Non-Candida Yeasts Fungemia in Cancer Patients

Abstract

This study examined the characteristics and risk factors associated with non-Candida fungemia. It is important to diagnose early and distinguish from Candida species because of the high mortality rate in non-Candida yeast fungemia. We performed a retrospective analysis of patients with cancer from 1999 to 2014 at Moffitt Cancer Center in Tampa, Florida with a positive blood cultures for non-Candida yeast. Nine patients were identified. Types of malignancy included both hematological and solid tumors. All patients received cytotoxic chemotherapy and were on prophylactic antifungal therapy. Five patients were diagnosed with Trichosporon species. Risk factors included prolonged neutropenia, hematological malignancy, hematopoietic stem cell transplantation (HSCT), chemotherapy and immunosuppressive therapy. We found a very high mortality rate in patients with non-Candida yeast fungemia with refractory and end-stage cancer. This demonstrated the need for early identification of non-Candida fungemia. In addition, many of these patients had prolonged neutropenia and a refractory malignancy as significant risk factors. There were 9 patients with positive blood cultures for non-Candida yeasts in our study. The most common non-Candida yeasts were Trichosporon species. The majority of the patients had a hematological malignancy. All patients received cytotoxic chemotherapy, and most of them were refractory to treatment with end-stage hematological malignancy. Prolonged neutropenia was found in the majority of the patients receiving chemotherapy. All patients were receiving potent antifungal therapy, such as liposomal amphotericin B, micafungin, posaconazole, or voriconazole, either alone or in combination, when breakthrough infection occurred. The central venous catheter was removed in all patients. However, prolonged fungemia persisted in all patients despite removal. We found a very high mortality rate in patients with non-Candida yeast fungemia with refractory malignancy. Yeast-related sepsis was the cause of death in most of the patients. Ongoing neutropenia was found at the time of death in most of the patients with yeast-related death. Non-Candida yeast fungemia is rare but associated with significant mortality. They usually occurred as breakthrough fungemia while on antifungal prophylaxis. Thus, in vitro susceptibility testing should be performed on all isolates, and antifungal therapy should be modified or broadened pending identification and susceptibly results. Without resolution of neutropenia and oncologic control of the malignancy, outcomes are poor.