A Cochrane review included 3 RCTs reporting two different sequencing comparisons. There were no significant differences between the various methods of sequencing adjuvant therapy for survival, distant metastases or local recurrence involving a total of 853 randomised patients (2 trials). In one of these two trials (647 women) haematological toxicity (OR 1.43, CI 1.01 to 2.03) and oesophageal toxicity (OR 1.44, CI 1.03 to 2.02) were significantly increased with concurrent therapy, and nausea and vomiting were significantly decreased (OR 0.70, CI 0.50 to 0.98). On the basis of one trial (244 women), radiotherapy before chemotherapy was associated with increased risk of neutropenic sepsis (OR 2.96, 95%CI 1.26 to 6.98) compared with chemotherapy before radiotherapy, but other measures of toxicity were not significantly different.
Comment: The quality of evidence is downgraded by imprecise results (few outcome events). The impact of newer modes of radiotherapy, chemotherapy regimens and biological agents is not included in this review.