Therapy-related chronic myeloid leukemia (CML) has been reported, but its clinical presentation and pathologic features have not yet been well characterized.

Twenty-one cases of CML following treatment for primary diseases were collected and retrospectively analyzed.

The clinical presentation, pathologic features, and cytogenetic profile were similar to de novo CML. In particular, those with an isolated Philadelphia chromosome constituted 88.9% of our cases, and additional aberrations characteristic of therapy-related acute myeloid leukemia/myelodysplastic syndrome (AML/MDS) were not identified in this study. The patients responded to imatinib/derivatives and survived with limited follow-up.

Therapy-related CML has a clinical presentation, pathologic features, and cytogenetic profile akin to de novo CML. Absence of additional significant aberrations seems to suggest a pathogenesis different from therapy-related AML/MDS. Therapy-related CML exhibits a robust therapeutic response to imatinib/derivatives and favorable clinical outcomes similar to de novo CML.

Therapy-related acute myeloid leukemia (t-AML) refers to a heterogeneous group of myeloid neoplasms that develop in patients following extensive exposure to either cytotoxic agents or radiation. The development of t-AML has been reported following treatment of cancers ranging from hematological malignancies to solid tumors; however, to our knowledge, t-AML has never been reported following treatment of gastric cancer. In this study, we report the development of t-acute promyelocytic leukemia in a cT4N1M0 gastric cancer patient after an approximate 44 mo latency period following treatment with 4 cycles of oxaliplatin (OXP) (85 mg/m(2) on day 1) plus capecitabine (1250 mg/m(2) orally twice daily on days 1-14) in combination with recombinant human granulocyte-colony stimulating factor treatment. Karyotype analysis of the patient revealed 46,XY,t(15;17)(q22;q21)[15]/46,idem,-9,+add(9)(p22)[2]/46,XY[3], which, according to previous studies, includes some "favorable" genetic abnormalities. The patient was then treated with all-trans retinoic acid (ATRA, 25 mg/m(2)/d) plus arsenic trioxide (ATO, 10 mg/d) and attained complete remission. Our case illuminated the role of certain cytotoxic agents in the induction of t-AML following gastric cancer treatment. We recommend instituting a mandatory additional evaluation for patients undergoing these therapies in the future.

Therapy-related leukemia (TRL) has been reported to occur after treatment with alkylating agents and/or topoisomerase II inhibitors. Oxaliplatin (OXP) is used as a key drug for the treatment of colorectal cancer (CRC). Cisplatin and carboplatin have been linked with TRL, but the involvement of OXP is questionable. A 74-year-old male was diagnosed with peritoneal metastasis from CRC in July 2011. The patient received nine cycles of 5-fluorouracil (5-FU), leucovorin (LV), and OXP (mFOLFOX-6 regimen) and three cycles of 5-FU and LV only, resulting in a clinical complete response. However, recurrence of CRC was detected by CT within 3 months after the last course of chemotherapy. In April 2013, laboratory tests showed pancytopenia and 15% blast cells. A bone marrow examination revealed multilineage dysplasia and 20.4% myeloblasts. Cytogenetic analysis indicated a complex karyotype that included chromosome 5 and 7 abnormalities. The patient was diagnosed with TRL and treated with a combination of azacitidine (AZA) and cetuximab (Cmab) for both cancers. AZA might be useful in TRL when a patient needs to be treated simultaneously for more than one primary cancer because of its low toxicity. Moreover, Cmab is an effective therapeutic tool in TRL patients with metastatic CRC with the wild-type K-ras gene.

Solid tumors may occur in 3% of the patients with chronic myeloid leukemia (CML). Philadelphia (Ph)-positive CML was diagnosed in a 66-year-old man upon a white blood cell count of 58.1 x 10(9)/L. He had no symptoms and physical findings 3 years after treatment for rectal adenocarcinoma. Imatinib mesylate 400 mg/day was started and white blood cell count was lowered to 5.7 x 10(9)/L in 1 month. The patient had received several chemotherapeutic agents such as 5-fluorouracil, irinotecan, raltitrexed, capecitabine, and oxaliplatin. In the literature, there are two reports on CML after the treatment of colorectal carcinoma. The possibility of a relationship between oxaliplatin and/or irinotecan and CML may not be fully excluded. In conclusion, hematological disorders such as CML may emerge in colorectal carcinoma and whole blood counts should be carefully checked. The possibility of a relationship between CML and the chemotherapeutic agents in colorectal carcinoma should be further evaluated.