Surgical outcomes in survivors of childhood cancer undergoing thyroidectomy: A single-institution experience.

BACKGROUND: Childhood cancer survivors (CCS) are at increased risk for thyroid disease, and many require definitive management with thyroid surgery. Despite this, there is limited evidence on surgical outcomes among CCS. We sought to evaluate postoperative outcomes at our institution among CCS undergoing thyroid surgery compared to patients without a history of primary childhood malignancy. PROCEDURE: Medical records were reviewed for 638 patients treated at the Children's Hospital of Philadelphia Pediatric Thyroid Center between 2009 and 2020. Rates of surgical complications, including recurrent laryngeal nerve (RLN) paralysis and hypoparathyroidism, among CCS were compared to patients with sporadic/familial thyroid cancer, Graves' disease, and other benign thyroid conditions. Operative time and intraoperative parathyroid hormone levels were also evaluated. RESULTS: There were no significant differences in long-term surgical complication rates, such as permanent RLN paralysis and hypoparathyroidism, between CCS and patients without a history of primary childhood malignancy (all p > .05). For all surgical outcomes, there were no significant differences in complication rates when CCS were compared to those undergoing surgery for sporadic/familial thyroid cancer or Graves' disease (all p > .05). CCS with benign final pathology had significantly higher rates of transient hypoparathyroidism compared to patients with benign thyroid conditions (p < .001). CONCLUSIONS: Our study suggests that CCS are not at higher risk of long-term complications from thyroid surgery when treated by high-volume surgeons within a multidisciplinary team.

Whole Chromosome 7 Gain Predicts Higher Risk of Recurrence in Pediatric Pilocytic Astrocytomas Independently From KIAA1549-BRAF Fusion Status.

The most frequent genetic alteration identified in pediatric pilocytic astrocytomas and pilomyxoid variant is the KIAA1549-BRAF fusion, which typically results from a 2.0 Mb tandem duplication in chromosome band 7q34. Less frequent abnormalities include fusion genes,BRAF, FGFR, KRAS, and NF1 point mutations, and whole chromosome gains. To correlate genetic alterations with clinical course data, we retrospectively analyzed the tumors with pilocytic and pilomyxoid histology of a cohort of 116 pediatric patients, aged 5 months to 23 years. Gross total resection was associated with a decreased risk of recurrence (p = 0.001), supporting previous findings that complete tumor excision correlates with long-term and disease-free survival. We found no significant association between recurrence rate and the presence of the KIAA1549-BRAF fusion or BRAF mutation (p = 0.167). Interestingly, gain of whole chromosome 7 (WC7) was associated with a 4.7-fold increased risk of tumor recurrence, even after adjusting for surgical status (p = 0.025), and other genetic alterations. Using fluorescence in situ hybridization, we demonstrated that when WC7 gain accompanies the KIAA1549-BRAF fusion, the fusion likely arises first. This study highlights the utility of genetic studies for risk assessment of pilocytic and pilomyxoid astrocytomas, which may impact treatment selections.