Dimethyl Trisulfide as a Characteristic Odor Associated with Fungating Breast Cancer Wounds.
Authors: Shirasu M. , Touhara K. , Ochiai A. , Hayashi R. , Nagai S. 
Published: December 2010

Abstract
Background: Some advanced cancer patients suffer from unpleasant odor from their fungating wounds. The fungating wounds have been reported to occur in about 5% of patients with cancer. These wounds are usually superinfected with bacteria, and therefore, the infected area tends to emit malodor. However, the odorant(s) causing the malodor has not been revealed. Here we aim to determine the chemical identity of the cancer wound-derived odor(s). Results: We examined three female patients with breast cancer (B1; stage IV, B2; stage IIIB, B3; stage IV) and two male patients with head and neck cancer (H1; stage III, H2; stage IVA). First, we evaluated the intensity and quality of body odors emitted from the fungating wounds of patients. All of them had a similar pungent sulfury odor. In addition to the sulfury odor, B1and B2 had a cheese-like odor and B3, H1 and H2 had a rotten fish odor. Next, we analyzed the malodor emitted from the wounds of each patient. Sterile gauze pads were placed on fungating wounds of the patients for 6-12h. The head-space volatiles of pads were extracted onto SPME fibers for 2h. The compounds on the SPME fibers were then analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) that enabled us to examine mass spectra and odor qualities of individual GC-separated odorants simultaneously. GC-MS-O analysis and evaluation of body odors were performed by three persons. As a result, the sulfury odor, which was the same as the odor we identified in body odors of all patients, came out at the retention time (RT) of 19.46min. Cheese-like odors in B1 and B2 patients came out at RT=24.01min, 25.47min and 26.08min. The structure of dimethyl trisulfide (DMTS) was predicted by the mass spectrum of the peak around 19.5min. The mass spectrum and the RT of authentic DMTS were identical to those of the peak compound, demonstrating that the sulfury odor at 19.46min was DMTS. Comparing the odor quality and intensity of various concentrations of DMTS solutions and cancer samples, we conclude that DMTS is emitted from the cancer wounds at the level significant enough to make ones feel uncomfortable. We also identified the structure of compounds with cheese-like odors: isobutyric acid for the cheese odor (24.01min), butyric acid for the cheese and vomit odor (25.47min), and isovaleric acid for the cheese and feet odor (26.08min). Discussion: We identified DMTS as the main odorant that caused the severe malodor in some advanced cancer patients. DMTS has been found in volatiles emitted from vegetables such as cooked onion. DMTS is also reported to be produced by aerobes such as Pseudomonas aeruginosa that reside in leg ulcers. Thus, although the source of DMTS found in the fungating cancer wounds in this study remains to be elucidated, DMTS may be a product of infected bacteria in fungating wounds. To improve the QOL of patients, the development of the way to prevent or reduce the DMTS odor is awaited. Indeed, almost all patients with fungating wounds are suffering from this malodor. Our results provide new insights into the better strategies toward the treatment of malodor in cancer patients.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5042.