Temporal trends in cancer among the oldest-old: incidence, stage at diagnosis, treatment and survival. A population-based study, Hérault, France, 1990-2022.

BACKGROUND: The rising burden of cancer in the ageing population represents a major public health issue, especially among the oldest age groups. There is limited data available on the cancer burden and care for the oldest age groups, particularly for those aged 85 and over. This study aimed to analyze trends in cancer incidence rates, stage at diagnosis, primary treatment, and net survival in an older population in a French administrative district from 1990 to 2022. METHODS: All new invasive cancers diagnosed in individuals aged ≥ 75 years and recorded in the Hérault cancer registry from 1990 to 2022 were included. Patients were categorized into four age groups (75-79, 80-84, 85-89, ≥90 years). Temporal trends in incidence, stage distribution, treatment, and net survival were analyzed using Joinpoint regression models. RESULTS: Among 55,571 cases aged ≥ 75 years, 15,377 (27.6%) occurred in individuals aged ≥ 85 years. Incidence increased with age, the sharpest increase was in ≥ 90 years (+1.9% per year). Metastatic and unknown-stage cancers increased with age, but decreased over time. The proportion of patients receiving no active treatment increased with age; declining over time in those aged 75-89 but remaining stable at ∼60% in patients ≥ 90 years. Three-year survival for patients aged ≥ 75 remained stable over time at around 55%. CONCLUSION: The increasing burden at the oldest ages highlights the need to adapt care pathways through an approach that is individualized, multidisciplinary, and informed by geriatric expertise.