Dear Editor, We have read with great interest the paper by Einhorn et al. [1], entitled “Antiemetic therapy for multiple-day chemotherapy and additional topics consisting of rescue antiemetics and high-dose chemotherapy with stem cell transplant: review and consensus statement,” in particular the “High-dose chemotherapy” section, in which the authors rightly point out the difficulty in defining evidence based guidelines in the setting of high-dose chemotherapy and hemopoietic stem cell transplant (HSCT); in this regard however, we think we can provide a contribution, examining, with some valuable clarification, aspects which we feel may be responsible for the current difficulties of chemotherapy-induced nausea and vomiting (CINV) management in this setting. Variations in ages, gender and diagnosis are certainly barriers to adequate epidemiological analysis and evaluation of therapeutic and prophylactic measures effectiveness, as stated by authors. Conversely, conditioning regimens for the different diseases vary less, when compared to first-line treatments, often being the same for groups of diseases, both in autologous (e.g., BEAM in lymphoma), and perhaps evenmore in allogeneic transplant, where treatment — having mostly myeloablative and immunosuppressive function — is often identical for different disease groups. On the other hand, the predominantly inpatient management of HSCT also facilitates monitoring and assessment of CINV in these patients. Multiple days and often multiple daily doses regimen, commonly used as condition for HSCT, not doubtfully represents the biggest barrier both to categorization of emetogenic risk (lack of evaluation methodologies for emesis from multiple drugs administration) and possibility to deduce a CINV prophylactic guidelines for such a regimens. However, not all condition regimens include multiple days’ administrations. Indeed, one of the most commonly used regimens, MEL200, provides for a single-day administration of high dose melphalan alone, therefore representing as an ideal test-bed for the study of high-dose therapy effects, whose CINV prophylaxis, should be, in our opinion, the encoded three drugs schedule for HEC regimens (aprepitant, dexamethasone and 5-HT3 receptor antagonist) [2]. Stem cell infusion is one of the least studied and reported confounding factors. Actually, nausea and vomiting are reported among the side effects of the cryopreservation mean dimethyl sulfoxide (DMSO), and cytokine release from infused non-viable cells may also potentially induce similar effects [3]. Supportive A. Tendas (*) :A. Bruno : L. Cupelli : P. Niscola : T. Dentamaro : P. de Fabritiis Hematology, S. Eugenio Hospital, Piazzale dell’Umanesimo 10, Rome 00144, Italy e-mail: tendas.andrea@aslrmc.it