The study aims to analyze the influence of the latent variable cancer concern (PPC) on the measurement of the single item Cancer Worry Chart (CWC) through the method of structural equations (SEM). 165 healthy adults with a family history of cancer participated (Mage = 40.25 years; SD = 12.99), who attended the outpatient clinic of health institutions in Peru. The CWC has a predominance of responses that express less concern about cancer (M = 2.27; SD = .98). The use of SEM reports very good adjustment rates for the model (SB- χ2 = .0051; gl = 1; p = .943; CFI = 1.00; RMSEA [IC90%] = .00 [.00, .04]; SRMR = .007), with a factor load of .949 and communality of .90. The PPC construct explains 90% of the variability of the CWC scores. This finding provides complementary evidence of CWC construct validity.