P-0226 Colorectal Cancer as a Second Malignancy in Patients with Chronic Myeloid Leukemia – Incidence and Treatment Tactics

Abstract

ABSTRACT Introduction Occurrence of second neoplasia in patients with chronic myeloid leukemia (CML) is a rare event - especially colorectal cancer (CRC). There are difficulties in choosing treatment strategy of two concurrent diseases, in particular, continuation of therapy for maintenance of cytogenetic or molecular remission of CML and radical treatment for CRC. The purposes of the work are: to assess frequency of CRC in patients with CML, registered in industrial region of Ukraine with population of 5.2 million inhabitants within the period of 2002 - 2011, as well as to assess connection between CRC frequency and previous treatment (chemotherapy / interferon / imatinib mesylate) and to evaluate retrospectively treatment tactics for patients with early CRC, locally advanced and metastatic CRC. Methods The analysis of 10-year period data provided by regional branches of the National Cancer Registry of Ukraine on number of patients registered with diagnosis of CML, as well as data on registration of colorectal cancer cases within this patients` group have been performed. The treatment tactics and status of CML patients at time of detection of colorectal cancer (complete remission, progression to accelerated phase or blast crisis), as well as time interval from the date of registration of CML to time of CRC detection have been evaluated. Results According to data of regional branch of the National Cancer Registry of Ukraine there were 4 cases of CRC out of 443 CML patients (0.9%) within the period of 2002 - 2011. Median observation of patients with the CML before detection of CRC was 24.5 months. Three patients with CML (75%) were in phase of cytogenetic or molecular remission at the moment of detection of CRC. Only one CML patient received imatinib mesylate as a first line therapy with cytogenetic and large molecular remission duration of 31 months. Sigmoid colon cancer (low-differentiated adenocarcinoma) was diagnosed in the TNM stage pT4pN1M0G3. Radical resection of the sigmoid colon was performed with subsequent adjuvant chemotherapy. At that, imatinib mesylate therapy (400 mg daily) was not interrupted. No significant side effects were observed. Conclusion Occurrence of second malignancy of CRC in CML patients corresponds to CRC frequency of Ukrainian population of appropriate age. Continuation with imatinib mesylate therapy may take place subject to relevant indications for chemotherapy of CRC. The toxicity of this combination therapy is acceptable.