Evaluation and reinforcement of the correlation of S-Phase fraction with nodal metastases, tumor grade and tumor size in breast carcinoma patients inPakistan

The aim of this study was to evaluate the S-phase fraction (SPF) of tumors in breast cancer patients in Pakistan. Its association with the traditional morphological prognostic markers, i.e., axillary lymph node metastasis, tu mor size and grade, was also studied. Flow cytometry was used to estimate SPF on breast cancer tissues from 166 p atients reported at the Aga Khan University Hospital between the years 1997 and 2000. Univariate analysis was done to find any association between SPF and the aforesaid variables. For the ease of analysis, the cases were subd ivided into two categories depending on the SPF value, i.e., < 10% (low-ris k group) and greater than or equal to 10 % (high-risk group). The mean and median SPF values were 21.45% and 20.035%, respectively, with a range of 3.26% to 54.30%. Twenty-six (15.66%) of the cases had SPF < 10%, 57 (34.34%) had SPF from 10%-20%, and 83 (50%) had SPF > 20%. A significan t correlation between SPF and nodal metastasis was observed (p = 0.0111), b ut not between SPF and the number of lymph nodes involved when metastatic c ases were subdivided into <4 lymph node-positive cases and greater than or equal to4 lymph node-positive cases. Significant correlations were also fou nd between SPF and tumor grade (p = 0.0244), as well as between SPF and tum or size (p = 0.048). In conclusion, DNA flow cytometric analysis of SPF carried out in our labor atory could reasonably predict the chances of lymph node metastasis, tumor grade and size in breast cancer patients, thus proving to be an important p rognostic marker in the Pakistani setting. This requires further investigat ions regarding the survival of patients so as to evaluate its capacity of p redicting the outcome of Pakistani patients.