Cytotoxic and antiproliferative activity of the single agent epirubicin versus epirubicin plus tamoxifen as primary chemotherapy in human breast cancer: a single-institution phase III trial

This study was designed to address whether simultaneous primary chemo-hormonal therapy provides additional activity compared with chemotherapy alone in breast cancer patients with operable or locally advanced disease. Between January 1997 and January 2002, 211 consecutive patients with T2-4, N0-1, M0 breast cancer were randomized to receive either epirubicin alone (EPI) or epirubicin plus tamoxifen (EPI-TAM). Ki67 expression was evaluated immunohistochemically in tumor specimens obtained before chemotherapy by incision biopsy and at definitive surgery. Tumor shrinkage of >50% was obtained in 76% of patients randomized in the EPI arm and 81.9% of patients randomized in the EPI-TAM arm (not significant). The corresponding rates of clinical and pathological complete response were 20.2 and 21.9% (not significant), and 4.8 and 6.7% (not significant), respectively. Pathologically complete response was more frequently observed in estrogen receptor (ER)-negative (ER-) tumors (P=0.04) and correlated with elevated baseline Ki67 expression (P<0.01). Both EPI and EPI-TAM treatments resulted in a significant reduction in Ki67 expression, either in overall patients (P=0.000) or in patients with ER+ breast cancer (P=0.000). The reduction in Ki67 immunostaining in the EPI-TAM arm was greater than in the EPI arm, leading to a lower Ki67 expression at post-operative residual histology (P=0.0041). The addition of tamoxifen to epirubicin chemotherapy did not improve the response rate but led to a significantly higher reduction in the Ki67 expression. Baseline elevated Ki67 expression and the ER- status were both associated with a greater chance of obtaining a pathological complete response at residual histology.

Pretreatment haemoglobin levels significantly predict the tumour response to primary chemotherapy in human breast cancer

The purpose of this study was to evaluate whether tumour response to primary chemotherapy in human breast cancer is influenced by baseline haemoglobin (Hb) status. A total of 157 patients with T2-4, N0-1 M0 breast cancer were treated with chemotherapy consisting of either the CMF regimen + tamoxifen (the first 76 cases) or the single-agent epirubicin (the subsequent 81) before definitive surgery. In total, 144 patients were fully assessable. Ki67, p53, bcl-2, c-erbB2, steroid hormone receptor, and microvessel density were evaluated immunohistochemically in tumour specimens obtained before chemotherapy and at surgery. Tumour shrinkage >50% occurred in 72.1% of patients. Responding patients had higher baseline Hb levels and red blood cell counts than nonresponders (P<0.01 and <0.003, respectively). The distribution of disease response according to increasing cutoffs of baseline Hb status showed that from 12.5 mg l(-1) onwards, patients with Hb levels above the cutoff obtained a greater response rate than those with lower Hb values. The difference attained the statistical significance at 12.5 (76.1 vs 59.5%, P<0.05) and 13.0 g/dl(-1) (81.0 vs 57.6%, P<0.002) cutoffs, respectively. The predictive role of Hb levels was maintained in multivariate analysis after adjustment for clinical and biological characteristics and treatment regimen. Patients with baseline Hb levels </=13 g dl(-1) showed a lower treatment-induced reduction in Ki67 expression (P<0.04) and a higher Ki67 expression at postoperative evaluation (P<0.02) than their counterparts. In conclusion, low Hb levels may negatively influence the response rate of chemotherapy in breast cancer patients. Inhibition of antiproliferative activity could be a possible mechanism.

