Changes in survival in de novo metastatic cancer in an era of new medicines

Background Over the past decades, the therapeutic landscape has markedly changed for patients with metastatic solid cancer, yet few studies have evaluated its effect on population-based survival. The objective of this study was to evaluate the change in survival of patients with de novo metastatic solid cancers during the last 30 years. Methods For this retrospective study, data from almost 2 million patients diagnosed with a solid cancer between January 1, 1989, and December 31, 2018, were obtained from the Netherlands Cancer Registry, with follow-up until January 31, 2021. We classified patients as with or without de novo metastatic disease (M1 or M0, respectively) at diagnosis and determined the proportion with M1 disease over time. Changes in age-standardized net survival were calculated as the difference in the 1- and 5-year survival rates of patients diagnosed in 1989-1993 and 2014-2018. Results Different cancers showed divergent trends in the proportion of M1 disease and increases in net survival for M1 disease (approximately 0-50 percentage points at both 1 and 5 years). Patients with gastrointestinal stromal tumors saw the largest increases in 5-year survival, but we also observed substantial 5-year survival increases for patients with neuroendocrine tumors, melanoma, prostate cancer, and breast cancer. Conclusion Over 30 years, the survival of patients with de novo M1 disease modestly and unevenly increased among cancers. Metastatic cancer still remains a very lethal disease. Next to better treatment options, we call for better preventive measures and early detection to reduce the incidence of metastatic disease.