Abstract GS4-07: Race, ethnicity and clinical outcomes in hormone receptor-positive, HER2-negative, node-negative breast cancer: results from the TAILORx trial

Background: Black race is associated with worse outcomes in localized hormone receptor (HR)-positive breast cancer in population-based and in clinical trial cohorts, whether using self-identified race (Albain et al. JNCI 2009 [PMID: 19584328; Sparano et al. JNCI 2012 [PMID: 22250182) or genetically-identified race (Schneider et al. J Precision Oncol 2017 [PMID: 29333527]). This disparity persists after adjustment for treatment delivery parameters (Hershman et al. JCO 2009 [PMID:19307504]). We evaluated clinicopathologic characteristics, treatment delivered and clinical outcomes in the Trial Assigning Individualized Options for Treatment (TAILORx) by race and ethnicity (Sparano et al. NEJM 2018 [PMID: 29860917]).

Methods: The analysis included 9719 evaluable TAILORx participants. The association between clinical outcomes and race (white, black, Asian, other/unknown) and ethnicity (Hispanic vs. non-Hispanic) was examined, including invasive disease-free survival (iDFS), distant relapse-free interval (DRFI), relapse-free interval (RFI), and overall survival (OS). Proportional hazards models were fit including age (5 categories), tumor size (>2 cm vs. <=2 cm), histologic grade (high vs. medium vs. low vs. unknown), continuous recurrence score (RS), race, and ethnicity in the overall population and randomized treatment arms in the RS 11-25 cohort.

Results: The study population included 8189 (84%) whites, 693 (7%) blacks, 405 (4%) Asians, and 432 (4%) with other/unknown race. Regarding ethnicity, 7635 (79%) were non-Hispanic, 889 (9%) Hispanic, and 1195 (12%) unknown. There was no significant difference in RS distribution (p=0.22) in blacks compared with whites, or in median (17 vs. 17) or mean RS (19.1 vs. 18.2). There was likewise no difference in Hispanic vs. non-Hispanic ethnicity for RS distribution (p=0.72) or median (17 vs. 17) or mean RS (18.5 vs. 18.0). Black race (39% vs. 30%) and Hispanic ethnicity (39% vs. 30%) were both associated with younger age (</=50 years) at diagnosis. The use and type of adjuvant chemotherapy and endocrine therapy, and duration of endocrine therapy, were similar in black (vs. white) and Hispanic (vs. non-Hispanic) populations. In proportional hazards models, black race (compared with white race) was associated with worse clinical outcomes in the entire population and in those with a RS 11-25 (see table). Hispanic ethnicity was generally associated with better outcomes (compared with non-Hispanic ethnicity). For the cohort with a RS of 11-25, there was no evidence for chemotherapy benefit for any racial or ethnic group.

Race (black vs.white) and clinical outcomes in proportional hazards modelsClinical endpointEntire Population (N=693 black) Hazard ratio for eventRS 11-25 (N=471 black) Hazard ratio for eveniDFS1.33 (p=0.005)1.49 (p=0.001)DRFI1.21 (p=0.28)1.60 (p=0.02)RFI1.39 (p=0.02)1.80 (p<0.001)OS1.52 (p=0.005)1.67 (p=0.003

Conclusions: In patients eligible and selected for participation in TAILORx, black women had worse clinical outcomes despite similar 21-gene assay RS results and comparable systemic therapy. This adds to an emerging body of evidence suggesting a biologic basis or other factors contributing to racial disparities in HR-positive breast cancer that requires further evaluation.

Citation Format: Albain K, Gray RJ, Sparano JA, Makower DF, Pritchard KI, Hayes DF, Geyer, Jr. CE, Dees EC, Goetz MP, Olson, Jr. JA, Lively T, Badve SS, Saphner TJ, Wagner LI, Whelan TJ, Ellis MJ, Paik S, Wood WC, Ravdin PM, Keane MM, Gomez HL, Reddy PS, Goggins TF, Mayer IA, Brufsky AM, Toppmeyer DL, Kaklamani VG, Berenberg JL, Abrams J, Sledge, Jr. GW. Race, ethnicity and clinical outcomes in hormone receptor-positive, HER2-negative, node-negative breast cancer: results from the TAILORx trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr GS4-07.

Abstract PD7-07: Discovery of molecular predictors of late breast cancer specific events (BCSE) in ER+, node+ breast cancer – new transcriptome expression whole gene analysis of the phase III adjuvant trial SWOG S8814

BACKGROUND: Unique genes and pathways were identified for prognosis on tamoxifen (T, 5 yrs) and prediction on CAF-T vs T in S8814 using whole transcriptome RNA-Seq from archival FFPE tissue. (Albain, et al; Cherbavaz, et al; SABCS 2015) Discovery was robust for early DFS events but sparse for late. The aims of this new analysis were to 1) utilize a new endpoint BCSE for gene discovery of late events, prognosis and prediction and 2) add intronic counts to the previous exonic results to define whole genes impacting on late BCSE.

METHODS: Charts of patients (pts) on CAF-T (212) vs T (142) were reviewed to define the BCSE endpoint (local/regional, contralateral, distant). Deaths without BC were treated as competing risks. BCSE models (including metagenes) of late prognosis and prediction used cumulative incidence functions. Consolidated intronic regions counts within genes were added to exonic regions counts. Using these “whole gene” (WG) counts, association of gene expression with time to BCSE was assessed by Cox regression. A multiple WG score (MWGS) for BCSE prognosis beyond 5 yrs (to 12.5 yrs) was constructed and evaluated for 1-3 and 4+ node (N) groups. False discovery rate was controlled at 10%.

RESULTS: More exons and WG were discovered for prognosis on T alone over 12.5 yrs with the BCSE endpoint than DFS. For prognosis of late BCSE after 5 yrs, more genes were discovered using WG (n=111) than by exons (n=9). There were significantly fewer genes for late BCSE on CAF-T (8, WG; 0, exons). The functions of WG prognostic for late BCSE were: cell cycle/proliferation-26 genes, chromosome segregation/mitotic spindle-22, DNA repair/maintenance-10, transcriptional/translational control-5, cell adhesion/migration-4, immune-3, diverse/unknown-32 and growth factor/hormone receptor signaling-9 (this group was only found by WGs, not exons). Of these 111 WG, a MWGS prognostic for late BCSE on T used 57 previously discovered genes pre-specified for this analysis. Probability of BCSE beyond 5 yrs for low vs high MWGS was 8% vs 21% in N1-3+ and 17% vs 42% in N4+. Late prognosis on T differed by low vs high risk defined in a metagene model: cumulative BCSE at year 10 was 0% vs 47% (low vs high risk, p=0.001). Prediction of 10-yr incidence of BCSE varied by risk level by treatment in a metagene model: low risk- CAF-T=47%, T=0% (p=0.045); high risk- CAF-T=35%, T=45% (p=0.027).

CONCLUSIONS: Gene discovery for prognosis of late BCSE is enhanced with a novel WG transcriptome expression approach. Use of chemotherapy (CT) before T significantly attenuated gene discovery, so that molecular tools for decisions on extending endocrine therapy (ET) may not be reliable in a setting of prior CT. Some pts on ET for 5 yrs may not require either longer ET or CT, given a N+ cohort was defined with no BCSE observed over 12.5 yrs. For prediction of CT benefit, CAF-T appeared to be inferior to T in a low risk metagene model for BCSE. In sum, these results add more evidence that ET alone may be sufficient (perhaps better) in select N+ settings. Validation in SWOG S1007 (RxPONDER) is planned.

SUPPORT: NCI CA180888, 180819, 180821, 180820, 180863; in part, Genomic Health, Inc.

Citation Format: Albain KS, Crager MR, Barlow WE, Baehner FL, Bergamaschi A, Rae JM, Ravdin PM, Tripathy D, Gralow JR, Livingston RB, Osborne CK, Ingle JN, Pritchard KI, Davidson NE, Carey LA, Cherbavaz DB, Sing AP, Shak S, Hortobagyi GN, Hayes DF. Discovery of molecular predictors of late breast cancer specific events (BCSE) in ER+, node+ breast cancer – new transcriptome expression whole gene analysis of the phase III adjuvant trial SWOG S8814 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD7-07.

