Elihu H. Estey, MD: leukemia expert, statistician, and gentle soul (July 15, 1946–October 8, 2021)

It is known that complete remission (CR) prolongs survival in acute myeloid leukemia (AML). In 2003, less stringent response categories were introduced, most notably CR with incomplete platelet recovery (CRp). Although the significance of CRp for survival remains unclear, reports of AML trials frequently combine CR with CRp rather than considering CR as a separate entity.

In this Perspective, the late Elihu Estey, along with Robert P. Hasserjian and Hartmut Döhner, argues for approaching patients currently identified as having either low-blast-count acute myeloid leukemia (AML; blasts 20%-30%) or myelodysplasia (MDS) with excess blasts 2 (MDS-EB2; blasts 10%-19%) as having the umbrella entity AML-MDS. They suggest that this reflects biological reality and could allow flexibility for enrollment in trials of new therapies, thereby speeding studies translatable into clinical practice. Patients with acute myeloid leukemia (AML) have conventionally received more intense therapy than patients with myelodysplastic syndrome (MDS). Although less intense therapies are being used more often in AML, the dichotomy between AML and MDS remains, with the presence of ≥20% myeloblasts in marrow or peripheral blood generally regarded as defining AML. Consequently, patients with 19% blasts are typically ineligible for AML studies, and patients with 21% blasts are ineligible for MDS studies. Here we cite biologic and clinical data to question this practice. Biologically, abnormalities in chromosome 3q26 and mutations in NPM1 and FLT3 , regarded as AML associated, also occur in MDS. The genetic signatures of MDS, particularly cases with 10% to 19% blasts (MDS-EB2), resemble those of AML following a preceding MDS (secondary AML). Mutationally, secondary AML appears at least as similar to MDS-EB2 as to de novo AML. Patients presenting with de novo AML but with secondary-type AML mutations seem to have the same poor prognosis associated with clinically defined secondary AML. Seattle data indicate that after accounting for European LeukemiaNet 2017 risk, age, performance status, clinically secondary AML, and treatment including allogeneic transplantation, patients with World Health Organization–defined AML (n = 769) have similar rates of overall survival, event-free survival, and complete remission (CR)/CR with incomplete hematologic recovery as patients with MDS-EB2 (n = 202). We suggest defining patients with 10% to 30% blasts (AML/MDS) as eligible for both AML and MDS studies. This would permit empiric testing of the independent effect of blast percentage on outcome, allow patients access to more therapies, and potentially simplify the regulatory approval process.

A neutropenic diet is often used to prevent infection in patients with acute myeloid leukemia (AML). Although such a diet potentially entails inconvenience, its value is uncertain. One hundred fifty-three patients admitted to a high-efficiency particulate air-filtered room (protected environment [PE]) to receive induction therapy for newly diagnosed AML were randomly assigned to a diet containing no raw fruits or vegetables (cooked diet) or to a diet containing fresh fruit and fresh vegetables (raw diet). Stratification was based on the patients' early risk of mortality (ERM) score. All patients received antibacterial and antifungal prophylaxis and remained on study until they were discharged from the PE. The outcomes of principal interest were major infection (pneumonia, bacteremia, or fungemia) and death; if the true probability of either event was 20% on the cooked arm and 40% on the raw arm, then the probability that the cooked arm would be selected as superior was 83%. Seventy-eight patients were randomly assigned to the cooked arm, and 75 were assigned to the raw arm. The two groups were similar with respect to age, ERM, chemotherapy received, and days at risk. Twenty-nine percent of patients in the cooked group and 35% of patients in the raw group developed a major infection (P = .60). Time to major infection and survival time were similar in the two groups. Fever of unknown origin occurred in 51% of the cooked group and 36% of the raw group. In patients treated in a PE, a neutropenic diet did not prevent major infection or death.