Prognostic analysis and establishment of a nomogram in patients with myoepithelial carcinoma of the salivary gland: A population‐based study

Abstract

Background: Currently, the clinicopathological characteristics and prognosis of myoepithelial carcinoma of salivary gland (MC-SG) have not been defined well. The present study aimed to describe the clinicopathological characteristics and prognosis of MC-SG patients. Methods:The Surveillance, Epidemiology, and End Results database was searched for all patients diagnosed with MC-SG between 1991 and 2016. The Kaplan-Meier method and log-rank tests were used to evaluate the survival. Univariate and multivariate Cox regression analysis were used to identify prognostic biomarkers for overall survival (OS) and disease-specific survival (DSS). Furthermore, a prognostic nomogram was established, and its predictive accuracy and discriminative ability were determined using the concordance index (C-index).Results: In total, 245 patients diagnosed with MC-SG were identified. The median OS was 152.0 months, with 3-, 5-, and 10-year survival rates of 79.8%, 69.2%, and 50.3%. The 3-, 5-, and 10-year DSS rates were 82.5%, 77.1%, and 61.9%, respectively.Regarding the treatment regimen, most patients (92.2%) underwent surgery, and 103 patients (42.4%) received postoperative radiotherapy. Surgery could significantly prolong OS and DSS (p < .05), but postoperative radiotherapy did not significantly prolong OS and DSS when compared with individuals receiving surgery alone (p > .05). Multivariate Cox analysis revealed that T category (T4), lymph node metastasis (N2), distant metastasis (M1), and poor differentiation were independent unfavorable prognostic factors for OS and DSS. Older age (>62 years) was also independently associated with OS. In addition, the C-index for the established OS-and DSS-specific nomogram was 0.80 (95% CI: 0.72-0.88) and 0.82 (95% CI: 0.73-0.90). Conclusion:Age, tumor invasion, metastases, and pathological grade were independently associated with prognosis of MC-SG patients, and the prognostic nomogram of this rare disease was established.

Major and minor salivary gland cancers: A multicenter retrospective study

“…Like AdCC, R/M can be seen frequently, and survival is longer due to its slower course. 17,19,[26][27][28][29] In our study distant metastasis in the major SGCs is statistically significantly more common than in the minor SGCs (p = 0.003). In a recent study distant metastasis was more common in major SGCs (56% vs. 44%).…”

“…Since myoepithelial carcinoma is a rare histological type, its clinicopathological and prognostic features are still unclear. Like AdCC, R/M can be seen frequently, and survival is longer due to its slower course 17,19,26–29 …”