Treating and Identifying the Factors Associated With Development of Bone Metastases

Two abstracts at the 2019 American Society of Clinical Oncology Annual Meeting analyzed bone metastases in cancer. The first looked at treatment of bone metastases in various cancer, whereas the other identified factors associated with the development of bone metastases in patients with colorectal cancer.

There have been limited data on the efficacy of treating patients with bone metastases with nivolumab plus denosumab. Researchers from Japan reviewed records of patients who had been treated with the combination from April 2011 to March 2018 at Toranomon Hospital in Tokyo.¹

The research included 201 patients who received denosumab for bone metastasis and 39 patients who received nivolumab. Of those 39 patients, 10 also received denosumab. Median progression-free survival (PFS) was longer in the patients without bone metastases compared with patients with (3.5 months vs 2.1 months), and the 6-month PFS was 39.3% in the group without and 26.7% in the group with bone metastases. As a result, the researchers concluded that being treated with denosumab along with a checkpoint inhibitor had no influence on PFS.

“This retrospective analysis revealed a trend towards lower immune responses in patients with bone metastases, even when nivolumab is administered in combination with denosumab,” they wrote. “Immunotherapy for bone metastasis needs to be further explored.”

The second abstract looked at bone metastases in colorectal cancer, which is fairly rare.² The researchers studied 23,846 patients with colorectal cancer who were diagnosed between 1972 and 2017 at the Mayo Clinic with the goal of understanding the risk factors and survival patterns of bone metastasis in these patients.

Of the patients evaluated, 798 (3.3%) were diagnosed with bone metastasis after their colorectal cancer diagnosis. Freedom from bone metastasis 35 years after diagnosis was 83%. The researchers found that being male, recent surgical years, and a higher cancer stage were associated with a higher risk of developing bone metastases after cancer diagnosis.

Patients with rectal cancer were also more likely to develop bone metastases compared with patients with left or right colon cancer. After 35 years, 77.26% of patients with rectal cancer were free from bone metastases compared with 87.13% for left colon cancer and 82.29% for right colon cancer.

Reference

1. Ozaki Y, Miura Y, Yamanaka T, et al. Combined treatment of patients with bone metastases from various cancers with nivolumab plus denosumab: a retrospective study. Presented at: 2019 American Society of Clinical Oncology Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract e14153.

2. Shahjehan F, Kamatham S, Cochuyt J, et al. Characteristics and outcomes of patients with colorectal cancer and bone metastasis. Presented at: 2019 American Society of Clinical Oncology Annual Meeting; May 31-June 4, 2019; Chicago, IL. Abstract e15063.