Investigating the Prognostic Impact of Postpartum Diagnosis in Women with De Novo Stage IV Inflammatory Breast Cancer.

BACKGROUND

Postpartum breast cancer (PPBC) and inflammatory breast cancer (IBC) are associated with poor prognosis. Despite similarities in mechanisms, data on the intersection of PPBC and IBC are limited, particularly for stage IV disease. We aimed to evaluate the impact of postpartum diagnosis on survival of patients with metastatic IBC.

PATIENTS AND METHODS

We retrospectively analyzed data from a prospectively maintained, single-center IBC registry for patients diagnosed with de novo metastatic IBC from 2007 to 2023. Clinical stage was subclassified into IVA, IVB, IVC, and IVD per the staging system by Plichta and colleagues. Overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan-Meier. Multivariate Cox regression analyses were performed.

RESULTS

Among 167 patients, 15 (8.9%) were nulliparous at diagnosis, 23 (13.8%) were 0-5 years postpartum, 11 (6.6%) were 6-10 years postpartum, 31 (18.6%) were 11-20 years postpartum, and 87 (52.1%) were > 20 years postpartum; 40 (24.0%) patients had stage IVB disease whereas 47 (28.1%) had stage IVC and 80 (47.9%) had stage IVD disease. Median follow-up was 84.1 months. Median OS and 95% confidence interval were 37.9 months (32.9-49.8); median PFS was 14.1 months (12.7-18.1 months). OS and PFS did not differ significantly by postpartum group (log rank p > 0.05). On multivariate analyses controlling for Plichta stage (p = 0.001), age, and treatment, postpartum group was not significantly associated with either survival outcome (p > 0.05).

CONCLUSIONS

In this cohort of patients with metastatic IBC, postpartum diagnosis did not significantly impact survival. Our findings suggest that the aggressive characteristics of IBC outweigh the poor prognosis associated with postpartum diagnosis.