Is there a familial component to Ductal Carcinoma In Situ (DCIS)?

From the Guidelines

Yes, there is a familial component to Ductal Carcinoma In Situ (DCIS), with women having a family history of breast cancer, particularly in first-degree relatives, being at increased risk. This familial risk is thought to be due to a combination of shared genetic factors and environmental influences, as suggested by studies such as 1. Specific genetic mutations, particularly in the BRCA1 and BRCA2 genes, significantly increase the risk of developing both DCIS and invasive breast cancer, with women having these mutations possibly facing up to a 60-80% lifetime risk of breast cancer, including DCIS 1. Other genes like PALB2, CHEK2, and ATM have also been associated with increased breast cancer risk, though to a lesser extent than BRCA mutations. The familial component works through various mechanisms, including inherited mutations that affect DNA repair, cell growth regulation, and hormone metabolism. For women with strong family histories of breast cancer, genetic counseling and testing may be appropriate to assess their personal risk and guide screening and prevention strategies, as recommended by guidelines such as those outlined in 1. Understanding this familial component is crucial for risk assessment and may influence decisions about screening frequency, starting age, and prevention strategies. Some studies, like 1, have noted controversies regarding the impact of young age and a positive family history of breast cancer on treatment options in women with DCIS, highlighting the need for further evaluation. However, the most recent and highest quality evidence, such as 1, supports the importance of considering familial risk in the management of DCIS. Key points to consider include:

• The role of genetic mutations in increasing DCIS risk
• The importance of family history in risk assessment
• The potential benefits of genetic counseling and testing for women with strong family histories of breast cancer
• The need for personalized screening and prevention strategies based on individual risk factors.

From the Research

Familial Component of Ductal Carcinoma In Situ (DCIS)

• A family history of breast cancer is an important risk factor for breast carcinoma in situ (BCIS), including DCIS 2.
• Studies have shown that cases with DCIS are significantly more likely to report a first-degree family history of breast cancer than controls, with an odds ratio (OR) of 1.6 (95% CI: 1.3,2.1) 2.
• DCIS cases are also more likely to report both an affected mother and sister, with an OR of 2.4 (95% CI: 0.8,7.2) compared to controls 2.
• An inverse association was suggested between age at onset and DCIS risk, with cases aged 49 years or younger having a higher risk than controls (OR: 2.1,95% CI: 1.3.4) 2.

Genetic Factors

• The breast cancer susceptibility genes, BRCA1 and BRCA2, may play a role in the development of DCIS, although the prevalence of these mutations in DCIS cases is estimated to be low (approximately 3.7% and 1.9% for BRCA1 and BRCA2, respectively) 2.
• A study found that DCIS is equally as prevalent in patients who carry deleterious BRCA mutations as in high familial-risk women who are noncarriers, but occurs at an earlier age 3.
• High-grade DCIS was more common in BRCA1 mutation carriers than in patients without a mutation (P = .02) 3.

Risk of Second Primary Breast Cancers

• Women with DCIS have a significantly increased risk of contralateral DCIS, contralateral invasive cancer, ipsilateral DCIS, and ipsilateral invasive cancer compared to the general population 4.
• Black women were found to be 1.9-fold more likely to develop ipsilateral invasive cancer than white women, and young age at onset, comedo histology, and certain treatment characteristics were predictive of ipsilateral cancers 4.

Clinical Management

• The management of DCIS is continually evolving towards more personalized and less aggressive therapies, taking into account the heterogeneous pathological and biological traits of the disease 5.
• Evidence-based guidelines for proper DCIS clinical management should be discussed within a multidisciplinary team, considering recent scientific studies and updated multidisciplinary treatment protocols and techniques 5.