Dukes C colorectal cancer: is the metastatic lymph node ratio important?

Prognostic role of the lymph node ratio in node positive colorectal cancer: a meta-analysis

The lymph node ratio (LNR) (i.e. the number of metastatic lymph nodes divided by the number of totally resected lymph nodes) has recently emerged as an important prognostic factor in colorectal cancer (CRC). However, the tumor node metastasis (TNM) staging system for colorectal cancer does not consider it as a prognostic parameter. Therefore, we conducted a meta-analysis to evaluate the prognostic role of the LNR in node positive CRC. A systematic search was performed in PubMed, Embase and the Cochrane Library for relevant studies up to November 2015. As a result, a total of 75,838 node positive patients in 33 studies were included in this meta-analysis. Higher LNR was significantly associated with shorter overall survival (OS) (HR = 1.91; 95% CI 1.71–2.14; P = 0.0000) and disease free survival (DFS) (HR = 2.75; 95% CI: 2.14–3.53; P = 0.0000). Subgroup analysis showed similar results. Based on these results, LNR was an independent predictor of survival in colorectal cancer patients and should be considered as a parameter in future oncologic staging systems.

Prognostic value of lymph node ratio in survival of patients with locally advanced rectal cancer

BACKGROUND

The lymph node ratio (LNR) has been shown to be an important prognostic factor in patients with gastric, breast, pancreatic and colorectal cancer. We investigated the prognostic impact of the LNR in addition to TNM classification in patients with locally advanced rectal cancer.

METHODS

We retrospectively analyzed patients who underwent curative resection for locally advanced rectal cancer between July 2005 and December 2010. We determined the LNR cutoff value using a receiver operating characteristic curve. The Kaplan-Meier method was used to estimate survival curves, while Cox regression analyses were used to evaluate the relationship between LNR and survival.

RESULTS

We included 180 patients aged 28-83 years with median follow-up of 41.8 months. The median number of lymph nodes examined and lymph nodes involved were 11.5 and 4, respectively, and the median LNR was 0.366. An LNR of 0.19 (19%) was the cutoff point to separate patients with regard to median overall survival. Median overall survival was 64.2 months for patients with an LNR of 0, 59.1 for an LNR of 0.19 or less and 37.6 for an LNR greater than 0.19 (p = 0.004). The median disease-free survival was 32.9 months for patients with an LNR of 0, 30.4 for an LNR of 0.19 or less and 17.8 for an LNR greater than 0.19 (p = 0.002).

CONCLUSION

Our results suggest that LNR should be considered an additional prognostic factor in patients with locally advanced rectal cancer.

Prognostic influences of lymph node ratio in major cancers of Taiwan: a longitudinal study from a single cancer center

BACKGROUND

The utility of lymph node ratio (LNR) in predicting outcomes has been reported previously. In current study, we further subgroup by LNR in subjects with lymph nodes metastasis of colorectal cancer, breast cancer, and head and neck cancer.

METHODS

Cancers with pathological lymph node metastasis (pN+) at time of diagnosis between 2004 and 2012 were identified from the cancer registry database of the Dalin Tzu Chi General Hospital. The Kaplan-Meier method with log-rank test and the Cox proportional hazards model were used to compare the disease-specific survival (DSS) rates for different LNR after adjusting for possible confounding risk factors.

RESULTS

A total of 431 cancer patients with pN+ were eligible in the current study: 149 patients with colorectal cancer; 141 patients with breast cancer; and 141 patients with head and neck cancer. High LNR was associated with poor DSS rates with the mean 24-45 months of follow-up period. In the multivariate analysis, high LNR was an independent poor prognostic factor in colorectal cancer (LNR ≥ 0.5; HR 4.10; p < 0.001), breast cancer (LNR ≥ 0.8; HR 5.75; p = 0.002), and head and neck cancer (LNR ≥ 0.4; HR 2.56; p = 0.005).

CONCLUSION

High LNR exerts a significant role as a negative prognostic factor when comparing the traditional American Joint Committee on Cancer (AJCC) lymph nodes classification for major cancers. Therefore, LNR could be considered as an alternative and superior to, at least partially, traditional AJCC lymph nodes classification for cancer patients.

