Analysif Of Correlative Factors For The Survival,Recurrence And Metastasis In The Adenoid Cystic Carcinoma Of The Salivary Glands

Adenoid cystic carcinomas (ACC), constituting approximately 20% of malignant salivary gland tumors, is an elusive tumor characterized by portracted natural history, aggressive growth, multiple late local recurrences and distant metastases after initial surgical treatment. Management of salivary gland adenoid cystic carcinoma is a controversial problem.Objective: This paper reviewed relative literatures and described a follow-up study on a total of 89 patients with adenoid cystic carcinoma in salivary glands. These patients underwent curative treatment in our department between 1984 and 1999. The prognosis and related factors of the patients were analyzed and the data was hoped to be useful for clinical practice.Material and Methods: 1. Various clinicopathological parameters (e.g. age, gender, primary sites, tumor size, presenting symptoms, tumor stage, histologic type of the lesion, margin status and perineural invasion and treatment, etc.) were evaluated for their impacts of the 89 patients on survival by using univariate and multivariate analysis. The Wilcoxon (Gehen) test was used to assess the statistical significance among the groups. 2. Seventy-one patients with primary ACC who underwent surgical treatment were reviewed to evaluate the factors influencing recurrence and metastasis. The Chi-square test was used to assess the statistical significance among the samples. The data were statistically analyzed by SPSS 8.0software and survival curves were obtained by the life table method. Results: 1. The overall survival rates were 86.3%, 75.8%, 49.2%, 36.7% postoperative 3, 5, 10, and 15 years respectively. The negative clinical prognosticators included: age over 50 years, signs and symptoms more than two, tumor size greater than 2cm, positive surgical margins, ACC in the floor of mouth, etc. Better prognosis could be expected if ACC is in early clinical stage, is classified histologically as glandular or tubular type, or it does not involve the nerve. The prognosis will be poor if ACC is classified as advanced clinical stage (stage III and IV) or solid type, or has infiltrated the nerve. 2. Recurrence rate was 35.2%. The rate was related with primary tumor site, infiltrative pattern, positive surgical margins, and perineural invasion. The involvement of regional lymph nodes was rare and only 5.7% of the patients suffered lymph metastasis. Distance metastasis was much more common (38.0% of patients). Poor prognosticators included: advanced clinical stages (stage III and IV), infiltrative pattern, solid histological type, and positive surgical margins.Conclusions: 1. Clinical stage, histological type, and nerve involvement are the most important factors influencing the prognosis of the patients with ACC. Early diagnosis and treatment are crucial to improve the prognosis of these patients. 2. ACC is an aggressive tumor. It will be difficult to make sure the surgical margins during the operation. Therefore adjunctive radiotherapy after surgery is necessary. 3. Pulmonary metastases are very common among the patients suffered solid type ACC or perineural invasion. The patients must be closely followed up. 4. Lymph node involvement is uncommon. Elective neck dissection seems unnecessary .