Five-year conditional relative survival up to 10 years post-diagnosis among adolescent and young adult breast cancer patients by age, stage, and receptor subtype

Abstract

Background: Conditional relative survival (CRS), the probability of survival given that an individual has already survived a certain period post-diagnosis, is a more clinically relevant measure for long-term survival than standard relative survival (RS). This study aims to evaluate the 5-year CRS among adolescent and young adult (AYA) breast cancer patients by age, tumor stage, and receptor subtype to guide disclosure periods for insurance.

Methods: Data of all females aged 18-39 years and diagnosed with invasive breast cancer between 2003 and 2021 (n = 13,075) were obtained from The Netherlands Cancer Registry (NCR). The five-year CRS was calculated annually up to 10 years post-diagnosis using a hybrid analysis approach.

Results: For the total AYA breast cancer study population the 5-year CRS exceeded 90 % from diagnosis and increased beyond 95 % 7 years post-diagnosis. Patients aged 18-24 reached 95 % 9 years post-diagnosis, those aged 25-29 after 5 years, and those aged 30-34 and 35-39 after 8 years. For stage I, the 5-year CRS reached 95 % from diagnosis, for stage II after 6 years, while the 5-year CRS for stages III and IV did not reach the 95 % threshold during the 10-year follow-up. Triple-negative tumors exceeded 95 % after 4 years, human epidermal growth factor receptor 2 (HER2) positive tumors after 6 years, while hormone receptor (HR) positive tumors did not reach 95 %.

Conclusion: Excess mortality among AYA breast cancer patients tends to be little (CRS 90 %-95 %) from diagnosis and becomes minimal (CRS>95 %) over time compared to the general population. These results can enhance expectation management and inform policymakers, suggesting a shorter disclosure period.

Keywords: Adolescents and young adults (AYAS); Breast cancer; Conditional relative survival (CRS); Excess mortality; Relative survival (RS); Survivorship.

Fig. 1

Five-year conditional relative survival of the total AYA breast cancer study population. At 0 year, the CRS is equivalent to the relative survival. The red dotted line indicates 95 % CRS, or minimal excess mortality relative to the general population. The blue dotted line indicates 90 % CRS, or little excess mortality relative to the general population. The grey area indicates the 95 % CIs. AYA, adolescent and young adult; CI, confidence interval; CRS, conditional relative survival.

Fig. 2

Five-year conditional relative survival by age at diagnosis. At 0 year, the CRS is equivalent to the relative survival. The red dotted line indicates 95 % CRS, or minimal excess mortality relative to the general population. The blue dotted line indicates 90 % CRS, or little excess mortality relative to the general population. The dashed colored lines represent the corresponding 95 % CIs. CI, confidence interval; CRS, conditional relative survival.

Fig. 3

Five-year conditional relative survival by tumor stage. At 0 year, the CRS is equivalent to the relative survival. The red dotted line indicates 95 % CRS, or minimal excess mortality relative to the general population. The blue dotted line indicates 90 % CRS, or little excess mortality relative to the general population. The dashed colored lines represent the corresponding 95 % CIs. CI, confidence interval; CRS, conditional relative survival.

Fig. 4

Five-year conditional relative survival by receptor subtype. At 0 year, the CRS is equivalent to the relative survival. The red dotted line indicates 95 % CRS, or minimal excess mortality relative to the general population. The blue dotted line indicates 90 % CRS, or little excess mortality relative to the general population. The dashed colored lines represent the corresponding 95 % CIs. CI, confidence interval; CRS, conditional relative survival; HER2, human epidermal growth factor receptor2; HR, hormone receptor.