CONSTRUCTION AND VALIDATION OF A PRACTICAL PROGNOSTIC INDEX FOR PATIENTS WITH METASTATIC BREAST-CANCER

Purpose: To identify the readily available prognostic; factors most he lpful in predicting survival and to construct and validate a prognosti c index for metastatic breast cancer (MBC) patients. Patients and Meth ods: Data from 233 MBC patients, accrued on a multiinstitutional rando mized phase III trial (Japan Clinical Oncology Group [JCOG] study 8808 ), were analyzed to identify significant prognostic factors and a prog nostic index was constructed by incorporating these prognostic factors . For validation of the prognostic index, another data set from 315 co nsecutive MBC patients, who had been treated with standard anthracycli ne-containing regimens, was analyzed. Results: In multivariate regress ion analyses, history of adjuvant chemotherapy (ADJCT) (P = .0005), pr esence of distant lymph nodes (DLNs) (P = .0117) and liver (HEP) (P = .0099) metastases, elevation of serum lactate dehydrogenase (LDH) (P < .0001), and shorter disease-free interval (DFI) (P < .0001) significa ntly contributed to poorer survival. The prognostic index was construc ted as follows: Prognostic Index = ADJCT (not received = 0, received = 1) + DLNs (absent = 0, present = 1) + HEP (absent = 0,present = 1) LDH (less than or equal to one rimes normal = 0, > one times normal = 1) + DFI (greater than or equal to 24 months = 0, < 24 months = 2). Wi th this prognostic index, patients could be stratified into three risk groups. The median survival times (MSTs) of low-, intermediate- and h igh risk groups were 45.5, 24.6, and 10.6 months, respectively (P <.00 01). This prognostic index was applied to the validation patients. The respective MSTs for each risk group were 49.6, 22.8, and 10.0 months (P <.0001). Conclusion: ADJCT, DLNs, HEP, LDH, and DFI were important prognostic factors for MBC patients. The prognostic index readily enab les MBC patients to be stratified into three risk groups and is worth considering for future clinical trials. (C) 1998 by American Society o f Clinical Oncology.