Conservative management of rectal adenocarcinoma by radiotherapy

The aim of this study was to analyze the experience of Centre GF Leclerc for conservative and curative treatment by radiotherapy of low rectal cancer.

A total of 151 patients received radiotherapy alone for rectal adenocarcinoma with curative intent. They were clinically staged according to size (T1 < 3 cm, and T2 > 3 cm) and depth of infiltration (A=superficial, and B=impaired mobility and T3 fixed). Over the past 6 years, rectal ultrasound (US) has been used systematically, compared with computed tomographic scan and magnetic resonance imaging when needed. Intracavitary contact X ray was given to 129 patients (69%), and brachytherapy in 45 of 151. External radiotherapy was used in 34 cases (22.5%).

Complete response was obtained in 93%. Local failures were observed in 50 cases (28%); two occurred in pelvic nodes after intracavitary X rays. Size (tumors > 3 cm) and alteration of mobility significantly influenced the rate of local failure (p=0.009 and 0.007). The addition of external radiotherapy in patients with poor prognostic factors improved the local control rate. A total of 39 patients with recurrence were amenable to salvage surgery. After salvage treatment, the local control rate was 82% with unlimited follow-up. The 5-year actuarial survival rate was 57%, with a specific survival of 66%. There was no difference in local control or survival according to differentiation of the tumors and distance between anal margin and the inferior level of the lesion. Severe late effect (grade 3) was 3.8%. The sphincter preservation was obtained in 104 of 124 cases (84%). The sphincter function was judged to normal in 102 of 104 patients (98%).

Intracavitary contact X ray is the treatment of choice for clinical Stage T1A rectal tumors. External radiotherapy significantly improved the results of treatment of tumors > 3 cm. Clinical staging and transrectal ultrasound allows a safe selection of indications. Radiotherapy alone may be proposed for selected cases as an alternative to mutilating surgery for small rectal adenocarcinoma.