Chapter 28: Other Cancers

BACKGROUND

Cancer in pregnancy is a rare and life-changing event. It brings significant challenges for the patient, patient’s family, and her physicians. Fortunately, cancer in pregnancy has an estimated incidence of only about 1:1000 pregnancies.¹

Pregnancy-associated cancer is defined as cancer diagnosed during pregnancy or within 12 months of delivery.^2,3 The reason to include the immediate postpartum period is a frequent delay in diagnosis for certain types of cancers due to physiologic changes of pregnancy and reluctance to perform most radiologic procedures.

No precise information is available on incidence of cancer during pregnancy as most of the data are based on case reports and small case series. Therefore, the literature varies significantly in regard to incidence of cancer in pregnancy by the disease site. The number of new cases of cancer diagnoses during pregnancy in the United States is reported to range from 3500 to 6000 per year.^1,4,5,6 Most authors agree that common malignancies diagnosed during pregnancy include breast cancer (1:3000-10,000), cervical cancer (1.2:10,000), malignant melanoma (2.6:10,000), lymphoma (1:1000-6000), and leukemia (1:75,000-100,000). Less frequent are ovarian cancer (1:10,000-100,000) and colorectal cancer (1:130,000).^6,8

Because the incidence of most cancers increases with age, the incidence of cancer in pregnancy is slowly increasing in recent years.^7,8,9 This trend is partially related to a general tendency to postpone childbearing and also to the fact that pregnancy requires a thorough physical examination including ultrasound and regular care. In fact, some malignancies, including cervical and ovarian cancer are diagnosed early solely due to state of pregnancy.

The first International consensus meeting was held in Leuven, Belgium; in 2008. The main goal of this consensus meeting was to evaluate the current state of diagnosis and management of cancer during pregnancy.¹⁰ The task force reviewed all available literature excluding that of endometrial cancer and gestational trophoblastic disease. They noted that there were no randomized trials or prospective trials available and emphasized urgent need to gain more experience in the field. Because this first consensus meeting an international organization was created (http://cancerinpregnancy.org) and more publications about cancer in pregnancy are emerging.

OVARIAN CANCER IN PREGNANCY

Due to the fact that most common types of ovarian cancer are of the epithelial type and usually occur in peri- and postmenopausal women,⁶ ovarian cancer is a rare event during pregnancy with a reported incidence of 1:10,000 to 100,000.^6,8 Most of the epithelial ovarian tumors diagnosed during pregnancy are of low malignant potential.

Palmer and colleagues performed a worldwide literature review of publications about epithelial ovarian cancer during pregnancy.¹⁰ They identified 28 publications and excluded 5 due to lack of information. From 1958 to 2007, 41 reported cases of invasive epithelial ovarian cancer had adequate ...