Relationship between tumour shrinkage and reduction in Ki67 expression after primary chemotherapy in human breast cancer

The association between tumour shrinkage and reduction in kinetic cell activity after primary chemotherapy in human breast cancer is still a matter of investigation. 157 patients with T2-4, N0-1, M0 breast cancer received primary chemotherapy consisting of either the CMF regimen + tamoxifen (the first consecutive 76 cases) or the single agent epirubicin (the subsequent 81). Ki67, p53, bcl2, c-erbB2 and steroid hormone receptors were evaluated immunohistochemically in tumour specimens obtained before chemotherapy and at surgery. Tumour shrinkage of >50% occurred in 72.4% of patients. Ki67 expression significantly decreased after chemotherapy; the reduction correlated with tumour response in both univariate (P < 0.005) and multivariate analysis (P = 0.02). p53, bcl-2, steroid hormone receptor and c-erbB2 immunostaining were scarcely affected. Baseline bcl2 (P = 0.04) and c-erbB2 (P = 0.02) were directly and inversely associated with the reduction in Ki67 immunostaining, respectively. Baseline p53 expression (P < 0.01) was directly related with Ki67 expression at residual tumour, whereas oestrogen receptor expression (P < 0.001) was inversely related. Ki67 at residual tumour was a better predictor for relapse-free survival (RFS) than baseline Ki67. Clinical response (P < 0.03), but not reduction in Ki67, was a significant independent predictor for disease recurrence. Chemotherapy was found to induce tumour shrinkage and to reduce the number of cells in the cell cycle, but its effect on tumour biology/aggressiveness was minimal. Reduction in Ki67 immunostaining correlated with clinical response but failed to be related to RFS. Ki67 expression at surgery rather than at baseline appears to be a better predictor for disease relapse.

p53 but not bcl-2 immunostaining is predictive of poor clinical complete response to primary chemotherapy in breast cancer patients

Preoperative chemotherapy administered to breast cancer (BC) patients is a model for studying in vivo the interaction between cytotoxic treatment and clinical and biological parameters. Apoptosis induced by anticancer agents is a mechanism of treatment activity; therefore, overexpression of genes inhibiting the apoptotic pathway could produce drug resistant tumors. In the present study, the two most studied inhibitors of apoptosis, the bcl-2 gene and the mutant p53, have been evaluated to assess whether they may play a role in modulating response of BC to primary chemotherapy. From August 1990 to January 1997, 143 patients bearing T(2-4)N(0-1)M0 primary BC were submitted to two different chemotherapeutic regimens before surgery. The first 64 received the cyclophosphamide, methotrexate, 5-fluorouracil (CMF) regimen (on days 1 and 8 and every 28 days thereafter) associated with tamoxifen (30 mg daily) in case of estrogen receptor (ER)-positive BC, and the remaining 79 were submitted to single agent epirubicin (120 mg/m2 every 21 days). The expression of p53, bcl-2, Ki67, ER, progesterone receptor, c-erbB2, and the multidrug resistance P-glycoprotein (gp-170) was evaluated in BC specimens obtained at diagnosis by incision biopsy and at postchemotherapy surgery. At the end of chemotherapy administration (median, 3 cycles; range, 2-6), the clinical complete response (cCR) rate was superimposable in the patient subgroups with bcl-2-positive or -negative primary tumors; conversely, p53 expression, at a cutoff of 10% positive cells, was significantly associated with a lower cCR rate (9.4 versus 27.0%; P < 0.04). p53 was a significant predictor for poor cCR in the subset submitted to epirubicin (3.6 versus 25.5%; P < 0.02; in patients with p53+ and p53- BC, respectively); by contrast, only a trend toward lower cCR has been observed in patients with p53+ tumors receiving CMF +/- tamoxifen with respect to p53- ones. The distribution of cCR according to the gp-170-positive or -negative tumors was 8 versus 22% in patients submitted to epirubicin and 29 versus 30% in those receiving CMF +/- tamoxifen, respectively. In a multivariate regression analysis, after adjusting for treatment administered (epirubicin versus CMF +/- tamoxifen), menopausal status, tumor and node status, histology grade, ER, progesterone receptor, c-erbB2, Ki67, bcl-2, and gp-170 expression, the p53 status maintained an independent predictive role for cCR. Most of the tumors undergoing change in percentage of p53 expression after both treatments originally harbored mutant protein, and only four BC specimens that were p53 negative before chemotherapy became positive afterward. These data confirm in vivo the concept that the responsiveness of tumors to chemotherapy in part derives from the capability of BC cells to undergo apoptosis. The role of mutated p53 in preventing response is more evident in patients submitted to epirubicin, and this may be caused by the up-regulation of multidrug resistance gene expression by p53 inactivation. p53 is a stable phenotype and is not inducible by at least three or four chemotherapy cycles.

