A study published in Cancer Management and Research did not indicate a worse prognosis for young women with hormone receptor (HR)-positive breast cancer who become pregnant after breast cancer surgery compared with women who do not become pregnant.
This retrospective cohort study comprised 1,323 young women (defined as 35 years or younger) with breast cancer from January 1, 2006, to December 31, 2014. The 68 women who became pregnant after breast cancer surgery were matched 1:4 to 264 women who were not pregnant based on similarities in tumor sizes, lymph node statuses, molecular subtypes, and years of diagnosis.
The primary endpoints were disease-free survival (DFS) and overall survival (OS) in patients with HR+ breast cancer. Secondary endpoints were DFS and OS in patients with HR-negative breast cancer. Subgroup analyses included the DFS of patients who became pregnant within five years after surgery and DFS according to endocrine therapy interval time (≤30 months vs. >30 months) among pregnant women.
Pregnant women had a younger median age compared with non-pregnant patients (28 vs. 33 years; P<0.01), and pregnant women were was more likely to have had no procreation or lactation before the operation (80.9% vs. 16.7% and 82.4% vs. 24.6%, respectively; P<0.01).
There were no statistically significant differences in DFS (P=0.657 vs. P=0.058) and OS (P=0.250 vs. P=0.152) among HR+ patients, respectively, versus the whole population. A breast cancer pregnancy interval of ≤5 years resulted in better DFS (P=0.042), while an endocrine therapy interval of ≤30 months was associated with worse DFS (P=0.01). “Patients were able to become pregnant within five years after surgery,” the researchers noted.
“We believe that young women who desire pregnancy after breast cancer diagnosis should be well informed of various potential and unknown risks through careful discussion with their physicians,” the researchers concluded.