Long-term results of International Breast Cancer Study Group Trial VIII: adjuvant chemotherapy plus goserelin compared with either therapy alone for premenopausal patients with node-negative breast cancer.

BACKGROUND: The International Breast Cancer Study Group Trial VIII compared long-term efficacy of endocrine therapy (goserelin), chemotherapy [cyclophosphamide, methotrexate and fluorouracil (CMF)], and chemoendocrine therapy (CMF followed by goserelin) for pre/perimenopausal women with lymph-node-negative breast cancer. PATIENTS AND METHODS: From 1990 to 1999, 1063 patients were randomized to receive (i) goserelin for 24 months (n = 346), (ii) six courses of 'classical' CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy (n = 360), or (iii) six courses of CMF plus 18 months goserelin (CMF→ goserelin; n = 357). Tumors were classified as estrogen receptor (ER) negative (19%), ER positive (80%), or ER unknown (1%); 19% of patients were younger than 40. Median follow-up was 12.1 years. RESULTS: For the ER-positive cohort, sequential therapy provided a statistically significant benefit in disease-free survival (DFS) (12-year DFS = 77%) compared with CMF alone (69%) and goserelin alone (68%) (P = 0.04 for each comparison), due largely to the effect in younger patients. Patients with ER-negative tumors whose treatment included CMF had similar DFS (12-year DFS CMF = 67%; 12-year DFS CMF→ goserelin = 69%) compared with goserelin alone (12-year DFS = 61%, P= NS). CONCLUSIONS: For pre/perimenopausal women with lymph-node-negative ER-positive breast cancer, CMF followed by goserelin improved DFS in comparison with either modality alone. The improvement was the most pronounced in those aged below 40, suggesting an endocrine effect of prolonged CMF-induced amenorrhea.

Differential efficacy of three cycles of CMF followed by tamoxifen in patients with ER-positive and ER-negative tumors: long-term follow up on IBCSG Trial IX.

BACKGROUND: The benefit of adjuvant chemotherapy in postmenopausal patients with estrogen receptor (ER)-positive lymph node-negative breast cancer is being reassessed. PATIENTS AND METHODS: After stratification by ER status, 1669 postmenopausal patients with operable lymph node-negative breast cancer were randomly assigned to three 28-day courses of 'classical' CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy followed by tamoxifen for 57 months (CMF→tamoxifen) or to tamoxifen alone for 5 years. RESULTS: ERs were positive in 81% of tumors. At a median follow-up of 13.1 years, patients with ER-positive breast cancers did not benefit from CMF [13-year disease-free survival (DFS) 64% CMF→tamoxifen, 66% tamoxifen; P = 0.99], whereas CMF substantially improved the prognosis of patients with ER-negative breast cancer (13-year DFS 73% versus 57%, P = 0.001). Similarly, breast cancer-free interval (BCFI) was identical in the ER-positive cohort but significantly improved by chemotherapy in the ER-negative cohort (13-year BCFI 80% versus 63%, P = 0.001). CMF had no influence on second nonbreast malignancies or deaths from other causes. CONCLUSION: CMF is not beneficial in postmenopausal patients with node-negative ER-positive breast cancer but is highly effective within the ER-negative cohort. In the future, other markers of chemotherapy response may define a subset of patients with ER-positive tumors who may benefit from adjuvant chemotherapy.

Adverse prognostic value of peritumoral vascular invasion: is it abrogated by adequate endocrine adjuvant therapy? Results from two International Breast Cancer Study Group randomized trials of chemoendocrine adjuvant therapy for early breast cancer.

BACKGROUND: Peritumoral vascular invasion (PVI) may assist in assigning optimal adjuvant systemic therapy for women with early breast cancer. PATIENTS AND METHODS: Patients participated in two International Breast Cancer Study Group randomized trials testing chemoendocrine adjuvant therapies in premenopausal (trial VIII) or postmenopausal (trial IX) node-negative breast cancer. PVI was assessed by institutional pathologists and/or central review on hematoxylin-eosin-stained slides in 99% of patients (analysis cohort 2754 patients, median follow-up >9 years). RESULTS: PVI, present in 23% of the tumors, was associated with higher grade tumors and larger tumor size (trial IX only). Presence of PVI increased locoregional and distant recurrence and was significantly associated with poorer disease-free survival. The adverse prognostic impact of PVI in trial VIII was limited to premenopausal patients with endocrine-responsive tumors randomized to therapies not containing goserelin, and conversely the beneficial effect of goserelin was limited to patients whose tumors showed PVI. In trial IX, all patients received tamoxifen: the adverse prognostic impact of PVI was limited to patients with receptor-negative tumors regardless of chemotherapy. CONCLUSION: Adequate endocrine adjuvant therapy appears to abrogate the adverse impact of PVI in node-negative disease, while PVI may identify patients who will benefit particularly from adjuvant therapy.

