Disease characteristics and prognostic factors of colorectal cancer patients with bone metastasis: A real-world data from Turkey.

BACKGROUND:Bone metastasis is rarely seen in colorectal cancer (CRC) patients, and there is insufficient data available regarding such cases. The study aimed to identify the prognostic factors and characteristics associated with overall survival in patients with bone metastatic CRC. METHOD:Data from bone metastatic CRC patients referred to a high-volume tertiary cancer center in Turkey, between January 2018 and April 2021, were retrospectively collected. The records of 150 consecutive patients treated for bone metastases due to CRC were reviewed. Overall survival curves were generated by the Kaplan-Meier method and analyzed using the log-rank test. RESULTS:Median age was 55 years (19-86 years). Bone metastases were more common in men and those with metachronous metastases. The axial skeleton was the most commonly involved site, and patients were frequently presented with single bone metastasis. Peritoneal metastases were significantly correlated with extra-axial metastases (P = 0.002), and radiotherapy was applied to axial metastases significantly, more frequently (P = 0.02). Lung metastasis was also more prevalent in K-RAS mutated patients (P = 0.008). The median survival time from diagnosis of bone metastasis was 8.3 months (95% confidence interval (CI), 5.5-10.6), and the three-year survival rate was 76.9% (95% CI, 69.8-84.0). Multivariate analysis revealed that brain metastases, right-sided colon tumor, high serum ALP, and Ca 19-9 levels were independent poor prognostic factors (P = 0.01, 0.02, <0.001, and 0.04, respectively). CONCLUSIONS:The location of CRC correlates significantly with the site of bone metastasis; the prognosis of CRC patients with bone metastasis is very poor, and the significant poor prognostic factors are brain metastases, right-sidedness, high serum ALP, and Ca 19-9 levels. More attention should be paid to bone metastasis in CRC patients.