Abstract
Multiple primary tumors are the ones that develop in the same patient at the same or different times. They are usually examined under two groups. If the second tumor is diagnosed 6 months after the first tumor is diagnosed, it is named as metachronous tumor. If it is diagnosed in 6 months after the first diagnosis, it is called as synchronous tumor. The malignancy of tumors should be proved histologically. At least 2 cm of solid tissue should be present between two tumors. If they are at localized at the same place, a gap of at least 5 years should be present between them. Metastatic disease should be eliminated. This study aimedto review the clinical, demographic, and pathological features of multiple primary tumors, detect the prevalence, compare the results with literature findings, and evaluate and improve the approach to multiple primary tumors. A total of 170 patients diagnosed with multiple primary tumors were included in this study. Patient data were obtained from pathology and medical reports of the patients. Most of the multiple primary tumors were metachronous. The number of male patients was more than that of female patients. The median time between double tumors was 3 monthsforsynchronous tumorsand 26 months for metachronous tumors. Synchronous tumors with the highest prevalence of comorbidity were lung–larynx and lung–colon, whereas metachronous tumors with the highest prevalence of comorbidity were lung–bladder, lung–larynx, breast–endometrium, and breast–colon. The history of smoking and alcohol was found to be higher in male patients andsynchronous tumors. The detection of the first tumor in the metastatic stage and an accompanying synchronous secondary tumor was found to be a poor prognostic factor. The treatment of the first tumor, smoking, squamous cell histology, and male gender were among the other factors negatively affecting survival, although they were not statistically significant.