Results of a recent study conducted in California show that patients with the myeloma precursor disease monoclonal gammopathy of undetermined significance (MGUS) do not receive adequate evaluation, follow-up, or treatment for their condition.
Based on their findings, the study authors recommended that these patients receive better care consistent with the guidelines for the management of MGUS produced by the first international consensus MGUS panel in 2009.
"[Because of inadequate evaluation], we are missing patients at risk for bone-related problems, which are more likely to occur in MGUS patients," said Dr. James Berenson of the Institute for Myeloma and Bone Cancer Research and lead author of the study.
According to the study authors, following established guidelines would improve the outcome of MGUS patients by reducing their risk of bone complications and promoting early identification of disease progression.
Dr. Ola Landgren of the U.S. National Cancer Institute, who was not involved in the study, agreed that physicians should follow established guidelines for the management of MGUS.
However, he also indicated that additional research is needed to enable physicians to tailor follow-ups based on the specific risks of each individual.
"We are doing extensive research to figure out the molecular profiles of MGUS patients who progress [to more advanced diseases] and those who do not progress," wrote Dr. Landgren in email correspondence with the Myeloma Beacon.
"Until we have all the molecular data available and fully interpreted, physicians have to follow clinical guidelines and also tailor follow-ups for their patients," he added.
MGUS is the most common plasma cell disorder, characterized by an elevated level of monoclonal protein in the blood. Unlike myeloma patients, however, MGUS patients do not experience any disease-related symptoms and typically do not receive treatment unless their disease worsens.
Results of a large analysis conducted in 2002 indicate that 1 percent of MGUS patients develop multiple myeloma or other serious plasma cell diseases every year. Moreover, nearly all myeloma patients have MGUS for years before developing multiple myeloma, although the MGUS often goes undetected.
Past studies have also shown that MGUS patients have an increased risk of experiencing osteoporosis, leading to fractures (see related Beacon news).
An international panel of myeloma experts met in 2009 to develop the first consensus guidelines for the proper screening and treatment of MGUS.
The panel recommended that MGUS patients receive urine and blood tests to measure their monoclonal protein levels every three to six months for a year following their diagnosis. After that point, they should receive follow-up tests at least every one to two years. In addition, the panel recommended dual-emission X-ray absorptiometry (DEXA) scans for patients to evaluate their bone density. At least half of the panel suggested bone surveys and bone marrow biopsies for all MGUS patients.
In order to evaluate how MGUS patients are currently being evaluated, followed-up, and treated, researchers conducted a retrospective study of 100 patients diagnosed with MGUS at seven different locations in the United States. The patients had a median age of 72 years and were followed-up for a median of 31 months after their diagnosis.
The researchers found that 6 percent of patients experienced at least one bone fracture immediately prior to their diagnosis, and 5 percent of patients experienced at least one fracture after their MGUS diagnosis.
They also found that the MGUS patients did not receive adequate bone-related evaluation and treatment. Although the MGUS guidelines suggest DEXA scans for all patients, only 10 percent of patients in the study received a DEXA scan. Moreover, although most myeloma experts on the panel recommended initial bone surveys for all patients, only 61 percent of patients received a bone survey.
The guidelines also recommend bisphosphonates such as Aredia (pamidronate) or Zometa (zolendronic acid) for MGUS patients with osteoporosis. Of the patients included in the study, only 11 percent received bisphosphonates. The researchers attributed the infrequent administration of bisphosphonates to the under-diagnosis of bone loss in the patient population, since only 10 percent of patients received a DEXA scan at diagnosis.
The researchers also found that at diagnosis, only 13 percent of patients received a urine test to evaluate their monoclonal protein levels. All patients, however, received a blood protein test.
In an interview with the Myeloma Beacon, Dr. Berenson commented that MGUS patients should receive follow-up blood protein tests at least once every six months after their diagnosis. In the study, however, 21 percent of MGUS patients did not receive a follow-up blood protein test. In addition, 23 percent of patients received a follow-up blood protein test once every 12 months or longer.
"The current follow-up of MGUS patients is inadequate because patients are not getting their protein levels and routine blood counts checked frequently enough," explained Dr. Berenson.
During the follow-up period, 4 percent of the MGUS patients developed cancer: 2 percent developed solid tumors, 1 percent multiple myeloma, and 1 percent lymphoma.
For more information, please see the article in Clinical Lymphoma, Myeloma, and Leukemia (abstract).