Carcinoma showing thymus-like element (CASTLE) of thyroid: combined modality treatment in 3 patients with locally advanced disease.

OBJECTIVES: To examine the value of chemotherapy, radiotherapy and surgery for treatment of locally advanced carcinoma showing thymus-like element (CASTLE) of the thyroid. METHODS: Retrospective analysis of 3 Chinese patients in a tertiary referral center in Hong Kong. RESULTS: CASTLE is a rare thyroid malignancy with a frequency of only 0.15% (3/2033 patients) in our center. Three patients (M:F=2:1) aged 43, 49 and 62 years were studied. All 3 patients had advanced T4 disease with extensive tracheal infiltration and airway compression. None had lymph node or distant metastasis. Total thyroidectomy, combined with chemotherapy and radiotherapy, was effective in local control and symptom relief. Etoposide and carboplatin were tried in 2 patients with positive response. Neoadjuvant chemotherapy shrank the tumor rapidly and relieved symptoms of airway compression. All 3 patients had external radiotherapy resulting in good local control. In a patient with inoperable disease, chemotherapy and radiotherapy rendered the disease operable. All 3 patients were symptom-free and alive at 6, 2.5 and 1.8 years after diagnosis. CONCLUSIONS: CASTLE is locally infiltrative and presents at advanced T stage in this small series. Chemotherapy and radiotherapy, apart from surgery, are effective treatment modalities. In cases of inoperable disease or advanced local disease, they can be employed in combination with surgery. Organ preservation of larynx and trachea may be achieved. Chemotherapy can be very useful for rapid relief of symptoms, especially in shrinking tumor to prevent airway obstruction.

Medullary thyroid carcinoma in Hong Kong Chinese patients.

OBJECTIVE: To study the clinical parameters and treatment outcome of medullary thyroid carcinoma in Hong Kong Chinese patients. DESIGN: Retrospective study. SETTING: Regional oncology unit, Hong Kong. PATIENTS: Patients with medullary thyroid carcinoma who were identified among 1656 patients with thyroid malignancies seen in a single institute in Hong Kong from January 1960 to June 2003. MAIN OUTCOME MEASURES: Ten-year cause-specific survival, locoregional failure-free survival, and distant metastasis failure-free survival. RESULTS: Twenty-two (1.3%) patients with medullary thyroid carcinoma were identified. The mean age at diagnosis was 43.7 (standard deviation, 16.5) years. The sex ratio was 1:1. The 10-year cause-specific survival, locoregional failure-free survival, and distant metastasis failure-free survival were 75.4%, 82.0%, and 62.4%, respectively. Lymph node metastasis was present in seven (31.8%) patients at diagnosis. Distant metastasis developed in nine (40.9%) patients: lung, 3 (13.6%); bone, 5 (22.7%); liver, 2 (9.1%); mediastinum, 4 (18.2%). Seven (31.8%) patients died of distant metastasis. Mediastinal (n=3) and bone metastases (n=3) were important causes of death. Genetic study confirmed multiple endocrine neoplasia type 2A in 3 (25.0%) of 12 patients who all had bilateral and multifocal diseases. Younger age (<45 years) was associated with better survival, better locoregional control, and less distant metastasis. Patients with pT1N0 disease (n=3) had an excellent prognosis: all were disease-free following total thyroidectomy. Among eight patients who received external radiation therapy, seven achieved good locoregional control. In seven patients with lymph node metastasis, external radiation therapy gave 100% (4/4) locoregional control compared with 33.3% (1/3) in those without external radiation therapy. Chemotherapy using dacarbazine and 5-fluorouracil was tried in three patients with poor response. CONCLUSIONS: Early stage (T1N0) medullary thyroid carcinoma is associated with a very good prognosis. Postoperative external radiation therapy can achieve good locoregional control in patients with lymph node metastasis or locally advanced disease.

Staging of nasopharyngeal carcinoma: suggestions for improving the current UICC/AJCC Staging System.

AIMS: To evaluate the current UICC/AJCC Staging System for nasopharyngeal carcinoma and to search for ways of improving the system. MATERIALS AND METHODS: This is a retrospective analysis of 2687 consecutive patients treated in five public centres in Hong Kong during the period 1996-2000. All patients were staged by computed tomography, magnetic resonance imaging, or both. The prognostic significance of the current stage assignment on various aspects of tumour control was evaluated. RESULTS: T-category, N-category and stage-group were all significant prognostic factors for major end points (P < 0.01). However, the distinction of prognosis between Stage I and II was insignificant (5-year cancer-specific survival being 92% vs 95%; P = 0.13). Multivariate analyses (corrected for age and sex) revealed lack of significance between T2a and T1 in hazards of local and distant failures, N3a and N2 in distant failure and subgroups of T1-2N0 in cancer-specific deaths. Corresponding down-staging of T2a to T1, N3a to N2, and subgroup T2N0 to stage I, resulted in more even and orderly increase in the hazard ratio of cancer-specific deaths (from 1 for stage I to 1.98 for II, 3.5 for III, 6.08 for IVA and 8.62 for IVB), better hazard consistency among subgroups of the same stage and more balanced stage distribution. CONCLUSIONS: The current UICC/AJCC Staging System could be further improved by the modifications suggested; validation of the current proposal by external data is urgently awaited.

