Elevated parathyroid hormone-related peptide serum levels were associated with breast cancer tumor progression.

Parathyroid hormone-related protein (PTHrP), recognized for its role in humoral hypercalcemia, has emerged as a potential prognostic biomarker in breast cancer (BC) due to its influence on tumor growth and metastasis. This study investigates the relationship between serum PTHrP levels and BC worse outcomes among Egyptian women. The study included 150 Egyptian women (90 BC patients, 30 with benign breast diseases, and 30 healthy controls). BC patients (12 ± 4.05) exhibited significantly (p < 0.0001) elevated PTHrP levels (pg/mL) compared to benign (7.1 ± 1.9) and healthy (2.9 ± 0.8) controls. PTHrP levels were strongly associated with BC progression including tumor late stages (14.6 ± 4.7 vs. 10 ± 1.7), lymph node invasion (13.1 ± 4.3 vs. 9.4 ± 1.4), distant metastasis (16.9 ± 4.7 vs. 10.6 ± 2.6), high grades (15.8 ± 5.2 vs. 10.34 ± 1.7) and large size (13.2 ± 4.3 vs. 9.4 ± 1.2). Moreover, PTHrP levels were significantly associated with negative estrogen (p = 0.0067), progesterone (p = 0.0057) receptors and HER2 (p = 0.0015) status. PTHrP was significantly correlated with CEA (r = 0.312; p = 0.0001) and CA 15.3 (r = 0.293; p = 0.0029) in BC patients. In conclusion, elevated PTHrP levels are associated with BC severity in Egyptian women, suggesting that integrating PTHrP, in practice, with other established measurements could provide a comprehensive biomarker profile and may improve early detection of disease progression and aid in treatment planning, particularly in resource-constrained settings.