MITO END-3: Efficacy of Avelumab immunotherapy according to molecular profiling in first-line endometrial cancer therapy

BACKGROUND

Immunotherapy combined with chemotherapy significantly improves progression-free survival compared to first-line chemotherapy alone in advanced endometrial cancer, with a much larger effect size in microsatellite-instability high (MSI-H) cases. New biomarkers might help to select patients that may have benefit among those with a microsatellite-stable (MSS) tumor.

METHODS

In a pre-planned translational analysis of the MITO END-3 trial, we assessed the significance of genomic abnormalities in patients randomized to standard carboplatin/paclitaxel without or with avelumab.

RESULTS

Out of 125 randomized patients, 109 had samples eligible for next-generation sequencing (NGS) analysis, and 102 had MSI tested. According to The Cancer Genome Atlas (TCGA), there were 29 cases MSI-H, 26 MSS TP53 wild-type (wt), 47 MSS TP53 mutated (mut), and one case with POLE mutation. Four mutated genes were present in more than 30% of cases: TP53, PIK3CA, ARID1A, and PTEN. Eleven patients (10%) had a BRCA1/2 mutation (five in MSI-H and six in MSS). High TMB (≥10 Muts/Mb) was observed in all MSI-H patients, in four out of 47 MSS/TP53 mut, and no case in the MSS/TP53 wt category. The effect of avelumab on progression-free survival significantly varied according to TCGA categories, being favorable in MSI-H and worst in MSS/TP53 mut (P interaction=0.003); a similar non-significant trend was seen in survival analysis. ARID1A and PTEN also showed a statistically significant interaction with treatment effect, which was better in the presence of the mutation (ARID1A P interaction=0.01; PTEN P interaction=0.002).

CONCLUSION

The MITO END-3 trial results suggest that TP53 mutation is associated with a poor effect of avelumab, while mutations of PTEN and ARID1A are related to a positive effect of the drug in patients with advanced endometrial cancer.

Norwegian e-Infrastructure for Life Sciences (NeLS)

The Norwegian e-Infrastructure for Life Sciences (NeLS) has been developed by ELIXIR Norway to provide its users with a system enabling data storage, sharing, and analysis in a project-oriented fashion. The system is available through easy-to-use web interfaces, including the Galaxy workbench for data analysis and workflow execution. Users confident with a command-line interface and programming may also access it through Secure Shell (SSH) and application programming interfaces (APIs).  NeLS has been in production since 2015, with training and support provided by the help desk of ELIXIR Norway. Through collaboration with NorSeq, the national consortium for high-throughput sequencing, an integrated service is offered so that sequencing data generated in a research project is provided to the involved researchers through NeLS. Sensitive data, such as individual genomic sequencing data, are handled using the TSD (Services for Sensitive Data) platform provided by Sigma2 and the University of Oslo. NeLS integrates national e-infrastructure storage and computing resources, and is also integrated with the SEEK platform in order to store large data files produced by experiments described in SEEK.   In this article, we outline the architecture of NeLS and discuss possible directions for further development.

Abstract P2-08-06: Usefulness of the pre-treatment neutrophil-to-lymphocyte ratio in predicting first-line progression free-survival in triple-negative breast cancer patients

Background: The neutrophil-to-lymphocyte ratio (NLR) is an independent predictor of poor prognosis inunselected breast cancer patients with NLR >3.3. Moreover, pre-treatment NLR has been associated with disease-free and overal survival (OS) in patients with early triple-negative breast cancer (TNBC). We aimed to determine whether the NLR is predictive of progression-free survival (PFS) in metastatic TNBC.

Methods: We reviewed the records of 48 TNBC patients who received at least one administration of first-line (1°L) chemotherapy for advanced disease from October 2004 to April 2014. The NLR (absolute neutrophil count/absolute lymphocyte count) was calculated from the full blood count routinely performed immediately before the initiation of first-line treatment. The association between categorical variables was calculated by X2 test. PFS (from start of 1°L treatment to disease progression or death) and OS (from start of 1°L treatment to death) were estimated using Kaplan Meier method. Multivariable Cox regression was used to determine the independent prognostic significances of the NLR (co-variables stage at diagnosis, histology, and tumor grade).

