The life expectancy for a person with bone metastases depends on many factors, including the type of cancer involved, the amount of time since the initial diagnosis and the person's age, explains WebMD. The person's ability to care for himself independently is also a factor, states American Family Physician.
In one study, the mean survival time for breast cancer patients with bone-only metastasis was 55.2 months, according to a 2013 article published on PubMed.org. According to this study, the most significant prognostic factor was the number of sites where metastasis occurred, with single-bone metastasis correlating with longer survival times. Treatment with bisphosphonates also appeared to improve life expectancy.
In a study of patients with prostate cancer, 47 percent of patients whose cancer that had spread to the bones survived for one year, compared to 87 percent of patients whose cancer had not spread, reports Healthline. Only 3 percent of those with bone metastases were alive after five years, compared to 56 percent of those whose cancer had not spread.