Cancer in adolescents and young adults (15-29 years)

Adolescents and young adults (AYA) aged 15-29 are a largely understudied and underserved population with regard to cancer. Lost in a system geared to patients two to three times their age, their needs are being poorly met. There is:

• a lack of age appropriate care
• no age-specific treatment protocols
• little clinical research; only 10 per cent to 20 per cent of adolescents participate in clinical trials
• in adult care centres, referral of adolescents for treatment is on average twice as long as it is in a paediatric centre
• incidence of cancers is increasing
• treatments tested in older adults are not suited to the biology of cancers occurring in younger adults

Incidence

• on average, the number of new cancer cases per year in this age group is 2,075 (1992-2005) and the number of deaths per year in this age group is 326 deaths (1991-2004)
• for unknown reasons, the incidence of cancer in AYA is increasing; up 0.8% per year in males and 1.4% for females
• there is a serious threat of a second cancer in childhood patients treated with chemotherapy/radiotherapy for a prior malignancy
• lymphomas are the most commonly diagnosed cancer. However, there has been a significant and unexplained increase in testicular cancer by 2.7% per year (accounts for 24% of cancer diagnoses in males), and in thyroid cancer in females up by 6.5% per year (accounts for 20% of all new cancer diagnoses)

Mortality

• Leukemias account for most cancer deaths (21% males, 17% females); followed by cancer of the brain and nervous system; and the third most common cause of death is non-Hodgkin lymphoma in males and cancers of the reproductive organs in females
• While the five-year survival rate has increased from 80% (1992-1995) to 85% (2001-2004), improvements in survival in this age group have not kept pace with improved outcomes seen in children and adults. While younger children and older adults with cancer have benefited from a steady improvement in five-year survival rates of 1.5% a year, AYA patients have seen little or no change

Differences in cancer patterns in the 15-29 age group

• 7.9% more females (15,043) than males in this age group diagnosed (14,005) which is the complete opposite across older age groups – 9.3% of males (89,300 new cases per year) versus females (81,700 cases)
• Lack of identifiable causes of cancer and risk factors limits opportunity for primary prevention in this age group
• The most common cancers differ from older adults
• AYA cancers may have biologically distinct behaviours, responding differently to chemotherapy and other treatment for different age groups. Treatments tested in older adults are not well suited to the biology of the cancers occurring in younger adults. The therapy young adults currently receive from oncologists accustomed to treating older adults is generally less aggressive than that administered by pediatric oncologists to children with the same malignancies