Prognosis and efficiency of adjuvant therapy in resected colon signet-ring cell carcinoma

Abstract

Background: Colon signet-ring cell carcinoma (SRCC) is associated with poor survival compared with other histologic subtypes such as adenocarcinoma (AC) and mucinous adenocarcinoma (MC). This present study analyzed the prognosis factors of SRCC and assessed whether the adjuvant therapy could supply benefit for SRCC with different regimens. Methods: Data on 82,606 colon cancer patients who received surgery in the period 1992–2005 was included in this population-based study. The survival benefit was evaluated using a Cox proportional hazards model and propensity score (PS)-matched techniques. Results: SRCC was found in 779 (0.9%) patients who were more frequently in stage III and IV colon cancer than other subtypes. The 5-year survival of SRCC patients were 30.1% (95% CI, 26.7–33.5) which was significantly lower compared with 51.6% (95% CI, 51.3–52.0) for AC and 48.8% (95% CI, 47.8–49.8) for MC. For patients in stage II, there was no significantly difference between chemo group and no-chemo group in all histologic subtypes. The results in stage III showed that 5-FU based adjuvant chemotherapy for AC and SRCC patients could improve overall survival (OS) which could be further enhanced by adding oxaliplatin. The similar benefit was found in stage IV patients. However, there was no significantly difference between different therapy regimens in stage IV SRCC patients. Conclusions: Although the prognosis of patients with colon SRCC was pessimistic, the effective role of adjuvant therapy for OS was still observed in stage III SRCC patients who received surgery. Similarly, patients with stage IV SRCC could also gain benefit from systemic therapy.