The importance of the histologic grade of invasive breast carcinoma and response to chemotherapy.

BACKGROUND: Histologic grade is well recognized for its prognostic significance in cases of primary operable invasive breast carcinoma; however, the majority of studies in which grade has been assessed have been based on single-center trials. In addition, the role of grade in predicting response to chemotherapy has not been examined in many previous studies. METHODS: The authors assessed the value of Nottingham histologic grade (NHG) in a group of 465 patients enrolled in a multicenter, randomized International Breast Cancer Study Group clinical trial of adjuvant chemotherapy for patients with lymph node (LN) positive and LN negative primary breast carcinoma (formerly named Ludwig Trial V). RESULTS: NHG was a predictor of overall survival for both LN negative and LN positive patients (P=0.045 and P < 0.001, respectively). NHG was associated with a poorer prognosis for both LN positive and LN negative patients, with hazard ratios of 1.651 (P < 0.001) and 1.437 (P=0.045), respectively, for an increase of one grade. Among LN negative patients, this survival disadvantage was observed only for those who received perioperative chemotherapy. For LN positive patients, an increase of one grade resulted in a significant overall survival disadvantage regardless of whether prolonged or perioperative chemotherapy was given. For LN negative patients grouped by grade, there was no observed difference in overall or disease free survival according to whether perioperative chemotherapy or no adjuvant therapy was given. However, LN positive patients with Grade 3 tumors had a significantly greater overall and disease free survival benefit from prolonged chemotherapy than from perioperative chemotherapy (P=0.016 and P=0.013, respectively); LN positive patients with Grade 1 or 2 disease in both treatment arms had comparable overall and disease free survival. A strong correlation between the previously utilized Bloom-Richardson grading system (BRG) and NHG was observed (P < 0.001 and kappa=82%) and no apparent differences in overall and disease free survival were observed between the two systems. NHG did, however, identify a greater proportion of tumors as Grade 1, and BRG identified a greater proportion of breast carcinomas as Grade 3. CONCLUSIONS: This multicenter clinical study confirms the value of histologic grade, and the authors propose that this technique be used to identify Grade 3, LN positive patients who will benefit from prolonged rather than perioperative chemotherapy.

Prognostic importance of thymidylate synthase expression in early breast cancer.

PURPOSE: To assess the prognostic importance of thymidylate synthase (TS) expression in breast tumors of patients with early-stage breast cancer, and to determine whether the benefit of chemotherapy (CT) is associated with TS expression. PATIENTS AND METHODS: The level of TS expression was evaluated in 210 node-negative and 278 node-positive patients enrolled onto Trial V of the International Breast Cancer Study Group ([IBCSG] formerly the Ludwig Breast Cancer Study Group) with a median follow-up time of 8.5 years. TS expression was assessed using the immunohistochemical method with the monoclonal antibody TS 106 on paraffin-embedded tissue specimens. RESULTS: High TS expression was associated with a significantly worse prognosis in node-positive but not in node-negative breast cancer patients. Twenty-seven percent of node-positive patients with high TS expression were disease-free at 10 years, compared with 44% of node-positive patients with low TS expression (P = .03). Forty-one percent of patients with node-positive high-TS-expressing tumors were alive after 10 years, compared with 49% of those with low TS expression (P = .06). The association between TS and disease-free survival (DFS) and overall survival (OS) was independent of other prognostic factors such as tumor size, tumor grade, nodal status, vessel invasion, estrogen receptor (ER)/ progestin receptor (PR) status, c-erb B-2, or Ki-67 expression. In node-positive patients, six cycles of standard adjuvant cyclophosphamide, methotrexate, and fluorouracil ([5-FU] CMF) CT improved DFS and OS compared with one cycle of perioperative CMF therapy. The magnitude of this benefit was greatest in patients whose tumors had high TS expression (P < .01 for DFS; P < .01 for OS). Node-negative patients demonstrated no difference in outcome to CT based on TS expression; however, the power to detect differences was limited by the small number of events in this group. CONCLUSION: In early-stage breast cancer, high TS expression is associated with a significantly worse prognosis in node-positive patients. Node-positive patients with high TS levels demonstrate the most significant improvement in DFS and OS when treated with six cycles of conventional adjuvant CMF therapy.

Expression of the receptor protein tyrosine kinase myk-1/htk in normal and malignant mammary epithelium.