Results: NLR was not associated with stage at diagnosis (p=0.214), histology (p=0.597), or tumor grade (p=0.775). After a median follow-up of 10.9 months (range 1.3-54.9), 88.6% of TNBC patients with NLR≤3.3 versus 0.0% of patients with NLR>3.3 had a 1°L PFS>3 months (p<0.001). Similarly, 62.9% of TNBC patients with NLR≤3.3 versus 30.8% of patients with NLR>3.3 had an OS>10 months (p=0.047). Metastatic TNBC patients with NLR≤3.3 had a longer median 1°L PFS (5.2 months) and median OS (13.5 months) compared with patients with NLR>3.3 (1°L PFS 2.1 months, p<0.001; OS 7.7 months, p=0.018). In multivariable analysis, NLR>3.3 is associated with a shorter PFS (hazard ratio [HR] 22.4; 95% confidence interval [CI] 6.7-75.1, p<0.001) and higher risk of death (HR 3.2, 95%CI 1.4-7.4, p=0.005).

Conclusion: Our study showed that pre-treatment NLR is associated with 1°L PFS and OS in patients with metastatic TNBC. However, further investigation in larger series of metastatic TNBC is warranted.

Citation Format: Fontanella C, Fanotto V, Gerratana L, Bonotto M, Cinausero M, Bozza C, Iacono D, Russo S, Andreetta C, Minisini AM, Moroso S, Mansutti M, Fasola G, Puglisi F. Usefulness of the pre-treatment neutrophil-to-lymphocyte ratio in predicting first-line progression free-survival in triple-negative breast cancer patients. [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 P2-08-06.

Formulation of probabilistic models of protein structure in atomic detail using the reference ratio method

We propose a method to formulate probabilistic models of protein structure in atomic detail, for a given amino acid sequence, based on Bayesian principles, while retaining a close link to physics. We start from two previously developed probabilistic models of protein structure on a local length scale, which concern the dihedral angles in main chain and side chains, respectively. Conceptually, this constitutes a probabilistic and continuous alternative to the use of discrete fragment and rotamer libraries. The local model is combined with a nonlocal model that involves a small number of energy terms according to a physical force field, and some information on the overall secondary structure content. In this initial study we focus on the formulation of the joint model and the evaluation of the use of an energy vector as a descriptor of a protein's nonlocal structure; hence, we derive the parameters of the nonlocal model from the native structure without loss of generality. The local and nonlocal models are combined using the reference ratio method, which is a well-justified probabilistic construction. For evaluation, we use the resulting joint models to predict the structure of four proteins. The results indicate that the proposed method and the probabilistic models show considerable promise for probabilistic protein structure prediction and related applications.

PHAISTOS: a framework for Markov chain Monte Carlo simulation and inference of protein structure

We present a new software framework for Markov chain Monte Carlo sampling for simulation, prediction, and inference of protein structure. The software package contains implementations of recent advances in Monte Carlo methodology, such as efficient local updates and sampling from probabilistic models of local protein structure. These models form a probabilistic alternative to the widely used fragment and rotamer libraries. Combined with an easily extendible software architecture, this makes PHAISTOS well suited for Bayesian inference of protein structure from sequence and/or experimental data. Currently, two force-fields are available within the framework: PROFASI and OPLS-AA/L, the latter including the generalized Born surface area solvent model. A flexible command-line and configuration-file interface allows users quickly to set up simulations with the desired configuration. PHAISTOS is released under the GNU General Public License v3.0. Source code and documentation are freely available from http://phaistos.sourceforge.net. The software is implemented in C++ and has been tested on Linux and OSX platforms.

