Predictive value of pretreatment lymphocyte count in stage II colorectal cancer and in high-risk patients treated with adjuvant chemotherapy

Pretreatment lymphocyte count (LC) has been associated with prognosis and chemotherapy response in several cancers. The predictive value of LC for stage II colorectal cancer (CRC) and for high-risk patients treated with adjuvant chemotherapy (AC) has not been determined. A retrospective review of prospectively collected data from 1332 consecutive stage II CRC patients who underwent curative tumor resection was conducted. A pretreatment LC value <1.3 Giga/L(28.1%, 373/1332) was defined as low LC. A total of 738 patients (55.4%) were considered high-risk, 459 (62.2%) of whom received AC. Patients with low LCs had significantly worse 5-year OS (74.6% vs. 90.2%, p < 0.001) and DFS (61.3% vs. 84.6%, p < 0.001). High-risk patients with low LCs had the poorest DFS (p < 0.001). Multivariate analysis indicated that low LC value or combined with high-risk status were both independent prognostic factors(p < 0.001). High-risk, AC-treated patients with high LCs had significantly longer DFS than untreated patients (HR, 0.594; 95% CI, 0.364-0.970; p = 0.035). There was no difference or trend for DFS or OS in patients with low LCs, regardless of the use of AC (DFS, p = 0.692; OS, p = 0.522). Low LC was also independently associated with poorer DFS in high-risk, AC-treated patients (HR, 1.885; 95% CI, 1.112-3.196; p = 0.019). CONCLUSIONS: Pretreatment LC is an independent prognostic factor for survival in stage II CRC. Furthermore, pretreatment LC reliably predicts chemotherapeutic efficacy in high-risk patients with stage II CRC.