A 72-year-old male patient with known prostate cancer presents with new complaints of persistent lower back pain and unexplained fatigue. His PSA levels have recently increased despite ongoing treatment. Which nursing action is the most appropriate priority in this situation?

Suggest the patient rest in bed to relieve back pain and postpone all physical activity until pain subsides.

Advise the patient to continue medications and monitor symptoms over the next week before reporting.

Report the findings to the healthcare provider immediately to evaluate for possible metastasis to the bone.

Encourage the patient to increase fluid intake to manage fatigue and support kidney function.