Cytotoxic and antiproliferative activity of the CMF regimen administered in association with tamoxifen as primary chemotherapy in breast cancer patients

Seventy six consecutive patients with T2-4, N0-1, M0 primary breast cancer (BC) received a median of 3 cycles of CMF (cyclophosphamide, methotrexate, 5-fluorouracil) regimen. Tamoxifen was concomitantly administered in patients with estrogen receptor positive (ER+) BC. Ki67 antigen was evaluated immunohistochemically in tumor specimens obtained before chemotherapy and at mastectomy. At post chemotherapy evaluation, tumor shrinkage greater than 50% was obtained in 60 patients (78.9%), 21 of them being complete responders (27.6%). As a whole, primary chemotherapy significantly decreased the number of Ki67 positive cells. More than 50% decrease in Ki67 expression was observed in 78.9% of patients attaining a clinical complete response (CR), in 44.7% of patients with partial remission (PR) and in 50.0% of non-responders, while an increase (>25%) in Ki67 expression was found in 5.3%, 18.4% and 18.7% of patients with CR, PR and non-response, respectively. Both CR and PR rates were superimposable in patients with ER+ and ER- primary BC, while the reduction in Ki67 expression was mainly found in ER+ cases. Patients with increased Ki67 expression from baseline, at the end of primary chemotherapy, had a shorter disease-free interval (70 months) with respect to patients with no change (88+ months) or decrease (87+ months), p<0. 05. To conclude, the activity of CMF + tamoxifen in primary BC does not seem superior to that expected administering CMF alone. The reduction in Ki67 expression, as a whole, correlated with clinical CR, but some individual discrepancies between tumor shrinkage and Ki67 pattern have been observed. The Ki67 reduction mainly confined to the ER+ primary BC suggests that tumor response in this subset may be linked to the reduction in proliferation activity, whereas other mechanisms such as apoptosis might be responsible for the tumor shrinkage in ER- tumors. Since the increase in proliferation activity after primary chemotherapy was associated with a greater recurrence rate and lower disease free interval, irrespective of tumor response, changes in proliferation activity after primary chemotherapy may represent a potentially available parameter that, in addition to the tumor response, can discriminate patients who would benefit from the cytotoxic treatment from patients who would not.

Effect of neoadjuvant chemotherapy on Ki67 labelling index, c-erbB-2 expression and steroid hormone receptor status in human breast tumours

The administration of neoadjuvant chemotherapy to breast cancer (BC) patients with operable disease allowed studies aimed of exploring the interaction between cytotoxic treatment and tumour biology in vivo. 99 patients with T2-4, NO-1, M0 primary BC received a median of 3 cycles of either CMF regimen (cyclophosphamide, methotrexate, 5-fluorouracil) or single agent epirubicin. Endocrine therapy was also concomitantly administered in the first 45 patients with estrogen receptor positive (ER+) BC. 92 ended the treatment plan. Ki67 labelling index, estrogen receptor (ER), progesterone receptor (PgR), and c-erbB-2 oncoprotein expression were evaluated immunohistochemically in tumour biopsies obtained before and after chemotherapy. At post-chemotherapy evaluation, tumour shrinkage greater than 50% was obtained in 71 patients (79.7%), 27 of them being complete responders (30.3%). The median Ki67 labelling index, which was 13% in the first biopsy, decreased to 4.5% (p < 0.001) upon mastectomy. No significant differences were observed in steroid hormone receptor and c-erbB-2 expression before and after neoadjuvant treatment. In conclusion, neoadjuvant chemotherapy, whether associated or not to endocrine therapy, leads to a significant decrease in BC proliferation without any appreciable impact on c-erbB-2 and steroid hormone receptor expression.