Risk‐adapted starting age of breast cancer screening in women with a family history of ovarian or other cancers: A nationwide cohort study

Abstract

BACKGROUND:There is a lack of evidence-based recommendations for the age at which women with a family history of cancers other than breast cancer should start breast cancer screening. METHODS: Using Swedish family cancer data sets, the authors conducted a nationwide cohort study including 5,099,172 Swedish women born after 1931 (follow-up, 1958-2015). Accounting for calendar time, they calculated the relative risk of breast cancer for women with a family history of a discordant cancer in 1 first-degree relative. Furthermore, the authors used 10-year cumulative risk to determine the ages at which women with a family history of discordant cancer reached risk thresholds at which women in the general population were recommended to start breast cancer screening. RESULTS: A family history of cancer at 15 sites was associated with an increased risk of breast cancer. Among women younger than 50 years, the highest risk of breast cancer was observed for those with a family history of ovarian cancer (standardized incidence ratio, 1.44; 95% confidence interval, 1.26-1.64). In these women, the risk of breast cancer associated with a family history at other cancer sites ranged from 1.08-fold for prostate cancer to 1.18-fold for liver cancer. When breast cancer screening was recommended to be started at the age of 50 years for the general population, women with 1 first-degree relative with ovarian cancer attained the threshold risk for screening at the age of 46 years. Women with a family history of other discordant cancers did not reach the risk thresholds for screening at younger ages. CONCLUSIONS: Many cancers showed familial associations with breast cancer, but women with a family history of these cancers (except for ovarian cancer) did not reach risk thresholds for screening at younger ages.

Use of Breast Cancer Risk Factors to Identify Risk-Adapted Starting Age of Screening in China

“…To date, studies focused on risk-adapted starting ages of breast cancer screening have been conducted with the Swedish family cancer data sets by Mukama et al 11 , 18 , 28 These authors considered a family history of breast cancer, reproductive profile (eg, age at first live birth and parity), and other family history of cancers separately in their study, which makes it difficult for individuals with more than 1 category of risk factors to decide when to screen.…”

“…27 Although all of these factors were considered in the China Guideline for the Screening and Early Detection of Female Breast Cancer, 19 the recommended starting age of screening for women at average and increased risk was based on expert opinion and lacked population-based evidence in Chinese women. Evidence of a risk-adapted starting age of screening is needed to determine populations at high risk and promote screening of To date, studies focused on risk-adapted starting ages of breast cancer screening have been conducted with the Swedish family cancer data sets by Mukama et al 11,18,28 These authors considered a family history of breast cancer, reproductive profile (eg, age at first live birth and parity), and other family history of cancers separately in their study, which makes it difficult for individuals with more than 1 category of risk factors to decide when to screen.…”

“… 6 To our knowledge, most randomized clinical trials and guidelines for breast cancer screening have recommended a one-size-fits-all approach in which all women are advised to begin screening at age 50 years, even those with risk factors (eg, a family history of breast cancer). 3 , 7 , 8 , 9 , 10 , 11 A one-size-fits-all or age-oriented screening strategy does not consider individual variation in terms of breast cancer risk, 12 which is not beneficial for young women at increased risk whose breast cancer incidence rate has gradually increased with distant-stage diseases in recent years. 13 , 14 Therefore, a risk-adapted starting age of screening is warranted to ensure the fairness and effectiveness of breast cancer screening applications.…”

“…In theory, screening interventions should be applied to high-risk populations based on a risk-adapted screening strategy; however, the evidence is limited worldwide . To our knowledge, most randomized clinical trials and guidelines for breast cancer screening have recommended a one-size-fits-all approach in which all women are advised to begin screening at age 50 years, even those with risk factors (eg, a family history of breast cancer) . A one-size-fits-all or age-oriented screening strategy does not consider individual variation in terms of breast cancer risk, which is not beneficial for young women at increased risk whose breast cancer incidence rate has gradually increased with distant-stage diseases in recent years .…”

Risk of estrogen receptor–specific breast cancer by family history of estrogen receptor subtypes and other cancers

“…Family history of breast cancer and some other cancers is an established risk factor for being diagnosed with breast cancer. Previous studies suggested that individuals with family history of breast cancer in first-degree relatives were at a 1.8-fold increased risk to be diagnosed with breast cancer, whereas those with family history of ovarian cancer had a moderately increased risk (1.3-fold), and those with family history of stomach, colorectum, pancreas, and lung cancer had slightly increased risk (approximately 1.1-fold) ( 11 , 12 ). However, whether such familial risk differs by ER status is unclear, and risk estimates of ER-specific breast cancers by family history of cancer are currently lacking.…”