Ring-expansion of strained small-size rings to forge larger all-carbon ones, allows a rapid build-up of molecular complexity.

Summary. Between 1972 and 1988, 869 adult patients received MOPP (mechlorethamine, vincristine, procarbazine and prednisone; 462 patients) or ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine; 373 patients) and subsequent high-dose irradiation for Hodgkin's disease. Nine patients developed a leukaemia after MOPP and four after ABVD; 11 patients were diagnosed as acute nonlymphoblastic leukaemia (ANLL) and two as acute lymphoblastic leukaemia (ALL). Both cases of ALL were observed after ABVD and were associated with a 11q23 translocation. The 15-year actuarial risk of secondary leukaemia was 2AE4% for the whole group of patients, 3AE4% after MOPP and 1AE3% after ABVD. For the MOPP subgroup, the risk of leukaemia was significantly associated with the extent of irradiation: 2AE4% for limited irradiation and 13AE9% for extended irradiation (P < 0AE001). For the ABVD subgroup, this risk remained low (1AE3%) whatever the type of irradiation. Concerning ANLL, the MOPP regimen was significantly associated with a higher risk: 3AE4% versus 0AE7% for ABVD (P £ 0AE05). The 15-year risk of ALL was 0AE6 after ABVD regimen. This study demonstrated that ABVD induced less ANLL than MOPP. However, a low risk of ALL with a 11q23 translocation related to topoisomerase II inhibitors was observed.