Fig. 1

Treatment response of primary tumour to preoperative neoadjuvant chemotherapy. a, b Computed tomography of primary tumour. The tumour had invaded adjacent retroperitoneum at diagnosis (a), and significant shrinkage and fibrosis was seen after chemotherapy (b). c, d Endoscopic findings of the primary tumour. The tumour occupied the whole lumen of the rectum (c), and significant response was seen after chemotherapy (d). e Resected primary tumour specimen. The viable cancer cells are indicated with red lines. f Pathological findings of the primary tumour after chemotherapy. More than 2/3 was replaced by fibrosis