Objective: To clarify the natural course and explore impact factors of distant metastasis in rectal cancer patients who received total mesorectal excision(TME) following neoadjuvant chemoradiotherapy (CRT).
Methods: Between Januray 2008 and December 2013, 317 patients with locally advanced rectal cancer who underwent radical surgical resection following neoadjuvant CRT (pre- and postoperative simple fluorouracil or fluorouracil combined with oxaliplatin plus preoperative three dimensional conformal radiotherapy) at Department of Colorectal Surgery in Fujian Medical University Union Hospital were included. Univariate analysis and Cox regression were performed to evaluate the clinicopathological parameters that may be associated with distant metastasis.
Results: During a median follow-up of 39 months(range 15 - 89 months), 72 patients(22.7%) had disease recurrence, including local recurrence in 8 patients, and distant metastasis in 67 patients (among whom 3 patients had both). Distant metastasis occurred in 86.5%(58/67) patients during the first three years after surgery. The 3-year cumulative distant metastatic rate in all the patients was 22.4%. The 5-year overall survival rate in distant metastatic patient was significantly lower than that of non-distant metastatic patients following neoadjuvant CRT (36.2% vs. 81.2%, P=0.000). Univariate analysis showed that ypT stage (χ(2)=13.304, P=0.010), ypN stage(χ(2)=23.416, P=0.000), ypTNM stage (χ(2)=31.765, P=0.000) and RCRG(χ(2)=16.246, P=0.000) were associated with distant metastasis. Cox regression revealed that ypTNM stage(HR=1.959, 95% CI:1.171 ~ 3.277, P=0.010) was the only independent risk factor of distant metastasis.
Conclusions: Distant metastasis is the early event during the progression in rectal cancer. ypTNM stage is the only independent risk factor of distant metastasis in locally advanced rectal cancer patients who undergo TME following neoadjuvant CRT.