Kaija Holli

Estrogen Receptor β Is Coexpressed with ERα and PR and Associated with Nodal Status, Grade, and Proliferation Rate in Breast Cancer

The role of estrogen (ER) and progesterone receptors (PR) in breast cancer is well established. Identification of the second human estrogen receptor, the estrogen receptor β (ERβ), prompted us to evaluate its role in breast cancer. We studied the expression of ERβ by immunohistochemistry and mRNA in situ hybridization in 92 primary breast cancers and studied its association with ERα, PR, and various other clinicopathological factors. Sixty percent of tumors were defined as ERβ-positive (nuclear staining in >20% of the cancer cells). Normal ductal epithelium and 5 of 7 intraductal cancers were also found to express ERβ. Three-fourths of the ERα- and PR-positive tumors were positive for ERβ, whereas ERα and PR were positive in 87% and 67. of ERβ-positive tumors, respectively. ERβ was associated with negative axillary node status ( P P = 0.0003), low S-phase fraction ( P = 0.0003), and premenopausal status ( P = 0.04). In conclusion, the coexpression of ERβ with ERα and PR as well as its association with the other indicators of low biological aggressiveness of breast cancer suggest that ERβ-positive tumors are likely to respond to hormonal therapy. The independent predictive value of ERβ remains to be established.

Loss of estrogen receptor in recurrent breast cancer is associated with poor response to endocrine therapy.

PURPOSE Up to 30% to 40% of metastases from hormone receptor-positive primary breast cancer do not respond to endocrine therapy. We studied how often hormone receptor status changes between primary and recurrent tumors and whether such a change might explain unresponsiveness to endocrine therapy. PATIENTS AND METHODS Primary breast cancer samples and matched asynchronous recurrences were studied from 50 patients who had not received any adjuvant therapy. Estrogen receptor (ER) and progesterone receptor (PR) status was determined immunohistochemically from histologically representative formalin-fixed paraffin-embedded tumor samples. ER status was ascertained by mRNA in situ hybridization. RESULTS Thirty-five (70%) of 50 primary tumors were positive for ER and 30 (60%) for PR. Hormone receptor status of the recurrent tumor differed from that of the primary tumor in 18 cases (36%). Discordant cases were due to the loss of ER (n = 6), loss of PR (n = 6), or loss of both receptors (n = 6). Receptor-negative primary tumors were always accompanied by receptor-negative recurrences. Among 27 patients with ER-positive primary tumors, loss of ER was a significant predictor (P = .0085) of poor response to subsequent endocrine therapy. Only one of eight patients (12.5%) with lost ER expression responded to tamoxifen therapy, whereas the response rate was 74% (14 of 19) for patients whose recurrent tumors retained ER expression. CONCLUSION Loss of ER expression in recurrent breast cancer should be considered as a cause for poor response to endocrine therapy in primarily ER-positive patients. We conclude that analysis of recurrent tumor samples may improve the predictive value of ER and PR assays.

NAD(P)H:quinone oxidoreductase 1 NQO1 * 2 genotype (P187S) is a strong prognostic and predictive factor in breast cancer

NQO1 guards against oxidative stress and carcinogenesis and stabilizes p53. We find that a homozygous common missense variant (NQO1*2, rs1800566(T), NM_000903.2:c.558C>T) that disables NQO1 strongly predicts poor survival among two independent series of women with breast cancer (P = 0.002, N = 1,005; P = 0.005, N = 1,162), an effect particularly evident after anthracycline-based adjuvant chemotherapy with epirubicin (P = 7.52 × 10−6) and in p53-aberrant tumors (P = 6.15 × 10−5). Survival after metastasis was reduced among NQO1*2 homozygotes, further implicating NQO1 deficiency in cancer progression and treatment resistance. Consistently, response to epirubicin was impaired in NQO1*2-homozygous breast carcinoma cells in vitro, reflecting both p53-linked and p53-independent roles of NQO1. We propose a model of defective anthracycline response in NQO1-deficient breast tumors, along with increased genomic instability promoted by elevated reactive oxygen species (ROS), and suggest that the NQO1 genotype is a prognostic and predictive marker for breast cancer.

