The Use of the Chuang's Prognostic Scale to Predict the Survival of Metastatic Colorectal Cancer Patients Receiving Palliative Systemic Anticancer Therapy

BACKGROUND: With the increasing number of agents active against cancer, advanced cancer patients including metastatic colorectal cancer (mCRC) patients may continue receiving palliative systemic anticancer therapy (PSAT) near the end-of-life. Validated palliative prognostic models, such as the Chuang's prognostic scale (CPS), may be helpful in identifying mCRC patients with limited survival who are unlikely to benefit from PSAT. AIM: To test the ability of the CPS to predict the survival of mCRC under treatment with PSAT. METHODS: CPS was prospectively assessed in 36 mCRC patients who were receiving PSAT. The scale is based on eight items: ascites, edema, cognitive impairment, liver and lung metastases, performance status, tiredness, and weight loss. The total CPS score ranges from 0 to 8.5 with the higher score indicating worse prognosis. RESULTS: Patients were divided into two groups using a CPS cutoff score of 5, Group 1 with a CPS score ≤5 and Group 2 with a CPS score >5. Using this cutoff value, 3-month mortality was predicted with a positive predictive value of 71%, a negative predictive value of 77%, a sensitivity of 67%, a specificity of 81% and an overall accuracy of 75%. Group 1 patients had a longer median survival of 149 days (95% confidence interval [CI]: 82-216) in comparison to Group 2 patients who had a median survival of 61 days (95% CI: 35-87). The difference in survival was statistically significant (P = 0.01). CONCLUSION: CPS may be useful in identifying mCRC patients with limited survival who are unlikely to benefit from PSAT.