A 12-year experience at a tertiary hospital on patients with multiple primary malignant neoplasms.

PURPOSE The incidence of multiple primary malignant neoplasms (MPMN) has dramatically increased. The purpose of this retrospective study was to present the 12-year experience at a University Hospital in patients with MPMN and to investigate the role of genetic factors in their pathogenesis. METHODS The medical records of 7516 cancer patients, treated in our Institution from 2000 to 2012, were reviewed. Diagnosis of MPMN was based on the Warren and Gates' criteria. RESULTS Among 7516 patients, 39 (0.5%) (10 men, mean age 70.0±6.98 years, and 29 women, mean age 64.7±8.24 years) presented with MPMN. Eighty-two percent of them developed 2 primary malignant neoplasms (PMNs), whereas 3 PMNs were developed in 7 patients. Breast cancer was the most common cancer type diagnosed among female patients (59%); 14 and 3 had 2 and 3 PMNs, respectively. Eight had a family history of breast cancer while in 3 genetic testing revealed mutations in BRCA1 and BRCA2 genes. The second most common type of malignancy was colorectal cancer (24%); 5 developed 2 PMNs, whereas 2 developed 3 PMNs. Five patients had a family history of colorectal cancer. Colon cancer was the most frequent neoplasm among male patients (50%; 3 developed 2 and 2 3 PMNs. In 2 patients the family history was positive for colorectal cancer. CONCLUSIONS Although many factors may contribute to MPMN development, positive family history and inherent mutations significantly predispose to MPMN appearance. Thus, management of MPMN patients should be based on a detailed family history and genetic testing.