Adenoid Cystic Carcinoma (AdCC): A Clinical Survey of a Large Patient Cohort

Primary and Recurrent Intraosseous Adenoid Cystic Carcinoma-Analysis of Two Cases and Literature Review

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that mostly occurs in minor glands, especially in the palate. Intraosseous adenoid cystic carcinoma (IACC) is rarer. There is no clear conclusion on the clinical, radiologic and pathological characteristics of IACC because of few reported IACC cases, leading to insufficient understanding of IACC. We reviewed 52 previous reports of primary IACC (PIACC) and analyzed the clinical features of those patients involved, attempting to provide a better understanding of PIACC. Moreover, we present a case of primary PIACC and a case of recurrent IACC (RIACC). The two patients showed similarities in clinical and pathological results, along with slight differences in radiological and immunohistochemical results. The patient of case 1 seemed to display a worse prognosis, which can only be proved after long term follow-up.

Clinicopathological characteristics of four major histological types of high-grade parotid carcinoma

OBJECTIVE

High-grade parotid carcinoma generally has a poor prognosis, and the histological type is mucoepidermoid carcinoma (MEC), salivary duct carcinoma (SDC), carcinoma ex pleomorphic adenoma (CEPA), or adenoid cystic carcinoma (AdCC) in the majority of cases.

METHODS

During the 23-year period from September 1999 to December 2022, 250 patients with parotid carcinoma underwent initial treatment and had the histopathological type of their carcinoma. Retrospective study evaluated 111 MEC, SDC, CEPA, or AdCC cases among 134 patients with high-grade parotid carcinoma. We examined pathological and clinical features and prognosis, evaluated factors associated with recurrence, and performed immunohistological examinations.

RESULTS

Pathological and clinical features and factors associated with recurrence were different for each histological type. The 10-year disease-free survival rates were as follows: MEC, 34.9%; SDC, 22.6%; CEPA, 47.1%; and AdCC, 56.3%. Human epidermal growth factor receptor type-2 and androgen receptor were positive in 48% and 56% of patients with SDC, respectively, 38% and 25% of those with CEPA.

CONCLUSION

Each histological type has its own pathological and clinical features, recurrence types, and tumor activities, suggesting that differentiating between high-grade parotid carcinomas according to histological type will improve diagnosis, and thus prognosis.

Epidemiology of and factors associated with overall survival for patients with head and neck adenoid cystic carcinoma

BACKGROUND

Updated epidemiologic and survival data of head and neck adenoid cystic carcinoma (HNACC) are lacking. This retrospective study aimed to clarify the incidence, prevalence, and overall survival (OS) of patients with HNACC and establish relevant nomogram.

METHODS

Trends in incidence, limited-duration prevalence, and relative survival (RS) rates were evaluated using data from the Surveillance, Epidemiology, and End Results (SEER) database, and annual percent change (APC) in rates was calculated using joinpoint regression. Data on age, sex, site, stage, and surgery were used in construction and validation of the nomogram.

RESULTS

The study included 6474 patients; 57.7% were female and 78.6% were white. The age-adjusted incidence rates of HNACC decreased significantly from 0.41 to 0.25 per 100,000 [1975-2018; average annual percent change (AAPC): - 1.37, P < 0.001], which was dominated by the localized stage. The 20-year limited duration prevalence increased from 0.00028% to 0.00262%. The 5- and 10-year RS rates of all HNACC patients were 80.0% and 65.5%, respectively. RS rates in HNACC showed a slight increase over time, with APC values of 0.03 for 5-year (P < 0.05) and 0.13 for 10-year (P < 0.05) RS. A prognostic model was constructed. The C-indices for the training and testing sets were both 0.734. The nomogram's discrimination efficiency was evaluated using the receiver operating characteristic curve and had moderate predictive power.

CONCLUSIONS

Over the past 40 years, the incidence of HNACC decreased accompanied by slightly improved survival rates. Nomogram was capable of predicting the 5- and 10-year OS rates with moderate accuracy.