Endocrine Abstracts

Subtotal parathyroidectomy (PTX) is considered the surgery of choice for patients with MEN1, because it optimally balances the risk of recurrence/persistence against surgical complications. Notably, MEN1 patients negative at the genetic test (MEN1-negative) seem to exhibit distinct clinical characteristics compared to their mutated counterparts (MEN1-positive). Therefore, we hypothesized that these patients may also have a different surgical outcome. The objective of our retrospective study, conducted at our Endocrine Unit from January 1993 to January 2023, was to compare the rate of remission, persistence, and recurrence of primary hyperparathyroidism (PHPT) in MEN1-positive and MEN1-negative patients according to different surgical procedures. We evaluated 101 MEN1 patients undergoing PTX, including 80 MEN1-positive and 21 MEN1-negative patients. The diagnosis of MEN1 occurred in 29 (28.7%) cases post-surgery (69% in MEN1-positive and 31% in MEN1-negative patients). Patients underwent several types of surgery: total PTX (n=4), subtotal PTX (n=48), PTX with cervical exploration (n=12), simple PTX (n=37); none of the MEN1-negative group underwent total or subtotal PTX. No significant difference was observed between the two groups in terms of remission rate (38.8 % vs 50%, P=0.37), persistence (32.5% cs. 28.6% P=0.9) and recurrence (28.7% vs 23.8% P=0.16). The median time to remission and recurrence was 84 (41-120) and 72 (36-120) months in MEN1-positive and 36 (12-36) and 36 (12-24) months in MEN1-negative respectively. By excluding patients who underwent total and subtotal PTX, we found a significantly higher rate of remission in MEN1-negative compared to MEN1-positive patients (50 % vs 10.7 %, P=0.007). We found a significantly higher rate of recurrence in MEN1-positive than in MEN1-negative patients (54% vs 20% P=0.01). No difference was found in the persistence rate between the two groups (35.7% vs 30% P=0.9). When including only patients who had simple PTX we observed a significant higher remission in MEN1-negative compared to MEN1 positive patients (35.7% vs 0%; P=0.0087). No difference in term of the rate of persistence (41% vs 36% P=0.7) and recurrence (59% vs 28%; P=0.09) was found between the two groups. Thirteen patients (12.7%) (n=11 subtotal, n=2 total PTX), all belonging to MEN1-genetic positive patients, developed a chronic post-surgical hypoparathyroidism. Only one patient, belonging to MEN1-positive group, developed permanent laryngeal palsy. According to our results, MEN1-negative patients might benefit from bilateral cervical neck exploration with selective removal of the pathological glands. This surgery could present a good trade-off between risk of recurrence/persistence and surgical complications.