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To explore the mechanisms whereby estrogen and antiestrogen (tamoxifen (TAM)) can regulate breast cancer cell growth, we investigated gene expression changes in MCF7 cells treated with 17beta-estradiol (E2) and/or with 4-OH-TAM. The patterns of differential expression were determined by the ValiGen Gene IDentification (VGID) process, a subtractive hybridization approach combined with microarray validation screening. Their possible biologic consequences were evaluated by integrative data analysis. Over 1000 cDNA inserts were isolated and subsequently cloned, sequenced and analyzed against nucleotide and protein databases (NT/NR/EST) with BLAST software. We revealed that E2 induced differential expression of 279 known and 28 unknown sequences, whereas TAM affected the expression of 286 known and 14 unknown sequences. Integrative data analysis singled out a set of 32 differentially expressed genes apparently involved in broad cellular mechanisms. The presence of E2 modulated the expression patterns of 23 genes involved in anchors and junction remodeling; extracellular matrix (ECM) degradation; cell cycle progression, including G1/S check point and S-phase regulation; and synthesis of genotoxic metabolites. In tumor cells, these four mechanisms are associated with the acquisition of a motile and invasive phenotype. TAM partly reversed the E2-induced differential expression patterns and consequently restored most of the biologic functions deregulated by E2, except the mechanisms associated with cell cycle progression. Furthermore, we found that TAM affects the expression of nine additional genes associated with cytoskeletal remodeling, DNA repair, active estrogen receptor formation and growth factor synthesis, and mitogenic pathways. These modulatory effects of E2 and TAM upon the gene expression patterns identified here could explain some of the mechanisms associated with the acquisition of a more aggressive phenotype by breast cancer cells, such as E2-independent growth and TAM resistance.

To understand the cellular mechanisms of malignant transformation induced by constitutive activation of the ras oncogene (Ha-ras), we used a subtractive hybridization method (VGID) together with an integrative analytical procedure based upon literature databases in the form of extensive interaction graphs. We found 166 over- and under-expressed genes which, in the human MCF7-ras breast epithelial cell line, are involved in the different aspects of tumoral transformation such as defined signaling pathways, cellular growth, protection against apoptosis, extracellular matrix and cytoskeleton remodeling. Integrative analysis led to the construction of a physiological model defining cross-talk and signaling pathway alterations which explicitly suggested mechanisms directly involved in tumor progression. The model further suggested points and means of intervention which could induce cell death in Ha-ras-transformed cells specifically. These hypotheses were directly tested in vitro and found to be largely correct, hence indicating that these new analytical and technological approaches allow the discovery of pathology-associated cellular mechanisms and physiologically defined targets leading to phenotype-specific pharmacological interventions.

