Transanorectal ultrasonography in the staging of anal epidermoid carcinoma.

Fifty consecutive patients with anal canal epidermoid carcinoma were evaluated by transanorectal ultrasonography (TRUS) at diagnosis. Forty-six patients were treated with primary radiotherapy plus bleomycin. Twenty-eight of the last 30 patients underwent, in addition, planimetric volume determination. The ultrasound findings were compared with clinical stage as assessed by digital palpation. Tumours in clinical stages T1-2 showed evidence of penetration through the anorectal muscular wall at ultrasound (UT3-4) in two-thirds of the cases. This was the case in all tumours in clinical stages T3-4. A clear correlation between tumour size, depth of invasion, and tumour volume, respectively, and residual tumour after a "pre-operative" dose of 40 Gy plus bleomycin was found. When combining clinical stage with TRUS, all tumours classified as T1-2/UT1-2 had a complete response (CR) after the first radiotherapy period, whereas the corresponding figures for those with deep invasion ultrasonographically (T1-2/UT3-4 and T3-4/UT3-4) were 64 percent and 0 percent, respectively. It thus appears that TRUS could complement digital palpation in staging anal canal carcinoma.