Mutational analysis of estrogen receptor-beta gene in human breast cancers.
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Breast Neoplasms↗
Biomedical subjects
Shinzaburo Noguchi
Publications and source records attributed to Shinzaburo Noguchi.
Endoscopic thyroid surgery through the axillo-bilateral-breast approach.
We developed a new endoscopic thyroid surgery by the axillo-bilateral-breast approach (ABBA) method, which is different from the previously described breast approach (BA) in that the port sites are modified to obtain a better view and to prevent the interference of surgical instruments. This modification also improves cosmetic results by eliminating the parasternal incision, which results in hypertrophic scar in a significant number of cases treated with BA. Twelve patients with benign thyroid tumors successfully underwent endoscopic thyroid surgery by ABBA, and their clinical outcomes were compared with those of four patients treated with BA. The mean operation time was significantly shorter in the ABBA group than in the BA group (188 minutes vs. 270 minutes; P < 0.01). Furthermore, the mean blood loss in the ABBA group (53 mL) was half of that in the BA group (108 mL). Neither conversion to open surgery nor significant intraoperative complications were experienced. The operative scars by ABBA became inconspicuous in a few weeks. These results seem to indicate that ABBA is a better method than BA and can be a feasible option, particularly for young patients who opt for the better cosmetic outcome.
Adenoma↗
Lymphoscintigraphic visualization of internal mammary nodes with subtumoral injection of radiocolloid in patients with breast cancer.
OBJECTIVE: To determine whether subtumoral injection of radiocolloid is useful for lymphoscintigraphic visualization of the internal mammary node and in sentinel lymph node (SLN) biopsy of the axilla in breast cancer patients. SUMMARY BACKGROUND DATA: The presence of retromammary lymphatics connecting to the axillary and internal mammary basins has been demonstrated by early anatomic studies. Thus, it is hypothesized that some lymph, especially that from the parenchyma under the tumor, may drain into both the axillary and internal mammary basins. METHODS: Patients (n = 196) with T1-2, N0 breast cancer underwent preoperative lymphoscintigraphy with radiocolloid (technetium 99m tin colloid) injection into various sites of the breast, followed by SLN biopsy using the combined method with blue dye. Patients were divided into four groups: group A (n = 41), peritumoral injection of both radiocolloid and blue dye; group B (n = 70), periareolar radiocolloid and peritumoral blue dye; group C (n = 45), intradermal radiocolloid and periareolar blue dye; and group D (n = 40), subtumoral radiocolloid and intradermal blue dye. A retrospective analysis of 1,297 breast cancer patients who underwent extended radical mastectomy with internal mammary node dissection was also conducted to determine the relationship between vertical tumor location (superficial or deep) and frequency of axillary and internal mammary node metastases. RESULTS: One patient (2%) in group A, 3 (4%) in group B, 0 (0%) in group C, and 15 (38%) in group D exhibited hot spots in the internal mammary region on lymphoscintigraphy (P <.001, group D vs. the other groups). The concordance rate of radiocolloid and blue dye methods in detection of SLNs in the axillary basin was significantly lower in group D than in the other groups. In contrast, the mismatch rate (some SLNs were identified by radiocolloid and other SLNs were identified by blue dye, but no SLN was identified by both in the same patient) was significantly higher in group D than in the other groups. In patients treated with extended radical mastectomy, positivity of axillary and internal mammary metastases was significantly higher in patients (n = 215) with deep tumors than those (n = 368) with superficial tumors. CONCLUSIONS: These results suggest the presence of a retromammary lymphatic pathway from the deep portion of the breast to both axillary and internal mammary basins, which is distinct from the superficial pathway. Therefore, SLN biopsy with a combination of subtumoral and other (peritumoral, dermal, or areolar) injections of radiocolloid will improve both axillary and internal mammary nodal staging.
Adult↗
Overexpression of the Wilms' tumor gene WT1 in primary thyroid cancer.
