To compare the ability of transvaginal sonography and serum CA 125
levels to predict myometrial invasion in patients with endometrial carcinoma.
DESIGN AND METHODS: Prospective study in 50 consecutive patients (mean age 60
years, SD 10.5, range 29-77 years) diagnosed as having endometrial cancer and
scheduled for surgical staging. All patients were evaluated by transvaginal
ultrasonography. Endometrial thickness was measured in all cases and myometrial
invasion was estimated as or = 50%. Serum CA 125 level was determined
in each patient. A cut-off level of > or = 35 IU/ml was considered to predict
myometrial invasion of > or = 50%. All patients underwent surgical staging, and
definitive histopathological findings regarding myometrial invasion were used as
the 'gold standard'. Sensitivity, specificity and positive predictive value (PPV)
and negative predictive value (NPV) were calculated for transvaginal
ultrasonography and CA 125 and compared. RESULTS: On histopathological analysis,
myometrial invasion was found to be or = 50% in 15
cases (30%). Mean endometrial thickness in patients with superficial invasion was
significantly lower than in those with deep invasion (13.4 mm (95% CI 11.2-15.7)
vs. 18.7 mm (95% CI 15.0-22.3), respectively; p = 0.014). Median CA 125 was
significantly higher in patients with deep invasion than in those with
superficial invasion (30 IU/ml, interquartile range (IQR) 46.0 vs. 16.9 IU/ml,
IQR 13.9, respectively; p = 0.002). The sensitivity, specificity, PPV and NPV for
transvaginal ultrasonography were 86.7% (95% CI 59.5-98.3), 94.3% (95% CI
80.8-99.3), 86.7% (95% CI 59.5-98.3) and 94.3% (95% CI 80.8-99.3), respectively.
The sensitivity, specificity, PPV and NPV for CA 125 were 40% (95% CI 16.3-67.7),
91.4% (95% CI 76.9-98.2), 66.7% (95% CI 29.9-92.5) and 78% (95% CI 63.4-89.5),
respectively. The sensitivity of transvaginal ultrasonography was significantly
higher than that of CA 125 (p = 0.008). No differences were found in terms of
specificity, PPV or NPV. CONCLUSION: Our results indicate that transvaginal
ultrasonography is more sensitive than CA 125 in predicting myometrial invasion
in endometrial cancer