Chemotherapy for pregnant women
Although the diagnosis of cancer in pregnancy is rare, it affects more and more women
One of the main reasons is the older age of the expectant mother. When their first child is born, women today are on average only a few years older than their mothers and grandmothers were. Overall, however, the reproductive phase is extending further and further back, so that the majority of children are now born to women over 30. However, with age, the risk of developing cancer also increases. Consequently, cancer is increasingly being diagnosed in pregnant women as well. Tendency increasing.
Even if it sounds unlikely, chemotherapy for pregnant women is possible – and not necessarily harmful to the unborn child. At least that is what the experience of doctors around the world proves over the past decades. One of the pioneers was the mexican doctor agustin aviles, who in 1973 treated a pregnant patient with acute leukemia for the first time. She was the first of 84 women aviles treated with chemotherapy over the next three decades, 58 of them in the first trimester of pregnancy, the critical period when all organs are formed in the fetus. All of the children survived, only 5.8 percent had malformations, the fewest of which were severe (the rate is within the usual range). The first patient also survived and gave birth to a healthy daughter, who today has six children of her own.
In the past, women were forced to terminate their pregnancies
Other studies have found a malformation rate of 14 to 19 percent, although there is only limited comparability between the studies. The number of cases is generally small, monitoring is patchy and the parameters vary widely. Many drugs are no longer used, and it is unclear whether chemotherapy or the original cancer or both are responsible for the malformation. In addition, extreme stress of the mother can also lead to severe malformations in the child. In any case, aviles has done further research and, after analyzing more than a thousand case histories, sees no reason to forego chemotherapy in the first trimester of pregnancy.
Around 1940, pregnant women with breast cancer were considered untreatable. As a rule, they were advised to terminate the pregnancy prematurely. They had to choose between themselves and their baby. However, a norwegian study from 2007 shows that the survival rate of women with cancer is independent of whether they are pregnant or not (the treatment success of more than 45 women was compared).0000 female cancer patients treated between 1967 and 2004). And two small studies suggest that a pregnancy carried to term increases the chances of survival.
Cancer in pregnancy has not been a focus of research to date
Obstetric medicine has adapted to the older age of the mother. For example, the older the mother, the higher the probability that her child will have a malformation. Every mother over 35 is aware of this, because she is automatically considered to be at risk and is therefore referred to a pranatal specialist as a precautionary measure, so that he or she can record the nuchal translucency and other parameters of the unborn child at the end of the first trimester of pregnancy. In addition, numerous other preventive examinations are available and customary in germany in order to assess the health of the unborn child in every respect.
While pranatal diagnostics is currently experiencing an upswing, cancer in pregnancy has not been a focus of research to date. Many doctors who diagnose cancer in a pregnant woman are correspondingly perplexed. If they discover it at all. Breast cancer, for example, is detected two to 15 months later in pregnant women than in non-pregnant women. A major reason is pregnancy-related changes in the breast.
Why breast cancer is often discovered late in pregnant women
Many women first suspect that they are pregnant when their breasts suddenly become unusually hard, firm and sensitive to pain. Even before the belly increases in size, they need to buy a new bust holder with coarser baskets. Although the baby will not be born until months later, the female breast is already converted to milk production in the first month of pregnancy. However, the flood of hormones, which sometimes results in sensational bust sizes, can have fatal consequences: if a woman develops breast cancer at this time of all times, the tumor will grow rapidly. At the same time, the mother’s immune system is more tolerant, otherwise it would reject the fetus, which is actually a genetic foreign body – comparable to a transplant.
However, the swelling milk glands make palpation difficult, and imaging techniques such as mammography provide only unreliable images during pregnancy: both cancerous tumors and the abundant milk glands appear as female spots. Deshalb werden viele der bosartigen geschwure erst spat entdeckt. The findings are correspondingly worse: the risk of breast cancer already being in an advanced stage is two and a half times higher in pregnant women than in non-pregnant women.
Women are particularly at risk in the first two years after pregnancy
Once the diagnosis has been made, a race against time begins, because with many types of cancer, every day counts. Depending on the severity of the cancer, pregnant breast cancer patients may need to have their breasts removed. But even if the breast can be preserved, breastfeeding is strictly prohibited if chemotherapy is continued. For some women, treatment with cytostatic drugs is only the beginning of an extensive cancer therapy. For example, radiation treatments are common only after childbirth.
Even after pregnancy, the danger is not over: studies show that pregnancy in principle minimizes the risk of developing breast cancer in the future. However, this does not apply to the first two to ten years after birth, because the risk is increased during this period. Women are most at risk in the two years after pregnancy: if they get breast cancer at this time, the mortality rate is doubled.
Doctors estimate an average of one cancer case per 1000 pregnancies. Detection is difficult because there is no national or international cancer registry. More precise figures can only be expected in the future. In germany there are currently about 700.000 pregnancies per year, that is, about 700 pregnant women who develop cancer. The most common forms include breast cancer, cervical cancer, hodgkin’s lymphoma, ovarian cancer, melanoma, colorectal cancer and leukemia.
Folic acid for all
For comparison: in an average of 1.5 out of 1000 pregnancies, the child suffers from a neural tube defect or so-called "open hernia". To minimize the risk of this often fatal malformation in the child, it is recommended that all pregnant women and women who wish to have children take folic acid regularly, especially in the first weeks of pregnancy. In fact, the neural tube closes already in the first four weeks of pregnancy, at a time when most women do not even know that they are pregnant (especially since the first two weeks of pregnancy exist only purely mathematically: officially, a pregnancy begins on the first day of the last bleeding, but ovulation and conception usually occur only in the second week of pregnancy). In the usa and canada, flour has been fortified with folic acid for ten years. In germany, too, there are plans to fortify flour with folic acid as standard in order to reach all pregnant women. Compared to this, efforts to detect cancer in pregnant women are close to zero. Although the risk is as high as 1 in 1000.
Centers of excellence and new long-term studies
A decisive step towards better care for pregnant women diagnosed with cancer was the establishment of a competence center in berlin at the end of 2007. The german center for neoplasia and pregnancy (nuss) is located in the obstetrics department of the charite, but works across disciplines. The staff coordinates the therapy and monitors mother and child during pregnancy, but the cancer therapy itself takes place in the individual disciplines. If there are acute problems and, for example, the birth has to be induced prematurely, the obstetrics department takes over. Contact with the mothers is maintained even after delivery. Since the nuss was founded, there have been numerous inquiries from patients, relatives and doctors from all over germany.
Overall, however, the treatment of pregnant women with cancer is still in its infancy. In the usa and canada, new, large-scale, long-term studies are expected to provide insights into the effects of chemotherapy during pregnancy on the child. There are also tentative attempts to further develop chemotherapy in pregnant women. At prestigious cancer hospitals such as memorial sloan-kettering cancer center and dana-farber cancer institute, for example, some pregnant women are now treated with cytostatic drugs every two weeks, as are non-pregnant patients, rather than only every three weeks. Pregnant cancer patients have one tiny advantage: they do not suffer from severe nausea, as is common and feared with chemotherapy.