CT detection of hydronephrosis in resected colorectal cancer: a predictor of recurrent disease.

AIM: To investigate the causes and significance of hydronephrosis in follow-up of colorectal cancer.

METHODS AND MATERIALS: Case notes and serial computed tomography (CT) examinations were reviewed of 75 patients (250 CT examinations) after resection for colorectal cancer in whom hydronephrosis developed on follow-up.

RESULTS

The most common cause of hydronephrosis was a focal plaque-like mass centred on the peritoneum, demonstrated in 37 cases (49%). Patients with R1 (microscopic residual tumour) or R2 (macroscopic residual tumour) disease developed hydronephrosis at a median time of 13 months (90% CI: 9-18 months) compared with 22 months (90% CI: 17-26 months) for those having (R0) curative resection. Patients with pT4 invasion of peritoneum or adjacent organs developed hydronephrosis at a median of 14 months (90% CI: 6-16 months) compared with a median of 22 months in patients with pT3 tumours (90% CI: 11-27 months). Of 26 patients without an obvious cause of hydronephrosis on initial CT examination, follow-up CT demonstrated a definite mass lesion in 50%. Median survival after the onset of hydronephrosis was 6 months (range 1-34 months) with a 1-year mortality of 62%.

CONCLUSIONS

Hydronephrosis is an important early indicator of colorectal cancer recurrence, even in the absence of a mass.