Aneusomy of chromosomes 7 and 17 predicts the recurrence of transitional cell carcinoma of the urinary bladder

Objective To determine if changes in chromosome 7 and 17 copy number can be used to predict recurrence in patients with primary noninvasive (pTa) or s uperficially invasive (pT1) transitional cell carcinoma (TCC) of the urinar y bladder. Patients and methods Tissue specimens for 129 tumours from 52 patients (38 men and 14 women) with pTa/pT1 TCC at first diagnosis were retrieved from p athology archives. All patient notes were accessed and disease outcome docu mented for superficial (pTa/ pT1) recurrence or progression to detrusor mus cle invasion (greater than or equal to pT2). The rumours were examined for chromosomal copy number of chromosomes 7 and 17 using fluorescence in situ hybridization (PISH) with chromosome-specific probes. The copy number of ch romosomes 7 and 17 was determined in interphase nuclei on intact 6 mu m tis sue sections. Results Aneusomy of chromosomes 7 and 17 was detected in the index primary tumours of 10 of 32 (31%) patients with subsequent recurrent disease. No an eusomy for these chromosomes was detected in primary tumours from 20 patien ts with no detectable recurrence (P = 0.0082). The relative risk of recurre nce was 3.62 times greater (95% confidence interval 1.6-8.1, Cox's multiple regression P = 0.0019) for patients with chromosomal aneusomy in primary T CC. Neither stage nor grade of the primary tumours was associated with recu rrence in these patients, nor was there a significant association with incr eased grade (G2/3) or stage (greater than or equal to pT2) at recurrence. Conclusion These results suggest that the measurement of aneusomy by FISH, using markers for chromosomes 7 and 17, predict recurrence in a subgroup of patients with pTa/pT1 tumours at presentation. This finding may offer a ne w objective and quantitative test for patients destined to recur.