Long-term survival after high-dose chemotherapy with autologous hematopoietic cell transplantation in metastatic breast cancer

Objective/background: The most common indication for high-dose chemotherapy (HDC) and autologous hematopoietic cell transplantation (AHCT) in the 1990s was breast cancer. Several randomized trials and a more recent meta-analysis failed to show a survival benefit for AHCT in metastatic breast cancer (MBC); however, they demonstrated a better-than-expected 10-year to 15-year survival in 5–15% of patients. We thus evaluated the long-term results of treatment with HDC and AHCT in MBC at our institution. Methods: From 1984 to 2000, 285 patients underwent AHCT for MBC. The patient characteristics were collected through the Cleveland Clinic, United Transplant Database. A retrospective review of the medical records of the long-term surviving breast-cancer patients treated with HDC and AHCT was conducted. Results: With a median follow-up of 169 months, 34 (12%) remain alive. Of the 251 patients who died, 218 (87%) died of metastatic disease. A comparison by age (50 years) and hormonal status did not demonstrate any differences in relapse (p = .33 and p = .32, respectively) or survival (p = .13 and p = .42). Of the 34 long-term survivors, sufficient data were available on 28 patients, and further evaluation revealed that the majority had a primary or locally recurrent oligometastatic disease. Conclusion: This retrospective evaluation of patients who underwent AHCT for MBC demonstrates long-term survival in a small subset of patients, primarily those with primary or recurrent oligometastatic disease. Oligometastatic breast cancer is a distinct entity within MBC, which may be curable with multimodality therapy. We thus conclude there remains no overall-survival benefit to HDC in MBC. Keywords: Autologous hematopoietic cell transplant, High-dose chemotherapy, Oligometastatic breast cance

Impact of allogeneic hematopoietic cell transplant in patients with myeloid neoplasms carrying spliceosomal mutations

Molecular predictors of outcome are increasingly important in determining optimal therapy for myeloid neoplasms. Mutations in the spliceosomal genes (U2AF1 and SRSF2) predict for poor outcomes in myelodysplastic syndromes (MDS) and related diseases. We investigated the effect of hematopoietic cell transplant (HCT) on the negative prognostic impact of U2AF1 and SRSF2 mutations. In total, 122 patients with MDS (30%), acute myeloid leukemia (51%), myeloproliferative neoplasms (MPN) (11%), and MDS/MPN (8%) receiving a HCT from 2003 to 2012 were evaluated for mutations in U2AF1 and SRSF2 by direct sequencing. Median time of follow up was 24 months (range 0.46-110). SRSF2 mutations were detected in 11 (10%) patients and U2AF1 in 3 (3%) patients. There were no significant differences in baseline characteristics between mutated and wild-type (WT) patients. Patients carrying SRSF2 and U2AF1 mutations had similar overall survival (P = 0.84), relapse mortality (P = 0.50), and non-relapse mortality (P = 0.72) compared to WT patients. However, taking into account disease status and cytogenetics in a subset of AML patients, SRSF2 and U2AF1 mutations were associated with worse survival (HR 3.71, P = 0.035)

T-cell large granular lymphocytic leukemia evolution post-transplant: The Cleveland Clinic experience

