Oncologic emergency in patients with skeletal metastasis of unknown primary

Patients with skeletal metastasis from prediagnosed primary malignancy sometimes have concurrent oncologic emergency (OE) during the first visit. This study aims to investigate the types of OEs and treatment outcome in such patients.

We have experienced 359 patients with skeletal metastasis from unknown primary malignancy. Among them, 130 patients required immediate admission for OE treatment (OE group), 229 patients had no OE and did not required immediate admission (non-OE group).

The recognized types of OE were spinal cord compression in 60 patients, cancer pain in 30, hypercalcemia in 19, delirium in 16, deep vein thrombosis in 13, acute renal failure in 6, respiratory failure in 3, gastrointestinal hemorrhage in 3, and disseminated intravascular coagulation in 1. The overall 5-year survival rates were 28% and 37% in the OE and non-OE groups, respectively (P < 0.001). The multivariate analysis revealed that delirium (hazard ratio 4.2; 95% confidence interval, 1.6-12.5; P < 0.005) and respiratory failure (hazard ratio 22.6; 95% confidence interval, 4.5-92.8; P < 0.001) were significant prognostic factors in patients with OEs, whereas other OEs did not confer a significant risk for patient outcomes.

In this study, OE was observed in as many as 36% of patients with skeletal metastasis from unknown primary malignancy. Delirium and respiratory failure were only two significant prognostic risk factors, which suggest that many of the OEs in untreated advanced cancer patients have probable chance to resolve. Early detection followed by appropriate treatment of such OEs is recommended.