The FINE Index: A Frailty- and Immunonutrition-Based Nomogram for Survival in Geriatric Breast Cancer: A Retrospective Study.

BACKGROUND

Elderly breast cancer patients generally have a poorer prognosis. This study developed and validated the FINE Index, a nomogram integrating frailty, immunonutritional, and tumor indicators to predict overall survival (OS) in elderly patients undergoing surgery.

METHODS

We retrospectively analyzed 1621 elderly breast cancer patients from West China Hospital, Sichuan University, who were randomly assigned to training (n = 1132) and internal validation (n = 489) cohorts. An additional 545 patients from Chengdu Shang Jin Nan Fu Hospital were included for external validation. Candidate variables were selected using univariate analysis, LASSO regression, and multivariate Cox regression. Model performance was evaluated using the C-index, time-dependent ROC curves, calibration plots, and decision curve analysis (DCA).

RESULTS

The FINE Index incorporated five independent predictors: age, prognostic nutritional index (PNI), TNM stage, modified five item frailty index (mFI-5), and endocrine therapy. The C-index values were 0.767, 0.739, and 0.731 in the training, internal validation, and external validation cohorts, respectively. Time-dependent AUCs for 3-, 5-, and 10-year OS exceeded 0.7, with good calibration and greater clinical utility than TNM staging alone. Exploratory analysis suggested an association between chemotherapy and improved OS among high-risk patients identified by the FINE Index; however, this finding should be considered hypothesis-generating due to the retrospective design.

CONCLUSIONS

The FINE Index is a prognostic nomogram integrating frailty, immunonutritional status, and tumor characteristics to estimate OS in elderly patients with breast cancer. The model provides a more individualized and accurate prognostic assessment, offering valuable guidance for clinical decision-making and patient management.