Serum metabolism during breast cancer treatment.

Abstract

e23043 Serum metabolism during breast cancer treatment Background: Breast cancer treatment may include surgery, systemic therapy and radiation, often involving side-effects. Many patients experience weight gain during treatment, which is associated with decreased survival rates1. The purpose of this study was to describe serum metabolic alterations in breast cancer patients undergoing treatment, and relate these alterations to weight gain during treatment. Methods: This pilot study includes 60 breast cancer patients, aged 35-75 years, with histologically verified stage I/II disease. All patients underwent tumor surgery, and were treated according to national guidelines. Samples were collected before and 6 months after surgery, and analyzed by MR spectroscopy (MRS) and mass spectrometry (MS). 170 metabolites and 105 lipoprotein subfractions were quantified by combined MRS and MS analyses. Results: Multilevel PLS-DA showed significant alterations in serum metabolite profiles post-treatment, both in patients receiving (n = 35) and not receiving (n = 25) chemotherapy (classification accuracy: 86.7% and 77.0%, resp., p < 0.001). Lipoprotein profiles were also significantly altered in both groups (p < 0.001). Chemotherapy recipients had decreased levels of citrate, ornithine, and methionine after treatment, while non-recipients had increased levels of glutamate, alanine, proline and two biogenic amines, and decreased levels of acylcarnitines. 17/52 patients (32.7%) gained weight (≥ 1.5 kg) during treatment. Weight gain was predicted from pre-treatment samples with accuracy 67.0% (p = 0.020). Weight gain patients had lower levels of three acylcarnitines and 20 phosphocholines, and higher levels of lysine and isoleucine, suggesting aberrant lipid and amino acid metabolism. Weight gain was also reflected in the post-treatment samples (accuracy 66.8%, p = 0.015), with weight gain patients having higher levels of five acylcarnitines, and lower levels of glycine, isoleucine and valine. Conclusions: This study indicates that treatment induces changes in serum metabolite levels. Patients gaining weight had significantly different metabolite profiles than those not gaining weight both before and after treatment. 1. Chan et al, Ann Oncol 25: 1901-14, 2014.