Lymph node ratio, an independent prognostic factor for patients with stage II-III rectal carcinoma

Abstract

Background: Identification of the proper surgical method and the most reliable prognostic parameters of rectal carcinomas is a challenging issue. The aim of this paper was to determine the possible prognostic role of the number of harvested lymph nodes versus lymph node ratio (LNR) in patients with rectal carcinomas, and the proper value of LNR that can be used as prognostic parameter.

Materials and methods: A retrospective study was performed in 186 consecutive patients with rectal carcinomas that underwent surgical resection. The LNR was calculated for cases from stage II-III, and was correlated with classic prognostic parameters and overall survival (OS).

Results: A statistically significant difference was found between LNR of 0.15 and OS (p = 0.03), respectively LNR > 0.15 and TNM stage (p < 0.0001), but also tumor infiltration level (p < 0.05). The number of harvested lymph nodes was not correlated with the tumor stage (r = 0.148, p = 0.06) and this parameter did not influence the OS, when the number of 12 or 14 lymph nodes was used as the ideal value (p = 0.6 and p = 0.66, respectively).

Conclusion: In patients with rectal carcinomas that underwent preoperative chemoradiotherapy, a LNR of 0.15 is a parameter with independent prognostic value, comparing with the number of harvested lymph nodes. The specific LNR should be calculated in larger cohorts.

Keywords: Lymph node ratio; Rectal cancer; Survival.