Lumpectomy with or without postoperative radiotherapy for breast cancer with favourable prognostic features: results of a randomized study

The aim of this trial was to study the value of adding post-operative radiotherapy to lumpectomy in a subgroup of breast cancer patients with favourable patient-, tumour-, and treatment-related prognostic features. 152 women aged over 40 with unifocal breast cancer seen in preoperative mammography were randomly assigned to lumpectomy alone (no-XRT group) or to lumpectomy followed by radiotherapy to the ipsilateral breast (50 Gy given within 5 weeks, XRT group). All cancers were required to be invasive node-negative, smaller than 2 cm in diameter and well or moderately differentiated, to contain no extensive intraductal component, to be progesterone receptor-positive, DNA diploid, have S-phase fraction ≤7 and be excised with at least 1 cm margin. During a mean follow-up time of 6.7 years, 13 (18.1%) cancers recurred locally in the no-XRT and 6 (7.5%) in the XRT group (P=0.03). There was no difference between the groups in the ultimate breast preservation rate (95.0% vs. 94.4% in XRT and no-XRT, respectively, P=0.88), distant metastasis-free survival (P=0.36), or 5-year cancer-specific survival (97.1% in XRT and 98.6 in no-XRT). Radiation therapy given after lumpectomy reduces the frequency of ipsilateral breast recurrences even in women with small breast cancer with several favourable clinical and biological features. However, the breast preservation rate may not increase due to more frequent use of salvage mastectomies in patients treated with postoperative radiotherapy.

Predictive value of topoisomerase IIalpha and other prognostic factors for epirubicin chemotherapy in advanced breast cancer.

Although cytotoxic chemotherapy is widely used in advanced breast cancer, there are no powerful predictors for the therapy response. Because topoisomerase IIalpha (Topo IIalpha) is the molecular target for the anthracycline class of anti-cancer drugs, we compared the immunocytochemical assay of Topo IIalpha with other biomarkers in the prediction of clinical response to Topo II inhibitor chemotherapy. Fifty-five patients with advanced breast cancer were treated with a single cytotoxic drug, Topo II-inhibitor, epirubicin (30 mg m(-2) weekly up to 1000 mg m(-2)), as first line cytotoxic chemotherapy. Objective response to treatment was analysed according to UICC criteria. The predictive value of Topo IIalpha expression, c-erbB2 oncoprotein, p53 tumour-suppressor protein, oestrogen (ER) and progesterone receptor (PR), S-phase fraction and DNA ploidy were analysed from representative formalin-fixed paraffin-embedded primary tumour samples. The proportion of Topo IIalpha-positive cells (Topo IIalpha index) failed to predict response to epirubicin therapy. Mean Topo IIalpha scores in 29 responding patients were similar when compared with those with no change in disease progression (n = 13) and those with progressive disease (n = 13) (14.9% +/- 11.4% vs 15.5% +/- 7.6% vs 17.3% +/- 13.2%, not significant). Among the other biomarkers tested, overexpression of c-erbB2 oncoprotein and hormone receptor negativity were significantly associated with poor response. Response rate in patients with c-erbB2-overexpressing tumours was 32% compared with 65% in patients with no c-erbB2 overexpression (P = 0.0058). Accordingly, the response rate for ER-positive patients was 67% compared with 26% in ER-negative patients (P = 0.0021). Although both negative ER status and c-erbB2 overexpression are associated with high Topo IIalpha expression in breast cancer, step-wise logistic regression analysis showed that ER and c-erbB2 were associated with therapy response independent of Topo IIalpha expression. Histological grade, p53, DNA-ploidy, tumour proliferation rate (S-phase fraction), stage of the disease at diagnosis, age of the patient, previous anti-oestrogen therapy or site of metastasis did not predict the response to epirubicin therapy. In conclusion, despite extensive in vitro evidence, expression of Topo IIalpha is unlikely to predict the response to Topo II inhibitor chemotherapy in advanced breast cancer. Among the prognostic biomarkers, overexpression of c-erbB2 oncogene and negative ER may have predictive value in epirubicin therapy in patients with advanced breast cancer.

Low biologic aggressiveness in breast cancer in women using hormone replacement therapy.

