Untreated Osteoporosis May Hasten Progression of Bone Metastasis

By David Douglas

March 14, 2019

NEW YORK (Reuters Health) - Certain women with breast cancer and untreated osteoporosis show accelerated progression of bone metastasis, according to a new study from Taiwan.

In a paper online March 8 in JAMA Network Open, Dr. Shin-Sheng Yuan of Academia Sinica, in Taipei, and colleagues note that malignant neoplasms of bone and bone marrow occur in up to 80% of breast cancer patients.

Given that osteoporotic bones may provide premetastatic niches for disseminated cancer cells, the team sought to determine whether precancer osteoporosis and osteoporosis therapy might be associated with alteration of bone-metastasis patterns.

Using national health insurance data, the researchers examined records of 9,104 women with early-stage breast cancer, 705 of whom had precancer osteoporosis. They also looked at a second cohort of 14,020 patients who had osteoporosis before breast cancer and 15,163 who did not have osteoporosis before their breast-cancer diagnosis.

After a median follow-up of close to seven years, in the initial set of 9,104 patients, precancer osteoporosis was not associated with a significant difference in risk of bone metastasis (adjusted hazard ratio, 0.87). Likewise, in the second cohort, osteoporosis therapy had no association with the risk of bone metastasis.

However, women with precancer osteoporosis developed bone-cancer relapse about a year before those without precancer osteoporosis did (median, 1.78 vs. 2.87 years; P<0.001).

In patients who had received bisphosphonates, the median time to bone metastasis was 2.34 years; in those given other osteoporosis drugs, it was 2.08 years. Neither was significantly different from the 2.87 years in women without precancer osteoporosis (P=0.08).

But the interval was significantly shorter (1.74 years) in patients who did not receive precancer treatment (P<0.001).

Thus, Dr. Yuan told Reuters Health by email, "Precancer osteoporosis was not associated with the risk of bone metastasis, but untreated osteoporosis was associated with accelerated progression of bone metastasis when it occurred."

SOURCE: https://bit.ly/2u8dMpC

JAMA Netw Open 2019.