Survival Analysis of Patients with Pathologic Fracture from Metastatic Bone Disease in A Single Tertiary Center

Background: Metastatic bone disease (MBD) poses a high risk for skeletal-related events including pathologic fractures and spinal cord compression, subsequently leading to higher mortality after definitive surgery. Estimation of survival is important in the treatment of metastatic pathologic fractures to help set patient, family, and physician expectations on prognosis. 

Method: This is a retrospective cohort study involving 128 patients – 109 treated surgically and 19 treated nonsurgically. Risk factors for six-month survival including age, preoperative serum albumin, absolute lymphocyte count (ALC), and hemoglobin, primary tumor site, presence or absence surgical procedure, presence of visceral metastases, presence of other bony lesions, and presence of chemotherapy/radiotherapy use were evaluated. Cox proportional-hazards regression was employed to determine the hematologic and serologic predictors of mortality. 

Results: Mean age of patients was 60.05 years old (SD=11.10) and 56.25% were female. The most common site is from breast (32.02%), then the lung (25.00%). Patients who expired within the first six months from time of MBD diagnosis comprised of those with low preoperative hemoglobin (17.54%), low ALC (16.90%), and low serum albumin (98.25%), compared to those who expired within 12 months, but were not found to be statistically significant (p=0.511, p-0.302, and p=0.628, respectively). 85.16% of the study population had surgery; the proportion of patients who survived within six months and had surgical intervention (82.46%) was not significantly different (χ2=0.59, p=0.441) from those who expired and had surgery (87.32%). 

Conclusion: Primary tumor site is an independent prognostic factor of survival in patients diagnosed with pathologic fracture from MBD treated surgically or nonsurgically, with primary lung malignancy as having the poorest chance of survival. Preoperative serum albumin, hemoglobin, and ALC were not found to be significant in predicting survival but may still be used as determinants of nutritional and clinical status of patients contemplated for surgery. 

Key words: Metastatic bone disease, Mortality, Pathologic fracture, Survival