Guidelines for Complications of Cancer Treatment Vol VIII Part B

vulva, anal canal and oropharynx) and treatment with RT &CT (eg. rectal, bladder cancers and pelvic sarcomas). In a largestudy of over 1 lakh patients of cervical cancer with longfollow-up, the RR of SMN was 1.3. In last few years cisplatinbased concurrent chemotherapy has become standard of carefor locally advanced cervical cancer; however, its impact onSMN remains to be seen (18).Leukemias: The term secondary leukemia indicates both acutemyeloid leukemia (AML) evolving from previousmyelodysplasia (MDS) and acute leukemia developing afterexposure to environmental or therapeutic toxins or radiation(therapy-related). Secondary leukemias account for 10-30%of all AML. The majority of secondary leukemias resultingfrom the use of cytotoxic drugs can be divided into two welldefined groups depending on whether the patient has received1) alkylating agents or 2) drugs binding to the enzyme DNAtopoisomeraseII. Alkylating agents related leukemias are verysimilar to post MDS leukemias being characterized frequentlyby a preleukemic phase, trilineage dysplasia, frequentcytogenetic abnormalities involving chromosomes 5 and 7 anda poor prognosis. Secondary leukemias related to therapy withtopoisomerase II inhibitors are not preceded by a preleukemicphase and show frequently balanced translocations involvingchromosome 11q23. Therapy related leukemias are a majorproblem in patients treated for Hodgkin’s disease, non-Hodgkin’s lymphoma, myeloma, polycythemia, breast cancer,ovarian carcinoma, or testicular carcinoma.Retinoblastoma: Overall risk of any second malignanciesamongst hereditary retinoblastoma survivors is reported to be20 times higher than the general population. Risk of secondmalignancies amongst survivors of hereditary retinoblastomapatients treated with combination of radiotherapy andchemotherapy is reported to be higher than hereditaryretinoblastoma patients treated otherwise.288