Oliver Peacock, MD The University of Texas MD Anderson Cancer Center answers common questions he has received for his ASCO 2020 Abstract on Improving the AJCC/TNM staging classification for colorectal cancer: The prognostic impact of tumor deposits.
Tumor deposit (TD) detection currently plays a limited role in colorectal cancer ( CRC) staging other than for N1c classification. The purpose of this research was to evaluate the prognostic effect of TD among primary CRC patients, beyond the AJCC N1c classification.
Patients with stage 1 to 3 primary CRC diagnosed between 2010 and 2015 were reported from the Monitoring, Epidemiology and End Results (SEER) database. TD stratified cancer specific survival (CSS) and nodal status were measured, and Kaplan-Meier technique and multivariable COX proportional hazards regression analyses were performed.
A total of 74,494 primary CRC patients were reported. The mean age was 66.4 years (SD+/-13.2), 36,988 years (49.7%) were female and 40,651 years (54.6%) were right-sided. TDs were present in 4,481 patients (6.0 percent), and lymph node metastases were present in 26,603 (35.7 percent). Adverse tumor characteristics including advanced pathological level, nodal and metastasis status, higher grade and perineural invasion were significantly correlated with the presence of TD's. The incorporation of TDs into each nodal status was independently associated with worse CSS and supported nodal status reclassification to incorporate TDs as outlined in the table, following multivariable regression analysis. The proposed AJCC nodal reclassification incorporating TDs, in combination with tumor level, was a good predictor of CSS following multivariable regression analysis, and also represents a new summary staging.
In CRC, TDs are an independent indicator of bad outcomes. The presence of TDs have distinctly different CSS and these data support modification of the current N classification. This study proposes for the CRC to reclassify the AJCC framework to integrate TDs and to notify an updated node and summary level.