Lymph node ratio improves TNM and Astler-Coller's assessment of colorectal cancer prognosis: an analysis of 761 node positive cases

BACKGROUND

Prognosis assessment of node-positive colorectal cancer patients by Astler-Coller (AC) and TNM classifications is suboptimal. Recently, several versions of lymph node ratio (LNR; ratio metastatic/examined nodes) have been proposed but are still mostly unused.

METHODS

The prognostic value of several criteria, including LNR (two classes-LNR1 and LNR2-identified by a 15% cut-off) was studied in 761 consecutive patients, from 2000 through 2010. The relationships between total examined nodes, N, T and LNR were also analysed. LNR1 and LNR2 patients' survival was analysed within AC and TNM subgroups, and then coupled with them.

RESULTS

Age, tumour location and LNR are independent factors predicting survival. The relationships between LNR, N stage and T stage with examined nodes suggest confusing factors. LNR allows for identification of subgroups with different survival within AC and TNM classifications (p < 0.0001). Patients with LNR class discordant from AC stage (LNR1-C2 and LNR2-C1) have a similar 5-year survival (54 and 57%, respectively). LNR2 and TNM stage IIIC define a poor 5-year prognosis (33%).

CONCLUSIONS

LNR is a powerful prognosis predictor, easily integrated with TNM and AC classifications to improve prognosis assessment and facilitate clinical use. Possible confusing factors should be considered in future studies.

Prognostic value of lymph node ratios in node positive rectal cancer treated with preoperative chemoradiation

BACKGROUND

To investigate the impact of the lymph node ratio (LNR) on the prognosis of patients with locally advanced rectal cancer undergoing pre-operative chemoradiation.

METHODS

Clinicopathologic and follow up data of 128 patients with stage III rectal cancer who underwent curative resection from 1996 to 2007 were reviewed. The patients were divided into two groups according to the lymph node ratio: LNR ≤ 0.2 (n=28), and >0.2 (n=100). Kaplan-Meier and the Cox proportional hazard regression models were used to evaluate the prognostic effects according to LNR.

RESULTS

Median numbers of lymph nodes examined and lymph nodes involved by tumour were 10.3 (range 2-28) and 5.8 (range 1-25), respectively, and the median LNR was 0.5 (range, 0-1.6). The 5-year survival rate significantly differed by LNR (≤ 0.2, 69%; >0.2, 19%; Log-rank p value < 0.001). LNR was also a significant prognostic factor of survival adjusted for age, sex, post-operative chemotherapy, total number of examined lymph nodes, metastasis and local recurrence (≤ 0.2, HR=1; >0.2, HR=4.8, 95%CI=2.1-11.1) and a significant predictor of local recurrence and distant metastasis during follow-up independently of total number of examined lymph node.

CONCLUSIONS

Total number of examined lymph nodes and LNR were significant prognostic factors for survival in patients with stage III rectal cancer undergoing pre-operative chemoradiotherapy.

Is the lymph node ratio superior to the Union for International Cancer Control (UICC) TNM system in prognosis of colon cancer?

Background

Decision making for adjuvant chemotherapy in stage III colon cancer is based on the TNM system. It is well known that prognosis worsens with higher pN classification, and several recent studies propose superiority of the lymph node ratio (ln ratio) to the TNM system. Therefore, we compared the prognosis of ln ratio to TNM system in our stage III colon cancer patients.

Methods

A total of 939 patients underwent radical surgery for colorectal cancer between January 2000 and December 2009. From this pool of patients, 142 colon cancer stage III patients were identified and taken for this analysis. Using martingale residuals, this cohort could be separated into a group with a low ln ratio and one with a high ln ratio. These groups were compared to pN1 and pN2 of the TNM system.

Results

For ln ratio, the cutoff was calculated at 0.2. There was a good prognosis of disease-free and cancer-related survival for the N-category of the TNM system as well as for the lymph node ratio. There was no statistical difference between using the N-category of the TNM system and the ln ratio.

Conclusions

There might not be a benefit in using the lymph node ratio rather than the N category of the TNM system as long as the number of subgroups is not increased. In our consideration, there is no need to change the N categorization of the TNM system to the ln ratio.