Relationship between cytological grading of breast cancers and lymph node metastasis

Abstract

Background: Breast cancer is the second most common type of cancer and the second leading cause of cancer related deaths in females. Since a less invasive pre-operative diagnosis is always preferred to open biopsy, fine needle aspiration cytology has been frequently used to decide the benign or malignant nature of particular breast lesions. But many studies have shown that this technique can provide additional information about the intrinsic features of the tumours as well as their prognosis. Grading of breast carcinoma, while the tumour is still in vivo, would be the most ideal and desirable situation, as it would be helpful in the selection of patients for appropriate therapy. Aims & Objective: (i) To evaluate and compare the cytograding of breast cancers using Robinson’s and Mouriquand’s grading methods. (ii) To evaluate the relationship between cytograding of breast cancers and lymph node metastasis. Materials and Methods: A 5-year retrospective (from Oct 2000 to Sept 2005) and 1-year prospective study (from Oct 2005to Oct 2006). A total of 110 fine-needle aspiration cytology (FNAC) cases of breast cancers were graded by Robinson’s and Mouriquand’s grading methods followed by comparison of the two methods. Relationship between grading and lymph node metastasis was evaluated. Results: By Robinson’s method, 28 (25.45%) cases were grade I, 46 (41.81%) grade II and 36 (32.72%) were grade III whereas using Mouriquand’s method, 28 (25.45%), 42 (38.18%) and 40 (36.36%) cases were graded as grade I, II, and III respectively. A high degree of concordance was observed between the two grading methods (90.9%). A highly significant relationship between the scores obtained by two methods was also observed (P=0.004). By Robinson’s method, Grade I, II and III tumours had lymph node involvement in 3.57%, 6.52% and 47.22% of cases respectively whereas by Mouriquand’s method, Grade I, II and III tumours had lymph node involvement in 3.57%, 7.14% and 42.5% of cases respectively. Although both grading systems showed significant relationship with lymph node involvement but Robinson’s grading was a much better predictor of lymph node metastasis. Our study showed that greater cell dissociation was associated with higher incidence of regional lymph node metastasis. A highly significant relationship was observed between cell dissociation and lymph node involvement (p=0.00000). Conclusion: A comprehensive cytological grading of breast cancers is possible by using Robinson’s and Mouriquand’s method. A high degree of concordance was observed between the two methods but Robinson’s grading system was found to be easier and better because of more objective set of criteria and easy reproducibility. Cytological grading of breast cancers is a strong predictor of lymph nodal metastasis and greater cell dissociation is associated with higher incidence of regional lymph node metastasis.