Second malignancy--a rare phenomenon.

The development of a second malignancy, in the same patient, with a different histologic type and/or morphological site is an increasingly appreciated phenomenon in cancer patients. Factors incriminated for this development include genetic makeup of an individual, cytotoxic chemotberapeutic intervention for the first malignancy, radiation therapy, endocrine therapy and immunotherapy. Second malignancy is more frequently associated with a first haematological malignancy in childhood. The time difference between the development of two malignancies and the actual risk of developing subsequent second malignant neoplasmis highly vanable ,yet it is directly proportional to the clinical stage of first malignancy at the time of initial diagnosis. The precise mechanism by which a second malignant neoplasm develops is not yet fully understood but exposure to a shared mutagen, abnormal onoogene activation, or an aberrant expression of tumour suppressor genes ate usually implicated”. This study reports the local experience of second malignancy in a teaching hospital atKamchifmrn 1991-1996. malignant neoplasm, at a different site/organ and having a different histopathological variant proven on biopsy, were included inthe analysis. Turnours exhibitingamixedortotally undifferentiated/anaplastic histology were excluded from the study and so were the cases having an incomplete information orwithout documentary evidence of diagnosis. A total of 2417 cases of malignant neoplasm with a proven histopathological diagnosis were seen from 1991-1996 with a male to female ratio of 1.2:1 (1359 males and 1058 females). Second histologically proven malignancy was found in3 1(1.3%) cases. No case ofa third or subsequent malignancy was found in this series. The youngestpatient was 23 years of age and the oldest 72 years. Majority of the cases (77.4%) were between 35-64 years of age with a mean age of 50.6 years and a male to female ratlo of 1.6:1. Average interval between the occurrence of first and second malignancy was 2.5 years (range 7 months to 7 years). In 58% cases, one of the two malignancies was either haeniatopoietic or lymphoid in origin (Table I). The tumours were representative of almost all the morphological sites. Twenty-seven cases had treatment for the first malignancy (Table II), which included radiotherapy, chemotherapy, surgery, endocrine therapy or any combination. Twenty-six percent cases had received radiotherapy for their first malignancy and sixtyone peitent were given chemotherapy either alone or as combined modality treatment.