The expression levels of the Wilms' tumor gene WT1 were examined in 34 primary thyroid cancers (24 papillary, 5 follicular, 1 anaplastic, and 4 medullary carcinomas), 17 thyroid follicular adenomas, and 6 normal-appearing thyroid tissues using quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). In 33 of 34 thyroid cancers, the WT1 mRNA was expressed at levels ranging from 5.0 x 10 (-5) to 8.3 x 10 (-2) levels (WT1 expression level in K562 leukemic cells was defined as 1.0). The WT1 mRNA expression levels were significantly higher than those in either thyroid follicular adenomas (P < 0.001) or normal-appearing thyroid tissues (P < 0.01). Immunohistochemical analysis confirmed the expression of WT1 protein in 20 of 21 thyroid cancers with WT1 mRNA expression. WT1 protein was also detected in 6 of 7 follicular adenomas with WT1 mRNA expression. However, the intensity of staining of WT1 protein in adenoma cells was weaker than that in cancer cells and its expression was restricted to approximately 30-80% of adenoma cells in the tumors examined. The direct sequencing analysis of the WT1 genomic DNA showed no mutations in any of the 10 exons of the WT1 gene in all of the 9 different thyroid cancers. These findings indicate an important role of the wild-type WT1 gene in the tumorigenesis of primary thyroid cancer.
Adenocarcinoma, Follicular↗
Phase II study of concurrent administration of doxorubicin and docetaxel as first-line chemotherapy for metastatic breast cancer.
OBJECTIVE: To evaluate the efficacy and toxicity of concurrent administration of doxorubicin and docetaxel, without prophylactic use of granulocyte colony-stimulating factor, as first-line chemotherapy in patients with metastatic breast cancer (MBC). METHODS: This multi-institutional study enrolled 40 women; 37 were assessable for efficacy and all 40 patients were evaluated for toxicity. Treatment consisted of 50 mg/m(2) doxorubicin and 60 mg/m(2) docetaxel on day 1 every 3-4 weeks. RESULTS: Patients received a total of 251 cycles of chemotherapy (median, 5 cycles; range, 1-13 cycles). Of the 37 patients assessable for efficacy, 2 had a complete response and 24 had partial responses, which accounted for a 70% objective response rate (95% confidence interval, 53-84%). The median time to treatment failure was 30.1 weeks (range, 3.3-80.7 weeks). Grade 4 neutropenia was observed in 88% of patients and was the most frequent haematological toxicity. Febrile neutropenia was seen in 40% of patients, but no severe infections were observed. Non-haematological toxicity was generally tolerable. There were 2 grade 4 adverse events, which included 1 bleeding duodenal ulcer and 1 hypersensitivity reaction, but grade 3 episodes were infrequent. None of the patients developed congestive heart failure or asymptomatic decrease of left ventricular ejection fraction to less than 50%. Fluid retention syndrome <or= grade 2 was observed in 25% of patients at a median cumulative dose of docetaxel of 270 mg/m(2). CONCLUSION: Concurrent administration of 50 mg/m(2) doxorubicin and 60 mg/m(2) docetaxel is active with a manageable toxicity profile as first-line chemotherapy for MBC.
Adult↗
Aromatase inhibitors for treatment of postmenopausal patients with breast cancer.
The third generation of aromatase inhibitors and inactivators, such as anastrozole (Arimidex), letrozole (Femara) and exemestane (Aromasin), have become available for treatment of postmenopausal breast cancer patients. Several clinical trials have demonstrated that these new drugs can achieve better treatment results than megestrol acetate (Megace) and may replace tamoxifen for the first-line hormonal therapy for metastatic breast cancer patients. In fact, these drugs are now used in many hospitals and clinics for patients with metastatic breast cancer who were previously given tamoxifen as adjuvant treatment. However, the primary concern is whether they can be used as first-line agents for adjuvant treatment of primary breast cancer or are suitable for breast cancer prevention in view of possible adverse side effects. Recently, the Arimidex and Tamoxifen Alone or in Combination trial demonstrated the superiority in terms of disease-free survival of anastrozole over tamoxifen in adjuvant use for postmenopausal patients with Stage I and II primary breast cancer. The results of this report indicate the potential of anastrozole as an alternative drug in the adjuvant setting, although the mean follow-up time is so far only 47 months. Additional data regarding survival resulting from comparative trials of letrozole and tamoxifen and of exemestane and tamoxifen are expected to be available in a few years. However, limited information is available regarding adverse events caused by long-term administration of aromatase inhibitors. Longer follow-up is needed to determine the efficacy and safety of these new aromatase inhibitors when used for adjuvant treatment of postmenopausal patients with breast cancer.
Antineoplastic Agents↗
[A case of metastatic pheochromocytoma with remarkable response to combination of cyclophosphamide, vincristine and dacarbazine].