Potentials of mean force for protein structure prediction vindicated, formalized and generalized

Understanding protein structure is of crucial importance in science, medicine and biotechnology. For about two decades, knowledge-based potentials based on pairwise distances – so-called “potentials of mean force” (PMFs) – have been center stage in the prediction and design of protein structure and the simulation of protein folding. However, the validity, scope and limitations of these potentials are still vigorously debated and disputed, and the optimal choice of the reference state – a necessary component of these potentials – is an unsolved problem. PMFs are loosely justified by analogy to the reversible work theorem in statistical physics, or by a statistical argument based on a likelihood function. Both justifications are insightful but leave many questions unanswered. Here, we show for the first time that PMFs can be seen as approximations to quantities that do have a rigorous probabilistic justification: they naturally arise when probability distributions over different features of proteins need to be combined. We call these quantities “reference ratio distributions” deriving from the application of the “reference ratio method.” This new view is not only of theoretical relevance but leads to many insights that are of direct practical use: the reference state is uniquely defined and does not require external physical insights; the approach can be generalized beyond pairwise distances to arbitrary features of protein structure; and it becomes clear for which purposes the use of these quantities is justified. We illustrate these insights with two applications, involving the radius of gyration and hydrogen bonding. In the latter case, we also show how the reference ratio method can be iteratively applied to sculpt an energy funnel. Our results considerably increase the understanding and scope of energy functions derived from known biomolecular structures.

Calculation of accurate small angle X-ray scattering curves from coarse-grained protein models

BACKGROUND

Genome sequencing projects have expanded the gap between the amount of known protein sequences and structures. The limitations of current high resolution structure determination methods make it unlikely that this gap will disappear in the near future. Small angle X-ray scattering (SAXS) is an established low resolution method for routinely determining the structure of proteins in solution. The purpose of this study is to develop a method for the efficient calculation of accurate SAXS curves from coarse-grained protein models. Such a method can for example be used to construct a likelihood function, which is paramount for structure determination based on statistical inference.

RESULTS

We present a method for the efficient calculation of accurate SAXS curves based on the Debye formula and a set of scattering form factors for dummy atom representations of amino acids. Such a method avoids the computationally costly iteration over all atoms. We estimated the form factors using generated data from a set of high quality protein structures. No ad hoc scaling or correction factors are applied in the calculation of the curves. Two coarse-grained representations of protein structure were investigated; two scattering bodies per amino acid led to significantly better results than a single scattering body.

CONCLUSION

We show that the obtained point estimates allow the calculation of accurate SAXS curves from coarse-grained protein models. The resulting curves are on par with the current state-of-the-art program CRYSOL, which requires full atomic detail. Our method was also comparable to CRYSOL in recognizing native structures among native-like decoys. As a proof-of-concept, we combined the coarse-grained Debye calculation with a previously described probabilistic model of protein structure, TorusDBN. This resulted in a significant improvement in the decoy recognition performance. In conclusion, the presented method shows great promise for use in statistical inference of protein structures from SAXS data.

Predictors of tumor shrinkage after anthracycline-based preoperative chemotherapy

e11531

Background: Anthracyclines are currently included in several chemotherapy (CT) regimens for the treatment of breast cancer (BC). However, increasing evidence suggests that benefit from these agents is limited to some subgroups of patients (pts). Aim of this study was to identify potential predictors of tumor shrinkage (TS) in a retrospective series of pts receiving preoperative anthracycline-based CT for operable BC. Methods: The study population consisted of 94 pts with large (>2 cm), any N, operable BC treated with preoperative anthracycline-based CT. Association between clinico-biological factors and clinico-radiological TS (by caliper and MRI) was assessed. TS was calculated as the difference between the maximum tumor diameter at baseline and the maximum tumor diameter after preoperative CT/ the maximum tumor diameter at baseline x 100. Immunohistochemical analyses for biological variables (ER, PgR, HER2, MIB1, topoisomerase II alpha) were performed on pretreatment biopsies. Results: In univariate analysis, the following variables were associated with clinical TS: high MIB-1 [Odd ratio (OR) 2.6, p = 0.03], type of taxane (docetaxel vs paclitaxel: OR 0.3, p = 0.01) and number of cycles of CT (> 4 vs ≤ 4: OR 9.2, p < 0.0001). In multivariate analysis, number of cycles of CT was the only independent predictor of clinical TS (OR = 9.2, p = 0.05). In univariate analysis, the following variables were associated with MRI TS: high MIB-1 (OR 2.4, p = 0.06), tumor size (≥ 40 mm vs < 40 mm: OR 5.6, p 0 0.01), taxane CT (yes vs no: OR 4.3, p = 0.02) and number of cycles of CT (> 4 vs ≤ 4: OR 4.4, p = 0.002). In multivariate analysis, high MIB-1 was the only independent predictor of MRI TS (OR = 3.7, p = 0.03). Conclusions: High MIB-1 expression and number of cycles of chemotherapy significantly predicted tumor shrinkage in patients treated with preoperative anthracycline-based chemotherapy. Further studies are warranted to better identify patients who derive benefit from anthracyclines.

