PGR and triple-negative breast carcinoma: Of the 22 studies that reported on tumor biology, triple-negative breast cancer (TNBC) was negatively correlated with 5-year survival rate (Pearson correlation coefficient r = –0.27, p = 0.35, n = 14 studies); and, positive progesterone receptor status was positively correlated with 5- year survival rate (r = 0.39, p = 0.08; n = 21 studies).