We report the case of a 58-year-old man with metastatic tumors 13 months after the initial surgery for paraganglioma at the left adrenal gland. A CT scan revealed a large tumor at the right scapula and abdominal paraaortic lymph nodes, and the patient received combination therapy of cyclophosphamide, vincristine and dacarbazine (CVD) every 3 to 4 weeks. After 11 courses, the serum catecholamine level was reduced to the normal range. The metastatic tumors showed optimal reduction in size, and the patient remains alive with no symptoms of the disease one year after the primary chemotherapy. The combination therapy of cyclophosphamide, vincristine and dacarbazine is considered a feasible and effective chemotherapy for metastatic malignant pheochromocytoma.
Adrenal Gland Neoplasms↗
Association of BRCA2 polymorphism at codon 784 (Met/Val) with breast cancer risk and prognosis.
PURPOSE: The association of BRCA2 polymorphisms at codon 372 [Asn (N)/His (H)]and codon 784 [Met (M)/Val (V)] with breast cancer risk was evaluated in Japanese women. In addition, the prognostic significance of these polymorphisms was studied in breast cancer patients. EXPERIMENTAL DESIGN: A case-control study was conducted to examine the association of the BRCA2 N/H372 polymorphism and M/V 784 polymorphism with breast cancer risk (cases = 149, controls = 154). The prognostic significance of these polymorphisms was evaluated in 139 patients with primary breast cancer. RESULTS: No significant association was observed between the N/H372 polymorphism and breast cancer risk. In contrast, a significant increase in breast cancer risk (odds ratio, 2.03; 95% confidence interval, 1.07-3.87) was observed in carriers of the variant allele (V784) of the M/V784 polymorphism as compared with noncarriers after adjustment for the classical risk factors, age, family history, parity, body mass index, and so forth. Among breast cancer patients, various clinicopathological parameters including menopausal status, tumor size, lymph node status, histological grade, and estrogen-receptor status were not significantly different between the carriers and noncarriers of the variant allele with regard to both N/H372 and M/V784 polymorphisms. The N/H 372 polymorphism was not significantly associated with patient prognosis. On the other hand, breast cancer patients carrying the variant allele of M/V784 polymorphism showed a significantly (P = 0.014) lower 3-year disease-free survival rate (63%) than noncarriers (92%). Multivariate analysis has revealed that the M/V784 polymorphism is a significant prognostic factor, being independent of the other conventional prognostic factors such as lymph node status and estrogen receptor status. CONCLUSION: These results suggest that the M/V784 polymorphism, but not the N/H372 polymorphism, would be useful in the selection of women at high risk for developing breast cancer and would also serve as a clinically useful prognostic factor in breast cancer patients.
Alleles↗
Association of serum estrone levels with estrogen receptor-positive breast cancer risk in postmenopausal Japanese women.
PURPOSE: Several reports have demonstrated the association between high serum estrogens levels and breast cancer risk in postmenopausal women. It is hypothesized that breast cancers arising in postmenopausal women with high serum estrogens levels are more likely to be estrogen receptor (ER)-positive. Thus, we have investigated whether or not high serum estrone (E(1)) levels are associated with ER-positive breast cancer risk in postmenopausal women. EXPERIMENTAL DESIGN: A case-control study was conducted on 71 cases (postmenopausal breast cancer patients) and 73 controls (postmenopausal healthy women). Serum E(1) levels were examined in their association with breast cancer risk after adjustment for the various epidemiological risk factors. In addition, clinicopathological characteristics of breast cancers arising in the women with high E(1) levels were investigated. RESULTS: Women in the high tertile of E(1) levels had a significantly (P < 0.01) increased risk of breast cancer as compared with women in the low tertile [odds ratio (OR), 4.14; 95% confidence interval (CI), 1.44-11.87]. Subset analysis according to the ER status showed that women in the high tertile of E(1) levels had a significantly increased risk for ER-positive breast cancer (OR, 23.79; 95% CI, 3.50-161.59) but not for ER-negative breast cancer (OR, 1.45; 95% CI, 0.41-5.15) as compared with women in the low tertile. Tumor size and lymph node status were not significantly different between women in the high tertile and those in the intermediate and low tertiles. But the frequency of low-histological-grade tumors and ER-positive tumors (88 and 67%, respectively) showed a greater trend toward an increase (P = 0.06 and P = 0.07, respectively) in women in the high tertile than those (69 and 46%, respectively) in the intermediate and low tertiles. In addition, ER levels in ER-positive tumors were significantly (P < 0.05) higher in women in the high tertile (245.3 +/- 37.1 fmol/mg protein) than those in the intermediate and low tertiles (134.0 +/- 31.3 fmol/mg protein). CONCLUSIONS: Postmenopausal women with high serum E(1) levels have a significantly increased risk for ER-positive, but not ER-negative, breast cancer. Breast cancers arising in women with high E(1) levels show a high ER positivity as well as high ER content. Measurement of serum E(1) levels would be clinically useful in the selection of postmenopausal women who can benefit from prophylactic use of tamoxifen because tamoxifen can prevent ER-positive, but not ER-negative, breast cancer.
