Anthracycline-based chemotherapies for breast cancer are known to adversely affect patients' quality of life (QOL) and immune function. For that reason, adjuvants that improve those impairments are required. A randomized double-blind study was conducted to evaluate the effectiveness of Lentinula edodes mycelia extract (LEM), which is an oral biological response modifier (BRM) medicine for cancer patients as such an adjuvant. A total of 47 breast cancer patients who were scheduled to receive postoperative adjuvant anthracycline-based chemotherapy, i.e., 5-fluorouracil (5-FU) + cyclophosphamide + epirubicin (FEC regimen), 5-FU + cyclophosphamide + doxorubicin/pirarubicin (FAC regimen), cyclophosphamide + doxorubicin/pirarubicin (AC regimen) and cyclophosphamide + epirubicin (EC regimen), were entered in the study. The patients were randomly divided into either an LEM or a placebo tablet group; the tablets were orally ingested daily over 2 courses of each therapy. In the placebo group, the total scores for QOL were lower on day 8 of the second course of chemotherapy compared with the baseline scores, whereas in the LEM group the scores had not decreased. In the placebo group, the QOL functional well-being score was lower on day 8 after both the first and second courses of chemotherapy compared with the baseline score, but it had not decreased in the LEM group. Evaluation of immunological parameters indicated that an increase in the proportion of regulatory T cells to peripheral blood CD4+ cells tended to be inhibited in the LEM group compared with the placebo group. Oral LEM that was coadministered with anthracycline-based chemotherapies was useful for maintaining patients' QOL and immune function. Thus, LEM appears to be a useful oral adjuvant for patients receiving anthracycline-based chemotherapy.
Keywords: Lentinula edodes; anthracycline; breast cancer; quality of life; randomized clinical study; regulatory T cell.