[Study on the relationship between tumor regression grade and lymph node regression grade]

Area of Science:

• Oncology
• Surgical Pathology
• Radiotherapy

Background:

• Neoadjuvant chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer.
• Assessing treatment response is crucial for predicting outcomes and guiding further management.
• Tumor and lymph node regression are key indicators of response to neoadjuvant CRT.

Purpose of the Study:

• To investigate the relationship between tumor regression grade (TRG) and lymph node regression grade (LRG) after neoadjuvant CRT in rectal cancer patients.
• To determine the clinical implications of TRG and LRG in evaluating treatment response.
• To assess whether TRG can adequately represent LRG in rectal cancer treated with neoadjuvant CRT.

Main Methods:

• Retrospective analysis of 176 rectal cancer patients who underwent radical excision after neoadjuvant CRT.
• TRG and LRG were assessed postoperatively based on fibrosis and cancer residue in resected specimens.
• Spearman correlation test was employed to evaluate the correlation between TRG and LRG.

Main Results:

• A total of 176 patients were analyzed, with varying stages of tumor and lymph node regression observed.
• TRG and LRG showed a statistically significant correlation (P=0.005), with a Spearman correlation coefficient of 0.24.
• In a subgroup analysis excluding LRG1, the correlation strengthened (P=0.0005, coefficient=0.40), but TRG did not fully represent LRG.

Conclusions:

• Tumor regression grade (TRG) cannot solely represent lymph node regression grade (LRG) in rectal cancer treated with neoadjuvant CRT.
• Both TRG and LRG should be evaluated independently to accurately assess the response to neoadjuvant CRT.
• Dual assessment of TRG and LRG provides a more comprehensive understanding of treatment efficacy.