Survival Analysis of Pathologic Fractures in Metastatic Bone Disease A Retrospective Study on the Prognostic Role of Primary Tumor Site and Hematologic Markers in a Single Philippine Tertiary Center

Abstract

Background. Metastatic bone disease (MBD) poses a risk for skeletal-related events, including pathologic fractures and spinal cord compression, subsequently leading to higher mortality after definitive surgery. Estimation of survival is crucial in the treatment of metastatic pathologic fractures to help set realistic expectations for patients, their families, and physicians.
Objective. To determine the predictors of mortality in patients diagnosed with pathologic fracture secondary to metastatic bone disease in terms of hematologic and serologic markers such as preoperative hemoglobin, absolute lymphocyte count, and preoperative albumin.
Methodology. This retrospective cohort study involved 128 patients: 109 who were treated surgically and 19 who were treated non-surgically, from January 2010 to December 2020. Risk factors studied were age, preoperative serum albumin, absolute lymphocyte count (ALC), and hemoglobin, primary tumor site, whether surgery was done, presence of visceral metastases, presence of other bony lesions, and  chemotherapy/radiotherapy use. Cox proportional hazards
regression was employed to determine the accuracy of each risk factor as a predictor of mortality.
Result. The patients’ mean age was 60.05 years (SD = 11.10), and 56.25% were female. The most common site of primary tumor was the breast (32.02%), then the lung (25.00%). Among patients with low hemoglobin, 11.27% expired within the first six months from the time MBD was established, while 17.54% survived up to one year; however, this difference was not statistically significant (p = 0.310). Similarly, no significant difference in survival was observed among patients with low albumin, with 95.77% expiring within six months and 98.25% surviving up to one year (p = 0.511). In contrast, a statistically significant difference was found among those with low ALC, with 16.90% expiring within six months compared to 10.53% surviving up to one year (p = 0.002). Surgical treatment was performed on 85.16% of the study population. The proportion of surgical patients who survived within six months (82.46%) did not differ significantly from those who expired (87.32%, χ2 = 0.59, p = 0.441).

Conclusion. The primary tumor site was an independent prognostic factor for survival in patients diagnosed with pathologic fractures from MBD, with primary lung malignancy having the poorest chance of survival. While preoperative serum albumin, hemoglobin, and ALC were not statistically significant predictors, they remain clinically useful as indicators of nutritional and physiologic status when assessing surgical risk. These findings are particularly relevant
in local settings where access to timely diagnostic scans may be limited. In such contexts, readily available laboratory tests can play a valuable role in guiding risk stratification and shared decision-making in the management of MBD.