Statistical analysis of factors affecting progression of superficial bladder cancer

Naoki Akebi, Tomoyasu Tsushima, Kenji Kobashi, Yasutomo Nasu, Yoshiyuki Miyaji, Takanori Murakami, Hiroyuki Ohmori, Hiromi Kumon

Research output: Contribution to journalArticlepeer-review


Three hundred and three consecutive patients with superficial bladder cancer, stages Ta and T1, who were initially treated at the Department of Urology, Okayama University Medical School between 1965 and 1990, were retrospectively reviewed regarding tumor progression. One hundred and fifty (49.5%) patients had disease recurrence, while 24 (7.0%) patients subsequently developed deep muscle invasion or distant metastasis. The interval between initial treatment and progression ranged from 8 to 122 months, with a median of 45.5 months. Of these 24 patients, 7 (29.2%) were initially diagnosed as stage Ta and 17 (70.8%) as stage T1, whilst 3 (12.5%) were diagnosed as histological grade 1, 17 (70.8%) as grade 2 and 4 (16.7%) as grade 3. Twelve factors including age, sex, clinical symptoms, number of tumors, tumor size, tumor shape, tumor involvement of the bladder neck, stage, grade, interval to first recurrence, urine cytology, and urethral recurrence were selected as variables of tumor progression and analyzed statistically. From univariate analysis of variables obtained from the initial diagnosis of 303 cases, nonpapillary tumor shape, stage T1, positive urine cytology and interval to first recurrence within 12 months were found to be significantly correlated with tumor progression. However, multivariate analysis using Cox's proportional hazards model revealed that only tumor shape and interval to first recurrence were of significant prognostic value. In 150 cases with recurrent tumors, the most unfavorable factor with regard to tumor progression as determined from the clinical records of each case was also analyzed statistically. Univariate analysis showed that urethral recurrence, grade 3, stage T1 and nonpapillary tumor shape were all significant predictors for progression. Further multivariate analysis using logistic model indicated that urethral recurrence was the most important factor followed by the histological grade.

Original languageEnglish
Pages (from-to)692-697
Number of pages6
JournalNishinihon Journal of Urology
Issue number10
Publication statusPublished - Oct 1998


  • Progression
  • Statistical analysis
  • Superficial bladder cancer

ASJC Scopus subject areas

  • Urology


Dive into the research topics of 'Statistical analysis of factors affecting progression of superficial bladder cancer'. Together they form a unique fingerprint.

Cite this