No significant financial relationships to disclose.

Thymidine phosphorylase expression and benefit from capecitabine in patients with advanced breast cancer

BACKGROUND AND AIM

Capecitabine is an orally bioavailable prodrug that is converted to 5-fluorouracil through several enzymatic steps, the last of which is mediated by thymidine phosphorylase (TP). TP has been reported to be expressed at higher levels in cancer tissue compared with normal counterpart. The present study aimed at evaluating the potential relationship between TP expression and benefit from capecitabine in patients with metastatic breast cancer (BC).

METHODS

Immunohistochemistry for TP and other biological markers was carried out on paraffin-embedded cancer tissues of 61 patients with BC treated with at least three cycles of capecitabine as single agent for metastatic disease. All patients had received capecitabine 1000 mg/m(2) b.i.d. days 1-14 every 21 days. The following variables were analyzed as potential determinants of benefit from capecitabine: TP expression, estrogen receptor (ER) and progesterone receptor status, human epidermal growth factor receptor-2 (HER-2) status, MIB-1 expression, performance status at the beginning of capecitabine treatment, stage at diagnosis, grade, presence of visceral metastases at the beginning of capecitabine treatment, and previous chemotherapy.

RESULTS

Overall, median time to progression (TTP) was 6.5 months (range 1.4-33). On multivariate analysis, ER status [hazard ratio (HR) for progression = 0.31; 95% confidence interval (CI) = 0.15-0.64; P = 0.002], presence of visceral metastases at the beginning of capecitabine treatment (HR = 2.30; 95% CI = 1.21-4.39; P = 0.01), and capecitabine as first- or second-line treatment (HR = 2.28; 95% CI = 1.21-4.32; P = 0.01) independently predicted TTP. TP was highly expressed in 34 of 61 cases (55.7%). In the subgroup of patients with TP-expressing tumor, TTP was significantly longer in patients who received anthracyclines and taxanes before capecitabine (median TTP 7.5 versus 3.3 months, P = 0.01, log-rank test). Similarly, patients with a TP-positive tumor showed a longer TTP if they received taxanes before capecitabine than patients with TP-positive tumor who did not receive this treatment (7.3 versus 3.4 months, P = 0.03).

CONCLUSIONS

These data provide further evidence that TP expression in BC could represent a biomarker of sensitivity to capecitabine treatment. Prospective studies with translational approach are desirable to confirm the predictive and prognostic role of TP.

Thymidine phosphorylase expression is associated with time to progression in patients receiving low-dose, docetaxel-modulated capecitabine for metastatic breast cancer

BACKGROUND

Preclinical data have indicated a synergistic interaction between docetaxel and capecitabine by means of taxane-induced up-regulation of thymidine phosphorylase (TP). On the basis of such premises, we conducted a phase II trial to determine the activity and tolerability of weekly docetaxel plus capecitabine in patients with metastatic breast cancer (MBC). Furthermore, we explored the relationship between TP tumor expression and benefit from this regimen.

PATIENTS AND METHODS

Patients received docetaxel 36 mg/m(2) i.v. on days 1, 8, and 15 and capecitabine orally 625 mg/m(2) b.i.d. from days 8 to 21. Cycles were repeated every 4 weeks. In the correlative study, we evaluated the TP expression by immunohistochemistry and the TP messenger RNA expression by real-time RT-PCR in the primary tumor.

RESULTS

Forty-seven women were enrolled. In the intention-to-treat analysis, objective responses were achieved in 24 patients (51%). Fourteen additional patients (30%) had stable disease. The median time to progression (TTP) was 6 months (range 1-44 months). Median survival was 17 months (range 1-48 months). Overall, the treatment was well tolerated. The most common clinical adverse events (all grades) were alopecia (55%), nail changes (53%), fatigue/asthenia (51%), nausea/vomiting (51%), neutropenia (49%), and neuropathy (49%). A significantly higher TTP was observed in patients with TP-positive tumors (log-rank test, P = 0.009). Interestingly, a subgroup analysis confirmed this TTP benefit in patients with TP-positive tumors obtaining a tumor response (log-rank test, P = 0.03), whereas the statistical significance was lost in nonresponders (log-rank test, P = 0.3).

