Ask Nurse A to explain her position regarding prostate cancer patients and seek alternatives to prevent future issues.

Allow them this flexibility: as long as the patient is well cared for, it doesn't matter if the assignments are changed.

Insist that they switch back to the original patient assignments and talk to each of them at the end of the shift.

Explain to Nurse A and B that all patients deserve kindness and care regardless of their condition or the nurses' personal feelings.