Risk factors and prognosis for salivary gland adenoid cystic carcinoma in southern china: A 25-year retrospective study

Abstract

Adenoid cystic carcinoma (ACC) is characterized by slow growth, frequent local recurrences, and high incidence of distant metastasis (DM). The aim of this study was to evaluate predictive factors for local-regional (LR) recurrence, DM, and survival in ACC.A retrospective review of the medical records for patients with salivary glands ACC from 1990 to 2015 was performed. The clinical parameters were assessed to identify correlations with the development of LR recurrence, DM, and survival of these patients.Among 228 patients who underwent surgery as definitive treatment, 210 (92.1%) were followed up in the study. DM was detected in 64 (30.5%) patients, LR recurrence was detected in 58 (27.6%) patients. The estimated 5, 10, and 15-year overall survival rates were 84.7%, 70.8%, and 34.0%, respectively. Multivariate analysis revealed that the presence of lymphovascular invasion and a high T classification were very strong adverse factors, which independently influenced LR recurrence, DM, and survival of ACC patients. Positive/close margin and N+ status were independent risk factors for DM and LR recurrence, respectively. Survival of ACC patents was also affected by tumor location.Presence of lymphovascular invasion and a high T classification were very strong adverse factors and independent predictors for ACC patients' prognosis, which influenced LR control, DM control, and survival.

Figure 1

Kaplan–Meier survival curves of (A) overall survival and (B) disease-free survival of ACC patients.

Figure 2

Cumulative survival curves of ACC patients. (A) Overall survival was significantly reduced in patients with LR recurrence (green line) compared with patients without LR recurrence (blue line). P = 0.014. (B) Overall survival was significantly reduced in patients with DM. P < 0.001. ACC = adenoid cystic carcinoma, LR = local-regional, DM = distant metastasis.

Figure 3

Summary of univariate analysis for LR recurrence, DM, and overall survival. HR and 95% CI of HR were showed in Forest plot. Factors of significance for overall survival were: age (P = 0.010), T classification (P = 0.001), N classification (P < 0.001), M classification (P < 0.001), location (P < 0.001), margin status (P < 0.001), perinerual/nerve invasion (P = 0.038), and lymphovascular invasion (P < 0.001). For LR-recurrence they were: T classification (P = 0.034), N classification (P = 0.001), location (P = 0.047), and lymphovascular invasion (P = 0.003). Significant factors for DM development were: T classification (P = 0.028), margin status (P < 0.001), location (P = 0.033), and lymphovascular invasion (P = 0.011). s, solid; c, cribriform; t, tubular. CI = confidence interval, DM = distant metastasis, FM = floor of mouth, HP = hard palate, HR = hazard ratio, LR = local-regional, RT = radiotherapy, SL = sublingual, ST = sinonasal tract.