TCM tongue diagnosis index of early-stage breast cancer

Abstract

ObjectivesThis paper investigates discriminating tongue features to distinguish between early stage breast cancer (BC) patients and non-breast cancer individuals through non-invasive traditional Chinese medicine (TCM) tongue diagnosis. DesignThe tongue features for 67 patients with 0 and 1 stages of BC, and 70 non-breast cancer individuals are extracted by the automatic tongue diagnosis system (ATDS). A total of nine tongue features, namely, tongue color, tongue quality, tongue fissure, tongue fur, red dot, ecchymosis, tooth mark, saliva, and tongue shape are identified for each tongue. Features extracted are further sub-divided according to the areas located, i.e., spleen–stomach, liver–gall-left, liver–gall-right, kidney, and heart–lung areas. This study focuses on deriving significant tongue features (p<0.05) to discriminate early-stage BC patients from non-breast cancer individuals. ResultsThe Mann–Whitney test shows that the amount of tongue fur (p=0.024), maximum covering area of tongue fur (p=0.009), thin tongue fur (p=0.009), the average area of red dot (p=0.049), the maximum area of red dot (p=0.009), red dot in the spleen–stomach area (p=0.000), and red dot in the heart–lung area (p=0.000) demonstrate significant differences. The data collected are further classified into two groups. The training group consists of 57 early-stage BC patients and 60 non-breast cancer individuals, while the testing group is composed of 10 early-stage BC patients and 10 non-breast cancer individuals. The logistic regression by utilizing these 7 tongue features with significant differences in Mann–Whitney test as factors is performed. In order to reduce the number of tongue features employed in prediction, tongue features with the least amount of significant difference, namely, maximum area of red dot and average area of red dot, are removed progressively. The tongue features of the testing group are employed in the aforementioned three models to test the power of significant tongue features identified in predicting early-stage BC. An accuracy of 80%, 80% and 90% is reached on non-breast cancer individuals by applying the 7, 6 and 5 significant tongue features obtained through Mann–Whitney test, respectively, while 60%, 60% and 50% is reached on the corresponding early-stage BC patients. ConclusionThe TCM tongue diagnosis can serve as a preliminary screening procedure in the early detection of BC in light of its simple and non-invasive nature, followed by other more accurate testing process. To the best of our knowledge, this is the first attempt in applying non-invasive TCM tongue diagnosis to the discrimination of early-stage BC patients and non-breast cancer individuals.