Abstract S3-02: Molecular predictors of outcome on adjuvant CAF plus tamoxifen (T) vs T in postmenopausal patients (pts) with ER+, node+ breast cancer – Transcriptome expression analysis of the phase III trial SWOG-8814

BACKGROUND: In SWOG-8814A, pts with ER+ node+ breast cancer and low 21 gene recurrence scores (RS) had good prognosis and no CAF benefit, but high RS predicted longer survival from CAF followed by T (CAF-T) vs T (Albain, Lancet Oncol 2010). The aims of SWOG-8814B were to identify novel genes and networks for 1) prognosis of early and late relapse and 2) prediction of CAF benefit, using whole transcriptome expression analysis with next generation RNA sequencing (NGS).

METHODS: Stored RNA previously extracted for SWOG-8814A (T, CAF-T arms; T, 5 yrs) was analyzed for RNA/library yield (see companion abstract Cherbavaz et al. for methods). Genes were sequenced and expression of mRNA species was related to disease-free survival (DFS) using Cox proportional hazards. Discovery analyses controlled false discovery rate (FDR) at 10%. Genes were identified for prognosis on T and prediction on CAF-T vs T. Networks of genes/pathways were explored. Early (0-5 yrs) and late (5-13+ yrs) time periods were studied. Gene Ontology, Cytoscape, pathway and hierarchical clustering were used for functional gene and metagene analyses.

RESULTS: Of 367 samples, 354 (96%; 142 T, 212 CAF-T; 141 DFS events) had sufficient RNA/library yield, with 20,101 genes sequenced. For prognosis on T, there were 2327 and 568 genes discovered in early and all-yrs follow-up, with only 9 genes prognostic after 5 yrs. Prognosis analyses for residual risk after CAF-T were uninformative. Functional mapping found that genes prognostic for worse DFS were enriched for proliferation (G2M, M-phase), cellular metabolism, DNA repair, stress response and EMT; whereas, those with better DFS involved transcription regulation/repression via zinc finger proteins. Hierarchical clustering (T arm) found significant DFS prognostic metagene signatures for ER-related genes, immune response, ECM/stroma, chromatin remodeling-transcription factor activity and TGFb pathway. All varied for early vs late DFS events. For example, low ER/high stroma expression signatures correlated with high proliferation gene expression and were strongly associated with early events (standardized [st] HR 2.94, p<0.001). Late recurrence was associated with high proliferation, both individually (stHR 1.51, p=.035) and in combination with higher ER expression (stHR 1.51, p=0.09). Fifteen genes predicted CAF benefit (9 better DFS, 6 worse), or 129 genes if FDR relaxed to 20%. Cluster analysis for CAF prediction is ongoing.

CONCLUSIONS: Unique genes, clusters and pathways were identified by NGS of archival material in ER+ N+ breast cancer, including previously unreported signatures. While ER, stroma and proliferation-related signatures were associated with early prognosis, proliferation best predicted worse DFS after 5 yrs. NGS of the primary tumor is most informative for early events in pts with only 5 years of T, with few genes selecting only for late relapse. If validated, these signatures may identify pts with excellent DFS despite positive nodes for endocrine therapy alone as well as others for whom chemotherapy and/or biologics are also required

.

SUPPORT: NCI CA 180888, 180819, 180821, 180820, 180863; in part, Genomic Health, Inc.

Citation Format: Albain KS, Crager MR, Barlow WE, Baehner FL, Bergamaschi A, Rae JM, Ravdin PM, Tripathy D, Gralow JR, Livingston RB, Osborne CK, Ingle JN, Pritchard KI, Davidson NE, Carey LA, Cherbavaz DB, Sing AP, Shak S, Hortobagyi GN, Hayes DF. Molecular predictors of outcome on adjuvant CAF plus tamoxifen (T) vs T in postmenopausal patients (pts) with ER+, node+ breast cancer – Transcriptome expression analysis of the phase III trial SWOG-8814. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S3-02.

Validation of the web-based tool Adjuvant! in 5,381 Dutch breast cancer patients

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Background: Adjuvant! is a web-based tool that calculates individualized 10-year survival probability and estimates the benefit of adjuvant systemic therapy based on age, co-morbidity, tumor size, tumor grade, number of involved lymph nodes and estrogen-receptor status. The Adjuvant! model was constructed using observed overall survival (OS) for women diagnosed with breast cancer between 1988 and 1992 recorded in the US SEER registry (surveillance, epidemiology and end results) and has not yet been validated in any European series. It is of interest to see whether intrinsic characteristics of tumors and survival of Dutch patients may differ from those in the US. Methods: For this validation all patients who were treated at the Netherlands Cancer Institute for primary breast cancer between 1987 and 1998 were selected according to the following criteria: T1–3 tumor, N0–3, M0, definitive primary surgery, complete axillary staging, and no prior malignancies. Follow-up for OS was complete for >99% of the patients until at least February 2007 (median follow-up 11.7 years). Clinicopathological characteristics as mentioned above and adjuvant treatment data were entered into Adjuvant! version 8.0 for each individual, blinded to the clinical outcome, to calculate predicted 10-year outcomes. Results: In this hospital-based cohort of 5381 patients, all known prognostic factors were significant predictors of overall survival. Across all patients, the 10-year OS was excellently predicted by Adjuvant! (predicted OS - observed OS=0.2%; p=n.s.). Also, for most relevant clinicopathological subgroups the differences between predicted and observed OS were within 2%. Adjuvant underestimated the OS in patients with tubular type of breast cancer (predicted - observed = -6.8; p<0.01); presently, histology is not incorporated in Adjuvant!. Conclusions: Adjuvant! accurately predicts 10-year OS for common tumor types in this first large scale European validation study and is of use for adjuvant treatment-decision making.

[Table: see text]

Adjuvant therapy report card: Patients with stage II/III colon cancer grade their oncologists

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Background: Our group previously reported on patient (Pt) recollections of adjuvant therapy (AT) for colon cancer and their grading of medical oncologists (MO) regarding various aspects of care. Overall, MO were highly rated, but grades for presenting information were lower, and patient expectations about side effects often did not match experiences. To further examine the Pt experience with AT, a prospective study was launched in Feb 2008. Methods: Pts with Stage II/III colon cancer about to begin or within 4 months of starting AT were recruited for a 4-part survey regarding sources and quality of treatment information and their experiences with AT. The survey also asked Pts to provide a grade (A-F) for their MO in 8 areas. Results: 85 Pts (71% female, 79% Stage III, median age 52 years) completed Part 1 of the survey. 93% stated that their MO explained the risks and benefits of AT. Of those, 92% stated they understood this information completely or almost completely (3 or 4 on a 0–4 scale) and 79% received numerical estimates of recurrence risk with and without treatment. When questioned about the potential absolute benefit of AT, 26% of Pts who received numerical estimates “had no idea” and other answers ranged from 3% to 100% for recurrence risk. Pt grade point averages for their MO ranged from 3.0 to 3.6 ( Table 1 ). As in the prior survey, expectations about side effects frequently did not accurately reflect experiences. For example, 54% of Pts expected alopecia but only 5% experienced it to a significant degree. 84% of Pts also sought information from websites, and 87% rated this as helpful and valuable (3 or 4 on a 0–4 scale). Conclusions: Pts are generally satisfied with their MO but less so with the presentation of treatment-related information and thus frequently consult additional resources, such as cancer information websites. This suggests an opportunity for improved information delivery within oncology offices and via the Internet.

