The need for a revised staging system of metastatic (M) colorectal cancer (CRC): Evidence from a national perspective on survival following surgically treated (HPX) liver metastases

Abstract

4099 Background: AJCC V.6 (2002) places all patients with MCRC beyond the lymph node basin of the primary tumor in a homogenous Stage 4. Patients with inoperable hepatic MCRC can be made operable with curative intent with chemotherapy yet remaining in Stage 4. Via the linkage of routine health datasets across England this population-based study sought to determine the impact of HPX for MCRC on stage-matched survival at initial presentation. Methods: All patients between 1998–2001 undergoing surgery for CRC in England were identified via the national-linked cancer registry HES dataset. All care episodes in the 3 years following initial colorectal surgery were examined to determine the frequency of subsequent HPX. Kaplan-Meier curves and log- rank tests were used to examine 5-year survival following HPX for MCRC compared to all Stage 3 and Stage 4 at presentation. Survival was calculated from the date of resection of each patient's primary colorectal tumor. Results: 68,307 individuals were identified as undergoing surgery for primary CRC over the study period. 20,298 were Stage 3 at presentation. 1,483 (2.2%) subsequently underwent HPX <3 years of their colorectal operation. 55 patients died within 30 days of HPX (mortality rate: 3.7%). Crude 5-year survival of patients who underwent HPX was 41.6% (95%CI 39.0–44.1%) from time of initial colectomy. This survival rate was significantly better than that for both Stage 3 (38.6% (95%CI 37.9%-39.2%, P<0.01) and 4 (6.1% 95%CI 5.3–6.9%, P<0.01) overall. Conclusions: 5-year survival following HPX for MCRC is better than that seen overall for all Stage 3 patients (with MCRC confined to the regional draining lymph node basin) following initial colectomy. Our data support the hypothesis that all MCRC that is potentially resectable with curative intent should be stratified within Stage 3, and Stage 4 should only contain those MCRC patients for whom surgery is not an option. If further evidence emerges to support this theory then a revision of the current staging system will be required. [Table: see text]