Aged↗
High expression of steroid sulfatase mRNA predicts poor prognosis in patients with estrogen receptor-positive breast cancer.
PURPOSE: Prognostic significance of the intratumoral mRNA expression of three enzymes related to in situ estrogen biosynthesis, i.e., aromatase, sulfatase, and 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1), was evaluated in patients with invasive breast cancer. EXPERIMENTAL DESIGN: Aromatase, sulfatase, and 17beta-HSD1 mRNA levels in tumor tissues (n = 181) and normal breast tissues (n = 34) were examined by a quantitative, real-time PCR assay and compared with various clinicopathological factors as well as prognosis. RESULTS: The sulfatase mRNA levels, but not the aromataseor 17beta-HSD1 mRNA levels, were significantly associated with lymph node metastases (P < 0.005), histological grade III (P < 0.001), and poor prognosis (P < 0.005). The association between the sulfatase mRNA and poor prognosis was found to be significant (P < 0.001) only in patients with estrogen receptor (ER)-positive tumors but not in ER negative tumors. In ER-positive tumors, the sulfatase mRNA levels was a significant prognostic factor independent of the lymph node status and histological grade by multivariate analysis. CONCLUSIONS: The sulfatase mRNA levels can serve as a significant, independent prognostic factor only in ER-positive tumors. It is speculated that the up-regulation of sulfatase mRNA levels leads to a high intratumoral estrogen concentration and, thus, an enhanced stimulation of tumor growth through ERs.
17-Hydroxysteroid Dehydrogenases↗
[Phase III additional clinical study of 111In-pentetreotide (MP-1727): diagnosis of gastrointestinal hormone producing tumors based on the presence of somatostatin receptors].
Additional phase III multicenter clinical study was performed to investigate the efficacy, safety, and usefulness of somatostatin receptor scintigraphy using 111In-pentetreotide (MP-1727), which binds to somatostatin receptors. Forty patients were included in the study; Group A: 18 patients, gastrointestinal hormone producing tumors had been detected with conventional imaging modalities, Group B: 22 patients, no tumors had been detected with conventional imaging modalities in spite of high serum hormone levels. By comparing the results of the octreotide suppression test, 12/16 cases (75.0%) of Group A and 11/19 cases (57.9%) of Group B were assessed as "effective." By comparing the results of immunohistological examination, 5/9 cases (55.6%) of Group A and 2/4 cases (50.0%) of Group B were assessed as "effective." Severe adverse events were not observed in any of the evaluable 35 cases. MP-1727 was judged as clinically useful in 11/16 cases (68.8%) of Group A and 5/19 cases (26.3%) of group B. These results suggest that MP-1727 scintigraphy is very useful for the diagnosis and decision of the therapeutic strategy of gastrointestinal hormone producing tumors.
Aged↗
[Detecting micrometastases in sentinel lymph nodes].
Many investigators have reported micrometastases in sentinel lymph nodes, which have been detected by various methods. The most common method of detecting micrometastases is pathological examination using a combination of hematoxylin-eosin and immunohistochemical staining of multisectioned specimens. However, no standard method has been established concerning how to slice the specimen and how many slides should be examined. On the other hand, a more sensitive method utilizing the reverse-transcriptase polymerase chain reaction (RT-PCR) has also been applied for the detection of micrometastases. However, this method is so sensitive that it may detect isolated tumor cells (ITC), which are not defined as metastases according to the 6th edition of the American Joint Committee on Cancer and Union Internationale contre le Cancer cancer staging manuals for breast cancer. Therefore it is an urgent task to establish a standard method for detecting micrometastases in sentinel lymph nodes. For this purpose, further examination of many patients is needed to determine the most efficient and convenient way for detection of micrometastases in sentinel lymph nodes, whether the micrometastases influences the prognosis of patients, and whether regional lymph node clearance is needed in the case of micrometastases in sentinel lymph nodes.
Breast Neoplasms↗
Influence of adjuvant tamoxifen treatment on bone mineral density and bone turnover markers in postmenopausal breast cancer patients in Japan.
