A groundbreaking study from researchers at the University of Calgary has revealed that survivors of cancer diagnosed during adolescence and young adulthood face more than double the risk of developing a new primary cancer compared to the general population. Published in the Canadian Medical Association Journal (CMAJ) on April 13, 2026, this population-based research from Alberta underscores the long-term challenges in cancer survivorship and calls for enhanced surveillance strategies across Canadian healthcare systems.
The findings highlight a persistent elevated risk that does not diminish over time, affecting nearly one in six survivors 30 years after their initial diagnosis. As survival rates for adolescent and young adult (AYA) cancers continue to improve in Canada—with approximately 9,000 new cases annually in the 15-39 age group—this research emphasizes the need for specialized follow-up care tailored to this unique demographic.
Background on Adolescent and Young Adult Cancer in Canada
Adolescent and young adult cancer, often defined as diagnoses between ages 15 and 39, represents a distinct group within oncology. In Canada, these cancers account for about 7% of all new cases, yet they pose unique biological, psychological, and social challenges. Unlike pediatric cancers, AYA tumors frequently occur in rare subtypes with poorer prognoses, such as sarcomas, melanomas, and certain lymphomas. Survival rates have climbed to over 80% for many types, thanks to advances in multimodal therapies including chemotherapy, radiation, and targeted treatments developed through rigorous research at institutions like the University of Calgary and the University of Toronto.
However, improved survival unmasks late effects. The Alberta Adolescent and Young Adult Cancer Survivor Study, underpinning this CMAJ paper, draws from comprehensive provincial registry data spanning 1983 to 2017. This resource, housed within University of Calgary's oncology departments, enables population-level insights absent in smaller cohorts.
Key Findings from the University of Calgary-Led CMAJ Study
Led by Arafat Ul Alam, PhD, from the Department of Oncology at the University of Calgary, the study examined 24,459 individuals diagnosed with their first neoplasm between ages 15 and 39. Over 252,030 person-years of follow-up, 1,442 survivors (5.9%) developed a subsequent primary neoplasm (SPN), excluding recurrences and nonmelanoma skin cancers.
Compared to age-, sex-, and period-matched general population rates, survivors exhibited a standardized incidence ratio (SIR) of 2.2 (95% CI 2.1-2.3), translating to an absolute excess risk (AER) of 31.7 SPNs per 10,000 person-years. For long-term survivors (beyond 5 years post-diagnosis, n=14,818), the SIR remained 2.0 (95% CI 1.9-2.2), with an AER of 35.7 per 10,000 person-years. The 30-year cumulative incidence reached 17.7% observed versus 11.2% expected—a gap widening over time.
Risks were elevated for nearly all sites, with the highest SIRs for oral cavity/pharynx (4.5), salivary gland (4.1), and thyroid (3.9) cancers. Breast cancer survivors showed particularly high burdens, with SIRs up to 3.4.
Most Common Subsequent Cancers and Patterns
Breast cancers comprised 27% of SPNs post-5-year survival, followed by digestive organs (13%, primarily colorectal), hematopoietic malignancies (9%), and respiratory cancers (8%, mainly lung). These screen-detectable cancers accounted for 43% of all SPNs, yet survivors developed them at younger ages—median 48 for breast (vs. 62 general), 50 for colorectal (vs. 70), and 58 for lung (vs. 72).
Site-specific patterns linked to initial treatments: Hodgkin lymphoma survivors faced tripled breast cancer risk, likely from chest radiation; leukemia survivors showed heightened thyroid risks. Male survivors had higher SIRs but similar AERs to females, while risks trended upward with diagnostic age.
- Breast: 27.3% cumulative incidence at 30 years (vs. 14.6% expected)
- Hodgkin lymphoma initial: 22.7% (vs. 7.6%)
- Leukemia: 16.7% (vs. 9.6%)
Risk Factors: Treatment Effects, Genetics, and Lifestyle
The doubled risk stems from a confluence of factors. Late effects of radiotherapy and chemotherapy dominate, with radiation inducing DNA damage in surrounding tissues and alkylating agents causing leukemogenesis. For instance, chest irradiation elevates contralateral breast and lung risks years later.
Genetic predispositions contribute 1-37% in younger AYAs, amplified by shared familial risks. Lifestyle modulators—smoking, obesity, alcohol—exacerbate vulnerabilities, particularly as survivors age into higher-incidence periods. The study's population-based design captured these without treatment data linkage, but prior UCalgary work on the Alberta cohort confirms therapy's role.
Implications for Canadian Cancer Survivors
With Canada's AYA incidence steady at ~9,000 yearly and 5-year survival exceeding 80%, tens of thousands face lifelong monitoring. The study's AER implies hundreds of excess SPNs annually nationwide, straining healthcare. Younger onset of second cancers disrupts life milestones—careers, fertility, family—unique to AYAs.
Psychosocial burdens compound: anxiety over recurrence, financial toxicity from screening, fertility concerns post-gonadotoxic therapy. University-led research like this informs policy, urging integration into primary care where most long-term follow-up occurs.
Current Survivorship Programs at Canadian Universities
Canadian universities spearhead AYA survivorship. The University of Calgary's Charbonneau Cancer Institute supports the Alberta AYA cohort, fostering multidisciplinary research. University Health Network's Princess Margaret Cancer Centre in Toronto runs a dedicated AYA Oncology Program for ages 15-39, offering fertility preservation, psychosocial support, and transition care.
Western University's London Health Sciences Centre provides AYA-specific clinics emphasizing holistic needs. The Partnership Against Cancer's national framework advocates developmentally appropriate care, with university hospitals piloting risk-based models. Young Adult Cancer Canada (AYA CAN) collaborates with academics for peer support and advocacy.
These programs address gaps: only 50% of AYAs report good mental health post-treatment, per surveys.
Recommendations for Enhanced Surveillance and Care
The CMAJ authors advocate risk-adapted screening starting earlier. Prioritize breast surveillance for irradiated females (mammography/MRI from age 25-30, akin to pediatric survivors). Expand colorectal screening pilots to high-risk AYAs; consider low-dose CT lung screening for smokers with chest radiation history.
- Develop individualized survivorship care plans detailing exposures and risks.
- Train primary providers via university CME programs.
- Promote genetic counseling and lifestyle interventions (smoking cessation, exercise).
- Fund AYA-specific registries nationally.
Future Outlook: Research and Policy Directions
UCalgary's ongoing Alberta AYA Study promises deeper dives into treatment linkages and interventions. Nationally, CIHR-funded projects at UBC and McMaster explore digital tools for adherence. Policy-wise, integrate findings into provincial cancer plans, mirroring pediatric long-term follow-up clinics.
Optimism lies in precision oncology: genomic profiling minimizes toxicity, immunotherapy reduces reliance on genotoxic agents. Universities like McGill and UofT lead trials tailoring therapies for AYAs, potentially halving future SPN risks.
Photo by Zulfugar Karimov on Unsplash
Actionable Insights for Survivors, Providers, and Policymakers
For survivors: Engage survivorship clinics at academic centers; track symptoms via apps; prioritize wellness. Providers: Adopt Children's Oncology Group-like risk stratification. Policymakers: Allocate funds for AYA hubs in every province.
This CMAJ study galvanizes action, positioning Canadian universities at the forefront of transforming AYA survivorship from reactive to proactive.
