Incidences of Secondary Malignancies After Androgen Deprivation Therapy for Prostate Cancer.

[PURPOSE] We aimed to assess the effects of ADT on the incidence of secondary malignancies in patients with prostate cancer.

[METHODS] Prostate cancer patients who initially treated with ADT from 2009 were included and followed up until 2019. We additionally included female patients, male patients without prostate cancer, and male patients with prostate cancer who did not undergo ADT to build comparison. A 1:1:1:1 match based on age was performed, and 55,865 individuals from each group were selected for analysis.

[RESULTS] The incidence of common cancers was compared between the groups. All cancers, except thyroid and breast cancers, were more common in men than women. All cancers were more common in men with prostate cancer than in men without prostate cancer, regardless of ADT. After ADT, the incidences of thyroid and breast cancers increased, whereas the incidences of liver and pancreatic cancers decreased. In the multivariate analysis, all types of cancer were more common in men with prostate cancer than in men without prostate cancer, regardless of ADT. Among these, the incidence of liver and pancreatic cancers significantly decreased after ADT.

[CONCLUSION] The incidence of several secondary malignancies was affected not only by sex but also by prostate cancer diagnosis and ADT. Although further studies are required, these data could be important for health checkups and the management of prostate cancer survivors, especially prostate cancer patients who have been treated with ADT.