[Table: see text]

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A computer program designed to assist in NSCLC adjuvant therapy decision making

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Background: The goal the computer program, Adjuvant! for NSCLC, is provide the health professional, and the NSCLC patient with information that might be helpful when deciding about adjuvant chemotherapy for completely resected Stage 1 to Stage 3A disease. The 4 elements of this decision are: estimates of prognosis, estimates of the efficacy of adjuvant chemotherapy, estimates of completing mortality, and estimates of toxicity. Methods: Estimates of prognosis are based on an analysis of 17, 130 patients in the SEER registry. Estimates for 5 year disease specific mortality for Stage 1A, 1B, 2A, 2B, and 3A disease are 22%, 37%, 51%, 63%, and 70%. Multivariate analysis justifies using tumor size, histologic grade, and BAC histology for refinement of prognostic estimates for Stage 1 patients. A small subgroup of Stage 1 patients (with tumors < 10mm, low grade, BAC histology) could be identified with a 5 year disease specific mortality risk of <10%. Estimates of the efficacy of chemotherapy were derived from meta-analyses. A proportional risk reduction of 20% is used by the program as the default efficacy estimate for platinum-based therapy. Pop-ups and help files discuss areas of uncertainty and controversy. The user has the option to adjust the default efficacy estimate to the more optimistic efficacy estimates of some of the recent trials, or to take into account some of the uncertainty as to whether adjuvant chemotherapy works as well in Stage 1 disease. SEER data shows the average NSCLC patient has competing mortality rates higher than would be suggested by chronologic age. Regimen specific risks of treatment related toxicity is given by the program. In the over 100 pages of help files there is a detailed discussion of the clinical evidence, adjuvant therapy guidelines, ongoing clinical trials, and corollary areas (radiotherapy, neoadjuvant therapy, biomarkers, etc.) Results: The program projects that for patients with favorable Stage 1 tumors the absolute OS benefit of therapy may be as low as 1% (of the same size as the risk of treatment related mortality), but for patients with Stage 2 and 3A disease the 5 yr OS benefit may be ∼10%. Conclusions: The impact of this tool on physician and patient knowledge about the adjuvant therapy of NSCLC will be presented.

[Table: see text]

Randomized Phase III Study of Docetaxel Compared With Paclitaxel in Metastatic Breast Cancer

Purpose

This randomized, controlled, multicenter, open-label, phase III study compared docetaxel versus paclitaxel in patients with advanced breast cancer that had progressed after an anthracycline-containing chemotherapy regimen.

Patients and Methods

Patients (n = 449) were randomly assigned to receive either docetaxel 100 mg/m2(n = 225) or paclitaxel 175 mg/m2(n = 224) on day 1, every 21 days until tumor progression, unacceptable toxicity, or withdrawal of consent.

Results

In the intent-to-treat population, both the median overall survival (OS, 15.4 v 12.7 months; hazard ratio [HR], 1.41; 95% CI, 1.15 to 1.73; P = .03) and the median time to progression (TTP, 5.7 months v 3.6 months; HR, 1.64; 95% CI, 1.33 to 2.02; P < .0001) for docetaxel were significantly longer than for paclitaxel, and the overall response rate (ORR, 32% v 25%; P = .10) was higher for docetaxel. These results were confirmed by multivariate analyses. The incidence of treatment-related hematologic and nonhematologic toxicities was greater for docetaxel than for paclitaxel; however, quality-of-life scores were not statistically different between treatment groups over time.

Conclusion

Docetaxel was superior to paclitaxel in terms of OS and TTP. ORR was higher for docetaxel. Hematologic and nonhematologic toxicities occurred more frequently in the docetaxel group. The global quality-of-life scores were similar for both agents over time.

Is Her2 of value in identifying patients who particularly benefit from anthracyclines during adjuvant therapy? A qualified yes

Data from several large adjuvant breast cancer chemotherapy trials suggest that anthracycline-based chemotherapies relative to non-anthracycline-based adjuvant therapies are particularly effective in patients whose tumors overexpress Her2. Most trials show some evidence of this effect, but the interaction generally has not been confirmed statistically, perhaps because the trials are underpowered. In addition, there have been a multiplicity of Her2 immunohistochemistry techniques used in these studies, which are clearly not of equivalent utility in detecting this effect. Thus, while there is good evidence that further work in this area will be of value, at this time the results are inconclusive and not ready for clinical application.

Decision-making in early breast cancer: guidelines and decision tools

The meta-analysis of trials of adjuvant systemic therapy for early breast cancer provides robust information on the impact of both cytotoxic chemotherapy and tamoxifen on relapse-free and overall survival to 15 years from diagnosis. These data are described in terms of relative risk reduction and are not meant to be viewed as a prescription for therapy. To translate relative risk reductions into absolute benefits for the individual patient and then trade off the gains against the long-term and short-term side-effects and toxicities is a highly complex process for the clinician, and current guidelines are formatted in such a way that they fail to use current information in a way that allows a quantitative assessment of the benefits and risks of adjuvant therapy. This review article explores current guidelines and describes some aids that may be used to help inform women about their treatment options for early breast cancer.

Computer program to assist in making decisions about adjuvant therapy for women with early breast cancer

PURPOSE

The goal of the computer program Adjuvant! is to allow health professionals and their patients with early breast cancer to make more informed decisions about adjuvant therapy.

METHODS

Actuarial analysis was used to project outcomes of patients with and without adjuvant therapy based on estimates of prognosis largely derived from Surveillance, Epidemiology, and End-Results data and estimates of the efficacy of adjuvant therapy based on the 1998 overviews of randomized trials of adjuvant therapy. These estimates can be refined using the Prognostic Factor Impact Calculator, which uses a Bayesian method to make adjustments based on relative risks conferred and prevalence of positive test results.

RESULTS

From the entries of patient information (age, menopausal status, comorbidity estimate) and tumor staging and characteristics (tumor size, number of positive axillary nodes, estrogen receptor status), baseline prognostic estimates are made. Estimates for the efficacy of endocrine therapy (5 years of tamoxifen) and of polychemotherapy (cyclophosphamide/methotrexate/fluorouracil-like regimens, or anthracycline-based therapy, or therapy based on both an anthracycline and a taxane) can then be used to project outcomes presented in both numerical and graphical formats. Outcomes for overall survival and disease-free survival and the improvement seen in clinical trials, are reasonably modeled by Adjuvant!, although an ideal validation for all patient subsets with all treatment options is not possible. Additional speculative estimates of years of remaining life expectancy and long-term survival curves can also be produced. Help files supply general information about breast cancer. The program's Internet links supply national treatment guidelines, cooperative group trial options, and other related information.

CONCLUSION

The computer program Adjuvant! can play practical and educational roles in clinical settings.

Preparation of a monoclonal antibody specific for the class I isotype of beta-tubulin: the beta isotypes of tubulin differ in their cellular distributions within human tissues

Tubulin, the subunit protein of microtubules, is an alpha/beta heterodimer. In many organisms, both alpha and beta consist of various isotypes. Although the isotypes differ in their tissue distributions, the question of whether the isotypes perform different functions in vivo is unanswered. In mammals, the betaI and betaIV isotypes are quite widespread, and betaII is less so, while betaIII and betaVI have narrow distributions and betaV distribution is unknown. As a tool for localizing the isotypes, we report the preparation of a monoclonal antibody specific for betaI, to add to our previously described monoclonal antibodies specific for betaII, betaIII, and betaIV [Banerjee et al., J. Biol. Chem. 263:3029-3034, 1988; 265:1794-1799, 1990; 267:5625-5630, 1992]. In order to prepare this antibody, we have purified betaI-rich rat thymus tubulin. We have used our battery of antibodies to localize the beta isotypes in four human tissues: oviduct, skin, colon, and pancreas. We have found striking differences in their tissue distributions. There is little or no betaIII in these tissues, except for the columnar epithelial cells of the colon. BetaII is restricted to very few cells, except in the skin, where it is concentrated in the stratum granulosum. BetaI is widespread in all the epithelia. In the skin it is found in the entire stratum malpighii. In the oviduct, betaI is found largely in the nonciliated epithelial cells. In the exocrine pancreas, betaI occurs only in the centroacinar cells and not in the acinar cells; the latter do not stain with any of these antibodies. BetaIV is present at very low levels in skin and pancreas. By contrast, it is prominent in the colon and also in the oviduct, where it occurs in all the epithelial cells, especially in the ciliated cells, with the highest concentrations in the cilia themselves. These results suggest that the regulation of the expression and localization of isotypes in tissues is very complex.

A prognostic model that makes quantitative estimates of probability of relapse for breast cancer patients

Tumor-node-metastasis (TNM) staging is the standard system for the estimation of prognosis of breast cancer patients. However, this system does not exploit information yielded by markers of the biological aggressiveness of breast cancer and is clearly unsatisfactory for optimal-treatment decision-making and for patient counseling. We have developed a prognostic model, based on a few routinely evaluated prognostic variables, that produces quantitative estimates for risk of relapse of individual breast cancer patients. We used data concerning 2441 of 2990 consecutive breast cancer patients to develop an artificial neural network (ANN) for the prediction of the probability of relapse over 5 years. The prognostic variables used were: patient age, tumor size, number of axillary metastases, estrogen and progesterone receptor levels, S-phase fraction, and tumor ploidy. Performances of the model were evaluated in terms of discrimination ability and quantitative precision. Predictions were validated on an independent series of 310 patients from an institution in another country. The ANN discriminated patients according to their risk of relapse better than the TNM classification (P = 0.0015). The quantitative precision of the model's estimates was accurate and was confirmed on the series from the second institution. The 5-year relapse risk yielded by the model varied greatly within the same TNM class, particularly for patients with four or more nodal metastases. The model discriminates prognosis better than the TNM classification and is able to identify patients with strikingly different risks of relapse within each TNM class.

