Surveillance of newly diagnosed breast cancer in pregnancy
The actual incidence of breast cancer in pregnancy in the UK is not known. Estimates from other countries range from 2.4 to 7.8 cases per 100,000 births. This gives an estimated 18 to 61 cases per year in the UK. We are seeing women with a history of breast cancer now getting pregnant as survival rates increase, but surveillance of this would inform a further study in the future. Although the incidence of breast cancer rises with age, the observation that many women are delaying their families until later in life means that the incidence of breast cancer arising for the first time in pregnancy may be rising. At the other end of the scale, for women under 30, a significant proportion (more than 10%) of breast cancers may be associated with pregnancy, or within a year afterwards.
The diagnosis of breast cancer in pregnant women may be difficult and there is a potential for under-treatment of the mother and iatrogenic prematurity for the fetus. There is apparent contradiction between advice in Europe in general and UK specific advice from the RCOG about the timing of interventions and delivery. A group in Australia and New Zealand are conducting a similar study, which will make comparisons hugely informative. This study will use the UK Obstetric Surveillance System (UKOSS) to determine the incidence of primary breast cancer in pregnancy in the UK and to describe its management as well as the short-term outcomes for both mother and infant.