[Malignancy grading in breast cancer as assessed by nuclear DNA content].

The relationship between nuclear DNA content measured by cytofluorometry and the prognostic factors, especially the histological lymph node metastasis was investigated in patients with breast cancer. Nuclear DNA content was measured in 82 cases to evaluate its clinical significance concerning the malignancy grading. Histograms of DNA content were classified into two basic ploidy patterns based on presence or absence of a prominent peak at the 2c (diploid) region. D type (diploid type) which had a prominent peak at the 2c region resembled the histogram pattern of normal cells more closely than N type (non-diploid type). The rate of lymph node metastasis of N type (57.4%) was significantly higher than that of D type (28.6%) (p less than 0.05). The rate of lymph node metastasis of N type was higher than D type regardless of the tumor size or histological types. The five year cumulative survival rate of D type (91.7%) was significantly higher than that of N type (68.2%) (p less than 0.05). Despite the lymph node metastasis, the survival rate of D type was higher than that of N type. From a view point of the relationship between nuclear DNA content and lymph node metastasis, breast cancers of D type might be much safer indications for modified radical mastectomy. From this study, it was suggested that the measurement of nuclear DNA content of the breast cancer would bring the important informations about the malignancy grading and decision of the operative procedure.