Paget’s disease (PD) of the breast, folks, it’s a rare, malignant tumor. Now, 50% to 60% of these patients, they also have invasive ductal carcinoma (PD-IDC). It’s a tough prognosis, worse than IDC alone. We’ve been lacking, folks, an accurate model for PD-IDC prognosis. We don’t know how chemotherapy and radiotherapy work for these patients.

But we’ve done something tremendous. We’ve developed a web-based nomogram, using data from the SEER database. We’ve tested it, validated it, and it’s fantastic. It’s accurate, it’s applicable, it predicts overall survival (OS) of PD-IDC patients. The three- and five-year AUCs, they’re 0.831 and 0.841. We’ve used external data too, and the results, they’re even better – 0.892 and 0.914.

We’ve found some factors, folks, that affect prognosis. Age, high grade, widowed status, higher T stages, bone metastases – these are all unfavorable. We’ve done a PSM-adjusted analysis, and it shows that chemotherapy doesn’t improve survival across molecular subtypes. But for grade III/IV, it improves OS and BCSS. Radiotherapy, it only benefits T4 and N3 stages, but it does improve OS and BCSS.

So, we’ve done a comprehensive analysis, folks. We’ve developed a user-friendly, web-based nomogram. It’s accurate, it’s simple, it’s accessible. And we’ve found that pathological grade, not molecular subtype, is key for chemotherapy efficacy. Radiotherapy, it helps T4 and N3 stage patients. We’re doing great things, folks, great things for PD-IDC patients.