A nomogram and risk stratification system for predicting survival in T1-2N0-1 breast cancer patients with liver metastasis in females: a population-based study

Liver was one of the most common distant metastatic sites in breast cancer. Patients with distant metastasis were identified as American Joint Committee on Cancer (AJCC) stage IV indicating poor prognosis. However, few studies have predicted the survival in females with T1-2N0-1 breast cancer who developed liver metastasis. This study aimed to explore the clinical features of these patients and establish a nomogram to predict their overall survival. 1923 patients were randomly divided into training (n = 1154) and validation (n = 769) cohorts. Univariate and multivariate analysis showed that age, marital status, race, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), chemotherapy, surgery and bone metastasis, brain metastasis were considered the independent prognostic indicators. We developed a nomogram according to these ten parameters. The consistency index (c-index) was 0.72 (95% confidence interval CI 0.70–0.74) in the training cohort, 0.72 (95% CI 0.69–0.74) in the validation cohort. Calibration plots indicated that the nomogram-predicted survival was consistent with the recorded 1-, 3- and 5-year prognoses. Decision curve analysis curves in both the training and validation cohorts demonstrated that the nomogram showed better prediction than the AJCC TNM (8th) staging system. Kaplan Meier curve based on the risk stratification system showed that the low-risk group had a better prognosis than the high-risk group (P < 0.001). A predictive nomogram and risk stratification system were constructed to assess prognosis in T1-2N0-1 breast cancer patients with liver metastasis in females. The risk model established in this study had good predictive performance and could provide personalized clinical decision-making for future clinical work.