Tissue polypeptide antigen & interleukin-6: Are their serum levels a predictor for response to chemotherapy in breast cancer?

Objective: To compare the serum level of tissue polypeptide antigen (TPA) and interleukin-6 (IL-6) in women with breast cancer at various stages of the disease and to consider the usefulness of these tumor markers in evaluating the response to chemotherapy.

Methods: This case control study included 60 women, from those who were attending the Oncology and Nuclear Hospital in Mosul / Iraq from the period of 1st of March 2012 and 1st of March 2013, complaining of breast cancer of stage 1-4 and receiving chemotherapy after they were operated on. Thirty women age ranged between 29-69 years, were receiving six cycles of chemotherapy after they were operated. This group was compared with the second group of 30 breast cancer women, age ranged between 28-61 years who came for the first time after they were operated on and before receiving chemotherapy. Another 30 apparently healthy, age matched women were included in this study as a healthy control group. The sera obtained from the precipitants used for the estimation of serum TPA and IL-6 level using special commercial kits.

Results: The mean serum levels of both TPA and IL-6 were significantly higher in breast cancer patients than healthy control group. The mean serum levels of both TPA and IL-6 in the breast cancer patients who received 6 cycles of chemotherapy were significantly lower than their levels in the breast cancer patients who did not received chemotherapy yet. There was a significant difference among the 4 stages of breast cancer regarding TPA and IL-6 serum levels, the highest value was detected in those with stage IV and the lowest value was detected in those with stage I. The mean serum levels of both TPA and IL-6 were significantly higher in patients with ductal type than those with lobular type in both breast cancer groups. Both TPA and IL-6 are highly sensitive in detecting breast cancer and the combination of the two tumor markers will increase the specificity for detecting breast cancer up to 96.7%.

Conclusion: Serum level of TPA and IL-6 discriminates between localized and metastatic breast cancer and their levels are good indicators of disease progression, TPA and IL-6 levels have a good predictive value for response to chemotherapy. The combination of the two tumor markers will increase the specificity for detecting breast cancer up to 96.7%.