Is ultrasound lymph node examination superior to clinical examination in melanoma follow-up? A monocentre cohort study of 373 patients.

BACKGROUND: There is still lack of consensus regarding the most effective follow-up for stage I and II melanoma patients although some consensus conferences have provided guidelines stating that clinical examination should be the standard.
OBJECTIVES: Our aim was to study the value of adding ultrasound lymph node examination (7.5 MHz) to the routine clinical examination recommended by French guidelines in melanoma follow-up.
METHODS: A cohort of melanoma patients was enrolled between 1 July 1995 and 1 July 2000 in a follow-up protocol including clinical examination performed four times a year for thick melanomas (Breslow index > or = 1.5 mm) and twice a year for thin melanomas (Breslow index < 1.5 mm) according to French guidelines, and ultrasound lymph node examination performed every 6 months for thick melanomas and every year for thin melanomas. Follow-up was continued up to 1 July 2003. When clinical or ultrasound examination indicated signs of node recurrence, surgical biopsy of the involved node was performed. When ultrasound examination was only suspicious, another ultrasound examination was performed within the following 3 months. The results of both clinical and ultrasound examinations were compared with histopathology examination when node biopsy was performed.
RESULTS: Ultrasound follow-up was performed for 373 patients (213 females and 160 males). Mean age at diagnosis of melanoma was 59 years (range 14-90, SD 15). In total, 1909 ultrasound examinations combined with clinical examination were analysed. Node biopsy was performed in 65 patients and demonstrated melanoma metastases in 54. Sensitivity of clinical examination and ultrasound examination was 71.4%[95% confidence interval (CI) 55.4-84.3] and 92.9 (95% CI 80.5-98.5), respectively, P = 0.02. Specificity of clinical examination and ultrasound examination was 99.6% (95% CI 99.2-99.8) and 97.8% (95% CI 97.0-98.4), respectively. Despite this apparent superiority of ultrasound examination over palpation, only 7.2% of the patients really benefited from ultrasound examination (earlier lymph node metastasis detection or avoidance of unnecessary surgery), while 5.9% had some deleterious effect from ultrasound examination (unnecessary stress caused by repetition of ultrasound examination for benign lymph nodes, useless removal of benign lymph node).
CONCLUSIONS: This study confirms the greater sensitivity of ultrasound examination to clinical examination in the diagnosis of node metastases from cutaneous melanoma. However, the place of ultrasound in routine follow-up is at least questionable as only a very small proportion of patients (1.3%) really benefited from adding ultrasound examination to clinical examination.