Metabolic phenotyping of human blood plasma: a powerful tool to discriminate between cancer types?

BACKGROUND: Accumulating evidence has shown that cancer cell metabolism differs from that of normal cells. However, up to now it is not clear whether different cancer types are characterized by a specific metabolite profile. Therefore, this study aims to evaluate whether the plasma metabolic phenotype allows to discriminate between lung and breast cancer. PATIENTS AND METHODS: The proton nuclear magnetic resonance spectrum of plasma is divided into 110 integration regions, representing the metabolic phenotype. These integration regions reflect the relative metabolite concentrations and were used to train a classification model in discriminating between 80 female breast cancer patients and 54 female lung cancer patients, all with an adenocarcinoma. The validity of the model was examined by permutation testing and by classifying an independent validation cohort of 60 female breast cancer patients and 81 male lung cancer patients, all with an adenocarcinoma. RESULTS: The model allows to classify 99% of the breast cancer patients and 93% of the lung cancer patients correctly with an area under the curve (AUC) of 0.96 and can be validated in the independent cohort with a sensitivity of 89%, a specificity of 82% and an AUC of 0.94. Decreased levels of sphingomyelin and phosphatidylcholine (phospholipids with choline head group) and phospholipids with short, unsaturated fatty acid chains next to increased levels of phospholipids with long, saturated fatty acid chains seem to indicate that cell membranes of lung tumors are more rigid and less sensitive to lipid peroxidation. The other discriminating metabolites are pointing to a more pronounced response of the body to the Warburg effect for lung cancer. CONCLUSION: Metabolic phenotyping of plasma allows to discriminate between lung and breast cancer, indicating that the metabolite profile reflects more than a general cancer marker. CLINICAL TRIAL REGISTRATION NUMBER: NCT02362776.

Registration of interstitial lung diseases by 20 centres of respiratory medicine in Flanders.

We report the results of a prospective registration of the prevalence of interstitial lung diseases by 20 centres of respiratory medicine in Flanders from January 1992 till July 1996. The 20 centres registered a total of 362 cases. Sarcoidosis (31% with inclusion of stage I, or 22% without stage I), idiopathic pulmonary fibrosis (20%), hypersensitivity pneumonitis (13%) and unclassified forms of interstitial lung diseases (9%) were the most often diagnosed diseases. The mean age of the patients was 52 +/- 17 (SD) years, but ranged from 32 +/- 10 years in histiocytosis X to 70 +/- 13 years in drug induced interstitial lung diseases. The male to female ratio was 1.3 but ranged from 2.3 in interstitial lung diseases due to inhalation of inorganic materials to 0.8 in interstitial lung diseases due to connective tissue disease. The diagnosis was considered certain in 60%, probable in 30% and possible in 10%. In 50% of the cases the diagnosis was proven by biopsy and the most often used biopsy technique was transbronchiolo-alveolar biopsy (40% of biopsies) followed by open lung biopsy (32%). At diagnosis vital capacity was 82 +/- 22% pred. (ranging from 92 +/- 19% in sarcoidosis to 71 +/- 24% in idiopathic pulmonary fibrosis) and CO-diffusing capacity was 77 +/- 19% pred. (ranging from 77 +/- 19% in sarcoidosis to 41 +/- 13% in drug induced pneumonitis). The regional frequency of interstitial lung diseases in Flanders varied widely and was not proportional to the regional distribution of the 20 contributing centres. In conclusion this registration provides interesting information on the occurrence and presentation of the different forms of interstitial lung diseases, although it may still underestimate the real prevalence and incidence of interstitial lung diseases.

Pulmonary histiocytosis X diagnosed by bone biopsy. Report of a case.

Histiocytosis X of the lung is associated with bone lesions in 4 to 20%. We report a case in which the diagnosis was missed in spite of repeated bronchoscopies with transbronchial lavage. The diagnosis was finally established by isotope bone scan, subsequent skeletal CT-scan and bone biopsy.