What is the optimal treatment in clinical stage T3N0M0 rectal cancer?

PURPOSE: Some previous studies suggested that certain rectal cancer patients with stage T3N0 and favorable features may be adequately treated with surgery and adjuvant chemotherapy. However, the optimal management of clinical (c) T3N0 rectal adenocarcinoma based on preoperative imaging is unclear. In this study, we aimed to determine the frequency of lymph node metastases in patients clinically staged as T3N0 rectal adenocarcinoma following preoperative chemoradiotherapy (CTR). METHODS: The medical records of 105 patients with clinico- imaging stage T3N0M0 rectal cancer who received preoperative CRT between 2004-2011 were retrospectively analyzed. Chemotherapy used concurrently with preoperative radiotherapy (RT) was protracted 5-fluorouracil (5FU) infusion. RESULTS: Twenty-seven percent of the patients clinically staged as T3N0 before preoperative CRT had pathological (p) lymph node involvement on surgical material. The rate of pathological lymph node involvement was 0% in pT1, 20% in pT2 , 35% in pT3 and 34% in pT4 patients. A significant association was demonstrated between pT stages and pN status (p=0.03). CONCLUSION: Our study demonstrated that the accuracy of preoperative imaging for staging rectal cancer is limited because at least 27% of the patients may have undetected lymph node involvement after preoperative CRT in surgical material.

Preoperative versus postoperative chemoradiotherapy in stage T3, N0 rectal cancer.

BACKGROUND: The study populations of previous preoperative chemoradiotherapy (pre-CRT) studies have consisted of mixed clinical stages, such as cT3-cT4 and/or cN positive. For this reason, it has not been possible to demonstrate whether pre-CRT is of benefit for individual subgroups. METHODS: The medical records of 137 rectal cancer patients with clinical stage T3, N0 disease who received either pre-CRT or postoperative chemoradiotherapy (post-CRT) between 2002 and 2011 were retrospectively analyzed. The regimen of pre-CRT consisted of slow fluorouracil (5FU) infusion and that of post-CRT consisted of bolus 5FU and leucovorin concurrent with radiation. RESULTS: Following pre-CRT, significant downstaging was achieved. However, administration of pre-CRT did not influence the type of surgical resection in tumours ≤5 cm distant from the anal verge (p = 0.14). Pathological complete response was achieved in 16 % of the patients in the pre-CRT group. The local recurrence rate (LRR) at 5 years was 5.7 % in the pre-CRT and 11.1 % in the post-CRT groups (p = 0.04). The distant recurrence rate (DRR) at 5 years was 76 % and 77 % in the pre-CRT and post-CRT groups, respectively (p = 0.1). Overall survival was similar in two groups (74.8 % vs. 75.3 %, p = 0.3). CONCLUSIONS: The treatment of stage T3, N0 rectal cancer patients with pre-CRT followed by surgery decreased LRR, but did not improve DRR or OS as compared with surgery followed by post-CRT in our patient cohort.