Understanding early-onset Cancers: Age, Aggressiveness, and Risk Factors

•  Early-onset cancers before age 50 pose distinct challenges and characteristics.
•  Younger individuals with breast and colorectal cancers often confront aggressive tumor types and unique molecular profiles.
•  Lifestyle factors like diet, tobacco, and physical activity greatly influence early-onset cancer development, emphasizing preventive measures.

Early-onset cancers differ from other types primarily due to the age at which they occur. The term "early-onset" varies depending on the cancer type; for instance, early-onset breast cancer typically refers to diagnosis before age 45, while early-onset colorectal cancer involves diagnosis before age 50. Normally, cell damage accumulates with age, leading to an increased risk of cancer after age 50. However, diagnoses before age 50 are not uncommon, although they diverge from the typical trajectory, considering the median age for cancer diagnosis is around 66.

Another notable difference is the aggressiveness of certain cancers in younger adults, such as breast cancer. Younger women are more likely to have aggressive types like triple-negative and HER2-positive breast cancers, which often require more intensive treatments due to their propensity for spread and potential side effects.

Genetic mutations are also more prevalent among younger women with breast cancer, although they account for only a fraction of cases. Despite this, the prognosis for early-onset breast cancer is generally positive, with high cure rates and favorable outcomes following treatment.

Similarly, colorectal cancer in younger adults may exhibit distinct molecular characteristics and pathways compared to older individuals. Younger patients often present with more aggressive tumors and at advanced stages, which cannot be solely attributed to delayed diagnosis due to lack of routine screening.

While some cases may be explained by age-related screening guidelines, there are likely other factors at play that remain unknown. Further research is needed to fully understand the complexities of early-onset cancers and improve diagnostic and treatment strategies for affected individuals.

For early-onset breast cancer, leading risk factors contributing to disability-adjusted life years included alcohol consumption, tobacco use, excessive red meat consumption, lack of physical activity, and high blood glucose levels. Early-onset tracheal, bronchus, and lung cancers were associated with tobacco use, low fruit consumption, and high blood glucose levels. For early-onset colorectal cancer, key risk factors included dietary habits (such as a diet high in red meat, low in fruits, high in sodium, and low in dairy), alcohol consumption, tobacco use, lack of physical activity, high body mass index (BMI), and high blood glucose levels. Tobacco use and a diet high in sodium were identified as primary risk factors for early-onset stomach cancer.