Preoperative CEA and PPD Values as Prognostic Factors for Immunochemotherapy Using PSK and 5-FU*

Purpose: Immunochemotherapy using PSK, used as postoperative adjuvant chemotherapy for colorectal cancer in Japan, is a treatment that depends on the immuno- competence of the host. Therefore, we analyzed the data of Hokuriku district conducted by the CIP study group to compare the long-term survival for preoperative CEA level and PPD reaction. Patients and Methods: Between February 1991 and March 1993, 87 patients with primary colon cancer and macroscopic lymph node metastasis (macroscopic Dukes' C) underwent macroscopic curative resection. The patients were randomly allocated to receive 5-FU/PSK therapy or 5-FU alone. The 7-year disease-free survival (DFS), 7-year overall survival (OS) and 7-year cancer death survival (CDS) were compared using the preoperative CEA levels and PPD values. Results: In cases with preoperative CEA level ≥3.0 ng/mL, the 7-year DFS, 7-year OS and 7-year CDS were significantly better in the PSK group (85.7, 90.5, 90.5%) than in the control group (52.4, 52.4, 57.1%; p=0.019, 0.007, 0.014,). In cases with preoperative PPD level <19.0 mm, the 7-year DFS, 7-year OS and 7-year CDS were significantly better in the PSK group (85.7, 85.7, 89.3%) than in the control group (56.7, 60.0, 63.3%; p=0.018, 0.036, 0.028). Recurrence was significantly less in the PSK group. The DFS tended to be superior in the PSK group (87.4%) compared to the control group (69.9%) for hematogenous metastasis. Conclusion: The present study demonstrated that preoperative CEA and PPD, that can be measured easily in the clinical setting, may be effective indicators of postoperative adjuvant immunochemotherapy using PSK. In the early nineties, the 5-fluorouracil (5-FU)/levamisole combination was considered to be the standard postoperative adjuvant chemotherapy for colon cancer (1). With the subsequent development of leucovorin (LV), 5-FU/LV became globally accepted as the standard therapy. According to the review of postoperative adjuvant therapy for colon cancer reported by Chau et al. at the 38 th ASCO Meeting in 2002, the 3- to 5-year disease-free survival (DFS) with 5-FU/LV therapy was 59-74%, and the 3- to 5-year overall survival (OS) was 65-83% (2).