Changes in clinical presentation, management and outcome in 1348 patients with differentiated thyroid carcinoma: experience in a single institute in Hong Kong, 1960-2000.

The clinical features, management and outcome of 1348 patients diagnosed with differentiated thyroid carcinoma in Queen Elizabeth Hospital, Hong Kong, were analysed according to the period of diagnosis: A (before 1980), B (1981-1990) and C (1991-2000). As time advanced, ratio of papillary carcinoma (PTC) to follicular carcinoma (FTC) increased (A:B:C = 1.6: 3.1: 7.2). The mean size of the primary tumour decreased (A:B:C = 3.5 cm: 2.8 cm: 2.5 cm), with a greater percentage of microcarcinoma of 1 cm or less (A:B:C = 5.1%: 16.1%: 21.7%). At presentation, the incidence of lymph-node metastasis decreased (A:B:C = 32.7%: 31.6%: 24.8%) and that of distant metastasis decreased (A:B:C = 9%: 6.1%: 5.3%). Bilateral surgical resection was more commonly used (A:B:C = 62.8%: 89.1%: 94.8%) than lobectomy (A:B:C = 26.3%: 2.8%: 1.8%). Radiation treatment, radioactive iodine (131I; RAI) and external radiotherapy (EXT), was more commonly used (A:B:C = 53.2%: 74.7%: 85.1%). RAI was used in 84.3% (A:B:C = 50%: 71.2%: 84.3%) and EXT in 14.5% of patients in the past decade (A:B:C = 10.9%: 8.7%: 14.5%). The proportion of patients who adopted a bilateral surgery and RAI treatment increased gradually with time (A:B:C = 33%: 68%: 83.8%). The 5-year cause-specific survival (A:B:C = 90.2%: 93.7%: 95.7%), locoregional failure-free survival (A:B:C = 72.6%: 82.9%: 91.6%) and distant metastasis failure-free survival (A:B:C = 84.5%: 89.1%: 92.6%) were improved. However, the period of diagnosis was not found to be an important explanatory variable (i.e. P > 0.05) in Cox regression after adjusting for other factors, indicating that the improvement was probably related to the temporal trend of other factors: presentation at earlier stage, increased ratio of PTC:FTC and more aggressive management by bilateral surgery and radiation therapy.

Diffuse sclerosing variant of papillary thyroid carcinoma--clinical features and outcome.

AIM: Diffuse sclerosing variant of papillary thyroid carcinoma (DSPC) is rare and occurs in young patients. This is a single institute retrospective analysis to report the clinical features and outcome of DSPC. METHOD: DSPC constituted 8 (0.74%) of 1086 papillary thyroid carcinomas (PTC) referred to the department of Clinical Oncology, Queen Elizabeth Hospital Hong Kong from 1960 to 2000. RESULTS: The mean follow-up was 8 years (range: 1.4 to 15.2 years). Six were females and two were males, with age ranging from 11 to 48 years. All were ethnic Chinese. Compared with the whole cohort of PTC followed in the same period, these patients showed younger age at presentation (mean 27.4 vs 45.3 years), larger tumor size (mean 6.9 cm vs 2.4 cm), higher incidence of lymph node metastasis (100% vs 32.4%), and more frequent presence of serum anti-thyroglobulin autoantibody (75% vs 11.3%). The patients were managed as for differentiated thyroid carcinoma according to the institute's protocol, including total thyroidectomy followed by radioiodine (RAI) treatment. External radiotherapy was given to two patients as primary treatment and one patient after regional relapse. One patient had distant metastases at presentation and she was successfully treated by surgery followed by RAI, remaining in complete remission at 12.1 years. One patient had lymph node recurrence after primary total thyroidectomy and RAI treatment and was successfully salvaged by surgery and external radiotherapy. At last follow-up, all eight patients were alive with no evidence of disease. CONCLUSIONS: Although DSPC is associated with some unfavourable features at presentation (such as large tumor size, extensive lymph node metastasis), the prognosis appears to be as good as classical PTC. After aggressive treatment by radical surgery, RAI ablation and/or external radiotherapy, the outcome and survival was excellent.