Should HER2 status be routinely measured for all breast cancer patients?

Several recent publications have re-opened the question of whether HER2 status should be determined for all patients with newly diagnosed breast cancer. The barrier in the past to the use of HER2 has been the nonstandardization of HER2 status determination, which is the major caveat to its use today. Two test kits have been recently approved by the Food and Drug Administration for HER2 testing, one for determining HER2 amplification by fluorescence in situ hybridization and the other for measuring HER2 overexpression by immunohistochemistry. Neither of these tests, nor any of the other myriad tests used for HER2 determinations, has been validated in all the potential arenas for the use of HER2: refinement of estimates of prognosis of untreated low-risk patients, selection among treatment options for adjuvant therapy, and selection of patients for treatment with trastuzumab (Herceptin; Genentech, San Francisco, CA). The nonstandardization of testing has led to conflicting results and controversy as to the value of HER2 in evaluating breast cancer patient prognosis and the selection among therapeutic options. Thus, testing for HER2 is not yet routine for patients with newly diagnosed breast cancer, although it is of value for patients who develop metastatic disease and who need to know if they are candidates for trastuzumab.

Emerging role of docetaxel (Taxotere) in the adjuvant therapy of breast cancer

The need for improved adjuvant chemotherapy programs for breast cancer patients is emphasized by the 1998 overview analysis of adjuvant trials, which demonstrates that although there has been substantial incremental advances in adjuvant therapy, relapse and death are prevented in less than half of women with micrometastatic disease. Because both docetaxel (Taxotere; Rhône-Pouleuc Rorer, Collegeville, PA) and paclitaxel have substantial non-cross-resistance with anthracyclines and therefore activity in anthracycline-resistant breast cancer, defining their roles in the adjuvant therapy of breast cancer is an area of great interest and active clinical investigation. The results of the adjuvant trials using docetaxel assume a particular importance because of the two taxanes in clinical use at this time, docetaxel may be the more active agent in the treatment of metastatic breast cancer, as demonstrated in the results from phase II and III randomized trials. Ongoing or soon-to-open adjuvant trials are evaluating the impact of docetaxel added to conventional adjuvant anthracyclines regimens, substituted for anthracyclines, used in combination with anthracyclines, and in direct comparison to paclitaxel. The results of these ongoing adjuvant trials will define the role of docetaxel in adjuvant chemotherapy programs for the management of patients with breast cancer and are eagerly awaited.

Time-dependence of hazard ratios for prognostic factors in primary breast cancer

Some prognostic factors, such as steroid receptors, appear strongly related to outcome in early studies with short follow-up, but as follow-up matures the relationships appear to weaken. We investigated this phenomenon for several factors (tumor size, axillary lymph nodes, S-phase fraction, estrogen receptor (ER) status, and adjuvant therapy) in a large sample of breast cancer cases (N=2,873) with up to 17 years of follow-up for disease-free survival (DFS). Subjects in the study were identified from patients who had hormone receptor assays performed in our laboratory. Analysis of DFS included fitting a multivariate Cox proportional hazards model, testing for nonproportionality, and examining diagnostic plots. The assumption of proportional hazards was violated for several factors including ER, tumor size, and S-phase fraction. For ER, the hazard ratio was initially less than 1.0, indicating a good effect on prognosis, but increased at later times to values greater than 1.0, indicating a bad effect on prognosis. In contrast, the hazard ratios for tumor size and S-phase were initially high and decreased asymptotically toward 1.0 over time. Analysis of p53 expression in a subset of cases yielded qualitatively similar results. We conclude that several standard prognostic factors (ER, tumor size, S-phase fraction) and possibly other investigational factors have important but nonproportional effects on hazard. It is likely that violation of proportional hazards is common and not limited to breast cancer. Failure to recognize violations of proportional hazards can lead to both over- and under-estimation of the effects of important prognostic factors.

How can prognostic and predictive factors in breast cancer be used in a practical way today?

Since the 1995 St. Gallen conference the standard prognostic and predictive variables have not changed. Good treatment planning (and clinical trial entry and stratification) can be made on the basis of TNM staging, age, and ER and menopausal status. Three years from now, in 2001, this situation will have changed enormously. This will be achieved by better designs for prognostic studies, studies of predictive factors with definitive data from large, statistically powerful cooperative group trials, and perhaps simple computer-based tools to make projections and present data clearly. These advances will lead to still better-individualized selection of adjuvant therapy for breast cancer patients.

A phase II study of docetaxel in patients with paclitaxel-resistant metastatic breast cancer

PURPOSE

To evaluate the efficacy and safety of docetaxel in patients with paclitaxel-resistant metastatic breast cancer (MBC).

PATIENTS AND METHODS

Docetaxel (100 mg/m2) was administered every 3 weeks to 46 patients registered at four centers. Patients had previously received < or = two chemotherapy regimens for MBC. All patients had progressive disease while receiving paclitaxel therapy. Treatment was repeated until there was evidence of disease progression or for a maximum of three cycles after best response.

RESULTS

Objective responses were seen in eight of 44 assessable patients (18.1%; 95% confidence interval [CI], 6.7% to 29.5%). Seven patients had partial responses and one patient responded completely. Response rates were not significantly different by previously received paclitaxel dose or resistance. No responses were seen in 12 patients who had previously received paclitaxel by 24-hour infusion, but the response rate in 32 patients who had received paclitaxel by 1- to 3-hour infusion was 25%. The median response duration was 29 weeks and the median time to disease progression was 10 weeks. Median survival was 10.5 months. Clinically significant (severe) adverse events included neutropenic fever (24% of patients), asthenia (22%), infection (13%), stomatitis (9%), neurosensory changes (7%), myalgia (7%), and diarrhea (7%).

CONCLUSION

Docetaxel is active in patients with paclitaxel-resistant breast cancer, particularly in those who failed to respond to brief infusions of paclitaxel. Response rates were comparable to or better than those seen with other therapies for patients with paclitaxel-resistant MBC. This confirms preclinical studies, which indicated only partial cross-resistance between paclitaxel and docetaxel.

Radiation therapy and survival in breast cancer patients with 10 or more positive axillary lymph nodes treated with mastectomy

PURPOSE

Adjuvant loco-regional radiation (XRT) frequently is recommended after mastectomy and adjuvant systemic therapy in patients with 10 or more positive axillary lymph nodes (ALN) to reduce the high loco-regional failure rate observed in this subset. In this study, we explored the possibility that adjuvant loco-regional radiation therapy (LR-XRT) also could decrease distant failure and improve overall survival (OS) in this subset of poor-prognosis patients.

PATIENTS AND METHODS

Retrospectively, 618 breast patients with 10 or more positive ALN were studied. The median follow-up time was 7.5 years. All patients received systemic adjuvant therapy and 35% also received adjuvant radiation therapy. Loco-regional failure, distant failure, and OS analyses were adjusted for age, tumor size, number of positive ALN, and estrogen receptor (ER) status using Cox regression model.

RESULTS

As expected, patients had a very high risk of loco-regional and distant failure. At 5 years, 30% of patients had loco-regional failure as a first event and 54% had distant failure. Radiation dramatically reduced loco-regional failure (hazards rate ratios [RR]=0.29; 95% confidence interval [CI], 0.19 to 0.45). The adjusted 5-year loco-regional failure rate was 13% with radiation and 38% without radiation (P=.0001). Radiation also was associated with improved distant control (RR=0.75; 95% CI, 0.58 to 0.96). The adjusted 5-year distant failure rate was 48% with radiation and 58% without radiation (P=.02). OS also improved with radiation (RR=0.68; 95% CI, 0.53 to 0.85). The adjusted 5-year OS was 56% with radiation and 42% without radiation (P=.001).

CONCLUSION

In this cohort of high-risk breast cancer patients, XRT was associated with less loco-regional and distant failure and improved OS. This suggests that improved loco-regional control might decrease secondary systemic spread and improve survival.