Purpose: To identify predicting factors for local failure and increased risk of distant metastases by statistical analysis of the data after breast-conserving treatment for early breast cancer., Methods and Materials: Between January 1976 and December 1993, 528 patients with nonmetastatic T1 (tumors < or = 1 cm [n = 197], >1 cm [n = 220]) or T2 (tumors < or = 3 cm [n = 111]) carcinoma of the breast underwent wide excision (n = 435) or quadrantectomy (n = 93) with axillary dissection (negative nodal status [n-]: 396; 1-3 involved nodes: 100; >3 involved nodes: 32). Radiotherapy consisted of 45 Gy to the entire breast via tangential fields. Patients with positive axillary lymph nodes received 45 Gy to the axillary and supraclavicular area. Patients with positive axillary nodes and/or inner or central tumor locations received 50 Gy to the internal mammary lymph node area. A boost dose was delivered to the primary site by iridium 192 Implant in 298 patients (mean total dose: 15.2+/-0.07 Gy, range: 15-25 Gy) or by electrons in 225 patients (mean total dose: 14.8+/-0.09 Gy, range: 5-20 Gy). The mean age was 52.5+/-0.5 years (range: 26-86 years) and 267 patient were postmenopausal. Histologic types were as follows: 463 infiltrating ductal carcinomas, 39 infiltrating lobular carcinomas, and 26 other histotypes. Grade distribution according to the Scarff, Bloom, and Richardson (SBR) classification was as follows: 149 grade 1, 271 grade 2, 73 grade 3, and 35 nonclassified. The mean tumor size was 1.6+/-0.3 cm (range: 0.3-3 cm). The intraductal component of the primary tumor was extensive (EIC = IC > or = 25%) in 39 patients. Tumors were microscopically bifocal in 33 cases. Margins were assessed in the majority of cases by inking of the resection margins and were classified as positive in 13 cases, close (< or = 2 mm) in 21, negative (>2 mm tumor-free margin) in 417, and indeterminate in 77. Peritumoral vascular invasion was observed in 40 patients. Tamoxifen was administered for at least 2 years in 176 patients. At least six cycles of adjuvant systemic chemotherapy were administered in 116 patients. The mean follow-up period from the beginning of the treatment was 84.5+/-1.7 months., Results: First events included 44 isolated local recurrences, 8 isolated axillary node recurrences, 44 isolated distant metastases, 1 local recurrence with synchronous axillary node recurrence, 7 local recurrences with synchronous metastases, and 2 local recurrences with synchronous axillary node recurrences and distant metastases. Of 39 pathologically evaluable local recurrences, 33 were classified as true local recurrences and 6 as ipsilateral new primary carcinomas. Seventy patients died (47 of breast carcinoma, 4 of other neoplastic diseases, 10 of other diseases and 9 of unknown causes). The 5- and 10-year rates were, respectively: specific survival 93% and 86%, disease-free survival 85% and 75%, distant metastasis 8.5% and 14%, and local recurrence 7% and 14%. Mean intervals from the beginning of treatment for local recurrence or distant metastases were, respectively, 60+/-6 months (median: 47 months, range: 6-217 months) and 49.5+/-5.4 months (median: 33 months, range: 6-217 months). After local recurrence, salvage mastectomy was performed in 46 patients (85%) and systemic hormonal therapy and/or chemotherapy was administered to 43 patients. The 5-year specific survival rate after treatment for local recurrence was 78+/-8.2%. Multivariate analysis (multivariate generalization of the proportional hazards model) showed that the probability of local control was decreased by the following four independent factors: young age (< or = 40 yr vs. >40 yr; relative risk [RR]: 3.15, 95% confidence interval [CI]: 1.7-5.8, p = 0.0002), premenopausal status (pre vs. post; RR: 2.9, 95% CI: 1.4-6, p = 0.0048), bifocality (uni- vs. bifocal; RR: 2.7, 95% CI: 2.6-2.8,p = 0.018), and extensive intraductal component (IC <25% vs. IC > or = 25%; RR: 2.6, 95% CI: 13-5.2, p = 0

Background and Purpose: To evaluate possibility of breast-conserving therapy and outcome for patients with locally advanced non-inflammatory breast cancer (LABC) and stage II >3 cm in diameter after primary chemotherapy (CT) followed by external preoperative irradiation (RT)., Materials and Methods: Between 1982 and 1990, 147 patients were treated by four courses of induction CT (doxorubicin, vincristine, cyclophosphamide, 5-fluorouracil) followed by preoperative RT (45 Gy to the breast and nodal areas) and a fifth course of CT. Three different loco-regional approaches were proposed depending on tumour characteristics and tumour response. After completion of local therapy, all patients received a sixth course of CT and a maintenance adjuvant CT regimen without anthracycline., Results: Mastectomy and axillary dissection were performed in 52 patients, and conservative treatment in 95 patients (48 achieved complete remission and received additional radiation boost to initial tumour bed; 47 had a residual mass < or =3 cm in diameter and were treated by wide excision and axillary dissection followed by a boost to the excision site. Ten-year actuarial loco-regional failure rate was 20% after RT alone, 23% after wide excision and RT and 6% after mastectomy (P = 0.85). After multivariate analysis, possibility of breast-conserving therapy was related to initial tumour size. Ten-year overall survival rate was 66%; it was not influenced by local treatment (conservative vs. non-conservative local treatment, P = 0.89). However, local failure significantly decreased overall survival (P < 0.0001). After multivariate analysis, tumour response after induction CT and clinical stage had a significant impact on survival., Conclusions: The present data indicate that induction CT followed by preoperative RT may permit the selection of some patients with LABC or stage II >3 cm for conservative treatment. The impact of this treatment modality on long term survival remains to be established.

