Synchronous and metachronous malignant tumours expect the unexpected.

Objective: To evaluate occurrence of synchronous and metachronous malignant tumours, to find tumour types, age group, and relationship to treatment received.

Methods: Previously diagnosed 1st primary tumour cases experiencing a synchronous or metachronous tumour, seen at AOI from February 2003 to August 2009 (78 months) were included. The cases were analyzed for morphology/histology of 1st primary tumour, age and gender of patient, treatment received for first tumour, time interval between the 1st and 2nd primary tumour, morphology/histology of second tumour, and the treatment conferred for 2nd tumour.

Results: The 2nd synchronous and metachronous tumours were 46/4025 (1.14%), in 18 males and 28 females (M:F 1:1.6). The age range was 16-75 years (median 43 years). The follow up time was 24-150 months. The time to 2nd primary tumour was 2-132 months. The 1st primary tumours were breast, ovary, GIT and urinary bladder. The patients received surgery, radiotherapy, chemotherapy, and hormonal therapy alone or as multi-modality treatment for the 1st tumours. The frequent 2nd tumours were breast, ovary and Gastro Intestinal tumours.

Conclusion: It is imperative that patients with a primary malignant tumour should be thoroughly, closely, and regularly followed. Genetic counseling, risk estimation, cancer screening and chemoprevention must be emphasized. Every subsequent occurring tumour should be biopsied. The effect of 1st tumour on the 2nd or vice versa are still not fully understood and need exploration. The 2nd primary tumour is usually more aggressive, treatment resistant, and metastasizes early requiring a more aggressive treatment strategy.