We have recently reported the molecular characterization of a novel murine receptor PTK (myk-1), belonging to the eph-related family, whose expression was differentially regulated during mammary gland development and elevated in invasive mouse mammary tumours. In this communication we have investigated the cellular origin of myk-1 expression by in situ hybridisation and RNase protection. Murine antisense myk-1 probe specifically recognised ductal and alveolar epithelium in the resting mouse mammary gland. In normal human breast, the expression of htk, the human homologue, was also confined to the secretory luminal epithelial cells. RNase protection analysis of enriched luminal and myoepithelial cells prepared from human reduction mammoplasty tissue confirmed the luminal specificity. Elevated expression of htk was found in several human breast carcinoma cell lines as well as in primary, high grade, infiltrating, ductal carcinomas of the breast. The specific epithelial expression of the myk-1/htk receptor PTK suggest a specialised role of this eph-related PTK in the differentiation and/or maintenance of secretory epithelium in the adult.

Fusion of SYT to two genes, SSX1 and SSX2, encoding proteins with homology to the Kruppel-associated box in human synovial sarcoma.

We demonstrate that the cytogenetically defined translocation t(X;18)(p11.2;q11.2) found in human synovial sarcoma results in the fusion of the chromosome 18 SYT gene to either of two distinct genes, SSX1 or SSX2, at Xp11.2. The SSX1 and SSX2 genes encode closely related proteins (81% identity) of 188 amino acids that are rich in charged amino acids. The N-terminal portion of each SSX protein exhibits homology to the Kruppel-associated box (KRAB), a transcriptional repressor domain previously found only in Kruppel-type zinc finger proteins. PCR analysis demonstrates the presence of SYT-SSX1 or SYT-SSX2 fusion transcripts in 29 of 32 of the synovial sarcomas examined, indicating that the detection of these hybrid transcripts by PCR may represent a very useful diagnostic method. Sequence analysis has demonstrated heterogeneity in the fusion transcripts with the formation of two distinct SYT-SSX1 fusion junctions and two distinct SYT-SSX2 fusion junctions.

Pez: a novel human cDNA encoding protein tyrosine phosphatase- and ezrin-like domains.

We have isolated cDNAs from normal human breast tissue and breast tumour cells that encode a protein (pez) with features of a novel non-receptor tyrosine phosphatase possessing N-terminal sequence homology to the ezrin-band 4.1-merlin-radixin protein family. Northern blot analysis indicates that pez is expressed in a variety of human tissues including kidney, skeletal muscle, lung and placenta. Fluorescence in situ hybridization has mapped pez to chromosome 1 region q32.2-41. Sequence identity to a characterized polymorphic marker confirms this localization.

Cloning and characterisation of cDNAs encoding a novel non-receptor tyrosine kinase, brk, expressed in human breast tumours.

Using a polymerase chain reaction based differential screening approach, we have isolated and characterised a cDNA from a human metastatic breast tumour representing a novel protein tyrosine kinase (brk). Sequencing of brk cDNAs isolated from T-47D and MCF-7 human breast tumour cell lines indicate that they encode a protein with the features of a novel nonreceptor tyrosine kinase, including amino terminal SH3 and SH2 domains. When synthesised in recombinant baculovirus and bacterial expression systems, brk protein products are capable of autophosphorylation on tyrosine residues. Initial expression studies have detected low levels of brk transcripts in some human breast tumours and breast tumour cell lines, but not in normal breast tissue.

Monitoring tumor growth and regression by 31P magnetic resonance spectroscopy.

Magnetic resonance spectroscopy (MRS) uniquely provides noninvasive access to chemistry in vivo. 31P MRS can be used to monitor the high energy phosphates--phosphocreatine (PCr) and ATP, and their breakdown product--Pi, in situ in animals or patients. In several experimental tumor lines in animals it has been shown that the PCr/ATP and other related ratios steadily decline as the tumor increases in size, and that this effect is reversed when the tumor is treated with a therapeutic modality to which it responds. Acid extracts of freeze-clamped tumors at different stages of growth have confirmed these MRS observations and give additional information on related compounds such as creatine and ADP. Results show that, in the tumors studied, at least 80% of the ADP and about 40% of the Pi are bound and not in solution in the cytosol. Histological sections have indicated that the MRS response to endocrine therapy, in an NMU-induced estrogen-sensitive mammary tumor model, precedes any histological changes or any measurable regression. If these findings can be translated into a clinical setting, this may mean that MRS can be used in the clinic as an early predictor of tumor responsiveness to treatment. In untreated tumor growth, the cause of the decrease in PCr and ATP relative to Pi is probably due to the tumors outgrowing their blood supply and the cells becoming increasingly hypoxic. The PCr is lost more rapidly than ATP, indicating that the equilibrium in the creatine kinase reaction is maintained in these tumors. When the tumor is treated, cellular growth ceases and the requirement for oxygen and other nutrients is greatly reduced. This would allow the cellular energy reserves to be repleted and thus lead to the paradoxical improvement in the high energy phosphate status of a tumor that is about to regress.