Survey of breast cancer patients concerning their knowledge and expectations of adjuvant therapy

PURPOSE

A survey of breast cancer survivors in the United States was conducted to define what they had been told about their prognosis and the value of adjuvant therapy, what they estimated their prognosis to be with and without adjuvant therapy, and what level of improvement they would have found minimally worthwhile.

MATERIALS AND METHODS

Survey questionnaires were mailed to individual members and member organizations of the National Alliance of Breast Cancer Organizations (NABCO). Questionnaires were returned anonymously in prepaid mailers. Five hundred sixty-two women responded. Of these, the 318 women who received adjuvant chemotherapy were included in this analysis.

RESULTS

Only 39% of the women recalled receiving quantitative estimates of their prognosis, and only 31% of women received a quantitative estimate both with and without adjuvant therapy. Sixty-eight percent of the women were able to provide a quantitative estimate for their outcome at 5 years both with and without adjuvant therapy. From these estimates, we calculated that the median estimated proportional risk reduction for recurrence that women thought they had achieved was 79%. Women were asked what degree of absolute benefit they would have found acceptable. The median acceptable extension of life expectancy was 3 to 6 months, and acceptable reduction in recurrence risk was 0.5% to 1.0%. However, there was considerable variation, with 27% of women not accepting less than 1 year and 26% not accepting a less than 5% reduction in recurrence risk.

CONCLUSION

In general, American women in the surveyed population (1) do not recall being provided quantitative estimates of outcome during the process of making decisions about adjuvant therapy, (2) overestimate the value of their therapy, and (3) often will accept remarkably low degrees of net benefit. Overall, these observations can be used to support the argument that improvements in doctor/patient communication may be important to truly informed decision-making, and that flexibility for individual patients' preferences should not be superseded by rigid treatment guidelines.

Population pharmacokinetics/pharmacodynamics of docetaxel in phase II studies in patients with cancer

PURPOSE

The population pharmacokinetic/pharmacodynamic (PK/PD) approach was prospectively integrated in the clinical development of docetaxel to assess the PK profile in a large population of patients and investigate systemic exposure as a prognostic factor for clinical outcome.

PATIENTS AND METHODS

PK analysis was performed at first course in 24 phase II studies of docetaxel monotherapy using four randomized limited-sampling schedules. Bayesian estimates of clearance (CL), area under the concentration-time curve (AUC), and peak and duration of plasma levels greater than threshold levels were used as measures of exposure. PD data included for efficacy, response rate, time to first response, and time to progression (TTP) in breast cancer and non-small-cell lung cancer (NSCLC), and for toxicity, grade 4 neutropenia, and febrile neutropenia at first course and time to onset of fluid retention. PK/PD analysis was conducted using logistic and Cox multivariate regression models.

RESULTS

PK protocol implementation was successful. Most of the patients registered (721 of 936, 77%) were sampled and 68% were assessable for PK (640 patients). First-course docetaxel AUC was a significant predictor (P = .0232) of TTP in NSCLC (n = 151). Docetaxel CL was a strong independent predictor (P < .0001) of both grade 4 neutropenia and febrile neutropenia (n = 582). Cumulative dose was the strongest predictor (P < .0001) of the time to onset of fluid retention (n = 631). However, the duration of exposure over 0.20 micromol/L (0.16 microg/mL) at first course was an independent predictor (P = .0029). Few patients (n = 25, 4%) received the recommended dexamethasone premedication.

CONCLUSION

First-course docetaxel PK is a predictor of first-course hematologic toxicity, but also of fluid retention, which is cumulative in nature. Patients with elevated hepatic enzymes have a 27% reduction in docetaxel CL and are at a higher risk of toxicity. A starting dose of 75 mg/m2 is currently being evaluated in this population. Prospective implementation of large-scale population PK/PD evaluation is feasible in early drug development and this approach generates clinically relevant findings.

Reflections on the development of resistance during therapy for advanced breast cancer. Implications of high levels of activity of docetaxel in anthracycline-resistant breast cancer patients

Anthracyclines play a central role in the treatment of breast cancer. They are perhaps the most active single agents available for the treatment of this disease. For patients with primary breast cancer for whom chemotherapy would be appropriate, anthracyclines are often incorporated in adjuvant regimens. For patients with endocrine-therapy-resistant metastatic disease, anthracyclines are nearly always included in the first or second-line therapeutic regimes. Unfortunately, despite the fact that anthracyclines and anthracycline-containing regimens can achieve impressive objective response rates, this impressive activity has not translated into a great improvement in disease-free survival for patients with early stage breast cancer or overall survival for patients with metastatic disease. The addition of anthracyclines to adjuvant therapy regimens in general only modestly improves their efficacy and the use of anthracyclines in metastatic disease does not cure these patients. The clinical utility of anthracyclines would be greatly improved if we could predict which patients would be anthracycline resistant, interfere with the development or expression of anthracycline resistance and predict which anticancer agents would be non-cross-resistant with anthracyclines. Some progress is being made in all these areas. Preclinical studies have identified several intracellular processes that are perturbed by anthracyclines, or that may modulate anthracycline sensitivity of cells. These processes include topoisomerase II activity, drug and toxin transmembrane pumps, intracellular detoxification systems (such as that related to gluatathione), stress-related proteins and apoptotic mechanisms. Although measurement of the components of these systems has not yet shown clinical utility in breast cancer, some preclinical work and exploratory studies with small numbers of patients suggest that we may in the future be able to predict which patients will respond or be resistant to anthracyclines. An important avenue of work is the identification of anticancer agents that are non-cross-resistant with anthracyclines in breast cancer patients. These agents would be particularly valuable in patients with metastatic disease who had progressed while on anthracyclines. In general, such patients have a very poor prognosis with a median survival of less than 1 year. Also of importance in non-cross-resistant agents is that they might be used in combination with anthracyclines in regimens with very high response rates. Recently completed work suggests that taxoids might be such agents. This finding opens up exciting possibilities in the treatment of metastatic disease and, even more importantly, in the adjuvant arena. The identification of agents that clinically are non-cross-resistant with anthracyclines depends on the careful interpretation of clinical trial data. Unfortunately, a number of definitions of anthracycline resistance have been used in the medical literature. These range from very weak definitions, which include many patients with only prior anthracycline exposure (for example, in an adjuvant regimen), to more biologically and clinically appropriate definitions, such as documented progression while receiving an anthracycline. This distinction is very important because it is clear that many patients who have relapsed after an anthracycline-based adjuvant therapy will respond to anthracyclines for metastatic disease and are, therefore, not truly anthracycline resistant. In this regard, the recently completed trials with docetaxel in patients with rigorously defined anthracycline resistance are particularly provocative. These trials show that docetaxel maintains much of its excellent first-line levels of efficacy in patients with anthracycline-resistant breast cancer. Agents with this type of maintenance of efficacy in anthracycline-resistant tumours may find immediate utility in this clinical scenario as single agents but, more importantly, have gr

Docetaxel (Taxotere) for the treatment of anthracycline-resistant breast cancer

Until the introduction of the taxoids, docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France) and paclitaxel (Taxol; Bristol-Myers Squibb Oncology, Princeton, NJ), in the 1990s, anthracyclines were widely recognized as the best single agents for the treatment of breast cancer. However, even when anthracyclines are used in combination regimens with response rates of over 50%, including complete responses in 17% of patients, few women (3%) with metastatic disease remain disease free at 5 years after treatment. The low level of sustained responses is largely due to the phenomenon of drug resistance. Anthracycline resistance often involves multidrug resistance efflux mechanisms, but also can involve factors affecting topoisomerase II and apoptosis. When combining other cytotoxic agents with anthracyclines, it is of value to use non-cross-resistant drugs so that the induction of anthracycline-resistance mechanisms does not also affect the efficacy of other agents in the combination therapy. Clinical studies have shown that docetaxel, which is highly active against metastatic breast cancer as a single agent, has a high level of non-cross-resistance with anthracyclines. The overall response rate to docetaxel monotherapy in patients with anthracycline-resistant or refractory metastatic disease has been shown to be 41%. The response rate to first-line docetaxel monotherapy for metastatic breast cancer has been shown to be 61%, suggesting that two thirds of the activity of docetaxel is retained in anthracycline-resistant disease. Treatment with a simultaneous combination of docetaxel and doxorubicin has been found to be very active, with a response rate of 89%, and trials to exploit the lack of cross-resistance between these agents, in sequential regimens and adjuvant therapies, are under way.

