Cancer Incidence Is Rising in Pregnant Women

On June 16, 2022, in JAMA Oncology, a published study reported that the incidence of cancer among pregnant patients in the United States is rising, and those diagnosed in this way also have a significantly increased risk of poorer disease outcomes.

The researchers found that the prevalence of pregnancies complicated by cancer increased by 13.8% from 2016 to 2019.

NOTE: Prevalence is a measure of how frequently a disease occurs in a population over a given period (for example, 1 year). In cancer, prevalence refers, for example, to the number of patients with that diagnosis per 100 thousand people.

In addition, pregnant patients with cancer had a greater risk of additional complications and death during their hospital stay compared with patients without cancer.

To uncover these findings, the researchers analyzed more than 14.6 million patient records from January 2016 to December 2019. 

The prevalence rate of pregnancies complicated by cancer was 69.3 cases per 100,000 deliveries. Prevalence rose from 64.5 cases per 100,000 deliveries in 2016 to 73.4 per 100,000 in 2019 (the difference was statistically significant, p <0.001). 

The most commonly recorded cancer types were breast cancer, lymphoma, leukemia and gynecological (female-specific) cancers. During the period studied, the annual number of new cancers increased for skin, soft tissue, breast, and oral cavity/pharyngeal cancers. 

The researchers compared outcomes in patients with and without cancer. The data showed that patients with cancer had a higher risk of severe illness and death during their hospital stays leading up to delivery.

The prevalence of severe additional health problems during pregnancy was 97.4 per 1000 deliveries among patients with cancer and 17.3 per 1000 deliveries among patients without cancer. 

The prevalence of death during hospitalization for delivery was 2.2 per 1000 deliveries among patients with cancer and less than 0.1 per 1000 deliveries among patients without cancer.

The researchers noted several limitations of this study, including a lack of information on cancer stage, anticancer treatment, and disease status at delivery. The dataset also contained no information on cause of death, oncological outcomes, neonatal outcomes, or events after discharge.

In conclusion, this study provides important evidence that cancer incidence during pregnancy is rising in a Western country. The reasons for this increase were not identified in this study. Becoming pregnant at an older age appears to be the first possible explanation that comes to mind, but this alone would not be sufficient to explain the rising incidence of leukemia and lymphoma. Future studies may focus on the reasons for this situation.

*

• Related topic: Marked Increase in the Incidence of Esophageal Cancer in Middle Age