Autophagy, a cellular degradation mechanism, plays a dual role in the progression and therapy of bone metastases in cancers, including prostate cancer. This review delves into the intricate roles of autophagy in both tumor suppression and progression, with a focus on its impact on bone metastasis and osteosarcoma (OS). Initially, autophagy acts as a tumor suppressor by eliminating damaged organelles and proteins, thus preventing tumor initiation. However, as cancer progresses, autophagy supports cancer cell survival under stress conditions, such as nutrient deprivation and hypoxia, and contributes to drug resistance. Specifically, in bone metastasis from breast and prostate cancers, autophagy facilitates tumor cell migration, invasion, and survival. The review also highlights the therapeutic potential of targeting autophagy in cancer treatment, especially in overcoming drug resistance in osteosarcoma, where autophagy modulation could reduce chemoresistance. By understanding the dual roles of autophagy in cancer and bone metastasis, new therapeutic strategies can be developed to target this process, offering hope for improved treatment outcomes in cancers prone to bone metastasis, including prostate cancer.AJCEU Copyright © 2025.