Increased lymph node evaluation with colorectal cancer resection: does it improve detection of stage III disease?

Hypothesis: Evaluation of 12 or more lymph nodes (LNs) with colorectal cancer (CRC) resection may not improve detection of stage III disease.

Design: Retrospective review after intervention.

Setting: Community teaching hospital.

Patients: We evaluated 701 consecutive operative CRC cases ascertained from our Cancer Registry.

Intervention: Patients undergoing resection before (n = 553) a multidisciplinary initiative emphasizing the importance of LN counts were compared with those undergoing operation afterward (n = 148).

Main Outcome Measures: Number of LNs evaluated, proportion of patients with stage III disease, and proportion of patients with N1 vs N2 disease.

Results: Demographic, tumor, and treatment variables were similar for both groups, except for younger age, fewer white patients, and more laparoscopic resections in the late period. Lymph node counts increased from a mean (SEM [median]) of 12.8 (0.3 [12]) to 17.3 (0.7 [16]) (P < .001), with 53.0% of the early vs 71.6% of the late patients having at least 12 LNs examined. The proportion diagnosed as having stage III CRC was 204 of 553 (36.9%) for the early group vs 48 of 148 (32.4%) for the late group (P = .31). Among patients with positive LNs, the distribution of N1 and N2 disease was unchanged (early, 50.5% N1 and 49.5% N2; late, 54.2% N1 and 45.8% N2; P = .54).

Conclusions: Increased LN retrieval does not identify a greater number of patients with stage III CRC nor does it increase the proportion of patients with positive LNs with N2 disease. Our data suggest that harvest of at least 12 LNs as a quality or performance measure appears unfounded.