At what age should a 36-year-old patient with a history of breast cancer in two second-degree relatives (e.g., grandparents, aunts, uncles) start screening for breast cancer?

From the Guidelines

For a 36-year-old patient with a history of breast cancer in two second-degree relatives, screening should begin now with annual mammograms, as the patient's age and family history warrant earlier screening than the general population recommendation of age 40. This patient should undergo annual mammography starting at age 36. Clinical breast exams should be performed annually as well. The patient should also consider genetic counseling to evaluate for hereditary breast cancer syndromes, particularly if the affected relatives were diagnosed at a young age (under 50) or if there are other concerning family history elements such as ovarian cancer or male breast cancer.

Key Considerations

• The recommendation for earlier screening is based on the increased risk conferred by having multiple family members with breast cancer, even if they are second-degree relatives, as noted in the study by 1.
• This family history approximately doubles the patient's baseline risk compared to someone without affected relatives.
• Supplemental screening with breast MRI might be considered if genetic testing reveals a pathogenic mutation or if risk assessment tools indicate a lifetime risk greater than 20%, as suggested by 1.
• The patient should also be counseled on breast awareness and promptly reporting any changes in their breasts.
• Regular screening is important as early detection improves treatment outcomes and survival rates in breast cancer, with studies such as 1 and 1 supporting the benefits of screening mammography in reducing breast cancer mortality.

Screening Guidelines

• The American College of Radiology recommends annual screening mammography beginning no later than 40 years of age for women at intermediate risk, but for those with a family history of breast cancer, mammography should begin earlier if familial breast cancer occurred at a young age, typically 10 years prior to the youngest age at presentation but generally not before age 30, as stated in 1.
• For women who have lobular neoplasia or atypical hyperplasia diagnosed prior to 40 years of age, annual screening mammography should be performed from time of diagnosis but generally not prior to 30 years of age, as recommended by 1.

From the FDA Drug Label

Tamoxifen citrate tablets are indicated to reduce the incidence of breast cancer in women at high risk for breast cancer. This effect was shown in a study of 5 years planned duration with a median follow-up of 4. 2 years. Twenty-five percent of the participants received drug for 5 years. The longer-term effects are not known. In this study, there was no impact of tamoxifen on overall or breast cancer-related mortality (see BOXED WARNING at the beginning of the label). Tamoxifen citrate tablets are indicated only for high-risk women “High risk” is defined as women at least 35 years of age with a 5 year predicted risk of breast cancer ≥ 1.67%, as calculated by the Gail Model.

The patient is 36 years old and has a history of breast cancer in two second-degree relatives. According to the label, high risk is defined as women at least 35 years of age with a 5 year predicted risk of breast cancer ≥ 1.67%, as calculated by the Gail Model. Since the patient's risk factors are not explicitly described in the examples provided, the Gail Model is necessary to estimate absolute breast cancer risk.

• The patient's age and family history may indicate an increased risk, but the label does not provide a clear recommendation for screening based on second-degree relatives.
• The decision regarding therapy with tamoxifen for the reduction in breast cancer incidence should be based upon an individual assessment of the benefits and risks of tamoxifen therapy 2. However, the label does not provide guidance on the age to start screening for breast cancer based on the patient's specific family history.

From the Research

Breast Cancer Screening Guidelines

The American College of Obstetricians and Gynecologists (ACOG) recommends that average-risk women start screening mammography at age 40 years 3. However, for women with a family history of breast cancer, the guidelines are less clear.

Family History and Screening Age

A study published in 2021 found that women with a first-degree family history of breast cancer are more likely to initiate screening before age 40, especially if their relative was diagnosed before age 50 4. Another study published in 2020 found that the risk-adapted starting age of breast cancer screening varies by the number of first-degree and second-degree relatives with breast cancer diagnosis and the age at diagnosis of the first-degree relatives 5.

Screening Recommendations for Women with a Family History

For women with a family history of breast cancer in second-degree relatives (e.g., grandparents, aunts, uncles), the screening recommendations are not as clear-cut. However, a study published in 2020 found that women with multiple affected first-degree relatives, with the youngest affected relative receiving a diagnosis before age 50 years, reached the benchmark risk level at age 27 years 5. When the youngest relative received a diagnosis after age 50 years, this risk level was attained at age 36 years.

Key Points to Consider

• The American College of Obstetricians and Gynecologists (ACOG) recommends that average-risk women start screening mammography at age 40 years 3.
• Women with a family history of breast cancer may need to start screening earlier, depending on the number of affected relatives and the age at diagnosis of the youngest relative 4, 5.
• There is no standardized approach to office-based breast cancer risk assessment in the United States, which can lead to missed opportunities to identify women at high risk of breast cancer 3.

Screening Age for a 36-Year-Old Patient

Based on the available evidence, a 36-year-old patient with a history of breast cancer in two second-degree relatives may not need to start screening immediately. However, it is essential to consider the individual's overall risk profile and discuss the benefits and harms of screening with a healthcare provider. The patient's healthcare provider may recommend starting screening at age 40, as per the ACOG guidelines, or earlier, depending on the patient's individual risk factors 3, 5.

Some key factors to consider when determining the screening age for this patient include:

• The number of affected relatives and the age at diagnosis of the youngest relative
• The patient's overall risk profile, including any other risk factors for breast cancer
• The benefits and harms of screening, including the potential for false-positive results and overdiagnosis
• The patient's personal values and preferences regarding screening 3, 6