The effect of adjuvant tamoxifen treatment on bone mineral density (BMD) and bone turnover markers was studied in postmenopausal breast cancer patients. The relationship of tamoxifen's effect with the genetic polymorphisms of estrogen receptor (ER)-alpha and ER-beta gene was also studied. Twenty-one postmenopausal breast cancer patients were given tamoxifen (20 mg/day) as the adjuvant treatment after the surgery. BMD of the lumbar supine (dual emission X-rays absorptiometry) and bone resorption (deoxypyridinoline, aminoterminal telopeptide of type I collagen, and carboxyterminal telopeptide of type I collagen) and formation (propeptide of type I procollagen, osteocalcin, and bone-specific alkaline phosphatase) markers were examined at baseline (before the surgery), 6 and 12 months after the start of tamoxifen treatment. Genetic polymorphisms analyzed were TA dinucleotide repeats polymorphism in the promoter region and PvuII and XbaI restriction fragment length polymorphism for the ER-alpha gene and the CA dinucleotide repeats polymorphism in the intron 5 for the ER-beta gene. Tamoxifen significantly increased BMD of the lumbar spine at both 6 (P<0.01) and 12 months (P<0.01) after the start of tamoxifen as compared with that at baseline. The mean percent increase in BMD was 3.3% at 6 months and 2.7% at 12 months. All bone resorption and formation markers significantly decreased at both 6 and 12 months. Among the four genetic polymorphisms studied, only ER-beta CA repeat polymorphism was found to be significantly associated with BMD at 12 months, i.e. BMD of the 21 CA repeats allele carriers was significantly higher than that of the non-carriers (P=0.025). These results suggest that tamoxifen increases BMD of the lumbar supine by reducing the bone turnover in postmenopausal breast cancer patients, and this bone restoring effect of tamoxifen is more marked in ER-beta 21 CA repeats allele carriers than non-carriers.
Age Factors↗
Mutational analysis of the class I beta-tubulin gene in human breast cancer.
Non-small cell lung cancers have a high incidence of somatic mutations of the beta-tubulin (class I) gene, suggesting involvement in the acquisition of resistance to taxanes, which exert their effects through binding to beta-tubulin. Since taxanes are often used in the treatment of breast cancer, we carried out a mutational analysis of the class I beta-tubulin (GenBank accession AF070600) gene in breast cancer. We paid special attention to the primer design so as not to amplify the pseudogenes. We identified 1 somatic mutation, codon 306 [Arg (CGC) to Cys (TGC)], and 2 genetic polymorphisms, codon 217 [Leu (CTG) to Leu (CTA)] and (C to T) at 57 bases downstream from exon 4. Our results suggest that acquisition of resistance to taxanes is unlikely to be explained by somatic mutations of the class I beta-tubulin gene in most breast cancers. In addition, the overestimation of the incidence of somatic mutations of the class I beta-tubulin gene due to the pseudogenes is discussed.
Base Sequence↗
High BRCA2 mRNA expression predicts poor prognosis in breast cancer patients.
The prognostic significance of BRCA2 mRNA levels in tumor tissues was studied in sporadic breast cancer patients. BRCA2 mRNA levels were determined by real-time PCR. Histologic grade III tumors showed significantly (p = 0.001) higher BRCA2 mRNA levels (0.828 +/- 0.102 BRCA2/beta-glucuronidase mRNA ratio, mean +/- SE) than histologic grade I and II tumors (0.438 +/- 0.055) and estrogen receptor (ER)-negative tumors (0.773 +/- 0.102) showed a nonsignificant (p = 0.072) trend toward an increase in BRCA2 mRNA levels compared to ER-positive tumors (0.541 +/- 0.079). Other clinicopathologic parameters, such as menopausal status, lymph node status and tumor size, were not significantly associated with BRCA2 mRNA levels. Patients with high BRCA2 mRNA levels showed a significantly (p = 0.006) lower 5-year disease free survival rate (63%) than those with low levels (94%). Lymph node metastases, ER negativity and high histologic grade were also significantly (p < 0.05) associated with poor prognosis. Multivariate analysis revealed that BRCA2 mRNA levels were a significant prognostic factor, being independent of the other conventional prognostic factors. Our results suggest that BRCA2 mRNA levels might serve as a clinically useful prognostic factor in breast cancer patients.
BRCA2 Protein↗
Prediction of chemotherapeutic response by collagen gel droplet embedded culture-drug sensitivity test in human breast cancers.
