Extended En Bloc Reoperation for Recurrent or Persistent Parathyroid Carcinoma: Analysis of 31 Cases in a Single Institute Experience

Background Parathyroid carcinoma (PC) is a rare malignancy that is difficult to eradicate completely after recurrence. We assessed the efficiency of extended en bloc resection (EEBR) in the management of recurrent or persistent PC. Methods In this observational cohort study, 31 patients who underwent reoperations for recurrent or persistent PC were enrolled after 2-9 surgeries by other medical teams. EEBRs, which provided the oncologic resection by removing all possible tumor-bearing scar tissues, were adopted in 25 patients. The other 6 with gross infiltration into the upper aerodigestive tract (UAT) underwent less radical procedures for unwillingness to sacrifice laryngeal function. Results The 5-year overall survival (OS) rate after EEBR was 59.6% compared with 16.7% after less radical procedures, with an improved median expected survival time of 90.0 months compared with 13.0 months after local excision. EEBR exhibited a favorable local control of relapses in 84.0% of patients after a median follow-up period of 27.0 months, 40.0% even achieved disease-free survival, although 56.0% had subsequent distant metastases (DMs) and suffered a worse 5-year OS of 36.7% in contrast with 100.0% in the absence of DM (p = 0.011). UAT invasion, rather than age, number of previous operations, or preoperative PTH levels, was the unique independent factor associated with both DM (HR = 5.466, p = 0.006) and mortality (HR = 7.606, p = 0.011). Conclusion EEBRs provide better outcomes than other conventional surgical approaches and might offer a second chance of cure for patients with recurrent or persistent PC in the absence of DM.