MADRID—In those rare cases in which cancer is diagnosed in a pregnant woman, treatment with standard anti-cancer regimens has been shown in new data to benefit the mother and not harm the child she is carrying, researchers reported here at the European Society for Medical Oncology Congress.
In a case-control study that included 38 women and their infants and a like number of controls, Belgian researchers determined that giving chemotherapy in the second and third trimesters of pregnancy did not have any late-term sequelae in the children's growth patterns.
“When chemotherapy is administered after the first trimester of pregnancy, we cannot discern any problems in the children,” said Frederic Amant, MD, Professor of Obstetrics and Gynecology at University Hospitals Leuven in Belgium. “Fear about the risks of chemotherapy administration should not be a reason to terminate a pregnancy, delay cancer treatment for the mother, or to deliver a baby prematurely.
“Before, we would say that you should not give chemotherapy before delivery, but that was not good for either the baby or the mother,” he said in an interview. “We now say, ‘It is better to give chemotherapy during the pregnancy because it is better for the child, and it is better for the mother’.”
In fact, he said during an ESMO news briefing, the only factor that appears to slow development of the child is prematurity—not chemoterapy or other treatments to treat the cancer.
“The clinical implications of this study should be that there are fewer terminations of pregnancy, less delay in maternal treatment, and less iatrogenic premature delivery.”
He said that in 61 percent of the cases the cancer discovered is breast cancer, usually found through breast palpitation: “These cases are never found through screening, but by clinical examination. The cancer stage is always more advanced in women who are pregnant than when breast cancer is found in the general public, due to physiological changes in the breast during pregnancy that make it more difficult to feel a mass.”
Amant also said that previous work appears to show similar long-term outcomes between women diagnosed with breast cancer while pregnant and those diagnosed when they are not pregnant. “We do think that in pregnancy, the diagnosis is not worse,” he said.
Another 22 percent of the women in the study were diagnosed with hematological cancers. There were an average of four cycles of chemotherapy during the patients' pregnancies, and about 91 percent of the women received polychemotherapy regimens.
Amant acknowledged that concerns about the potential impact of cancer treatment on unborn children have until recently left some oncologists hesitant to administer treatments to pregnant cancer patients, but his study appears to be reassuring that prompt treatment—at least after the first trimester of pregnancy—is safe.
Bayley Scales of Mental Development
In scrutinizing outcomes on the Bayley Scales of mental development comparing the control children and those exposed to chemotherapy, Amant said, “You can see there is a nice overlap of these outcomes. We did not see any difference in Bayley scale whether the children were or were not exposed to chemotherapy.”
He said the data reveal that children who are born prematurely appear to do worse in development that children who were carried to full term—“but this is the same for children if they were exposed to chemotherapy in utero or not. So prematurity is a problem, but not chemotherapy.”
All the women in the study were treated in the second or third trimester. “We did not compare whether there was a difference in the duration of treatment, because the numbers were not large enough to see a difference,” he said. “In the future we will do this. The cognitive system is still forming in the second trimester, more so than in the third trimester, so there might be a difference, but we haven't done that comparison for this study.”
The researchers followed children who were exposed to chemotherapy in utero from the International Network for Cancer, Infertility and Pregnancy registry and who were assessed for mental development and cardiac health.
At a median age of almost two years, mental development as measured by the Mental Development Index was in the normal range for both groups of children, and were not significantly different. Similarly cardiac dimensions and functions were within normal ranges for both groups. The children underwent electrocardiography and echocardiography to obtain their comparisons.
The children were a median age of 20.5 months, range of 18 to 42 months. Echocardiography was administered to 24 children who were exposed to anthracyclines in utero and 24 controls who were a median age of 22 months.
In a second study, the team also determined that in a study of 16 children and 10 adults who had been exposed to radiotherapy in utero, neuropsychological, behavioral, and general health outcomes for those exposed to radiotherapy were within normal ranges. One child had a severe cognitive delay, but other pregnancy-related complications are confounding factors, the researchers reported.
Becoming Pregnant after Cancer Diagnosis or Treatment
Another study from the group shows the importance of thinking about contraception during cancer diagnosis and cancer treatment: The pregnancy database identified 29 out of 897 women who became pregnant after an initial diagnosis of cancer.
“We need much more work in this field, especially among women who get pregnant during chemotherapy,” the moderator of the news briefing, Giuseppe Curigliano, MD, Director of Experiment Therapeutics at the European Institute for Oncology in Milan, said in an interview.
“The primary message of his study is that you have nine weeks in which you don't have to deliver chemotherapy to women who got pregnant, but after this interval, if you expose a woman to a chemotherapy to treat a breast cancer or any other type of cancer, this is safe for the children.
“The findings are important even if it is just 38 children in the study. This really is a huge number when you consider that pregnancy and cancer is a rare entity in clinical practice. Knowing that delivering chemotherapy does not affect the brain development or the heart development is really gratifying information.”