Does lymph node yield affect survival among patients with node-negative rectal adenocarcinoma who had received neoadjuvant chemoradiotherapy?

To investigate this, researchers from University Hospitals Research in Surgical Outcomes and Effectiveness (UH RISES) in Cleveland, Ohio enrolled patients with clinical stage II and III rectal adenocarcinoma with neoadjuvant chemoradiation, primary tumor resection, negative resection margins and pN0M0 pathologic stage from the National Cancer Database between 2010 and 2016.

The mortality risk increased by 29% among patients with lymph node yield less than 12 compared to patients in whom the lymph node yield was ≥12 nodes, which is an adequate lymph node yield as recommended by the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC).

The 5-year survival was 73% for inadequate lymph node yield and 78% for adequate lymph node yield in patients with an incomplete pathologic complete response to neoadjuvant therapy. On the other hand, the 5-year survival was 82% for inadequate lymph node yield and 90% for adequate lymph node yield among patients with a complete pathologic response.

An improvement in the 5-year survival was noted following adjuvant chemotherapy among patients with inadequate lymph node yield and complete pathologic response compared to patients who did not receive adjuvant chemotherapy; 90.4% vs 78.5%, respectively.

The American Joint Committee on Cancer (AJCC) currently recommends that a minimum of 12 lymph nodes must be present in the surgical specimen to confirm node-negative disease in rectal cancer. Higher number of lymph nodes is indicative of adequate resection margin.

This study published in the November 2022 issue of the journal Surgery shows that the survival rate is decreased in patients with inadequate lymph node yield despite being lymph node-negative and a pathologic complete response to neoadjuvant therapy.

Reference

1. Bliggenstorfer JT, et al. Lymph node yield after rectal resection is a predictor of survival among patients with node-negative rectal adenocarcinoma. Surgery. 2022 Nov;172(5):1292-1299. doi: 10.1016/j.surg.2022.01.041.