CONCLUSIONS

This study indicates that a regimen with low doses of capecitabine plus weekly docetaxel is active against MBC. The correlative analysis provides preliminary evidence that TP expression may be a predictive marker for therapeutic benefit.

Expression of periostin in human breast cancer

Background:

Periostin is a secreted adhesion protein, normally expressed in mesenchime-derived cells. Aberrant expression of the periostin gene in epithelial tumours seems to play a role in angiogenesis and metastases.

Aims:

To investigate periostin expression in a consecutive series of breast carcinomas and correlate it with established biological and prognostic factors.

Methods:

A consecutive series of 206 breast carcinomas was investigated by immunohistochemistry with a specific antiperiostin antibody. Immunohistochemical expression of oestrogen and progesterone receptors, Ki-67 (MIB-1), HER-2/neu, VEGF-A, VEGFR-1 and VEGFR-2 was analysed. Periostin expression was also investigated in MCF-7 and MDA-468 cell lines by immunohistochemistry, western blot and quantitative RT-PCR. Localisation of periostin was investigated in MCF-7 cells by the green fluorescent protein (GFP) approach.

Results:

Periostin was highly expressed in carcinoma cells, but not in normal breast tissues. The pattern of expression was mainly cytoplasmic. However, in 12% of cases a nuclear reactivity was observed. Nuclear periostin significantly correlated with tumour size, and with expression of oestrogen receptor, progesterone receptor, VEGF-A, VEGFR-1 and VEGFR-2. A nuclear localisation of periostin was also observed in MCF-7 and MDA-468 cell lines. In MCF-7 cells the nuclear localisation of periostin was also shown by transfection of a vector expressing a GFP-periostin chimeric protein.

Conclusions:

Results indicate that the aberrant gene expression of periostin in breast cancer cells is associated with an abnormal nuclear localisation of the protein. The nuclear localisation of periostin in breast cancer may induce significant biological effects.

Expression of periostin in human breast cancer: Biological and clinico-pathological correlations

21090

Background: Mesenchyme-specific genes are highly expressed by various types of human cancers. Recent lines of evidence suggest that periostin, a myoepithelial/basal gene, may play a role in the biology of breast cancer. Periostin is involved in metastatic process by taking part in mechanisms of adhesion and migration of epithelial cells. Furthermore, periostin seems to have a role in tumor angiogenesis through the up-regulation of vascular endothelial growth factor receptors in endothelial cells. We aimed at investigating the immunohistochemical expression of periostin in breast cancer and its correlation with established biological and prognostic factors. Methods: We performed immunohistochemical analysis of periostin in a consecutive series of 206 tumor samples from 200 patients with early breast carcinoma. To this aim, we used a specific antiperiostin antibody (Biovendor Laboratory Medicine, Inc., Palackeho 56, 612 00 Brno, Czech Republic). The intensity of immunoreactivity was scored as 0, 1, 2 or 3 denoting negative, weak, moderate and strong staining, respectively. Therefore, for statistical analysis, the periostin expression level for each case was putatively defined as positive if the predominant intensity was =1. We also analyzed immunohistochemical expression of Ki-67 (MIB-1), HER-2/neu, VEGF, VEGFR-1 and VEGFR- 2. Results: Periostin was found to be highly expressed by carcinoma cells, whereas it was absent in normal breast tissues. The pattern of expression was mainly cytoplasmic, although in some cases (11%) a nuclear reactivity was observed. A cytoplasmic expression was found in 108 out of 189 (57%) evaluable cases. Interestingly, a significant correlation was found between periostin expression and VEGF and VEGFR-1 (Spearman's rank test rho =0.37, p <0.0001 and rho=0.26, p=0.0005, respectively). Conclusions: These results strengthen the hypothesis of a relationship between periostin and vascular endothelial growth factor system. The role of periostin in angiogenesis and in other relevant molecular pathways in breast carcinoma deserves to be further investigated.

No significant financial relationships to disclose.

