Changing incidence and clinical implications of bone metastases in colorectal cancer: a pooled analysis

Abstract

Background: Bone metastases (BM) in colorectal cancer (CRC) are uncommon, usually present late in the natural history of metastatic disease, and are associated with liver or lung metastases. Affected patients had limited survival. Higher survival rates in CRC and multiple systemic treatments have led to a change in the temporal pattern of metastatic spread and consequent clinical implications. Methods: Articles retrieved by MEDLINE search (English language, 1970-2015).We analyzed data from nine studies involving 13134 patients with CRC, in order to evaluate BM incidence and patient outcomes. Results: Our analysis documented an incidence of BM of approximately 9.2% (range 4.5-23.7%.) The median time from CRC diagnosis to BM detection was 21.6 months (range 11-33.8). Median overall survival after BM diagnosis was 10.3 months (range 7-15.9). No clear data are available on tumor histology and tumor site. Conclusions: These results show a notable variability in the several studies of BM rates and prognosis, probably related to the different therapeutic approach, changing in the last 40 years. However, survival after bone metastases remain poor. Therefore, the early detection is imperative to significantly improve prognosis and prevent skeletal events. Further insights into tumor histology, RAS status correlations and OPG/RANK/ RANKL expression analysis are warranted for better understanding the molecular biology of BM in CRC. (Table Presented).