Prognostic accuracy of different lymph node staging system in predicting overall survival in stage IV colon cancer

Lymph node ratio prognosticates overall survival in patients with stage IV colorectal cancer

BACKGROUND

Lymph node ratio (LNR) is suggested to address the shortcomings of using only lymph node yield (LNY) or status in colorectal cancer (CRC) prognosis. This study explores how LNR affects survival in patients with metastatic colorectal cancer (mCRC), seeking to provide clearer insights into its application.

METHODS

This observational cohort study investigated stage IV patients with CRC (1995-2021) who underwent an upfront resection of their primary tumour at Concord Hospital, Sydney. Clinicopathological data were extracted from a prospective database, and LNR was calculated both continuously and dichotomously (LNR of 0 and LNR > 0). The primary endpoint was overall survival (OS). The associations between LNR and various clinicopathological variables were tested using regression analyses. Kaplan-Meier and Cox regression analyses estimated OS in univariate and multivariate survival models.

RESULTS

A total of 464 patients who underwent a primary CRC resection with clear margins (mean age 68.1 years [SD 13.4]; 58.0% M; colon cancer [n = 339,73.1%]) had AJCC stage IV disease. The median LNR was 0.18 (IQR 0.05-0.42) for colon cancer (CC) resections and 0.21 (IQR 0.09-0.47) for rectal cancer (RC) resections. A total of 84 patients had an LNR = 0 (CC = 66 patients; RC = 18 patients). The 5-year OS for the CC cohort was 10.5% (95% CI 8.7-12.3) and 11.5% (95% CI 8.4-14.6) for RC. Increasing LNR demonstrated a decline in OS in both CC (P < 0.001) and RC (P < 0.001). In patients with non-lymphatic dissemination only (LNR = 0 or N0 status), there was better survival compared with those with lymphatic spread (CC aHR1.50 [1.08-2.07;P = 0.02], RC aHR 2.21 [1.16-4.24;P = 0.02]).

CONCLUSIONS

LNR is worthy of consideration in patients with mCRC. An LNR of 0 indicates patients have a better prognosis, underscoring the need for adequate lymphadenectomy to facilitate precise mCRC staging.

Cancer histology in metastatic lymph node predicts prognosis in patients with node-positive stage IV colorectal cancer

Background

Appropriate prognostic indicators are required for patients with stage IV colorectal cancer (CRC). Lymph node metastasis mainly involves four histological types of CRC. Some metastatic lymph nodes (mLNs) showing cribriform carcinoma are associated with distant metastasis in patients with node-positive CRC and are correlated with recurrence and survival in stage III disease. However, the significance of mLN histology in the prognosis of patients with node-positive stage IV disease remains unclear.

Methods

We enrolled 449 consecutive patients with CRC who underwent primary tumor resection with lymph node dissection between January 2011 and November 2018. This study included 88 patients with node-positive stage IV CRC and synchronous or metachronous distant metastases. We retrospectively investigated the association between cancer histology in the mLNs based on our classification and cancer-specific survival (CSS) in patients with node-positive stage IV CRC.

Results

Kaplan-Meier analysis showed that CSS was better in patients with CRC and all the mLNs showing tubular-type carcinoma. In contrast, patients with at least some mLNs showing poorly differentiated-type carcinoma had poor prognosis. Multivariate analysis showed that "all mLNs showing tubular-type carcinoma" was an independent good prognostic factor for CSS in patients with node-positive stage IV CRC. In addition, "at least some mLNs showing poorly differentiated-type carcinoma" was an independent poor prognostic factor for CSS in patients with node-positive stage IV disease.

Conclusions

The histological type of the mLN may indicate a better or poor prognosis for patients with stage IV CRC.

Comparison of model fit and discriminatory ability of the 8th edition of the tumor-node-metastasis classification and the 9th edition of the Japanese classification to identify stage III colorectal cancer

BACKGROUND

The most widely accepted staging system for colorectal cancer (CRC) is the tumor-node-metastasis (TNM) classification. In Japan, the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma (JCCRC) system is used. The two systems differ mainly in relation to tumor deposits (TD) and metastasis in the regional lymph nodes along the main feeding arteries and lateral pelvic lymph nodes (N3). Here, we investigated the prognostic ability of the two systems for stage III CRC.

METHODS

We reviewed 696 consecutive patients who underwent curative resection of stage III CRC at the National Cancer Center Hospital between May 2007 and April 2014. We examined the clinicopathological features of CRC and predicted overall survival (OS) and relapse-free survival (RFS) according to the 8th TNM and 9th JCCRC systems. The systems were compared using Akaike's information criterion (AIC), Harrell's concordance index (C-index), and time-dependent receiver-operating characteristic (ROC) curves.

RESULTS

The 9th JCCRC system was more clinically effective according to AIC (OS, 1199 vs. 1206; RFS, 2047 vs. 2057), showed better discriminatory ability according to the C-index (OS, 0.65 vs. 0.62; RFS, 0.62 vs. 0.58), and its time-dependent ROC curve was superior compared with the 8th TNM system.

CONCLUSION

These results suggest that the 9th JCCRC system has superior discriminative ability to the 8th TNM system, because the 9th JCCRC accounts for the presence of TD and N3 disease, which were both significant predictors of poor prognosis. Reconsidering the clinical value of these two factors in the TNM system could improve its clinical significance.

Log odds of positive lymph nodes is a better prognostic factor for oesophageal signet ring cell carcinoma than N stage

BACKGROUND

Signet ring cell carcinoma is a rare type of oesophageal cancer, and we hypothesized that log odds of positive lymph nodes (LODDS) is a better prognostic factor for oesophageal signet ring cell carcinoma.

AIM

To explore a novel prognostic factor for oesophageal signet ring cell carcinoma by comparing two lymph node-related prognostic factors, log odds of positive LODDS and N stage.

METHODS

A total of 259 cases of oesophageal signet ring cell carcinoma after oesopha-gectomy were obtained from the Surveillance, Epidemiology, and End Results database between 2006 and 2016. The prognostic value of LODDS and N stage for oesophageal signet ring cell carcinoma was evaluated by univariate and multivariate analyses. The Akaike information criterion and Harrell’s C-index were used to assess the value of two prediction models based on lymph nodes. External validation was performed to further confirm the conclusion.

RESULTS

The 5-year cancer-specific survival (CSS) and 5-year overall survival (OS) rates of all the cases were 41.3% and 27.0%, respectively. The Kaplan-Meier method showed that LODDS had a higher score of log rank chi-squared (OS: 46.162, CSS: 41.178) than N stage (OS: 36.215, CSS: 31.583). Univariate analyses showed that insurance, race, T stage, M stage, TNM stage, radiation therapy, N stage, and LODDS were potential prognostic factors for OS (P < 0.1). The multivariate Cox regression model showed that LODDS was an significant independent prognostic factor for oesophageal signet ring carcinoma patients after surgical resection (P < 0.05), while N stage was not considered to be a significant prognostic factor (P = 0.122). Model 2 (LODDS) had a higher degree of discrimination and fit than Model 1 (N stage) (LODDS vs N stage, Harell’s C-index 0.673 vs 0.656, P < 0.001; Akaike information criterion 1688.824 vs 1697.519, P < 0.001). The results of external validation were consistent with those in the study cohort.

CONCLUSION

LODDS is a superior prognostic factor to N stage for patients with oesophageal signet ring cell carcinoma after oesophagectomy.