What is the most important, and simple, number used to determine whether a woman with gestational trophoblastic neoplasia (GTN) should receive single agent or multiagent chemotherapy?

I think Dr. Schink’s comment is very important.  As with the case presented in the tumor board, the patient did not have metastatic disease, but had a high risk score and needed multi-agent chemotherapy.  Other patients can have metastases (e.g., lung and/or vagina) and have a low risk score, and can receive single agent therapy, avoiding exposure to multi-agent chemotherapy and the associated short and long term side effects.  The risk score, not the extent of disease is the primary way to determine the correct treatment for a patient.  This is very different than many solid tumors.