Background: One of the benefits from neoadjuvant CRT for distal rectal cancer is tumor downstaging determined by radiation necrosis. It is still controversial if final disease stage, recurrence or survival is dependent on initial (radiological) staging.
Methods: Patients with non-metastatic distal rectal cancer who underwent neoadjuvant CRT (50.4Gy and 5FU/Leucovorin) followed by radical surgery (TME) and available initial disease staging were eligible for the study. all patients with distal rectal cancer managed by neoadjuvant CRT were staged according to estimation of TNM parameters based on spiral CT scans or endorectal ultrasound.
Results: Overall, 331 patients had available information on initial radiological staging and were included in the study. There were 39 patients with stage I (12%), 198 with stage II (60%) and 94 patients with stage III disease (28%). There was no correlation between initial disease stage and final pathological ypT status (p=0.5), final tumor size (p=0.06), ypN status (p=0.7), overall recurrences (p=0.8) or final disease stage (p=0.2). 5-year overall and disease-free survival were similar for radiological stage I, stage II and stage III disease (p=0.4 and p=0.9 respectively). Post-CRT staging was significantly associated with development of recurrent disease (p<0.001) and with overall and disease-free survival (p<0.001).
Conclusions: Even though Initial radiological staging is crucial for patient selection there is no influence in final disease staging, recurrence or survival.