Lack of prognostic value of cathepsin D levels for predicting short term outcomes of breast cancer patients

The value of cathepsin D determinations done on tumor cytosols in evaluating the prognosis of breast cancer patients has been debated in the literature. Our previous work suggested that cathepsin D determinations were not of prognostic value, but in that study we used immunoblotting and immunohistochemical methods rather than the more widely used double antibody immunoradiometric (IRMA) assay for measuring cathepsin levels. Here we report our results determining cathepsin D using components of a commercially available IRMA system on a large patient sample (n = 1984). Reagents from a commercially available IRMA kit were used to analyze cathepsin D levels in the cytosols of 1984 patients with breast cancer. All patients had invasive breast cancer with known tumor size and with some axillary nodes pathologically examined. Only patients with T1 and T2 tumor sizes were included. Median follow-up was 37 months. The hypothesis that high cathepsin D levels correlated with poorer outcome (poorer DFS or OS) was not confirmed, either in all patients, or in node-positive or node-negative subsets. Only in patients treated with adjuvant therapy were higher cathepsin D levels correlated with negative outcome (worsened OS, but not DFS), although given the large number of subsets analyzed this correlation may be spurious. Multivariate analyses using interaction terms did not support the concept that high cathepsin D levels correlate with resistance to adjuvant therapy. In this study evaluating the value of cathepsin D using components from a kit widely used for measuring cathepsin D levels, we conclude that cathepsin D is of doubtful value in predicting risk of early relapse or death for patients with newly diagnosed invasive breast cancer.

The international experience with docetaxel in the treatment of breast cancer

The extensively studied agent docetaxel (Taxotere) has shown marked clinical activity in the treatment of anthracycline-resistant breast cancer. Phase I trials indicate that toxicities, such as mucositis and neutropenia, limit the administration of docetaxel to shorter perfusion schedules. Pharmacokinetic studies have shown that docetaxel's clearance by hepatic metabolism is correlated with a marked increase in risk of toxicity in patients with impaired liver function. Nevertheless, studies of docetaxel as front-line therapy for breast cancer were initiated because of its good activity against tumors in early studies and its close relationship to paclitaxel (Taxol), an agent with proven efficacy. Phase II studies have demonstrated excellent activity for docetaxel as a single agent, with an overall response rate of 61% in trials of a 100-mg/m2 dose. A phase III study is currently comparing docetaxel with paclitaxel as single-agent therapy. Docetaxel is expected to provide a better response rate but a higher incidence of neutropenia. The agent shows promise in adjuvant therapy, with very high response rates in anthracycline-resistant patients. Preliminary results of tests using docetaxel in combination with doxorubicin show high objective response rates but low complete response rates; early results suggest that this combination may have some advantages over paclitaxel/doxorubicin.

Treatment of patients resistant to anthracycline therapy

The results of three multicentre phase II trials in which docetaxel (Taxotere) was used in previously treated patients with metastatic breast cancer resistant to anthracyclines or anthracenediones are summarized here. Docetaxel was given to a total of 134 patients who had evidence of disease progression while receiving anthracyclines or anthracenediones for metastatic disease or had relapsed during adjuvant therapy which included these agents. The overall response rate (ORR) across the three studies was 41% in an intent-to-treat analysis. The median duration of response varied from 24 to 28 weeks between studies and the median survival varied from 9 to 12 months. The response rate was well maintained in evaluable patients with visceral metastases (ORR 43%), or multiple (> 2) sites of disease (ORR 48%). These response rates are the highest ever reported for a single agent in patients with anthracycline-resistant disease. The recommended dose and schedule for docetaxel (100 mg/m2 intravenously over 1-h every 3 weeks), which was used in all three studies, was found to be well tolerated, with neutropenia as the most common toxicity (grade 4 in 90% of patients) and febrile neutropenia requiring hospitalisation occurring in only 4% of cycles of therapy.

A computer program to assist in making breast cancer adjuvant therapy decisions

This report describes a computer program designed to assist health care professionals in making projections of the average benefit of systemic adjuvant therapy for individual breast cancer patients. It requires as input patient age (used to make projections of natural mortality), an estimate of breast cancer-related mortality at 5 years (used to make projections of breast cancer-specific mortality), and the proportional risk reduction for breast cancer mortality expected for the adjuvant therapy (with included tables from the Early Breast Cancer Trialist's 1992 meta-analysis). The program uses life table analytical techniques to make projections of outcome in three scenarios: that the breast cancer never occurred, that the breast cancer patient received definitive local therapy but no adjuvant systemic therapy, and that the patient received adjuvant therapy. The outcome projections are given for total, natural (non-breast cancer-related), and breast cancer-related mortality at several time points and also of total remaining life expectancy. These estimates are currently widely made by clinicians by nonnumerical techniques. Computer-based tools can serve as valuable aids in physician and patient education and in the process of informed decision making.

A computer based program to assist in adjuvant therapy decisions for individual breast cancer patients

This paper describes a personal computer based tool to aid in decision making about whether a woman should receive adjuvant therapy for breast cancer. This tool can assist in engaging women with primary breast cancer in the discussion about: 1) her risk of breast cancer related mortality if she receives only local control measures, but no systemic adjuvant therapy, 2) how much receiving adjuvant therapy may reduce this risk, and 3) what the impact of receiving the adjuvant systemic therapy is in terms of survival. The tool utilizes life table analytical techniques to project outcomes after entry of patient age (used to calculate natural mortality rates), estimated risk of breast cancer related mortality (with a help tool allowing the physician to use estimates based on national database information), and estimate of the efficacy of adjuvant chemotherapy (with included tables of estimates based on the Early Breast Cancer Trialists' meta-analysis). Computer based tools can serve as valuable aids in patient and physician education, and the process of informed decision making.

Phase II trial of docetaxel in advanced anthracycline-resistant or anthracenedione-resistant breast cancer

PURPOSE

The purpose of this study was to evaluate the clinical efficacy and safety of docetaxel in patients with metastatic breast cancer (MBC) resistant to doxorubicin or mitoxantrone.

PATIENTS AND METHODS

Docetaxel 100 mg/m2 was administered as a 1-hour intravenous (IV) infusion every 3 weeks to 42 patients registered at four centers. Patients must have received at least one but no more than two prior chemotherapy regimens for MBC (in addition to any prior adjuvant therapy). One of the regimens for metastatic breast cancer must have included an anthracycline or anthracenedione and the cancer must have progressed on that regimen.

RESULTS

Objective responses were seen in 20 of 35 assessable patients (three complete responses [CRs] and 17 partial responses [PRs]), for an objective response rate of 57% (95% confidence interval [CI], 39% to 74%) and in 21 of 42 registered patients (50% response rate [RR]; 95% CI, 34% to 66%) entered onto the trial. The median response duration was 28 weeks. The most common toxicity in this study was grade 4 neutropenia, which occurred in 95% of patients. Other clinically significant nonhematologic side effects included stomatitis, skin reactions, neurosensory changes, asthenia, and fluid retention. Patients who received dexamethasone premedication had a later onset of fluid retention than those who did not receive dexamethasone (onset at a median cumulative docetaxel dose of 503 mg/m2 and 291 mg/m2, respectively).

CONCLUSION

Docetaxel at this dose and schedule has a high level of antitumor activity in patients with treatment-refractory advanced breast cancer, and appears to be one of the most active agents for the treatment of this patient population.

Taxoids: effective agents in anthracycline-resistant breast cancer

The results of recent clinical trials have shown that docetaxel (Taxotere; Rhône-Poulenc Rorer, Antony, France), like paclitaxel (Taxol; Bristol-Myers Squibb Oncology, Princeton, NJ), has high levels of activity in patients with anthracycline-resistant breast cancer. Agents that are at least partially non-cross-resistant with anthracyclines are especially promising for the treatment of breast cancer; the taxoids (docetaxel and paclitaxel) are such agents. Although preclinical evaluations shows clear instances of strong cross-resistance (particularly in cells lines expressing the P-glycoprotein, multidrug resistance), high response rates have been reported in patients with prior anthracycline exposure and/or anthracycline resistance. Phase I studies of anthracycline and taxoid combinations have been conducted. Excellent response rates have been noted in some of these studies. In some studies using regimens combining doxorubicin and paclitaxel, unanticipated toxicities have occurred, such as typhlitis, as well as congestive heart failure at lower than expected cumulative doses of doxorubicin. Phase II and III studies of regimens including both anthracyclines and taxoids have been initiated. Docetaxel and paclitaxel appear to be valuable agents for use in anthracycline-resistant breast cancer patients, and may find a place in anthracycline-containing combination regimens.

