Table 2. Conclusions of evidence for breast cancer surveillance for female childhood, adolescent and young adult cancer survivors.

Who needs breast cancer surveillance?

Breast cancer risk in childhood, adolescent and young adult cancer survivors

○ High risk after >20 Gy chest radiation	Level A ⁶
• High risk after 10-19 Gy chest radiation^*	Level B ^26-30
• High risk after 1-9 Gy chest radiation^*	Level C ^26-30
• High risk after total body irradiation^*	Level C³⁵
• High risk after high abdominal field radiation	Level C ²⁸
• Decreased risk after alkylating agent chemotherapy^*	Level B ^{27,29,30,36-39}
○ Decreased risk after ≥5 Gy radiation to the ovaries^*	Level B ^27,29,36

At what age should breast cancer surveillance be initiated?

Breast cancer risk in childhood, adolescent and young adult cancer survivors

○ Increased risk as early as 8 years after chest radiation or 25 years of age	Level A ^6,36,38-41

At what frequency should breast cancer surveillance be performed?

Breast cancer risk in childhood, adolescent and young adult cancer survivors

○ Risk increases with increasing length of follow-up in survivors up to age 50 years	Level A ^6,36,38-41

At what age should breast cancer surveillance be stopped?

Breast cancer risk in childhood, adolescent and young adult cancer survivors

• Course of breast cancer risk over time in survivors aged >50 years	No evidence

What surveillance modality should be used?

Diagnostic value clinical breast exam, mammography and breast MRI in childhood, adolescent and young adult cancer survivors

• Diagnostic value for breast cancer	No evidence
• Mammography can detect breast cancer in Hodgkin lymphoma survivors treated with chest radiation	Level B ^{46,48-50,65,66}

Diagnostic value clinical breast exam in other populations

○ Poor diagnostic value for breast cancer in women in the general population and in women with an inherited susceptibility to breast cancer	Level B ^54-59

Diagnostic value clinical breast exam in women aged <25 years in other populations

• Diagnostic value for breast cancer	No evidence

Diagnostic value mammography in other populations

○ Good diagnostic value for breast cancer in women with an inherited susceptibility to breast cancer	Level A^64,71

Diagnostic value breast MRI in other populations

○ Good diagnostic value for breast cancer in women with an inherited susceptibility to breast cancer	Level A ^{64, 11}

Diagnostic value breast MRI and mammography compared to either test alone in other populations

○ Better diagnostic value for breast cancer of a breast MRI and mammography than either test alone in women with an inherited susceptibility to breast cancer	Level A^64,71

Diagnostic value breast MRI and mammography compared to breast MRI alone in women aged 25-35 years in other populations

• Diagnostic value for breast cancer of a breast MRI and mammography compared to breast MRI alone in women aged 25-35 years	No evidence

Diagnostic value mammography compared to breast MRI in women in a young age group compared to another age group in other populations

• Different diagnostic value for breast cancer in the younger age group (<40 year or <50 year) than in the older age group (≥50 year) for both mammography and breast MRI in women with an inherited susceptibility to breast cancer	Level B ^72,73

Level A = high level of evidence; Level B = moderate/low level of evidence; Level C = very low level of evidence.

○Evidence extracted from the existing guidelines: COG,¹⁷ DCOG¹⁸ (including the National Breast Cancer Organization Netherlands (NABON) guideline),³⁴ and UKCCLG.²⁰ •Evidence as presented in the evidence summaries (Appendix 2).

Reference numbers 30 and 36 also included women aged >30 years at Hodgkin lymphoma diagnosis.