Is there any significant reduction of patients' outcome following delay in commencing postoperative radiotherapy?

Purpose of review: Postoperative radiation treatment is a key factor in the outcome of advanced head and neck cancer. The start of postoperative radiation treatment may be delayed in a substantial number of patients for medical or technical reasons. The aim of this review is to evaluate clinical implications of a delay in postoperative radiation treatment, further our understanding of the biological mechanisms involved, and discuss ways to minimize these effects. Recent findings: Some studies have shown that an interval between surgery and postoperative radiation treatment of more than 6 weeks may impair outcome. Others, however, reported that this delay was not associated with lower survival or decreased local control, and still others reported an increase in local recurrence, but no difference in overall survival. Because the cell repopulation induced by the postoperative presence of microscopic residual tumor mass varies in rate and timing by the aggressiveness of the particular type of head and neck cancer, a delay in postoperative radiation treatment may have a different effect in different disease subsites. The methods proposed to date to reduce the influence of postoperative radiation treatment delay are based mainly on the principle of shortening the overall treatment time. Summary: It remains uncertain if outcome is significantly worsened by a delay in commencing postoperative radiation treatment in patients with advanced head and neck cancer tumors. The data accrued in the last 5 years indicate that the use of advanced treatment techniques such as altered fractionation, reduction of overall treatment time, and combined postoperative radiation treatment and chemotherapy may minimize any adverse effects of delay.