Table 2.
Tumor characteristics and metastasis of 609 patients with parathyroid cancer from the Surveillance, Epidemiology, and End Results (SEER) database, 1975–2016.
| Variable (n = 609) | Frequency (%) | ||
|---|---|---|---|
| Stage * | Unknown | 267 (43.8) | |
| Known | 342 (56.2) | ||
| When Stage was known (n = 342) | p-value | ||
| Localized to the gland | 224 (36.8) | <0.001 | |
| Regional spread only | 105 (17.2) | ||
| Distant Metastasis | 13 (2.2) | ||
| Tumor Size | Unknown | 388 (63.7) | |
| Known | 221 (36.3) | ||
| When tumor size was known (221) | p-value | ||
| Microscopic | 3 (0.5) | <0.001 | |
| Under 2 cm | 58 (9.5) | ||
| 2 to 4 cm | 125 (20.5) | ||
| Over 4 cm | 35 (5.7) | ||
* = The information related to the extent of the disease (EOD) is derived from the SEER summary stage data collection system, which incorporates (EOD Primary Tumor, EOD Regional Nodes, and EOD Mets) algorithm. The EOD in this classification is assigned a code based on the extent of the disease. Various codes for EOD are used, which include in situ 0 for carcinoma in site, 1 for localized tumors to the involved organ only, 2 for direct regional extension only, 3 for the extent to the regional lymph nodes only, 4 for direct extension and regional lymph nodes involvement, 7 for distant extension, 8 for benign, borderline tumors, and 9 if extension and metastasis are unknown (https://seer.cancer.gov/archive/manuals/2021/SPCSM_2021_MainDoc.pdf, accessed 05 March 2022).