PURPOSE Hormone replacement therapy (HRT) has been associated with an increased risk for breast cancer. Cancers in women who use HRT are often less advanced, and lower mortality has been reported in those who use HRT than in nonusers. We sought to explain this by a comparison of indicators of tumor aggressiveness in patients who received HRT with those in patients who did not. PATIENTS AND METHODS A population-based cohort of 477 postmenopausal women with breast cancer were interviewed for the use, type, and duration of HRT. Clinical variables and indicators of tumor aggressiveness (histologic grade, hormone receptors, DNA ploidy, S-phase fraction, and c-erbB-2 oncoprotein overexpression) were analyzed. RESULTS Breast tumors from HRT users were smaller (odds ratio, 0.47; P=.005), had better histologic differentiation (P=.04), and had a lower proliferation rate (S-phase fraction, P=.009) than tumors from nonusers. These differences persisted after adjustments for age and method of diagnosis (mammography screening v self-referral) by multiple logistic regression. No significant differences were observed in the estrogen (ER) or progesterone receptor content, c-erbB-2 oncogene overexpression, or axillary node involvement. A subgroup analysis showed that the tumor proliferation rates among HRT users were significantly lower only if HRT had been used at the time of diagnosis (P=.001). The type of HRT (estrogen v combination of estrogen and progesterone) was not associated with any clinical parameter or tumor phenotype. The association of HRT with lower proliferation rate and smaller tumor size was exclusively caused by ER-positive tumors (P=.0001 and P=.0035 v P > .1, respectively). CONCLUSION The results indicate that breast cancer in women who receive HRT is biologically less aggressive than those without previous HRT. The lower cell-proliferation rate and smaller tumor size found in ER-positive tumors from current HRT users suggest a direct ER-mediated growth inhibitory effect of HRT on established breast tumors. This may at least partly explain why breast cancer in HRT users has a more favorable clinical course.

Combination chemotherapy versus single-agent therapy as first- and second-line treatment in metastatic breast cancer: a prospective randomized trial.

PURPOSE We report results of a randomized prospective study that compared single agents of low toxicity given both as the first-line and second-line chemotherapy with combination chemotherapy in advanced breast cancer with distant metastases. PATIENTS AND METHODS Patients in the single-agent arm (n = 153) received weekly epirubicin (E) 20 mg/m2 until progression or until the cumulative dose of 1,000 mg/m2, followed by mitomycin (M) 8 mg/m2 every 4 weeks, and those in the combination chemotherapy arm (n = 150) were first given cyclophosphamide 500 mg/m2, E 60 mg/m2, and fluorouracil 500 mg/m2 three times per week (CEF) followed by M 8 mg/m2 plus vinblastine (V) 6 mg/m2 every 4 weeks. Exclusion criteria included age greater than 70 years, World Health Organization (WHO) performance status greater than 2, prior chemotherapy for metastatic disease, and presence of liver metastases in patients younger than 50. RESULTS An objective response (complete [CR] or partial [PR]) was obtained in 55%, 48%, 16%, and 7% of patients treated with CEF, E, M, and MV, respectively. A response to CEF tended to last longer than a response to E (median, 12 v 10.5 months; P = .07). Treatment-related toxicity was less in the single-agent arm and quality-of-life (QOL) analysis favored the single-agent arm. No significant difference in time to progression or survival was found between the two arms. Similarly, no difference in survival was found when the patients who received both the planned first-and second-line treatments were compared or when survival was calculated from the beginning of the second-line therapy. CONCLUSION Patients treated with single-agent E followed by single-agent M had similar survival, but less treatment-related toxicity and better QOL as compared with those treated with CEF followed by MV.

CHEK2 variant I157T may be associated with increased breast cancer risk

Cell cycle checkpoint kinase 2 (CHEK2) is a transducer of cellular responses to DNA damage. The CHEK2 1100delC has previously been shown to be a low‐penetrance breast cancer susceptibility allele. We have evaluated the role of another CHEK2 variant, I157T in the FHA domain of the gene, for association with breast cancer. I157T was found at a significantly higher frequency in the population‐based series of breast cancer patients (77/1035, 7.4%, odds ratio [OR] = 1.43, 95% confidence interval [CI] = 1.06–1.95, p = 0.021) than among population controls (100/1885, 5.3%). The frequency in the familial breast cancer patients was not elevated (28/507, 5.5%, OR = 1.04, 95% CI = 0.68–1.61). The I157T protein, that undermines cellular responses to ionizing radiation and shows deficiency in substrate recognition in vivo, was expressed at normal level in tumor tissues as well as in cultured cells. The I157T protein was stable and it dimerized with the wild‐type CHEK2 co‐expressed in human cells. These functional properties of the I157T protein suggest that this variant may have negative effect on the pool of normal CHEK2 protein in heterozygous carrier cells by formation of heterodimers with wild‐type CHEK2. The I157T variant may be associated with breast cancer risk, but the risk is lower than for 1100delC.

