CHICAGO---Vitamin D supplementation improved the symptoms of fatigue among a cohort of 69 cancer patients, according to a new study presented at the annual meeting of the American Society of Clinical Oncology (ASCO).
"The nuclei of most cells have receptors for vitamin D, which can regulate the expression of more than 200 genes responsible for cell proliferation and apoptosis," said Dragan Trivanovic, MD, head of the oncology and hematology department at Pula General Hospital, Croatia. More than 70% of cancer patients experience a problem with fatigue, he noted.
"It seems that vitamin D is highly important in health and cancer," added Dr. Trivanovic. "More than 50% of healthy adults are vitamin D deficient, and this problem is more advanced in oncology, and especially in breast cancer patients. We also know that higher levels of serum vitamin D at the time of diagnosis are positive prognostic factor in terms of survival rates," he added.
Dr. Trivanovic studied vitamin D supplementation in 69 vitamin D–deficient men and women with cancer who had not yet received chemotherapy. Eligible patients had a variety of types of cancer, had life expectancies of at least six months, and showed a performance standard between zero and three on the Eastern Cooperative Oncology Group (ECOG) scale.
In the prospective trial, patients were randomized into two groups: 34 patients received oral supplementation with cholecalciferol, 2,000 IU per day, for three months, beginning at the time of chemotherapy; 35 patients did not get the vitamin supplement. Investigators evaluated the patients at three months follow-up.
Patients with lung cancer made up 24% of the supplementation group, compared to 25% in the control group. Those with primary colorectal cancer amounted to 24% of those in the experimental group, compared with 23% in the controls. Twenty percent of those patients in the supplementation group had primary breast cancer, compared with 23% in the control group.
At three months, patients in the vitamin D group showed improvement in fatigue, as measured by the Functional Assessment of Cancer Therapy Fatigue scale (FACT-F). However, those in the control arm reported a worsening of their fatigue symptoms. Those in the supplementation arm reported an increase in the FACT-F score of 3.8 points, compared with a decrease of 2.3 points in the control arm (Trivanovic D, et al. J Clin Oncol 30, 2012 (suppl; abstr 9097). A higher FACT-F score equates to lower fatigue, Dr. Trivanovic explained.
Levels of adverse events were acceptable in the group that received the vitamin D intervention, said Dr. Trivanovic. Of those in the experimental arm, 53% reported hematologic adverse event, compared with 49% in the control arm. For non-hematologic events, the numbers were 56% and 51% respectively. Three percent of patients in the control arm experienced a pulmonary embolism; none of the patients in the vitamin D group had this problem.
The study was conducted as part of a multi-center psycho-oncology project. "We prospectively follow cancer patients to study fatigue, vitamin D status, and 'chemo-brain,'" said Dr. Trivanovic, adding that the team also presented a phase II study of 67 patients at ASCO in 2011, which only looked at the safety of vitamin D, and found no safety issues (Trivanovic D, et al. J Clin Oncol 29: 2011 (suppl; abstr e19566)
A big and still unanswered question is whether vitamin D supplementation would have any impact on survival in people with various types of cancer. That, says Dr. Trivanovic, would be difficult to evaluate in a truly scientific manner.
"It is not fair to do a statistical analysis on such a small number of patients. You would have to have perhaps 100 patients, and follow them for ten years to look at effects on survival. We know from a meta-analysis that if the serum vitamin D goes up, that is associated with a reduction in mortality, especially in breast cancer patients. But we don't know what is the right dose, or how long we have to supplement," he said.