Objectives: To evaluate treatment results and identify prognostics factors which determine local and regional treatment failure and crude survival in adenoid cystic tumours (ACT) in the head and neck.
Methods: A retrospective study (1984 to 2001) of 30 cases of adenoid cystic tumour. The mean age was 56.9 years, with a sex ratio female to male of 2:1. Tumours of all sites were encountered, most (26.7%) being in the nose and sinuses and major salivary glands (26.6%). Tumours at the T4 stage were found in 14 cases, mainly situated in the nose and sinuses (50%). No patient had cervical lymphadenopathy, while two patients (6.7%) had bony metastases at the time of diagnosis. Two patients (6.7%) were treated by surgery alone, for T1 and T2 tumours; four patients (13%) had radiotherapy alone, and 24 patients (80%) had surgery with post-operative radiotherapy with a mean dose of 60.3 Grays (56-65 Grays).
Results: Local recurrence occurred in 30.8% (nine cases) after a mean interval of 43 months (1 to 10 years). Treatment of these recurrences was by revision surgery in six cases, leading to local control in one case, but in a patient with pulmonary metastases. No cases of lymph node recurrence were observed. 30% of patients developed metastases; these were pulmonary in 44% and bony in 33.3%. Mean follow-up was five years. Crude survival at 3 years was 91%, at 5 years 86%, and at 10 years 50%. The percentage tumour-free survival was 70% at 3 years, and 57% at 5 years. 22 patients (73.3%) are still alive, 17 of them recurrence-free. Analysis of the prognostic factors has shown tumour to be more aggressive in the nose and sinuses when they presented at an advanced stage (T4); recurrence was more common when excision was incomplete, or if there was peri-neural spread. Tumours of "massive" histological type carried a poorer prognosis than those of cribrigorm type (60% death compared with 10%). The development of metastases is independent of local recurrence. Metastases to bone appear to be more rapidly aggressive than pulmonary metastases, which may remain asymptomatic for some time.
Conclusion: Combined radiotherapy and surgery have allowed improved local control of ACT, but the therapeutic challenge remains the multiply recurrent ACT, or those with symptomatic metastases, and this despite new research techniques (neutral therapy, immuno-histochemistry, molecular biology). ACT are rare tumours, whose prognosis remains poor.