Abstract Objective To investigate the routine pathological examination of lymph node metastasis (pN0) colorectal cancer prognostic factors. Methods A retrospective analysis of the clinical and pathological features of 57 cases of pN0 colorectal cancer patients and its relationship with the prognosis. Results of lymph node metastasis of colorectal cancer shallow depth of invasion, rarely soaked serosa, limit Bureau of type, well-differentiated adenocarcinoma more; postoperative 5-year survival rate was 83.1%. Lymph node metastasis of colorectal conclusion the purposes of better prognosis after radical resection of the depth of invasion and gross type is an independent prognostic factor.

Key words colorectal cancer lymph node metastasis prognosis of radical surgery

    One of the lymph node metastasis is an important factor affecting the prognosis of colorectal cancer [1,2,8] for lymph node metastasis positive colorectal clinicopathological characteristics and prognostic factors, domestic and foreign scholars have been more systematic study. But fewer lymph node negative colorectal. The clinical and pathological data of 57 patients with lymph node metastasis of colorectal cancer were retrospectively analyzed to investigate the clinical and pathological features and prognostic factors, in order to provide the basis for clinical treatment.

    1 Materials and Methods

    1.1 General Information

    Select 2000 to 2001, hospital oncology purposes of colorectal cancer radical surgery and resection specimens seized lymph node more than 12 [2] 168 cases, follow-up to do the analysis, 94 patients (56% follow-up rate). Lymph node metastases were confirmed histologically negative (LN ) 57 patients (60.6%), positive (LN +) and 37 patients (39.4%). Cause of death in patients with both colorectal cancer recurrence, metastasis.

    1.2 Observation Method

    Choose the age, gender, tumor size, tumor type, histological grade, tumor location, growth pattern, lymphatic invasion, macroscopic type, invasion depth of 10 possible prognostic factors as observed. Cohort study using survival was observed.

    1.3 statistical methods

    Χ2 test was used to compare differences between groups. Univariate analysis using the Kaplan  Meier method, and multivariate analysis using the Cox proportional hazards model. The statistical analysis SPSS13.0 software is complete.

    2 Results

    2.1 lymph node negative and lymph node metastasis-positive colorectal cancer clinical and pathological features comparison

    Lymph node metastasis-positive colorectal cancer with lymph node metastasis in age, lymphatic invasion, invasion depth group difference was statistically significant compared. Lymph node metastasis of colorectal cancer in the younger group (≥ 60 years) the proportion of 59.6%, significantly higher than the lymph node metastasis-positive colorectal Table LN-and LN + clinical and pathological features of colorectal contrast *: pT2 and pT4 relatively high age group the proportion of 29.7%. Negative colorectal cancer lymph node metastasis in well-differentiated adenocarcinoma 57.9%, 42.1% limit Bureau type relatively high proportion, shallow depth of invasion, few soaked serosa. Positive colorectal cancer lymph node metastasis in poorly differentiated adenocarcinoma 59.5%, 70.3% of the infiltrating relatively high proportion, deep depth of invasion, a higher proportion of saturated serosa. Both tumor diameter, tumor type, histological grade, tumor location, growth pattern, gross type biological indicators grouped significant differences, as shown in Table 1. Lymph node negative and lymph node metastasis-positive colorectal cancer 5-year survival rates were 83.1% and 51.4%, respectively, and the difference between groups was significant significance (P <0.001), as shown in Figure 1.

    Figure 1 gross type of survival curve

    Fig 1 Survival curve of different macroscopic type

    2.2 different clinical and pathological features and the relationship of the 5-year survival

    General limits Bureau 5-year survival rate (95%) than in the type group infiltrative type (74%) (P = 0.036), and the difference was statistically significant, as shown in Figure 1.

    Lymphatic invasion groups lymphatic invasion group The 5-year survival rate (85%) than lymphatic invasion group (50%) (P = 0.024), the difference was statistically significant, as shown in Figure 2.

    Figure 2 is a presence of lymphatic invasion survival curves

    Fig 2 Survival curve of patient with lymphovascular invasion

    Depth of invasion between groups is not soaked serosal 5-year survival (86%) than saturated the serosal group (50%) (P = 0.024), and the difference was statistically significant, as shown in Figure 3.

    Compare the 5-year survival differences in age, tumor location, tumor diameter, histological type, growth pattern, histological grade between the groups was not statistically significant.

    Figure 3 tumor infiltration depth of the survival curves

    Fig 3 Survival curve of patient with different depth of invasion

    2.3 lymph node metastasis-negative colorectal cancer prognosis analysis

    2.3.1 The single factor analysis

    Analysis Kaplan  Meier method to filter out the depth of invasion, lymphatic invasion, and the gross type closely related to negative colorectal cancer prognosis (P <0.05) and lymph node metastasis. 0.05)。">Age, tumor size, tumor type, tumor location, growth pattern, histological grade biological indicators were not statistically significant (P> 0.05).

    2.3.2 Multi-factor analysis

    Univariate analysis to filter out the depth of invasion, lymphatic invasion, and macroscopic type indicators into the Cox proportional hazards model. The results show that the depth of invasion and gross type is an independent prognostic factor (P <0.05), lymph node metastasis of colorectal cancer. Table 2 Cox proportional hazards model multiple factors of survival analysis

    3 Discussion

    3.1 clinicopathological features of colorectal cancer lymph node metastasis

    Proportion of lymph node metastasis negative colorectal age group (≥ 60 years) was significantly higher than the proportion of lymph node metastasis colorectal high age group share, a higher degree of malignancy of colorectal consider low age group are more prone to lymph node metastasis [3,4]. Lymph node metastasis negative colorectal cancer histological grade, mostly well-differentiated type [9], more gross type limits Bureau of type, depth of invasion rarely soaked serosa. After radical resection of the 5-year survival rate was 83.1%, significantly higher than the 51.4% of positive lymph node metastasis, this similar results reported in the literature [2,5]. The lymph node metastasis of colorectal tumor diameter, tumor type, histological grade, tumor location, growth pattern, lymphatic infiltration, gross type, depth of invasion, the 5-year survival rate of the packet statistics. The results showed that, generally limit the type of bureau-type, lymphatic invasion, not soaked serosal 5-year survival rate [6]; 5 years of age, tumor type, growth pattern, histological grade group compared postoperative survival rate differences No statistically significant. Which depth of invasion, lymphatic invasion, and the 5-year survival rate in the gross type of group difference was statistically significant (P <0.05), suggesting that the three negative colorectal cancer prognosis of lymph node metastasis.

    3.2 prognostic factors for lymph node metastasis of colorectal cancer

    10 In this study, age, gender, tumor size, tumor type, histological grade, tumor location, growth pattern, lymphatic vessel invasion, macroscopic type, depth of invasion, lymph node metastasis of colorectal cancer prognostic factors, which may affect as observed After univariate and multivariate analysis, the results show that the depth of invasion are independent prognostic factors [7]. Not saturated the serosa and soaked serosal 5-year survival rates were 86% and 50%, the difference was statistically significant.

    Preoperative or intraoperative lymph node metastasis accurately determine the current lack of effective means, combined with clinicopathological factors and molecular markers predictive of lymph node metastasis will be the direction of future research. In summary, the independent prognostic factors for lymph node metastasis of colorectal cancer is 83.1% of the depth of invasion and gross type, radical after 5-year survival rate is higher. Lymphadenectomy should be performed.