e19072 Background: T-cell large granular lymphocytic leukemia (LGLL) has been reported after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT); yet its underlying pathophysiological evolution has been poorly explained. Methods: We retrospectively screened a cohort of 243 LGLL patients at Cleveland Clinic for disease development post-transplantation and postulated several possible responsible pathophysiological mechanisms. Results: Five percent (n = 12) of the patients had a history of transplant. Of these, 67% (n = 8) had SOT (kidney, liver or heart) while 33% (n = 4) had HSCT. Twenty-five percent were females while 75% were males. The median age was 56 years (range: 15-65). The median time from transplant to diagnosis was 7 years. Conventional cytogenetic showed normal karyotype in 89% of the patients. TCR gene re-arrangement by PCR was detected in all tested individuals. Targeted deep sequencing identified somatic STAT3 mutations in 17% (n = 2) of the cases. Fifty percent (n = 6) had EBV DNA, IgM and/or IgG post-transplant. Forty-two percent (n = 5) had CMV DNA, IgM and/or IgG; of which 80% (n = 4) were post-transplant and 20% (n = 1) pre-transplant. The median survival from disease diagnosis was 64.3 months (8.37-232.9). Indeed, T-LGL clonal expansion resulted from long-term stimulation by viral antigens including EBV and CMV causing continuous cytotoxic T cell immune response or by “oncomodulation” as explained in 83% of patients. The latter theory suggests that CMV infects tumor cells and modulates their malignant properties, without direct transformation. Immunosuppression in setting of pre-transplant exposure to CMV, caused reactivation of the latent oncogenic viral genome as seen in 8% of patients. In 17% of cases that were seronegative for viral genome, graft allo-antigenic stimulation has triggered long-term recipient LGLL expansion from antigenic mismatch. Somatic STAT3 mutations, which are highly expressed in leukemic LGL, has led to aberrant signaling and transformation (17%). Conclusions: Our study highlights the complex nature of LGLL evolution post SOT and HSCT and points out confounding mechanisms. Certainly, investigating pre- vs. post-transplantation baseline, clinical and molecular characteristics is warranted to deeply understand this phenomenon

Impact of allogeneic hematopoietic stem cell transplant (HSCT) on patients harboring the spliceosome mutation SRSF2

7008 Background: Molecular predictors of outcome are increasingly important in determining optimal therapy for myeloid neoplasms. Mutations (mut) in spliceosome genes U2AF1 and SRSF2 predict poor outcome in MDS and related diseases. The purpose of this study was to investigate the role of HCT on the prognostic impact of U2AF1 and SRSF2 in myeloid malignancies. Methods: 123 patients (pts) with MDS (33%), AML (51%), MPN (10%), and MDS/MPN (5%) receiving an allogeneic HCT from 2003-2012 for whom genomic DNA was available from a time when the disease was active, were evaluated for mut in U2AF1 and SRSF2 by direct sequencing. Data were analyzed using competing risks methods (relapse and non-relapse mortality, NRM), proportional hazards (overall survival, OS) and logistic regression models (GVHD). Results: Median time of follow up was 38 months (range 1.5-108). Median age at HCT was 51 yrs (range 18-71). 53 (43%) pts were in remission and 70 (57%) had active disease prior to HCT. 20 (16%) pts had low, 48 (39%) intermediate and 32 (26%) high risk cytogenetics respective to their disease, (per CALGB criteria for AML, IPSS-MF for MPN and IPSS-R for MDS), with missing data on 23 (19%) pts. 89 (72%) had myeloablative transplants, and 34 (28%) received reduced intensity regimens. 54 (44%) had related, 52 (42%) unrelated and 17 (14%) cord blood donors. SRSF2 mut were detected in 13 (11%) pts and U2AF1 in 2 (2%) pts. Due to the low incidence of U2AF1 mut in our cohort, further analysis was focused on SRSF2. There were no significant differences in baseline characteristics between mut and wild-type (wt) pts except SRSF2 mut tended to occur in older AML pts (median age 64 vs 50 yrs, p=0.0004). SRSF2 mut and wt had similar OS (p=0.95), relapse (p=0.28), NRM (p=0.45) and rates of acute (p=0.41) and chronic (p=0.67) GVHD. Results were similar, adjusting for factors such as age, disease type, cytogenetics, comorbidity, transplant type and stem cell source. Conclusions: SRSF2 has previously been associated with dismal outcomes in MDS pts, with 5 yr-OS of <20%. In this cohort of transplanted pts, SRSF2 mut had similar outcomes to wt, suggesting HSCT may compensate for the adverse impact of SRSF2