在轉移性攝護腺癌中伴隨不可檢測的攝護腺特異性抗原的復發性肺轉移
楊聿寬、邵翊紘、陳昱廷、蔡翰宇、曹書瀚、侯鎮邦、林友翔、陳建綸

林口長庚醫院 外科部 泌尿科

Recurrent solitary lung metastasis with undetectable prostate-specific antigen in metastatic prostate cancer

Yu-Kuan Yang, I-Hung Shao, Yu-Ting Chen, Han-Yu Tsai, Shu-Han Tsao, Chen-Pang Hou, Yu-Hsiang Lin, Chien-Lun Chen

Division of Urology, Department of Surgery, Linkou Chang Gung Memorial Hospital

Introduction:

Serum prostate specific antigen (PSA) is a sensitive indicator of prostate cancer recurrence after radiotherapy (RT). Prostate cancer rarely recurs after RT without PSA elevation. Moreover, although pulmonary involvement from prostate cancer is well-known, solitary lung metastasis is rare, with its clinical characteristics not yet fully elucidated.
Case presentation:

A 73-year-old man with a history of prostate cancer and hypertension was diagnosed with prostate cancer six years ago. At diagnosis, he presented with an initial PSA level of 10.18 ng/mL, clinical stage T2aN0M0, and a Gleason score of 4+3. Since March 2017, he had undergone RT and regular androgen deprivation therapy with leuprorelin. One year after diagnosis, his PSA level rose from 0.14 to 2.6 ng/mL, without additional symptoms. A prostate-specific membrane antigen (PSMA) ligand positron emission tomography (PET) scan was subsequently conducted, revealing a nodule in the right lower lung and lesions in the right hilum nodes. Following video-assisted thoracoscopic surgery (VATS), metastatic adenocarcinoma was diagnosed. One month postoperatively, his PSA level decreased to 1.3 ng/mL. His PSA levels were effectively managed, ranging from 0.04 to 0.38 ng/mL with continuous androgen deprivation therapy. However, a follow-up computed tomography (CT) scan five years later showed enlargement of the left upper and lower lung nodules (12 mm and 14 mm, respectively) as illustrated in Figure 1, with a PSA of 0.38 ng/mL and no accompanying symptoms. A second VATS procedure was carried out, and the pathology confirmed metastatic adenocarcinoma in both the upper and lower lung tumors. One month after the second surgery, the PSA level had decreased to below 0.025 ng/mL.

Conclusion:

This case illustrates that, though uncommon, prostate cancer can recur and metastasize after RT without an increase in serum PSA levels. Even after the surgical resection of isolated lung metastasis, ongoing treatment may be necessary.

Figure 1. CT of lung revealed (A) left upper lung nodule (12mm) (B) left lower lung nodule (14mm).