Progesterone receptor isoform B in the stroma of squamous cervical carcinoma: An independent favorable prognostic marker correlating with hematogenous metastasis

Objectives: To ascertain the prognostic role of the expression levels of estrogen receptor (ER) and progesterone receptor (PR) within the stroma microenvironment of cervical cancer and explore their correlation with clinical parameters. Materials and methods: This retrospective cohort study involved patients with cervical cancer diagnosed and treated at Hualien Tzu Chi Hospital between 2000 and 2010. ERα, PRB, and PR (A + B) expression levels in 169 cervical carcinoma samples, including both the tumor and stromal components, were independently scored by two pathologists, and survival and clinicopathological parameters were analyzed. Results: ERα or PRs were predominantly expressed in the stromal compartment rather than within cervical cancer cells. Their expression was observed comprehensively within the intra- and peritumor stroma cells. A stromal PRB expression significantly correlated with a lower 5-year mortality because of cervical cancer (p = 0.011). Particularly, levels of both stromal ERα and PRB expressions correlated with lower hematogenous distant metastase rates (p = 0.013 and p = 0.011, respectively). In the multivariable logistic regression analyses, stromal PRB independently conferred a lower risk of 5-year mortality (p = 0.022), regardless of age, histology, International Federation of Gynecology and Obstetrics (FIGO) stage, tumor differentiation, lymphovascular space invasion, and lymphatic and hematogenous metastases. Moreover, the incorporation of stromal PR (A + B) and PRB expression in the FIGO stage significantly enhanced the accuracy of survival prediction. Conclusion: Stromal PRB expression emerges as an independent and favorable prognostic marker for cervical squamous cell carcinoma and correlated with a low risk of hematogenous metastases. The findings imply that incorporating this marker into the FIGO stage better predicts the survival for cervical cancer.