Anthracycline resistance in breast cancer: clinical applications of current knowledge

Anthracyclines are highly effective antineoplastic agents for the treatment of breast cancer. Nevertheless, essentially all breast cancer patients have tumours which are intrinsically resistant or which develop resistance during the course of therapy. Clinical trials provide indirect information on the nature of anthracycline resistance and work in the basic sciences has demonstrated molecular mechanisms which play a role. Initial clinical attempts to exploit and translate these mechanisms to predict, and interfere with, anthracycline resistance have met with mixed success, and have not yet led to accepted clinical applications.

The c-erbB-2 proto-oncogene as a prognostic and predictive marker in breast cancer: a paradigm for the development of other macromolecular markers--a review

Seven years after the initial studies of the prognostic value of the proto-oncogene c-erbB-2 in breast cancer, its role is still being defined. The interpretation of studies on the use of this gene and its protein product in prognostic and predictive tests for breast cancer is complicated by multiple methodologies and the inherent difficulties in the studies. The work has moved beyond the stage at which small studies with short follow-up (useful for hypothesis generation) are of value, to the stage in which large studies with sufficient statistical power to find significant correlations are central. These larger studies do not lend support for the use of c-erbB-2 in the evaluation of axillary-node-negative patients, the group of breast cancer patients for whom refinement of prognostic estimates is now most important. There are, however, hints that c-erbB-2 may have value in predicting response to certain treatments, though the studies so far are too few, often too small and too conflicting to reliably confirm this.

Review of docetaxel (Taxotere), a highly active new agent for the treatment of metastatic breast cancer

Phase II studies have demonstrated that docetaxel (Taxotere; Rhône-Poulenc Rorer, Collegeville, PA) is one of the most active single agents in the treatment of metastatic breast cancer. The overall response rate as front-line therapy for metastatic disease was 59% (95% confidence interval, 51% to 67%) in five phase II trials (four of which were multicenter) when 100 mg/m2 docetaxel was infused over 1 hour every 3 weeks. In the three phase II trials reported to date of patients with metastatic cancer who had failed previous frontline therapy, 100 mg/m2 docetaxel infused over 1 hour every 3 weeks produced an objective response rate of 49% (95% confidence interval, 40% to 58%). Two of these trials specifically included patients who had progressed while receiving either an anthracycline or an anthracenedione; the overall response rate in this subset of 83 patients was 48%. The most significant acute toxicity noted in these trials was neutropenia. Grade 4 neutropenia occurred in the majority of patients but rarely resulted in treatment delays. Hypersensitivity reactions also were common in nonpremedicated patients, but were rare after the institution of premedication with antihistamines and/or glucocorticoids. A novel toxicity observed in many patients was fluid retention syndrome, with onset at a median of four to five cycles. The fluid retention was of noncardiac or renal origin, was slowly progressive with additional cycles of therapy, was reversible after cessation of the drug, and could be largely ameliorated by oral diuretics and glucocorticoid premedication. Phase III studies to further define docetaxel's role in the treatment of breast cancer are now under way.

Prediction of axillary lymph node status in breast cancer patients by use of prognostic indicators

BACKGROUND

If axillary lymph node status of breast cancer patients could be accurately predicted from basic clinical information and from characteristics of their primary tumors, then many patients could be spared axillary lymph node dissection. Tumor size alone does not allow the identification of groups with very low or high risk of being axillary node positive.

PURPOSE

Our goal was to investigate the possibility of using prognostic indicators to predict axillary node status of patients with primary breast cancer.

METHODS

Data from 26,683 patients from the National Breast Cancer Tissue Resource were used in this study. Patients in this dataset were randomly assigned to a training set (patient information used to construct predictive models) or a validation set (patient information used to prospectively evaluate predictive models). The records of a total of 11,964 case patients that had complete prognostic factors and pathologic data were analyzed: 5963 patients in the training set and 6001 patients in the validation set. All of the patients studied had tumors 5 cm or less in size and at least 15 axillary lymph nodes that had been examined. Data used for construction of the predictive models were available for all patients and included tumor size, number of nodes positive, patient age, quantitative estrogen receptor levels, quantitative progesterone receptor (PgR) levels, DNA flow cytometry-derived ploidy, and S-phase fraction. Logistic regression models were used to predict nodal status.

RESULTS

Multivariate predictive models were produced that used tumor size, patient age, S phase, and PgR as independent predictors. These models allowed identification of patient risks of being node positive ranging from 6%-79% and as having 10 or more positive nodes ranging from less than 1% to slightly more than 30%.

CONCLUSION

Addition of prognostic indicator information to tumor size can refine estimates of whether a patient is likely to be node positive. However, no patient subsets could be identified as having greater than 95% chance of being node negative or node positive.

IMPLICATIONS

These predictive models cannot alleviate the necessity of axillary node dissection for staging of breast cancer patients in situations in which nodal status would affect therapeutic decisions. Subsets of patients could be identified who had a less than 5% chance of having 10 or more positive nodes. Thus, some patients could be spared axillary dissection if it was being performed solely to identify patients with this high-risk feature.

Prognostic factors in early breast carcinoma

Several investigators, the SEER data, and the ECOG/Intergroup study have shown that patients with small tumors (< 0.5 cm) have a recurrence rate of less than 2%, compared to 20-25% for large tumors (> or = 5 cm). Nuclear grade and tumor differentiation are established indicators; however, the interobserver lack of concordance has thwarted their use in clinical trials. The presence of peritumoral lymphatic and blood vessel invasion (PLBI) is associated with a relative risk of recurrence of 4.7. The predictive value of the presence of hormone receptors in tumors is associated with a favorable disease free and overall survival difference of 8-10%; however, this advantage is being eroded by the early appearance of other factors, such as the epidermal growth factor receptor (EGFR), proliferative capacity (S-phase), nuclear grade, and HER-2/neu oncogene. Concordance among the different methods of hormone-receptor assay (immunocytochemical, sucrose gradient, and dextran-coated charcoal) is essential to refine the true value of these factors. DNA flow cytometry measurements of ploidy (DNA content) and S-phase fraction are the most characterized of the prognostic factors. There are conflicting reports regarding the clinical significance of ploidy status, while measurements of S-phase fraction clearly indicate a robust association with disease free and overall survival. Our data continue to show that S-phase, but not ploidy, can predict time to recurrence significantly in untreated patients, even when data are stratified for tumor size. HER-2/neu oncogene is expressed in about 50% of ductal carcinoma in situ and 14% of invasive ductal carcinoma. The presence of this oncogene at high copy number may be a useful independent marker of poor prognosis and may be associated with drug resistance and correlated with tumor recurrence and shorter survival. EGFR could be measured in most breast tumors, and the level of its expression has inversely correlated with estrogen receptor protein expression. The value of EGFR as a predictor of prognosis remains controversial and is still being investigated. Cathepsin-D provides a provocative biologic rationale but is hindered by different and incongruent methods of analysis. The majority of large studies with more than 3-years' follow-up suggests that high cathepsin-D levels may be predictive of greater recurrence and lower survival. Angiogenesis has been implicated as a critical component of the metastatic process. Early studies show that tumor angiogenesis is an independent and highly significant prognostic indicator, and its presence may suggest the selection of "anti-angiogenic therapy."(ABSTRACT TRUNCATED AT 400 WORDS)

Do American oncologists know how to use prognostic variables for patients with newly diagnosed primary breast cancer?

PURPOSE

This project was designed to investigate how American medical oncologists actually use prognostic information to treat primary breast cancer patients, and to study their difficulties in combining complex and sometimes contradictory information.

METHODS

A simple 2-page questionnaire was faxed in May and June 1993 to a sample of American medical oncologists who were members of the American Society of Clinical Oncology (ASCO).