Anticancer treatment and cognitive functions in elderly cancer patients: A prospective study

8543

Background: It has been reported that anticancer treatment may alterate cognitive functions in cancer patients but very few prospective studied addressed this issue. Moreover, little is known about the cognitive impact of anticancer treatment in elderly cancer patients. We aimed at investigating the effect on cognitive functions of antiblastic chemotherapy and endocrine therapy in a consecutive series of elderly cancer outpatients. Methods: We evaluated cognitive functions by means of the Cambridge Cognitive Examination (CAMCOG) test and the Mini-Mental Scale Examination (MMSE) at baseline (before anticancer systemic treatment), after 3 months and after 6 months in cancer patients aged more than 65 years. Mood disturbances such as anxiety and depression were also evaluated (Hospital Anxiety and Depression Scale); comprehensive geriatric assessment and blood tests were performed at each evaluation. Results: Sixty patients were enrolled, 15 patients received chemotherapy (group 1), 13 patients received endocrine therapy (group 2) and 32 patients had neither chemotherapy nor endocrine therapy (group 3, control). Fifty-eight (97%) patients had no evidence of disease at the time of assessment. Median age was 71.5, 73 and 71 years in group 1, 2 and 3, respectively. At baseline, median Activities of Daily Living (ADL) score, Instrumental Activity of Daily Living (IADL) score, number of comorbidities and concomitant medications were 6, 8, 5, 1 in group 1, and 6, 8, 3, 2 in group 2, and 6, 8, 4, 2 in group 3, respectively. Median hemoglobin value was 12.9, 12.8, 13.3 g/dl in group 1, 2 and 3 respectively. At baseline, no significant unbalance was evident among groups. There was a statistically significant correlation between ADL or IADL score and CAMCOG total score (Spearman test, rho=0.4, p<0.05). Higher scolarity level was associated with higher CAMCOG total score. No deterioration of CAMCOG score was evident in group 1, 2 and 3 after 3 and 6 months (paired t-test p>.05); the separate analyses for the different items in CAMCOG test did not evidence any deterioration in time in the 3 groups. No worsening was seen in MMSE. Conclusions: Our study showed that anticancer treatment is not associated with rapid cognitive deterioration in elderly cancer patients.

No significant financial relationships to disclose.

Changes in thymidine phosphorylase expression in response to neoadjuvant chemotherapy for primary breast cancer

655

Background: Thymidine phosphorilase (TP) is a key enzyme involved in nucleoside metabolism. Recently, it has been hypothesized that TP modulation could enhance the therapeutic activity of TP-targeting chemotherapy such as capecitabine. In addition, some evidence exists that anticancer agents could upregulate TP. The present study analyzed TP immunohistochemical expression in response to neoadjuvant chemotherapy for primary breast cancer. Methods: Fifty-five women with operable breast cancer (T ≥ 2 cm, N0–1, M0) were treated with anthracycline-based (all cases) and anthracycline/taxane-based (n= 40 cases) neoadjuvant chemotherapy. Tumor samples from diagnostic large core biopsy (n=55) and from surgery (n=53) were available for histological evaluation and immunohistochemical analysis of TP. Immunohistochemistry was performed at a single central laboratory using a primary mouse anti-TP monoclonal antibody (Roche molecular biochemicals).TP expression was evaluated on tumor cells (nuclear and cytoplasmic staining) and on stromal cells. The intensity of cytoplasmic immunoreactivity was scored as 0, 1, 2 or 3 denoting negative, weak, moderate and strong staining, respectively. Results: An increase in TP cytoplasmic expression was observed in 35.89% (95% CI: 0.21–0.52%) of tumor samples after neoadjuvant chemotherapy. In particular, increases in cytoplasmic TP score were more common after taxane-containing regimens (40.74%, 95% CI: 0.22–0.61%) than after regimens without taxanes (25%, 95% CI: 0.05–0.57%). No significant changes of TP expression were found in nuclei of tumor cells after neoadjuvant chemotherapy. Similarly, no significant changes of TP expression were observed in stromal cells. There was no significant association between clinical or pathological response rate and TP changes in both tumor and stromal cells. Conclusions: This study provides further evidence that, at least in breast cancer, TP is upregulated after anthracycline and/or taxane-containing chemotherapy. According to these results, a strong rationale exists in combining TP-inducing and TP-targeting anticancer agents.

