MKI67 and pulmonary valve insufficiency: On the contrary, other potential prognostic factors such as histopathological grade, gender, age, primary tumor size, Ki-67, cardiac surgery, stable disease due to peptide-receptor radionuclide therapy (PRRT), SSA use, coexistence of tricuspid regurgitation with pulmonary regurgitation and presence of bone metastasis were not significantly associated to OS.