The clue is in the calcium

High levels of calcium in the blood stream might be indicative of ovarian cancer, according to a news study.

Examination of associations between blood calcium and ovarian cancer in two national population-based groups showed that women who were diagnosed with ovarian cancer or later died of ovarian cancer had higher levels of calcium in their blood than women without the disease.

Lead author of the study, published in the journal Gynecologic Oncology, Dr Gary G. Schwartz, a cancer epidemiologist, said the idea for this study came about because of previous research he’d done with his group, which showed that men whose calcium levels were higher than normal have an increased risk of prostate cancer. He considered that there might be a similar relationship with ovarian cancer.

“One approach to cancer biomarker discovery is to identify a factor that is differentially expressed in individuals with and without cancer, and to examine that factor’s ability to detect cancer in an independent sample of individuals,” said Dr Schwartz.

Dr Halcyon G Skinner of the University of Wisconsin Carbone Cancer Centre, another study author, said: “Everyone’s got calcium and the body regulates it very tightly. We know that some rare forms of ovarian cancer are associated with very high calcium, so it’s worth considering whether more common ovarian cancers are associated with moderately high calcium.”

Many ovarian cancers express increased levels of parathyroid hormone-related protein (PTRHrP), which is known to raise calcium levels in blood in many other cancers.
Ovarian cancer has a high fatality rate because it is hard to detect, and by the time symptoms arise, the cancer is usually advanced. According to the authors, early diagnosis might be accomplished through the use of a calcium biomarker, but cautions that more research is needed to confirm these results.

“Even though the study is small, we’re reporting it because it’s a very simple thing in theory to test,” said Dr Schwartz.

Staff Writer