No significant financial relationships to disclose.

Comparison of mammography, sonography and MRI in patients receiving neoadjuvant chemotherapy for breast cancer: Final results of a prospective study

10538

Background: Imaging techniques used to evaluate response during neoadjuvant chemotherapy for breast cancer include mammography (Mx), sonography (US) and MRI. This study prospectively evaluated the ability of each technique to determine pathologic response in breast cancer patients undergoing neoadjuvant chemotherapy. Methods: Forty women with operable breast cancer (T ≥ 2 cm, N0–1, M0) were treated with four cycles of anthracycline-based and taxane-based neoadjuvant chemotherapy as part of a phase II clinical trial. The longest diameter of each tumor (n = 48 neoplastic foci) was measured by Mx, US and MRI at baseline, after two cycles and after 4 cycles of chemotherapy, before surgery. Tumor size at pathology was determined and considered as gold standard of response. Differences among techniques in measuring tumor diameters were evaluated by means of t-test. Results: At baseline, US provided statistically higher measures than Mx (mean difference: 6.3 mm, p < 0.0001) or MRI (mean difference: 5.6 mm, p < 0.0001). No difference was observed between Mx and MRI (mean difference: 0.59 mm, p = 0.5). After two cycles of chemotherapy, tumor diameter measured by US was significantly longer than that measured by Mx (mean difference: 8.8 mm, p < 0.0001) and significantly shorter than that measured by MRI (mean difference: −5.1 mm, p = 0.0009). Mx provided longer measures than MRI (mean difference: 4.4 mm, p = 0.0034). After four cycles of chemotherapy, US provided significantly shorter measures than Mx (mean difference: 11.8 mm, p < 0.0001) and MRI (mean difference: −3.3 mm, p = 0.007), whereas tumor size measured by Mx was significantly longer than that measured by MRI (mean difference: 6.75 mm, p = 0.0027). In addition, the tumor diameter measured by the pathologist was longer than that measured by US (mean difference: 2.6 mm, p = 0.09) and significantly shorter than that measured by Mx (mean difference: −7.8 mm, p < 0.0001). No statistically significant difference was observed between MRI and pathological measures (mean difference: −1.0, p = 0.5). Conclusions: This study provides further evidence that, among imaging techniques, MRI is the best method to evaluate the tumor size after neoadjuvant chemotherapy for breast cancer.

No significant financial relationships to disclose.

Baseline staging tests after a new diagnosis of breast cancer: further evidence of their limited indications

BACKGROUND

Bone scanning (BS), liver ultrasonography (LUS) and chest radiography (CXR) are commonly used in patients with newly diagnosed breast cancer as part of baseline staging. However, in the absence of symptomatic disease, the usefulness of this routine diagnostic work-up is not evidence-based.

METHODS

We selected the study sample from 516 consecutive patients with newly diagnosed invasive breast cancer. For each diagnostic test (BS, LUS, CXR), we analyzed the prevalence defined as the number of patients with diagnosis of metastatic disease after an imaging technique divided by the total number of patients tested. In addition, sensitivity and specificity were calculated. Initial suspicion was confirmed by other independent tests (bone X-ray, computerized tomography scan, magnetic resonance imaging) in order to identify "true" positive diagnoses.

RESULTS

At baseline, BS was carried out in 412 patients, LUS in 412 patients and CXR in 428 patients. Thirty-three patients were correctly diagnosed by the initial staging investigations as having metastatic disease (true positive cases). BS detected skeletal metastases in 6.31% of patients, LUS detected liver metastases in 0.72% of patients and CXR detected lung metastases in 0.93% of patients. Before imaging tests, all patients with either LUS or CXR evidence of metastases were previously classified as having stage III disease. On the other hand, only 26.9% of bone metastases were detected in patients with stage III. Accordingly, the detection rate in stage III patients was 14%, 5.6% and 7.2%, respectively for BS, LUS and CXR.

CONCLUSIONS

These findings indicate that a complete diagnostic work-up to detect metastases is unnecessary in the majority of patients with newly diagnosed breast cancer, whereas it may be indicated for specific patient categories such as those with stage III disease.