Surgical quality and nodal ultrastaging is associated with long-term disease-free survival in early colorectal cancer: an analysis of 2 international multicenter prospective trials.

BACKGROUND

The National Quality Forum has endorsed a minimum of 12 lymph node (LN) as a surrogate measure of quality in colorectal cancer (CRC). The prognostic value of ultrastaging hematoxylin and eosin (H&E) negative LNs (N0) using pan-cytokeratin immunohistochemistry (pan-CK-IHC) is unknown.

PURPOSE

To assess the effect on survival of surgical quality and focused pathologic analysis.

PATIENTS AND METHODS

Between 2001 and 2007, 253 evaluable patients with resectable CRC were enrolled. Multiple sectioning and pan-CK-IHC were performed on N0 LNs (American Joint Commission on Cancer Stage II). Follow-up was performed at 6-month intervals with a 4-year disease-free survival (DFS) primary end-point.

RESULTS

There were 253 patients, 177 N0 and 76 N1/N2 patients, staged conventionally. Thirty-six (20%) N0 patients were upstaged using ultrastaging (N0-->N0i+ [n = 27] and N0-->N1mi [n = 9]). At a mean follow-up of 3.4 +/- 1.6 years, 38 (15%) have recurred. Only 3% (3/108) of patients with > or =12 LNs, negative by H&E and pan-CK-IHC (N0i-), compared with 18% (6/33) with <12 LNs/N0i- (6/33; P = 0.0015) have recurred. Four-year DFS differed significantly according to surgical quality (<12 vs. > or =12 LNs) among Stage II patients only (DFS, <12 vs. > or =12 LNs: Stage I, 90.5% vs. 97.7%, P = 0.22; Stage II, 67.5% vs. 94.7%, P = 0.0036; Stage III, 61% vs. 61%, P = 0.61).

CONCLUSION

This represents the first prospective report demonstrating that both surgical quality and nodal ultrastaging impacts survival in Stage II CRC. Patients with Stage II CRC having > or =12 LNs negative for micrometastases (N0i-) are likely cured by surgery alone. Both surgical and pathologic quality measures are imperative in early CRC to improve patient selection for adjuvant chemotherapy.