, even more remarkable, his cancer-free mother is 22 weeks pregnant with his sibling.

Kristina Abernathy, 28, of Crescent City, Calif., was also beginning a harrowing ordeal when she called Cardonick in 2014. Abernathy had spent eight months seeking an explanation for abnormal menstrual bleeding. By the time she was diagnosed with a rare type of cervical cancer, she was three months pregnant and the tumor was growing into her uterus.

Cardonick conferred with Abernathy's doctors and assured her that their plan - chemotherapy, a carefully timed cesarean section birth, then more cycles of chemo plus intensive radiation - was sound.

"She was a huge support system," Abernathy said. "It was so neat to find someone who knew what we were going through and could verify that we had what we needed."

Although Abernathy has permanent nerve damage from the aggressive treatment, she has been cancer-free for a year. And her daughter Johanna - born prematurely, just under three pounds - is an exuberant, healthy toddler.

"She can talk in full sentences," her mother said proudly. "She climbs everything. She figures out puzzles, and it blows my mind."

Specialist in Belgium

In 2004, Cardonick published one of a series of reassuring studies in the journal Lancet Oncology. She drew on the registry data submitted annually by women and their obstetricians, oncologists, and pediatricians.

Six thousand miles away at University Hospitals Leuven in Belgium, gynecological oncologist Frederic Amant thought that Cardonick's findings reinforced his decision to subspecialize in a fairly obscure area - cancer in pregnancy.

"She was an expert before my time. She had a landmark publication . . . and I used it when I started with this project," he said recently by phone.

Amant now has a large research group underwritten by big funders, including his university, the Belgian government, and a European institute. He also founded the International Network on Cancer, Infertility and Pregnancy - of which Cardonick is a member.

Cardonick, in contrast, has struggled to find money for database management, and for developmental testing of children in her most recent study, published last year. Cooper and a few small charities have helped, but she has struck out with federal grants and big cancer philanthropies.

"I need to find a benefactor," Cardonick said. "But I'll continue to do this on my own. It's a labor of love."

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