Comprehensive geriatric assessment in older patients with cancer: an external validation of the Multidimensional Prognostic Index in a French prospective cohort study

Abstract Background: Older patients with cancer require specific and individualized management. The Multidimensional Prognostic Index (MPI) based on the Comprehensive Geriatric Assessment (CGA) has shown a predictive interest in terms of mortality. Methods: From 2015 to 2017, consecutive patients ≥75 years old with cancer in Poitiers University Hospital referred to an oncogeriatric consultation. Patients underwent CGA with MPI that is categorized into three risk groups of mortality at one year. Results: Overall, 433 patients were included (women 42%; mean age 82.8±4.8 years). Most common tumor sites were prostate (23%), skin (17%), colorectum (15%) and breast (12%); 29% patients had a metastatic disease; 231 patients (53%) belonged to "MPI-1" group, 172 (40%) to "MPI-2" group and 30 patients (7%) were classified in "MPI-3" group. One-year mortality rate was 32% (23% in MPI-1, 41% in MPI-2 and 53% in MPI-3, p=0.024). All domains of MPI except cognition and living status were significantly associated with mortality at one-year, as well as tumor sites and metastatic status. Cox proportional hazard regression analysis, adjusted on age, gender, tumor sites and metastatic status, validated MPI as being associated with a higher mortality risk (p<0.0001). The prognostic value of MPI was confirmed by the area under the ROC curve at 0.826 (P <0.0001). Conclusion: Our study confirmed the predictive value of MPI for one-year mortality in older patients with cancer. This practical prognostic tool may help to optimize the management of these vulnerable patients.