Progesterone receptors and cancer prognosis

This study evaluated the use of progesterone receptor status as an independent predictor of disease prognosis in patients with early breast cancer.

Most breast cancer cells grow in response to female hormones, such as progesterone and estrogen. Cancer response to these growth stimuli not only directs treatment efforts, but also affects disease prognosis. Currently, breast cancer prognosis is estimated mainly through cancer staging and the extent of lymph node involvement. This study investigated whether progesterone receptor status might act as an independent prognostic factor regardless of cancer stage.

A total of 1,072 women who underwent surgery to remove early breast cancer took part in this study. 67.2% of the women had progesterone-receptor positive tumors and 80.2% had estrogen-receptor positive tumors. Average overall survival rate at 8.3 years of follow-up was 71%.

Results of the study demonstrated that absence of progesterone receptor expression was associated with poor diseases prognosis regardless of cancer stage or lymph node involvement. Among estrogen-receptor positive patients, those also with progesterone-positive tumors were about 6 times more likely to achieve breast cancer specific survival compared to those with progesterone-negative tumors. In addition, absence of progesterone receptor expression among patients with lymph node involvement was associated with a significant reduction in the likelihood of breast cancer specific survival.

This study showed that expression of progesterone receptors is an independent positive prognostic factor among patients with early breast cancer. Absence of progesterone receptor expression in primary breast cancers is associated with worse disease prognosis.