RESULTS

When presented with simple case histories of patients with newly diagnosed invasive breast cancer and asked to assess prognosis on the basis of tumor size, number of involved axillary nodes, patient age, estrogen receptor level, and progesterone receptor level, there was a wide divergence of opinions about the probability of disease-free survival at 10 years (both for cases in which the patient received no adjuvant therapy and for those in which the patient did receive such therapy). The use of additional prognostic data (such as S-phase, tumor histologic and nuclear grading, and cathepsin D status) did not refine the estimates, but led to an equal or greater dispersion of estimates of prognosis.

CONCLUSION

There is a clear need for tools to help oncologists integrate prognostic information for primary breast cancer patients. Such tools might lead to greater accuracy and uniformity of prognostic estimates. Such tools might also help make clear what prognostic tests are worth using for routine clinical practice.

A technique for using neural network analysis to perform survival analysis of censored data

The purpose of this study was to demonstrate how a form of neural network analysis could be used to perform survival analysis on censored data, and to compare neural network analysis with the most commonly used technique for this type of analysis, Cox regression. In this study computer simulated data sets were used. The underlying rules connecting prognostic information to the hazard of death were defined to allow the construction of data sets with specific realistic properties that could be used to demonstrate situations in which neural network analysis had particular strengths in comparison with Cox regression modeling. Using these simulated data sets neural network analysis could produce successful predictive models, find interactions between variables, and recognize the importance of variables that contributed to the hazard rate as a complex function of the variables value and in situations where the proportionality of hazards assumption was violated. It was also demonstrated that neural network analysis was not a 'black box', but could lead to useful insights into the roles played by different prognostic variables in determining patient outcome.

Cathepsin D by western blotting and immunohistochemistry: failure to confirm correlations with prognosis in node-negative breast cancer

PURPOSE

We attempted to replicate and improve on our previous study (N Engl J Med 322:297-302, 1990) that showed that 34-kd cathepsin D levels as determined by Western blotting strongly correlated with disease-free survival (DFS) and overall survival (OS) of axillary node-negative (N-) breast cancer patients. We also examined the prognostic significance of cathepsin D measured by immunohistochemistry (IHC) in these patients.

PATIENTS AND METHODS

Western blotting was performed on cytosols from frozen tumor specimens of 927 N- breast cancer patients in the San Antonio Breast Tumor Bank. The monoclonal antibody M1G8 was used to detect cathepsin D (in previous study, a polyclonal antiserum had been used). The same monoclonal antibody was also used for frozen-section IHC staining of tumor specimens from 562 N- patients from the same tumor bank. Levels of cathepsin D expression were then correlated with DFS and OS.

RESULTS

Although the levels of cathepsin D expression as measured by Western blotting and IHC correlated with each other and with levels of cathepsin D measured in previous work using Western blotting with the polyclonal antiserum, in this present study, using the monoclonal antibody M1G8, we were unable to demonstrate that cathepsin D expression (measured by either Western blotting or by IHC) correlates with DFS or OS.

CONCLUSION

In this study, cathepsin D expression as determined by either Western blotting or IHC using the monoclonal antibody M1G8 failed to improve the prognostic evaluation of N- breast cancer patients. The role of cathepsin D expression as a prognostic factor is still not precisely defined, raising questions about its use in the routine evaluation of N- breast cancer patients.

A practical view of prognostic factors for staging, adjuvant treatment planning, and as baseline studies for possible future therapy

At this time the initial prognostic assessment of breast cancer patients is still most powerfully driven by basic histopathologic information, axillary nodal involvement, and tumor size. Estrogen and progesterone receptor status are important initial pieces of information for many patients, but this information is more important in deciding the most appropriate type of treatment, rather than the prognosis of the patient. Histologic and nuclear grading can provide important prognostic information, but broader application of this information awaits better methods to ensure accuracy and decrease intraobserver variability. Whether flow cytometry-derived information can be used to select patient subsets at very low risk of relapse awaits prospective validation in cooperative group trials. A number of new prognostic tests such as cathepsin D that have shown promise in some studies await definitive prospective validation. Further development of techniques to integrate prognostic factor information and the use of this information in individualized prognostic factor decisions is needed.

Case report: use of insulin-like growth factor-I gene expression to distinguish between breast and ovarian cancer

Autocrine expression of polypeptide growth factors may be important in the growth regulation of cancer cells. Different growth factor activities have been identified in a variety of tumors. This article describes a case of malignant ascites in a patient recently treated for breast cancer. The use of growth factor mRNA expression as a factor to differentiate between breast and ovarian origins of cancer cells contained in malignant ascites was examined. Expression of insulin-like growth factor-I (IGF-I), IGF-II, and transforming growth factor alpha mRNA was examined by ribonuclease protection assay. The tumor cells expressed IGF-II and transforming growth factor alpha, but not IGF-I mRNA. This pattern of growth factor expression is compatible with a breast cancer primary of the malignant cells contained in the ascites fluid. Therefore, IGF-I mRNA expression may be useful in distinguishing between adenocarcinomas of breast or ovarian origins.

Phase II trial of piroxantrone in metastatic breast cancer. A Southwest Oncology Group study

Thirty-two eligible patients with advanced metastatic breast cancer who had received no more than 1 prior chemotherapy regimen for metastatic disease (16 had received prior doxorubicin) were treated with piroxantrone at a dose of 120 mg/m2 intravenously every 21 days. In the twenty-seven patients evaluable for response, two partial responses were seen. Toxicities observed were primarily hematologic with grade 3 or greater granulocytopenia occurring in 34% of the patients. One patient developed symptomatic congestive heart failure at a total cumulative dose of 960 mg/m2. We conclude that piroxantrone given at this dose and schedule has minimal activity in patients with metastatic breast cancer.

Survival analysis of censored data: neural network analysis detection of complex interactions between variables

Neural networks can be used as pattern recognition systems in complex data sets. We are exploring their utility in performing survival analysis to predict time to relapse or death. This technique has the potential to find easily some types of very complex interactions in data that would not be easily recognized by conventional statistical methods. In this paper we demonstrate that there are several ways neural networks can be used to find three-way interactions among variables. Thus, in data sets where such complex interactions exist, neural networks may find utility in detecting such interactions and in helping to produce predictive models.

Prognostic factors: rationale and methods of analysis and integration

With the proliferation of potential prognostic factors for breast cancer, it is becoming increasingly more difficult for physicians and patients to integrate the information provided by these factors into a single accurate prediction of clinical outcome. Here we review Cox's proportional hazards model, recursive partitioning, correspondence analysis, and neural networks for their respective capabilities in analyzing censored survival data in the presence of multiple prognostic factors, and we present some clinical applications where these models have been used.

Failure of GM-CSF to permit dose-escalation in an every other week dose-intensive regimen for advanced breast cancer

BACKGROUND

In an attempt to improve dose intensity and therapeutic effectiveness in breast cancer, GM-CSF was incorporated into a multi-drug every other week chemotherapy regimen that had been previously reported to have promising activity, but whose dose-limiting toxicity was neutropenia.

PATIENTS AND METHODS

A Phase I-II study in patients with locally advanced or metastatic breast cancer was initiated using GM-CSF and a 5-drug chemotherapy regimen employing oral cyclophosphamide daily for 7 days and doxorubicin, vincristine, methotrexate, 5-fluorouracil, and leucovorin IV every 2 weeks for 10 courses. In the first 8 patients, GM-CSF in escalating doses (1-20 micrograms/kg s.c. per day) was given on days 8-13 of each 2 week cycle. In the last 12 patients, GM-CSF was given on days 3-14 of each cycle in an attempt to improve its effectiveness by prolonging treatment duration.

RESULTS

The regimen was poorly tolerated. Only 10 patients completed all 10 courses of treatment, and most of those required dose delays and/or reductions. GM-CSF failed to reduce neutropenia when given by either schedule. Furthermore, thrombocytopenia was severe and progressive, especially with the more prolonged GM-CSF schedule in which the mean lowest nadir platelet count was 15,000/microliters. Anemia, fatigue, mucositis, and neutropenic fevers were also common, and dose escalations were not possible in any patient. Central venous catheter complications were also common. Complete or partial remissions were observed in 15 of 20 patients, but response durations were brief.

CONCLUSIONS

GM-CSF in two different schedules failed to ameliorate myelosuppression when used in combination with this multiple drug, every other week regimen. Neutropenia and, especially, thrombocytopenia remained dose limiting.