Purpose: The aims of this prospective study were to evaluate the outcome and the possibility of breast conservation therapy for patients with locally advanced noninflammatory breast cancer after primary chemotherapy followed by external preoperative irradiation., Methods and Materials: Between April 1982 and June 1990, 97 patients with locally advanced nonmetastatic and noninflammatory breast cancer were treated. The median follow-up was 93 months from the beginning of treatment. The induction treatment consisted of four courses of chemotherapy (doxorubicin, vincristine, cyclophosphamide, 5-fluorouracil) followed by preoperative irradiation (45 Gy to the breast and nodal areas). A fifth course of chemotherapy was given after irradiation therapy. Three different loco-regional approaches were proposed, depending on the tumoral response. In 37 patients (38%) with residual tumor larger than 3 cm in diameter or located behind the nipple or with bifocal tumors, mastectomy and axillary dissection were performed. Sixty other patients (62%) benefited from conservative treatment: 33 patients (34%) achieved complete remission and no surgery was done but additional radiation boost was given to the initial tumor bed; 27 patients (28%) who had a residual mass less than or equal to 3 cm in diameter were treated by wide excision and axillary dissection followed by a boost to the excision site. After completion of local therapy, all patients received a sixth course of chemotherapy. A maintenance adjuvant chemotherapy regimen without anthracycline was prescribed (12 monthly cycles)., Results: The 5-year actuarial loco-regional relapse rate was 16% after radiotherapy alone, 16% following wide excision and radiotherapy, and 5.4% following mastectomy. The 5-year loco-regional relapse rate was significantly higher after conservative local treatment (wide excision and radiotherapy, and radiotherapy alone) than after mastectomy (p= 0.04). After conservative local treatment, the 5-year breast conserving rate of patients with loco-regional disease-free status was 84%. For all patients included in this study, the 5-year breast-conserving rate of those who were loco-regional disease-free was 52%. In multivariate analysis, the possibility of breast conservative treatment was significantly related to the initial tumor size and age (more conservative treatment for tumor size < 6cm and age < 50 years). Five- and 10-year overall survival rates and disease-free survival rates were 80, 69, 73, and 61% respectively. Five- and 10-year overall survival rates were not influenced by the local treatment (conservative vs. nonconservative local treatment, p = 0.9). On the other hand, local failure significantly decreased the 5- and 10-year overall survival rates (p , 0.0001). In multivariate analysis, three factors had a significant impact on overall survival and disease-free survival: tumor response after induction chemotherapy, initial tumor size, and clinical stage. Arm lymphedema was noted in 12.5% (8 out of 64) of the patients treated with axillary dissection and in 3% (1 out of 33) without axillary dissection. Cosmetic results were satisfactory in 79% of patients after wide excision and radiotherapy and in 71% of patients treated by radiotherapy alone., Conclusions: Induction chemotherapy followed by preoperative irradiation may permit the selection of some patients with locally advanced breast cancer for conservative treatment. However, the impact of this treatment modality on long-term survival remains to be established.

Between December 1981 and December 1988, 329 consecutive patients with stage I and II breast cancers who underwent wide excision (n = 261) or quadrantectomy (n = 68) with (n = 303) or without (n = 26) axillary dissection were referred to radiotherapy. Final margins of resection were microscopically free from tumor involvement in all cases. Radiotherapy consisted in 40-45 Gy over 4-4.5 weeks to the breast, with (n = 168) or without (n = 161) regional nodal irradiation of 45-50 Gy over 4.5-5 weeks. A mean booster dose of 15 Gy was delivered to the primary site by iridium-192 implant in 169 patients (group 1) or by electrons in 160 patients (group 2). Twenty-seven percent (n = 88) of patients received tamoxifen for > or = 2 years. Adjuvant chemotherapy was administered in 22% (n = 71) of patients. Groups 1 and 2 were not strictly comparable. Group 1 patients were significantly younger, had smaller tumors, were treated with cobalt at 5 x 2 Gy per week and axillary dissection was more frequently performed. Group 2 patients were more frequently bifocal and more frequently treated by quadrantectomy and tamoxifen, and irradiation used accelerator photons at 4 x 2.50 Gy per week. No difference in terms of follow-up and survival rates was observed between the two groups. For all patients the 5- and 10-year local breast relapse rates were 6.7% and 11%, respectively. No difference was observed regarding local control either by the electron or the iridium-192 implant boosts. Axillary dissection and age had an impact on the breast cosmetic outcome.(ABSTRACT TRUNCATED AT 250 WORDS)