Comparing survival in urinary tract cancer patients with various second primary malignancies: A population-based study

Purpose We aimed to identify the patterns and combinations of second primary malignancies (SPMs) observed in patients with malignant neoplasms of the urinary tract (MNUT) and to explore the independent risk factors for survival outcomes in these patients. Materials and Methods We analysed the data of MNUT patients with SPM in 25 hospitals in Shanghai between 2002 and 2015. A life table was used to calculate the survival rates, Kaplan–Meier analysis was used to determine the survival status of MNUT patients, and Cox regression analysis was used to perform multivariate analysis of survival risk factors in MNUT patients with SPM. Results Among the 154 patients included, the first primary malignancy (PM) most commonly occurred in the bladder (50.65%) and kidney (41.56%), and the SPM most commonly occurred in the lung (22.73%) and stomach (13.64%). The most common combinations included the bladder + lung and bladder + stomach. The Cox regression results showed that age older than 60 years (HR = 2.36 [95% CI 1.30–4.28] vs. age ≤60 years, p = 0.005), TNM 1 stage III+IV disease (HR = 2.19 [95% CI 1.37-4.57] vs. I+ II), p = 0.037), TNM 2 stage III+IV disease (HR = 7.43 [95% CI 1.49-19.68] vs. I + II), p <0.001), and SPM in the lung (HR = 4.36 [95% CI 1.74-18.69], p = 0.047) were associated with a significantly worse cancer-specific survival. Conclusion The survival of MNUT patients with SPM may be related to the SPM site, first and second PM staging and latency time.