Spectrum, Management Strategies, and Early Outcomes of Dual Primary Malignancies: A Single Tertiary-Center Experience

Abstract

Introduction: The occurrence of a second primary malignancy in a patient with a known cancer is referred to as a dual primary malignancy, which may be synchronous or metachronous. The incidence of dual malignancies is increasing worldwide (2–17%). This study aimed to document the incidence of dual primary malignancies, factors influencing treatment decision-making, and short-term outcomes at a single tertiary care center.

Materials and Methods: This retrospective cross-sectional study included patients diagnosed with dual primary malignancies between February 2023 and February 2025. All patients met the Warren and Gates criteria and had histologically confirmed malignancies. Demographic characteristics, tumor details, treatment strategies, and outcomes were collected and analyzed.

Results: Among 42 cases of dual primary malignancies, 17 were synchronous and 25 were metachronous. Nineteen patients were male and 23 were female, with a mean age of 63 years. Breast cancer was the most common primary tumor site (n=11). The disease-free interval between metachronous primaries ranged from 1 to 26 years. Seventy-five percent of patients received treatment with curative intent using multimodality therapy.

Conclusion: The rising incidence of dual primary malignancies underscores the importance of vigilant follow-up and multidisciplinary evaluation for early detection and optimal management. Treatment decisions guided by a multidisciplinary tumor board are essential for achieving favorable outcomes.