Impact of the interval between short-course radiotherapy and surgery on outcomes of rectal cancer patients.

AIMS

Pre-operative radiotherapy has proven to reduce local recurrences after curative surgery for rectal cancer. Radiotherapy is generally well tolerated, although postoperative morbidity and mortality was increased in some patients. Current study was undertaken to analyse whether the interval between preoperative radiotherapy and surgery influences post-operative mortality and recurrence for two cohorts.

METHODS

All Dutch patients included in the total mesorectal excision (TME)-trial receiving radiotherapy for resectable rectal cancer were included in this study (n=642). The verification set consisted of all patients receiving short-course radiotherapy for resectable rectal cancer in two radiotherapy clinics in The Netherlands (n=600). Univariate and multivariable survival analyses for overall survival, disease-free survival, local recurrence-free survival and non-cancer related survival were calculated.

RESULTS

Patients aged 75 years and older treated during the TME-trial showed a worse overall and non-cancer-related survival when surgically treated 4-7 days after the last fraction of radiotherapy. No differences in survival between the interval groups were found in the verification set.

CONCLUSION

Present study found that elderly patients aged 75 years and older operated 4-7 days after the last fraction of radiotherapy had a higher chance of dying due to non-cancer-related causes during the TME-trial as compared to patients with an interval of 0-3 days. In the verification set similar differences could not be confirmed, which could be due to awareness of the clinicians who avoided delayed surgery after radiotherapy since the results have been presented during congresses. A longer than recommended interval between radiotherapy and surgery should be avoided. Besides, the verification set suggests that radiotherapy duration of 7 days is acceptable.