Safety and Efficacy Results of a Randomized Trial Comparing Adjuvant Toremifene and Tamoxifen in Postmenopausal Patients With Node-Positive Breast Cancer

PURPOSE In this multicenter trial, toremifene 40 mg/d was compared with tamoxifen 20 mg/d, both given orally for 3 years to postmenopausal, axillary node-positive women after breast surgery. PATIENTS AND METHODS The first 899 patients (toremifene, n = 459; tamoxifen, n = 440) of the total of 1,480 patients accrued to the trial were included in this scheduled safety analysis. The mean follow-up time was 3.4 years. RESULTS The two treatment groups were well balanced with respect to patient and disease characteristics. The subjective side-effect profile was similar in both treatment groups. Slightly more vascular complications (deep vein thromboses, cerebrovascular events, and pulmonary embolisms) were seen among tamoxifen-treated patients (5.9%) as compared with toremifene-treated patients (3.5%) (P: =.11), whereas bone fractures (P: =.09) and vaginal leukorrhea (P: =.05) were more common in the toremifene group. The number of subsequent second cancers was similar. The breast cancer recurrence rate was 23.1% (n = 106) in the toremifene group and 26.1% (n = 115) in the tamoxifen group (P: =.31). When only patients with estrogen receptor (ER)-positive cancer were considered (n = 556), the risk for breast cancer recurrence was nonsignificantly lower among the toremifene-treated women, with a hazards ratio of 0.74 (90% confidence interval, 0.52 to 1.04; P: =.14). The mean time to breast cancer recurrence and overall survival were similar in both groups. CONCLUSION The side-effect profile of toremifene resembles that of tamoxifen. The efficacy of toremifene seems to be no less than that of tamoxifen. The trend for fewer breast cancer recurrences in the ER-positive subgroup is encouraging, but a longer follow-up is needed to confirm this.

Breast cancer biological subtypes and protein expression predict for the preferential distant metastasis sites: a nationwide cohort study

IntroductionSome molecular subtypes of breast cancer have preferential sites of distant relapse. The protein expression pattern of the primary tumor may influence the first distant metastasis site.MethodsWe identified from the files of the Finnish Cancer Registry patients diagnosed with breast cancer in five geographical regions Finland in 1991-1992, reviewed the hospital case records, and collected primary tumor tissue. Out of the 2,032 cases identified, 234 developed distant metastases after a median follow-up time of 2.7 years and had the first metastatic site documented (a total of 321 sites). Primary tumor microarray (TMA) cores were analyzed for 17 proteins using immunohistochemistry and for erbB2 using chromogenic in situ hybridization, and their associations with the first metastasis site were examined. The cancers were classified into luminal A, luminal B, HER2+ enriched, basal-like or non-expressor subtypes.ResultsA total of 3,886 TMA cores were analyzed. Luminal A cancers had a propensity to give rise first to bone metastases, HER2-enriched cancers to liver and lung metastases, and basal type cancers to liver and brain metastases. Primary tumors that gave first rise to bone metastases expressed frequently estrogen receptor (ER) and SNAI1 (SNAIL) and rarely COX2 and HER2, tumors with first metastases in the liver expressed infrequently SNAI1, those with lung metastases expressed frequently the epidermal growth factor receptor (EGFR), cytokeratin-5 (CK5) and HER2, and infrequently progesterone receptor (PgR), tumors with early skin metastases expressed infrequently E-cadherin, and breast tumors with first metastases in the brain expressed nestin, prominin-1 and CK5 and infrequently ER and PgR.ConclusionsBreast tumor biological subtypes have a tendency to give rise to first distant metastases at certain body sites. Several primary tumor proteins were associated with homing of breast cancer cells.