[Recurrence and metastasis of pheochromocytoma/paraganglioma after tumor resection and clinical characteristics analysis].

Objective: The purpose of this study is to investigate the incidence of recurrence or metastasis of pheochromocytoma/paraganglioma (PPGL) patients after primary tumor resection, and to compare the differences of clinical indicators between patients with or without recurrence or metastasis. Methods: This study is a retrospective study. All 157 patients were followed up after tumor resection in Peking Union Medical College Hospital from 2008 to 2016. We obtained the basic information [age of diagnosis, gender, height, weight and body mass index (BMI)], the onset status of PPGL (age of onset, course of disease, family history, tumor location, whether the tumor is bilateral or multiple, and preoperative blood pressure), clinical and pathological features of PPGL tumor (tumor size, whether it could adhere, invade or infiltrate during operation, whether the tumor capsule is smooth and complete on the postoperative pathological diagnosis, whether there is infiltration growth and cystic necrosis on tumor pathology and Ki-67 index), and laboratory examination results [24 hours urinary norepinephrine (NE), epinephrine (E), dopamine (DA) before operation]. According to the outpatient or telephone follow-up, the postoperative incidences of recurrence and metastasis were explored, and the basic information, status of onset, clinical and pathological characteristics of tumors, and laboratory test results of patients were compared. Results: A total of 157 patients, 69 males and 88 females, were with an average age of (42.4±13.4) years old. There were 103 patients with PCC and 54 with PGL. The average follow-up time was (9.5±2.0) years. Of the 103 patients with PCC, 13 (12.6%) had postoperative recurrence and 9 (8.7%) had distant metastasis. Compared with the patients without recurrence and metastasis, the onset age of the 13 patients with recurrence was younger [(27.3±15.7) years vs (39.3±12.2) years, P=0.003], the course of disease was longer [48.0 (23.0, 141.0) months vs 12.0 (4.0, 60.0) months, P=0.010]. The tumor size of 9 patients with distant metastasis was larger [8.0 (6.1, 12.8) cm vs 5.0 (4.0, 7.0) cm, P=0.027]. Of the 54 patients with PGL, 8 (14.8%) had postoperative recurrence and 5 (9.3%) had distant metastasis. Compared with the patients without recurrence and metastasis, the course of disease of the 8 patients with recurrence was longer [90.0 (36.3, 165.0) months vs 24.0 (8.0, 72.0) months, P=0.009], and the proportion of primary tumors with multiple lesions was higher (4/8 vs 4.4%, P=0.003). The preoperative diastolic blood pressure was higher in 5 patients with distant metastasis [(146.0±32.1) mmHg vs (120.6±25.3) mmHg, P=0.043] (1 mmHg=0.133 kPa), and the proportion of primary tumors with multiple lesions was higher (2/4 vs 4.4%, P=0.029). Conclusion: PPGL patients are prone to have recurrence or metastasis. PPGL patients with postoperative recurrence or distant metastasis had younger onset age, longer course of disease, larger tumor size and higher proportion of multiple lesions.