Table 3.
Studies looking at the impact of positive FH of breast cancer on CBC rates, disease-free and overall survival.
| The Impact of Positive FH of Breast Cancer on CBC Rates, Disease-Free and Overall Survival | |||||
|---|---|---|---|---|---|
| Author | Year | Study Type | Follow up | Patients | Findings |
| Reiner [46] | 2018 | Multicentre, population-based, case-control study | Not stated | 1521 CBC cases with 2212 UBC controls | A 1st degree relative with BC confers increased risk of CBC RR 1.9 (95% CI 1.6–2.3) A 1st degree relative with BBC confers the highest risk of CBC RR 3.4 (95% CI 2.4–5) A 2nd degree relative increases the risk of CBC RR 1.4 (95% CI 1.2–1.7) Any 1st degree relative with breast cancer confers a 10-year AR of developing CBC of 8.1% (95% CI 6.7–9.8). The 10-year AR increases to 13.5% (95% CI 8.8–20.8) if this relative was <40 years at age of diagnosis. The 10-year AR is highest at 36% (95% CI 14.5–90.5) if the first degree relative was diagnosed with BBC at age <40 years. On subgroup analysis and exclusion of mutation carriers i.e., BRCA, ATM, PALB2 and CHEK2, the increased 10-year AR associated with a 1st degree relative and a 1st degree relative with BBC remained significant similar to above-reported. |
| Kuchenbaecker [20] | 2017 | Prospective, multicentre, cohort study | Median 4 years (2–7) | 3886 eligible for breast cancer analysis BRCA1 (n = 2276); BRCA2 (n = 1610) |
Increased risk if ≥two 1st or 2nd degree relatives with breast cancer compared to no family history of BC; HR 1.99 Did not evaluate the effect of FH on CBC risk |
| Bernstein [51] | 1992 | Prospective cohort study | Mean 52 months | 136/4550 (2.9%) patients with CBC and varying familial risk | Compared with no FH of breast cancer: Increased risk of CBC ~2x with a 1st degree relative with BC Increased risk of CBC ~3x if 1st degree relative was diagnosed at a young age (<35 years) |
| Ji [52] | 2007 | Population based, national database study | Not stated | 56190 invasive and 6841 in situ BC patients | The risk of metachronous CBC measured by SIRs was higher with primary in situ disease compared to invasive cancer. SIR for metachronous CBC in women diagnosed with invasive BC: <45 years: 5.12 (95% CI 4.47–5.85) 45–55 years: 1.95 (95% CI 1.76–2.16) >55 years: 1.49 (95% CI 1.37–1.61) SIR for metachronous CBC in women diagnosed with 1st invasive BC and have: A positive FH 2.74 (95% CI 2.3–3.23) No FH 1.85 (95% CI 1.75–1.96) SIR for metachronous CBC in women diagnosed with in situ disease: <45 years: 5.12 (95% CI 4.47–5.85) 45–55 years: 1.95 (95% CI 1.76–2.16) >55 years: 1.49 (95% CI 1.37–1.61) |
| Narod [53] | 2016 | Population based, national database study | Not stated | 4839 CBC patients out of 84819 patients with BC * (5.7%) | Young age at 1st BC diagnosis and a maternal cancer history increases the risk of CBC The 15-year cumulative risk of CBC was: 8.8% (95% CI 8.5–9.1) in the general population (regardless of maternal BC status) 12% (95% CI 11–13) in maternal UBC 13% (95% CI 9.5–17) in maternal BBC A maternal cancer history of UBC at an early age conferred the daughter a lifetime CBC risk of 35% (95% CI 25–46) * Mutation carriers not excluded as information not available from cancer registry |
| Vaittinen [54] | 2000 | Population based, national database study | Not stated | 2529/72,092 (3.5%) CBC patients. 147 (5.8%) of CBC cases with 1st degree relative |
Modest elevation in CBC risk for women with an affected 1st degree relative RR of 1.53 |
| Boughey [55] | 2010 | Retrospective cohort | Median 17.3 years | 385 patients with a positive FH; 385 matched controls | Patients with stage I or II BC and a positive family history who underwent CPM had: A 95% reduction in CBC rates; adjusted HR 0.05 (95% CI 0.01–0.19, p < 0.0001) |
CPM: contralateral prophylactic mastectomy; BC: breast cancer; BBC: bilateral breast cancer; CBC: contralateral breast cancer; UBC: unilateral breast cancer; AR: absolute risk; SIR: Standardized incidence ratio; FH: family history; RD: risk difference; HR: hazard ratio.