ESR1 and Marchiafava-Bignami disease: Subgroup analyses with a forest plot revealed that prognoses in the high MBD group were better than those in the low MBD group in subgroups, regardless of tumor size, nodal positivity, stage, estrogen receptor, progesterone receptor, histologic grade, lymphovascular invasion, BMI, operation, radiation therapy, and chemotherapy (Table 2).