表在性膀胱癌再発予知因子としての術後3日間の尿細胞診検査の意義

Abstract

経尿道的膀胱腫瘍切除術(TUR-Bt)を施行し, 腫瘍を根治的に切除し得たと考えられた表在性膀胱癌初発患者64例を対象に, 術後翌日より3日間連続で尿細胞診検査を行い, 術後の細胞診陽性例と陰性例で再発率に差があるのか, また, 本検査が従来の因子と共に膀胱癌再発の予知因子となり得るかを続計学的に解析を行いretrospectiveに検討した.組織型は全例TCCであり, 異型度ではG2が最も多く, 腫瘍数は単発, 多発共に32例であった.腫瘍の多くは乳頭状であった.進達度はpTa:42例, pT1:22例であった.術後3日間の尿細胞診は1回でも陽性となった症例33例, 全て陰性であった症例31例であった.腫瘍個数が増加するにつれ検出回数や検出される細胞のclassが高くなり, 検出回数, 細胞のclassが高くなるにつれ再発率が上昇していた.細胞診陽性率と相関を認めたのは, 年齢・腫瘍の個数・gradeであり, いずれも弱い相関であった.再発予知因子を検討したところ, 単変量解析・多変量解析ともに年齢, 腫瘍径が再発予知因子となった.膀胱注入施行群は非施行群より再発率が有意に低く, 術後尿細胞診の結果と膀胱注入施行の有無で患者を4グループに分けたところ, 細胞診陰性で注入施行の群は他に比べ有意に再発率が低下していたが他の3群間では再発率に有意差はなかった

To determine whether there was any correlation between recurrence of superficial bladder cancer and the results of urinary cytology examined for 3 consecutive days after transurethral resection of the bladder cancer (TURBT), we retrospectively studied 64 patients with newly diagnosed Ta/T1 transitional cell carcinoma (TCC) of the bladder who had previously undergone TURBT. Urine cytology samples were reported as negative (class I, II) or positive (class III, IV, V). We used the Kaplan-Meier method to calculate the non-recurrence rate, and Cox-proportional hazard models to determine the prognostic significance of clinical and pathological findings. If any sample among the three consecutive cytology examinations was positive, we defined the case as positive. After a mean follow up of 19.5 months, 22 cases (34.4%) demonstrated recurrence probabilities of 24.1% and 42.3%, at 12 and 24 months, respectively. Of the positive cytology group (n = 33), 15 patients (45.5%) had recurrent tumor, while in the negative group (n = 31), only 7 cases (22.6%) developed recurrence. Multivarite analysis demonstrated that tumor size (p = 0.0022, Hazard ratio 8.9316), result of urine cytology for three consecutive days after TUR (p = 0.0051, Hazard ratio 4.5728), and age (p = 0.0124, Hazard ratio 3.7652) were associated with tumor recurrence. We suggest that positive results on urinary cytology for three consecutive days after TUR are indicative for tumor recurrence.