Study: Low White Blood Cell Count Often Delays Start of Chemotherapy

A low white blood cell count may delay the start of chemotherapy for half of all breast cancer patients, according to researchers at Albany Medical Center in New York.

Neutropenia, a condition where a woman has very low levels of white blood cells, may also cause as many as one in four breast cancer patients to receive lower than standard doses of chemotherapy, according to the study presented at the 37th annual meeting of the American Society of Clinical Oncology.

Because neutropenia may require the delay or reduction of chemotherapy, it possibly compromises the effectiveness of treatment and potential for cure. At-risk patients may benefit from preventive treatment with Granulocyte Colony Stimulating Factor (G-CSF), which stimulates production of infection-fighting white blood cells, according to the Albany researchers in a second study.

"G-CSF is very helpful to us in managing neutropenia, but it's cost-prohibitive to treat everyone preventively," said Dr. Gary Lyman of Albany Medical Center and author of both studies. "Current risk projection models appear to set the barrier too high."

In a study of medical records of 20,000 breast cancer patients, researchers found that more than 50 percent of patients with neutropenia experienced delays in receiving chemotherapy, and 20 to 25 percent received less than 85 percent of the targeted dose of chemotherapy, the minimum percentage below which chemotherapy is thought to lose effectiveness. Elderly patients were twice as likely to receive below standard doses of chemotherapy.

"The findings from our studies have important public health implications," said Lyman. "They suggest that the delivery of lower than standard chemotherapy is common in patients with early breast cancer being treated in community oncology studies. This potentially compromises treatment effectiveness and long-term outcomes. These findings also lay important ground work for further research models to predict which patients are most at risk for severe neutropenia, and who can benefit from prophylactic treatment with G-CDF."

Other sources: Albany Medical Center