Endocrine
Ace St. John, MD, MS (he/him/his)
Resident Physician
University of Maryland Medical Center, United States
Ace St. John, MD, MS (he/him/his)
Resident Physician
University of Maryland Medical Center, United States
Ace St. John, MD, MS (he/him/his)
Resident Physician
University of Maryland Medical Center, United States
Patricia Erickson, MPH
School of Public Health
University of Maryland, United States
JJ Newland, MD, MS
Resident
University of Maryland Medical Center
Baltimore, Maryland, United States
Julia Terhune, MD
Assistant Professor
University of Maryland Medical Center, United States
Doug Turner, MD
Professor of Surgery
Department of Surgery, University of Maryland Baltimore, United States
Yinin Hu, MD (he/him/his)
Assistant Professor of Surgery
Department of Surgery, University of Maryland Baltimore, University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center
Baltimore, Maryland, United States
Parathyroid carcinoma (PC) is a rare malignancy presenting diagnostic and management challenges. This study aims to identify factors associated with margin positivity following PC surgery. We hypothesize that there are factors related to margin status that may aid in intraoperative guidance.
Methods: Using the 2004-2020 National Cancer Database (NCDB), we retrospectively analyzed patients with parathyroid carcinoma for whom either a positive margin (PM) or negative margin (NM) was recorded. Surgical approaches were categorized as Local Resection (LR) or Radical Surgery (RS). Based on surgical approach and margin status, patients were divided into four subgroups: LR/NM (indicative of lower-risk cases), RS/PM (R0 resection may not be feasible), LR/PM (inadequate resection), and RS/NM (adequate resection). Statistical associations were assessed using Chi-Square for univariate analyses and multivariable logistic regression.
Results: Out of 1175 patients, 935 had a determinable margin status. 26.52% (n=248) had positive margins (PM) and 73.48% (n=687) had negative margins (NM). The LR/PM subgroup accounted for 14.44% (n=135) of patients, while RS/PM accounted for 2.03% (n=19). The univariate analysis pinpointed older age (p=0.03), positive lymph nodes ((OR 2.89; 95% CI: 1.46-5.69; p=0.002), and lymphovascular invasion (OR 2.33; 95% CI: 1.46-3.71; p< 0.001) as factors associated with positive margins. However, multivariable analysis revealed no modifiable factors associated with positive margins. Notably, tumor size and institutional case volume did not correlate with margin positivity in either analysis. On univariate and multivariable analyses assessing predictors of inadequate resection, LR/PM surgery was not associated with facility type, geographic region, age, sex, race, insurance status, median Income, urban vs rural, Charlson-Deyo score, year of diagnosis.
Conclusions: One out of every four PCA cases are treated with a margin-positive resection. More than half of these are due to inadequate extent of surgery, signifying that most cases of PCA are not recognized until after the index operation. Outcomes are suboptimal across all demographic and institutional strata. Future research should focus on radiographic and biochemical markers that can help differentiate between benign and malignant parathyroid pathology in the preoperative setting.