Approximately 1:1000 pregnancies are complicated by cancer. Breast cancer is the most common type diagnosed during pregnancy. Termination of pregnancy has not demonstrated an improvement in survival. Results of an international collaborative study reported similar overall survival for patients diagnosed with breast cancer in pregnancy compared to non-pregnant patients. The consensus medical opinion supports the option to start treatment with continuation of the pregnancy. The purpose of this Cancer and Pregnancy Registry study is to prospectively follow the women diagnosed with cancer during pregnancy-collecting information about the method of diagnosis, treatment options and maternal and neonatal outcomes at delivery and yearly at follow up during childhood and adult development. Some children in this cohort have been followed up to 28 years of age.

The majority of fetal organ development is completed by 12 weeks of pregnancy, consistent with the literature showing no increased malformation rate for chemotherapy use after the first trimester of pregnancy. The central nervous system continues to develop throughout gestation and after birth. Whether chemotherapy given after the first trimester affects central nervous system maturity and results in developmental delays requires further study. The first authors to provide detailed follow up on children exposed to chemotherapy in utero were Aviles and Niz in 1988. At that time 17 children ranging in age from 4-22 years born to mothers with acute leukemia who received chemotherapy during pregnancy were examined for physical health, growth and development. Each child demonstrated normal growth and development, school performance, intelligence testing, neurological examination, and hematologic evaluation including bone marrow biopsies. This study was expanded twice. First in 1991, to 43 children ranging in age from 3 to 19 years, also after exposure in utero to chemotherapy for maternal hematologic malignancies. All children were normal physically and neurologically. School performances and standardized intelligence testing were not significantly different from controls (unrelated matched children and unexposed siblings). The same authors expanded their study again to a final report of 84 children in 2001, confirming their previous reports that chemotherapy at full doses for an aggressive hematological malignancy can be safely administered. Standardized testing on children exposed to chemotherapy was not repeated for 11 years. Drs. Amant, et al reported developmental outcomes of 70 children in Europe exposed to cancer treatment in utero. The children with developmental delays were concentrated in the group delivered preterm. In this study there was not a control group of unexposed children.

Cardonick also performed developmental testing on 57 children of women diagnosed with cancer during pregnancy, 35 were exposed to chemotherapy. Ninety-five percent of children scored within normal limits on cognitive assessments; 71% and 79% of children demonstrated at or above age equivalency in mathematics and reading scores respectively. Together Dr Cardonick and Dr Amant have evaluated children up to age 9 who were exposed to chemotherapy before birth. Reassuringly chemotherapy did not impact neurologic development, or heart performance up to age 9 years. A current study is looking at children at age 12. Studies are looking at children after exposure to both chemotherapy or radiation or cancer surgery during pregnancy. Currently Dr Cardonick is in contact with young adults in the study who are at least 18 years of age who are participating in a self-assessment tool of their physical, mental and social health. Such long follow up is what helps newly diagnosed pregnant women make informed decisions about cancer treatment during pregnancy.

Women diagnosed with cancer of any type during pregnancy can enroll voluntarily in the Cancer and Pregnancy Registry. Signed medical release forms allow the investigator to review cancer diagnostic studies and treatment course. Records are requested yearly from the treating pediatrician to follow the growth and development of the child. Participants do not have to collect their own records. All information is kept confidential. Oncologic follow up on the women is also requested yearly.