Long-Term Survival in Patients with Cancers: Surveillance, epidemiology and end results-based analysis

This study aimed to explore real-world data on the long-term survival of cancer patients using historical records from the Surveillance, Epidemiology, and End Results (SEER) Programme. Long-term survival is an important endpoint in the management of different malignancies. It is rarely assessed due to the unfeasibility of follow-up for a long duration of time. Besides reporting the five-year relative survival, the 10- and 20-year survival rates for different types of cancers were analysed. Additionally, survival trends as a function of time, age and tumour type were reviewed and reported.

The study used SEER*Stat (Version 8.3.6.1) for data acquisition from the SEER 9 Regs (November 2019) database. Data from patients diagnosed with cancer between 1975 and 2014 were retrieved and included in the analysis.

For patients diagnosed with any malignant disease (N = 4,412,024), there was a significant increase in median overall survival over time (P <0.001). The 20-, 10-, and 5-year survival rates were higher in solid tumours compared to haematological malignancies (50.8% versus 38%; 57% versus 47.4%; and 62.2% versus 57.4%, respectively). The highest 20-year relative survival rates were observed in thyroid cancer (95.2%), germ cell and trophoblastic neoplasms (90.3%), melanoma (86.8%), Wilms' tumour (86.2%) and prostate cancer (83.5%).

Long-term follow-up data were suggestive of high 20-year relative survival rates for most tumour types. Relative survival showed an improving trend over time, especially in solid tumours.