進行精巣腫瘍の化学療法後残存腫瘍に対する経過観察の臨床的検討

Abstract

1993～2004年に経験した進行性胚細胞腫瘍患者で, 化学療法により腫瘍マーカーは正常化したが画像上残存腫瘍を認める25例の予後について検討した.症例の内訳は精巣原発20例(SGCT 6例, NSGCT 14例), 精巣外原発5例(すべてNSGCT)であった.残存腫瘍の取扱い方針として, SGCT例は残存腫瘍径にかかわらず経過観察とした.NSGCT例は残存腫瘍径が2cm以下の場合は経過観察, 5cm以上は切除, 2～5cmは奇形腫の有無や縮小率などから症例ごとに判断した.2年非再発率は精巣原発SGCT群で90%, 精巣原発NSGCT群100%, 精巣外原発群40%, 疾患特異生存率は精巣原発SGCT群90%, 精巣原発NSGCT群100%, 精巣外原発群75%であった

Twenty-five patients with germ cell tumors who had marker-free residual masses after undergoing chemotherapy were followed for up to 10 years (median, 21 months). The primary tumor sites were the gonads in 20 patients (6 seminomas [SGCTs] and 14 non-seminomatous germ cell tumors [NSGCTs]) and extra-gonadal regions in 5 patients (5 NSGCTs). All residual masses were observed in patients with SGCT. Residual masses that were 2 cm or less in size were left unresected, while masses that were 5 cm or more in size were resected in patients with NSGCT lesions. The management of other residual masses was decided based on the size, shrinkage, and pathological findings of the tumors. Residual masses were resected in six of the patients with gonadal NSGCTs. Recurrence occurred in one of the six patients with gonadal SGCTs (chemotherapy shrinkage; 11 cm to 3.5 cm) and three of the four cases with extra-gonadal NSGCTs (embryonal cell carcinoma: 3 cm to 1 cm, embryonal cell carcinoma+york sac tumor: 5 cm to 4 cm, embryonal cell carcinoma+chorio carcinoma; 4 cm to 1.2 cm). None of the patients with gonadal NSGCTs experienced a recurrence. Considering the pathologic diagnosis, shrinkage, and international germ cell consensus classification, unnecessary resections of residual masses that were less than 5 cm in size after chemotherapy for gonadal NSGCT should be avoided. However, residual masses in extra-gonadal NSGCTs should be resected.