Establishment and characterization of a human adenoid cystic carcinoma line of the salivary gland which is serially transplantable and spontaneously metastasises to the lung in nude mice.

Adenoid cystic carcinoma (ACC) is a rare malignant tumour of the head and neck occurring in the salivary glands. We established a human ACC line which is serially transplantable in nude mice and designated it as KOA-1. The KOA-1 tumour doubled in 9.3 days and retained the histological characteristics of a solid pattern of ACC even after 22 serial passages. The KOA-1 metastasised to the lung when transplanted subcutaneously into the back. This tumour line may serve as a useful model for exploration of the biological behaviour and treatment of human ACC.

Experimental model of invasion and metastasis by orthotopic transplantation of oral squamous and adenoid cystic carcinomas into the tongue of nude mice.

Three squamous cell carcinoma (SCC) cell lines established from oral cancer, seven specimens of SCC and three of adenoid cystic carcinomas taken from the oral cavity during operations were transplanted into the tongues of nude mice. Metastases to the regional lymph nodes and the lungs were examined histologically. We were able to transplant every cell line or specimen of tissue into the tongue of nude mice, and found that cancer transplanted in the tongue invaded diffusely to the surrounding tissues without forming a capsule, and that the mode of invasion of the transplanted SCC was similar to that of the biopsy specimen of the patient from whom the material had been obtained. We also found that all three of the SCC cell lines, 3 of the 7 SCC specimens and 2 of the 3 adenoid cystic carcinoma tissues metastasized to the regional lymph node. SCC did not metastasize to the lung, but in two of the three adenoid cystic carcinomas we did see micrometastases to the lung. The study indicates that this method can be used as a model of metastasis in oral squamous cell carcinoma and adenoid cystic carcinoma to show the stages of metastasis in cancer.

High-dose rate interstitial brachytherapy for stage I-II tongue cancer.

OBJECTIVE: This retrospective clinical study evaluated the usefulness of high-dose rate (HDR) brachytherapy for stage I-II tongue cancer in comparison with traditional low-dose rate (LDR) brachytherapy. MATERIALS AND METHODS: Twenty-five patients with stage I-II tongue cancer underwent HDR between 1995 and 1999. The status of local control and late neck metastasis, survival rate, and frequency of osteonecrosis in these patients were examined in comparison with a historical control made up of 71 patients who underwent LDR between 1980 and 1995. RESULTS: The local control rate and survival rate were lower in the HDR group than in the LDR group. There were no apparent differences in the frequency of late neck metastasis between the two groups. Osteonecrosis occurred earlier and more frequently in the HDR group. CONCLUSION: We would caution the use of HDR brachytherapy until further studies are done in many institutions.

The role of radiotherapy for patients with adenoid cystic carcinoma of the salivary gland.

OBJECTIVE: Adenoid cystic carcinoma (ACC) is a rare malignant tumor occurring in the salivary gland that has some characteristic features, including slow growth, extremely diffuse invasion, and a high incidence of distant metastasis. The indication of radiotherapy (RT) for ACC is controversial. The aim of this study was to examine the usefulness of RT for patients with ACC. STUDY DESIGN: The study group was composed of 17 patients (18 lesions) with ACC of the salivary gland who underwent RT. They were divided into 3 groups: (1) those who underwent RT alone for a primary tumor, (2) those who underwent RT alone for a recurrent tumor after surgery, and (3) those who underwent postoperative RT because of a histologically positive surgical margin. The clinical course of each patient was examined retrospectively. RESULTS: Of the 11 patients undergoing RT alone for a primary or recurrent tumor, 5 showed complete remission of the tumor, and 3 were free from local recurrence for a long period. Seven patients who underwent postoperative RT seemed to show better local control than did those who did not undergo postoperative RT, although there were no significant differences. CONCLUSIONS: We find RT to be an effective treatment procedure, especially for those who had an inoperable, advanced tumor or who had distant metastasis. Postoperative RT was recommended for those who had a histologically positive surgical margin.

Tumor-doubling time and onset of pulmonary metastasis from adenoid cystic carcinoma of the salivary gland.

Adenoid cystic carcinoma (ACC), an uncommon malignancy in the head and neck region, invades diffusely and often metastasizes to the lung, although the growth rate is very slow. A retrospective study was conducted in 30 patients with ACC to ascertain the frequency of pulmonary metastasis, the doubling time of metastatic tumor deposits, and the time of onset for pulmonary metastasis. The following results were obtained: (1) Of 30 patients with ACC, 21 had pulmonary metastases (4 initially and 17 during observation), 7 were free of metastases but have not been observed for 5 years, and 2 were free of metastases for more than 5 years but less than 10 years after the initial treatment. The cumulative metastasis rate at 5 and 10 years for this group of patients was 70% and 100%, respectively. (2) Patients with T1 or T2 tumors that have a tubular or cribriform histopathologic pattern showed pulmonary metastases about 20 months later than those with T3 or T4 tumors and a solid pattern. However, the final metastasis rate did not differ between the 2 groups after a long period. (3) The tumor doubling time of the metastatic deposits of ACC was 86 to 1064 days with an average of 393 days, which was much longer than that of most other malignant neoplasms reported previously. (4) The time of onset of pulmonary metastasis was calculated to be much earlier (average of 227 months) before the first visit. These findings suggest that the treatment method for ACC should be chosen with the consideration that many of the patients may have occult pulmonary metastases at the time of their initial evaluation.

Criteria for diagnosing lymph node metastasis from squamous cell carcinoma of the oral cavity: a study of the relationship between computed tomographic and histologic findings and outcome.

PURPOSE: This retrospective study was conducted to determine the relationship between the computed tomographic findings for cervical lymph nodes (LN), histologic findings, and outcome in patients with squamous cell carcinoma of the oral cavity who underwent radical neck dissection. PATIENTS AND MATERIALS: Sixty-six patients were analyzed. Of these 66 operations, 43 were immediate therapeutic dissections in clinically N+ necks, and 23 were subsequent therapeutic dissections in patients whose necks were initially node free but progressed to positive nodes during observation. RESULTS: When the size criterion (area of the axial section) of nodal metastasis depicted on the scan of 45 mm2 was selected, almost 78% of LN were diagnosed consistent with the histologic diagnosis. As the size of the LN increased, the frequency of extranodal invasion also became higher, whereas patients with the higher histologic grades of malignancy often showed neck metastases with extranodal invasion in the early stage. Patients having LN smaller than 100 mm2, or without extranodal invasion, showed good outcome, whereas those having LN 100 mm2 or larger, with extranodal invasion, showed extremely poor outcome. CONCLUSIONS: These findings indicate that it is possible to delay neck dissection in node-free patients until neck disease is diagnosed with timely CT examination, although great caution is necessary, especially in those with a high histologic grade of malignancy.