ESR1 and serous adenocarcinoma: Furthermore, in high grade serous carcinoma with ER or PR positive, we found that 81% or 78% cases had peritoneal metastases, which were significantly higher than that in low grade serous carcinoma with ER or PR positive (70% or 60%) (Table 4), but the majority of low grade serous carcinoma with ER or PR positive also had peritoneal metastases (>60%).