Background : Multiple primary malignant tumors are defined as two or more histologically distinct malignancies in one person, not metastasis. Recently, increased screening system of health care can be detected multiple tumor and early stage cancer. Hepatobiliary pancreas (HBP) malignancies were very poor prognosis, most HBP malignancies were soley diagnosed in all stages. However, there was no studies about multiple primary tumors with HBP malignancies. We aimed to analyze the incidence and survival of multiple primary tumor with HBP malignancies.

Methods : This study retrospectively analyzed multiple malignant tumor patients with HBP malignancies diagnosed by surgical resection between March 2014 and June 2022. The survival analysis was performed with SPSS version 22.0 (SPSS Inc., Chicago, IL, USA) with Kaplan-Meier methodology.

Results : 143 patients was multiple primary tumors with HBP malignancies in our institution. 4 patients were diagnosed with three multiple tumors. 139 patients were diagnosed with two malignancies. HBP malignancies were HCC(46 patients), Cholangiocarcinoma(25 patients), Gallbladder cancer(16 patients ), Pancreatic cancer( 35 patients), Ampulla of vater cancer(12 patients ), other types of tumor in HBP (9 patients). Multiple primary tumors were cancer of colon, stomach, breast, thyroid, liver, lung, kidney, ureter and bladder, cervix, brain, prostate, skin, lymphoma. The most common tumor was thyroid cancer(28 patients, 16.7%). The overall survival 2- and 5-year survival rates were 47% and 20.5% and median survival was 23.2 months in pancreatic cancer with multiple primary tumor patients.

Conclusions : In case of pancreatic cancer, which is known to have the worst prognosis among HBP malignancies, the survival rate of patients diagnosed with multiple primary tumors was slightly lower than that of pancreatic cancer patients who underwent surgery at our institution. This results showed that early diagnosis and treatment of HBP malignancy is important, and nevertheless, multiple primary tumor should be early detected and treated.