Objective: To determine the radiologic downstaging and histological response after neo-adjuvant concurrent chemoradiation in locally advanced rectal cancers.
Study design: Case series.
Place and duration of study: Radiation Oncology department of Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, from December 2004 to November 2005.
Methodology: Thirty patients with histopathologically confirmed locally advanced carcinoma rectum who had not received any treatment (chemotherapy, radiotherapy or surgery) prior to presentation were enrolled. Radiation therapy was delivered with a three-field technique to a dose of 50.4 Gy over 5 weeks at the rate of 1.8 Gy/day. Two cycles of chemotherapy were given synchronously, which comprised of 5-fluorouracil 350 mg/m2 and folinic acid 20 mg/m2 continuous intravenous infusion over first five days and last five days of radiotherapy. Surgery was planned 4-6 weeks later to chemoradiation after radiologic post therapy staging. Viable specimens were identified and toxicity was observed.
Results: All patients completed treatment without modification. Radiologic downstaging was found in 56.7%, stable disease was seen in 30.0% and progressive disease was present in 13.3% of the patients. Radiologically complete resolution of tumour was not observed. Pathological complete resolution of tumour was achieved in 3.3% and near complete resolution was observed in 13.3% of the patients. In 86.6% cases, a total gross tumour resection with no macroscopic residual disease was possible. All the patients tolerated the treatment well.
Conclusion: Neo-adjuvant chemoradiation for locally advanced rectal cancers is associated with high resectability rate and is relatively safe with acceptable morbidity which favours its use in future.