PROSTATE cancer survivors face a long-term threat that often goes undetected, a third primary cancer, according to new findings that highlight an under-recognized but serious risk with significant survival implications. A large population-based cohort study followed 13,222 men diagnosed with prostate cancer in northern Portugal between 2000 and 2009. Researchers tracked their health status until 2021 to better understand the occurrence and impact of third primary cancers (TPCs).
Over a follow-up period of up to 22 years, 169 patients were diagnosed with a TPC, primarily in the digestive system, lungs, and urinary tract. While the 20-year cumulative incidence of TPCs in the entire prostate cancer cohort remained relatively low at 1.5%, the rate rose to 12.0% among patients who had already developed a second primary cancer (SPC). These third malignancies substantially worsened prognosis.
By the 15-year mark following a second primary cancer diagnosis, the all-cause cumulative mortality reached 88.2% for TPC patients, compared to 75.7% in those with only an SPC. After adjusting for age and other variables, the hazard of death in men with a TPC was nearly twice as high, with an adjusted hazard ratio of 1.79 (95% CI: 1.37–2.34).
The findings suggest clinicians should be more vigilant in long-term follow-up care, particularly for survivors already diagnosed with multiple cancers. Screening strategies may need to evolve to better address the elevated risks that accumulate over decades.
This study sheds light on the importance of recognizing third primary cancers as a distinct and dangerous development in prostate cancer survivorship, offering new insights for oncologists, urologists, and primary care teams managing long-term patient outcomes.
Reference:
Sá P et al. Risk and survival of third primary cancers in a population-based cohort of prostate cancer survivors. Eur J Cancer Prev. 2025. doi: 10.1097/CEJ.0000000000000977. [Online ahead of print].
