表在性膀胱癌に対するEpirubicin膀胱腔内注入療法の投与方法別再発予防効果

Abstract

表在性膀胱癌に対する抗癌剤塩酸エピルビシン(EPI)を用いて, 異なる投与法での再発予防効果について検討した。表在性膀胱癌は経尿道的膀胱腫瘍切除術(TURBT)後6ヵ月頃に再発リスクが高まるとされる仮説を検証するため, 1999～2003年にTURBT後に表在性膀胱癌と判明した54症例を対象に, 術後途中3ヵ月の休薬を含む9ヵ月にわたる長期投与群と, 術後短期投与群に分けて比較した。割付けは乱数表により無作為に2群に分けた。その結果, 再発率に有意差は認めなかった。再発因子の単変量解析では腫瘍深達度と悪性度で有意差が認められ, 長期投与群が短期投与群よりも再発予防効果が有意に高かった。両群合わせて22例が再発し, 両群で1例ずつ局所浸潤を認めた。

Intravesical chemotherapy is performed after transurethral resection of bladder tumor (TURBT) for superficial bladder cancer. We conducted a prospective randomized controlled study on the prophylactic effects of intravesical instillation of epirubicin (EPI) against recurrence to determine the effective administration schedule. Between April 1999 and March 2003, 54 patients with superficial bladder tumor (pTa or pT1, and G1 or G2 cancer) were assigned to two groups (25 in Group A, 29 in Group B) after TURBT. The schedule of instillation (intravesically 40 mg of EPI dissolved in 40 ml saline) was subsequently once every two weeks for 3 months (7 times) starting one week after TURBT (Group A, short period), and subsequently added every two weeks for 3 months starting 6 months after TURBT (Group B, long period). The patients were followed up by cystoscopy and urinary cytology. There was no significant difference in non-recurrence rates after either one year (A; 62.5%, B; 82.8%) or three years (A; 53.6%, B; 67.3%). A univariate analysis demonstrated that tumor grade and staging were significant predictors of high risk for recurrence. A multivariate analysis performed by using the Cox's proportional hazard model showed that the schedule of instillation was an independent prognostic factor for reccurence. In the present study, only 2 patients showed progression and one patient died of UC. There was no adverse event that forced discontinuation of the therapy. In conclusion, epirubicin instillation influenced the prevention of recurrence, but the benefit of long-term period was not confirmed.