Preoperative versus pathological staging of rectal cancer-challenging the indication of neoadjuvant chemoradiotherapy

Neoadjuvant chemoradiotherapy (CRT) followed by surgery is recommended for patients with diagnosed rectal cancer UICC stage II/III. The present study aimed to evaluate the accuracy of preoperative staging with focus on tumor infiltration depth and lymph node status challenging the indication of neoadjuvant CRT.

All consecutive rectal cancer patients who underwent surgical resection without neoadjuvant CRT at the Klinikum Stuttgart, Germany, between January 2015 and December 2018, were included into the study. Clinicopathologic features focusing on preoperative tumor staging and histological outcome were assessed.

A total of 100/162 patients (61.7%) underwent primary surgical rectal resection with curative intent. Among these patients, 54/100 had a correct preoperative T-staging, while 34 were overstaged and 12 understaged. With regard to the nodal status, 68 were accurately staged, while 28 were overstaged and 4 understaged. Only 4/40 perirectal lymph nodes of more than 5 mm in diameter in preoperative MRI histologically revealed to be metastasis.

For patients without neoadjuvant CRT, a tendency to preoperative overstaging was observed. Lymph node size alone did not reliably predict metastasis. According to current guidelines, 21/62 (33.9%) of these patients would have been overtreated by using CRT. On the background of relevant side effects, complications, and the limited benefit of CRT on overall survival, we suggest that primary surgical resection should be recommended more liberally for stages II and III rectal cancer.