Cancer during pregnancy

Incidence is rising with later childbearing. Principles (INCIP, ESMO 2013/2019 guidelines): staging with ultrasound and non-contrast MRI, avoid radiotherapy to the abdomen and most targeted/immune agents; surgery any trimester; anthracycline- and taxane-based chemotherapy from 14 weeks with delivery ≥3 weeks after the last cycle and not before 37 weeks where possible; no chemotherapy in the first trimester (malformation risk). The INCIP cohort showed children exposed in utero have normal cognitive and cardiac development at 3 and 6 years (Amant, NEJM 2015), with prematurity, not chemotherapy, driving outcomes. Trastuzumab (oligohydramnios), endocrine therapy, immunotherapy, TKIs and methotrexate are contraindicated or avoided. Pregnancy-associated breast cancer within a few years postpartum has worse biology. Placental metastasis is rare (melanoma most common).