Collagen gel droplet embedded culture-drug sensitivity test (CD-DST) is the newly developed in vitro chemosensitivity test that has several advantages over the conventional ones. The aim of the present study is to examine the clinical usefulness of this test in the prediction of response to chemotherapy in breast cancer patients. Seventy patients with primary (n = 45) or locally recurrent (n = 25) breast cancers were recruited, and each patient underwent tumor biopsy before chemotherapy. The biopsy specimens were used for CD-DST and immunohistological examination of 6 biological markers (P-gp, erbB2, p53, BCL2, MIB1 and ER-alpha). As chemotherapy, cyclophosphamide 600 mg/m(2) plus epirubicin 60 mg/m(2) q3w (CE, n = 28) or docetaxel 60 mg/m(2) q3w (DOC, n = 42) was given. Interpretable results using the CD-DST assay were obtained from 84.3% (59/70) of tumor specimens studied. Of the 18 tumors diagnosed as CE sensitive by CD-DST, 15 (83.3%) exhibited a response to CE therapy and none of the 5 tumors diagnosed as CE resistant by CD-DST exhibited a response to CE therapy. Of the 14 tumors diagnosed as DOC sensitive by CD-DST, 13 (92.9%) exhibited a response to DOC therapy and only one of the 22 tumors diagnosed as DOC resistant by CD-DST exhibited a response to DOC therapy. P-gp expression was found to exhibit a significant (p < 0.05) association with the resistance to CE therapy but not to DOC therapy. Diagnostic accuracy (72.7%) achieved by P-gp was lower than that (87.0%) achieved by CD-DST in CE therapy. Expressions of other biological markers (erbB2, p53, BCL2, MIB1 and ER-alpha) were not significantly associated with response to CE or DOC therapy. These results demonstrate that CD-DST can predict the response to CE and DOC therapy with a high accuracy in breast cancer patients and seems to be superior to the conventional predictors.
Adult↗
Molecular classification of primary breast tumors possessing distinct prognostic properties.
The natural progression of breast cancer differs greatly between patients; the precise prediction of this disease course will improve the efficacy of therapeutics. Gene expression profiling may elucidate the undiscovered biological variations between seemingly similar cancers, leading to a new cancer classification system valuable in accurate diagnosis. The expression levels of 2412 genes, derived from 98 cancer samples, were precisely recorded by a high throughput RT-PCR technique, adapter-tagged competitive PCR. Subsequent cluster analysis revealed a molecular profile, correlating with estrogen receptor levels and the presence of lymph node metastases. We analyzed 301 cancer samples for the expression patterns of 21 genes critical in this categorization. The classification of the samples into three major groups was verified utilizing principal component analysis. This molecular classification system correlated significantly with early recurrence, independent of lymph node status. This malignant potential is associated with the expression levels of a group of genes, which comprise a set of candidates potentially useful in diagnostic prediction. These genes and the associated control mechanisms may also be effective therapeutic targets.
Breast Neoplasms↗
Prediction of response to docetaxel by CYP3A4 mRNA expression in breast cancer tissues.
We studied the relationship between response of breast cancer to docetaxel (DOC) or cylophosphamide + epirubucin (CE) treatment and CYP3A4 mRNA expression in breast tumors. CYP3A4 inactivates DOC but not E, which is a predominant effector in CE treatment. Twenty patients with locally advanced breast tumors and 18 patients with locally recurrent tumors underwent tumor biopsy before chemotherapy, and CYP3A4 mRNA expression levels in tumor tissues were assayed by real-time quantitative polymerase chain reaction. Twenty-three patients were treated with DOC (60 mg/m(2) q3w) and 15 patients were treated with CE (C 600 mg/m(2) and E 60 mg/m(2) q3w). Patients with low CYP3A4 mRNA levels (n = 14) exhibited a significantly (p < 0.01) higher response rate (71%) to DOC treatment than those (n = 9) with high CYP3A4 mRNA levels (response rate, 11%). Positive predictive value, negative predictive value and diagnostic accuracy of CYP3A4 mRNA levels in the prediction of response to DOC were 71, 89, and 78%, respectively. However, no significant association was observed between CYP3A4 mRNA expression and response to CE treatment. These results suggest that intratumoral CYP3A4 mRNA levels might be useful as a predictor of response to DOC treatment, but not to CE treatment, in breast cancer patients. The increased inactivation of DOC by CYP3A4 in tumor tissues may play some role in the acquisition of resistance to DOC.
Adult↗