[A case of therapy-related acute myeloid leukemia associated with inv(16)]

Therapy-related myeloid neoplasms in 39 Korean patients: a single institution experience

Background

Therapy-related myeloid neoplasms (t-MN) occur as late complications of cytotoxic therapy. This study reviewed clinical and cytogenetic characteristics of patients with t-MN at a single institution in Korea.

Methods

The study subjects included 39 consecutive patients diagnosed with t-MN. Each subject's clinical history of previous diseases, treatments, and laboratory data was reviewed, including cytogenetics. The primary diagnosis was hematologic malignancy in 14 patients and solid tumor in 25 patients.

Results

Therapy-related acute myeloid leukemia (t-AML, 66.7%) was found to be more common than therapy-related myelodysplastic syndrome (t-MDS). Primary hematologic malignancies that were commonly implicated included mature B-cell neoplasm and acute leukemia. Breast cancer was the most common primary solid tumor. The mean time interval from cytotoxic therapy initiation to t-MN detection was 49 months. Chromosomal aberrations were observed in 35 patients, and loss of chromosome 5, 7, or both accounted for 41% of all cases. Balanced rearrangements occurred in 13 patients; these patients showed shorter latency intervals (mean, 38 months) than patients with loss of chromosome 5 or 7 (mean, 61 months).

Conclusions

In this study, we determined the clinical and cytogenetic characteristics of Korean patients with t-MN. Although our results were generally consistent with those of previous reports, we found that t-MN resulting from de novo leukemia was common and that t-AML was more common than t-MDS at presentation. Multi-institutional studies involving a larger number of patients and additional parameters are required to investigate the epidemiology, genetic predisposition, and survival rate of t-MN in Korea.

A case of therapy-related ALL with MLL gene rearrangement following treatment of breast cancer

ALL with MLL gene rearrangement secondary to chemotherapy has been rarely reported. We report a case of therapy-related ALL (t-ALL) with MLL gene rearrangement in a patient who had undergone treatment for breast cancer. A 60-yr-old woman with breast cancer underwent breast-conserving surgery followed by 6 cycles of adjuvant chemotherapy (cyclophosphamide, epirubicin, and fluorouracil) and radiation therapy (dose, 5,040 cGy to the left breast and a 1,000 cGy boost to the tumor bed). A follow-up examination performed 14 months after the chemotherapy revealed no evidence of breast malignancy. However, the patient's complete blood cell count indicated acute leukemia: white blood cell count, 174.1 x 10(9)/L with 88% blasts; Hb level, 12.5 g/dL; and platelet count, 103.0 x 10(9)/L. Examination of the bone marrow aspirate smear revealed a high percentage of blasts (85.1% of all nucleated cells); the blasts showed a pro-B immunophenotype and were positive for CD19, CD79a, HLA-DR, CD34, and terminal deoxynucleotidyl transferase (TdT). Cytogenetic and FISH analyses revealed t(4;11)(q21;q23) and MLL gene rearrangement, respectively. The patient received induction chemotherapy with cyclophosphamide, vincristine, doxorubicin, and dexamethasone and achieved complete remission. Following consolidation chemotherapy, she underwent allogenic peripheral blood stem cell transplantation and has been clinically stable. To our knowledge, this is the first reported case of t-ALL with MLL gene rearrangement following treatment of breast cancer in Korea.

Acute leukemia in women

The treatment and survival outcome of acute leukemia in women is generally similar to that of men. However, acute leukemia in women poses additional challenges in clinical practice. In addition to important precautions during therapy, such as prevention of abnormal uterine bleeding in premenopausal women and therapy during pregnancy, women who are survivors of acute leukemia face unique and potentially long-term health-related problems. In this review, we address the aforementioned issues, as well as the various health and psychosocial challenges faced by women who survive childhood leukemia during their path to adulthood. Finally, we address the issue of therapy-related acute leukemia in the category of women who are survivors of breast and ovarian cancer.