Development and validation of a simple questionnaire for the identification of hereditary breast cancer in primary care

Abstract

Background: Breast cancer is a significant public health problem worldwide and the development of tools to identify individuals at-risk for hereditary breast cancer syndromes, where specific interventions can be proposed to reduce risk, has become increasingly relevant. A previous study in Southern Brazil has shown that a family history suggestive of these syndromes may be prevalent at the primary care level. Development of a simple and sensitive instrument, easily applicable in primary care units, would be particularly helpful in underserved communities in which identification and referral of high-risk individuals is difficult.

Methods: A simple 7-question instrument about family history of breast, ovarian and colorectal cancer, FHS-7, was developed to screen for individuals with an increased risk for hereditary breast cancer syndromes. FHS-7 was applied to 9218 women during routine visits to primary care units in Southern Brazil. Two consecutive samples of 885 women and 910 women who answered positively to at least one question and negatively to all questions were included, respectively. The sensitivity, specificity and positive and negative predictive values were determined.

Results: Of the 885 women reporting a positive family history, 211 (23.8%; CI95%: 21.5-26.2) had a pedigree suggestive of a hereditary breast and/or breast and colorectal cancer syndrome. Using as cut point one positive answer, the sensitivity and specificity of the instrument were 87.6% and 56.4%, respectively. Concordance between answers in two different applications was given by a intra-class correlation (ICC) of 0.84 for at least one positive answer. Temporal stability of the instrument was adequate (ICC = 0.65).

Conclusion: A simple instrument for the identification of the most common hereditary breast cancer syndrome phenotypes, showing good specificity and temporal stability was developed and could be used as a screening tool in primary care to refer at-risk individuals for genetic evaluations.

Figure 1

Overview of the questionnaire validation procedure and its results. NMPOA = Nucleo Mama Porto Alegre cohort; FH = family history; BC = breast cancer; OC = ovarian cancer; CRC = colorectal cancer; GCRA = genetic cancer risk assessment; BCPS = breast cancer predisposition syndrome; PCU = primary care unit.

Figure 2

Specificity, sensitivity, positive and negative predictive values and their respective 95% confidence intervals, for each of different cut points used for the identification of the hereditary breast cancer phenotype. PPV = positive predictive value; NPV = negative predictive value.