Plasmodium falciparum Drug Resistance Genes pfmdr1 and pfcrt In Vivo Co-Expression During Artemether-Lumefantrine Therapy

Background: Artemisinin-based combination therapies (ACTs) are the global mainstay treatment of uncomplicated Plasmodium falciparum infections. PfMDR1 and PfCRT are two transmembrane transporters, associated with sensitivity to several antimalarials, found in the parasite food vacuole. Herein, we explore if their relatedness extends to overlapping patterns of gene transcriptional activity before and during ACT administration.

Methods: In a clinical trial performed in Tanzania, we explored the pfmdr1 and pfcrt transcription levels from 48 patients with uncomplicated P. falciparum malaria infections who underwent treatment with artemether-lumefantrine (AL). Samples analyzed were collected before treatment initiation and during the first 24 h of treatment. The frequency of PfMDR1 N86Y and PfCRT K76T was determined through PCR-RFLP or direct amplicon sequencing. Gene expression was analyzed by real-time quantitative PCR.

Results: A wide range of pre-treatment expression levels was observed for both genes, approximately 10-fold for pfcrt and 50-fold for pfmdr1. In addition, a significant positive correlation demonstrates pfmdr1 and pfcrt co-expression. After AL treatment initiation, pfmdr1 and pfcrt maintained the positive co-expression correlation, with mild downregulation throughout the 24 h post-treatment. Additionally, a trend was observed for PfMDR1 N86 alleles and higher expression before treatment initiation.

Conclusion:pfmdr1 and pfcrt showed significant co-expression patterns in vivo, which were generally maintained during ACT treatment. This observation points to relevant related roles in the normal parasite physiology, which seem essential to be maintained when the parasite is exposed to drug stress. In addition, keeping the simultaneous expression of both transporters might be advantageous for responding to the drug action.

Minimizing inequality in access to precision medicine in breast cancer by real-time population-based molecular analysis in the SCAN-B initiative

BACKGROUND

Selection of systemic therapy for primary breast cancer is currently based on clinical biomarkers along with stage. Novel genomic tests are continuously being introduced as more precise tools for guidance of therapy, although they are often developed for specific patient subgroups. The Sweden Cancerome Analysis Network - Breast (SCAN-B) initiative aims to include all patients with breast cancer for tumour genomic analysis, and to deliver molecular subtype and mutational data back to the treating physician.

METHODS

An infrastructure for collection of blood and fresh tumour tissue from all patients newly diagnosed with breast cancer was set up in 2010, initially including seven hospitals within the southern Sweden regional catchment area, which has 1.8 million inhabitants. Inclusion of patients was implemented into routine clinical care, with collection of tumour tissue at local pathology departments for transport to the central laboratory, where routines for rapid sample processing, RNA sequencing and biomarker reporting were developed.

RESULTS

More than 10 000 patients from nine hospitals have currently consented to inclusion in SCAN-B with high (90 per cent) inclusion rates from both university and secondary hospitals. Tumour samples and successful RNA sequencing are being obtained from more than 70 per cent of patients, showing excellent representation compared with the national quality registry as a truly population-based cohort. Molecular biomarker reports can be delivered to multidisciplinary conferences within 1 week.

CONCLUSION

Population-based collection of fresh tumour tissue is feasible given a decisive joint effort between academia and collaborative healthcare groups, and with governmental support. An infrastructure for genomic analysis and prompt data output paves the way for novel systemic therapy for patients from all hospitals, irrespective of size and location.

Abstract P3-02-02: Concordance between immunohistochemical and gene-expression based subtyping of early breast cancer using core needle biopsies and surgical specimens - experices from SCAN-B

Introduction: Preoperative chemotherapy in early breast cancer increases the rate of breast preservation and provides prognostic information. Treatment decisions in these cases rely on biomarker assessments and subtyping from tissue acquired through core needle biopsies. Tumor heterogeneity and representativity are pit-falls when limited tissue is available. Biomarker expression may change considerably as a result of preoperative chemotherapy, and in a subset of cases a complete pathological response at time of surgery may even preclude any further assessment. Therefore, the reliability and reproducibility of biomarkers in base-line core biopsies are of utmost importance for patients treated with preoperative chemotherapy.

Material and Methods: In an ongoing population-based study of early breast cancer, the SCAN-B (NCT02306096), patients were identified for whom an ultra-sound guided core needle biopsy was analyzed for biomarkers during primary clinical work-up and the patient was offered primary surgery as initial treatment. Clinical biomarker profiles including immunohistochemical (IHC) determinations of ER, PgR, HER2 and Ki67 were translated to subtypes according to modified St Gallen criteria (2013) and compared with paired samples from surgical specimens. In addition, tumor specimens for biomolecule extraction and RNA sequencing were collected fresh in RNAlater.

Results: IHC data was available from 51 paired samples. The subtype distribution in core needle biopsies was DCIS in 1 case (2 %), LCIS in 1 case (2 %) Luminal A-like in 16 cases (31 %), Luminal B-like (HER2 negative) in 26 cases (51 %), Luminal B-HER2-like (HER2 positive) in 4 cases (8 %), HER2-positive (non-luminal) in 1 case (2 %) and triple negative (ductal) breast cancer in 2 cases (4 %). The subtype distribution in surgical specimens was DCIS in 0 case (0 %), LCIS in 1 case (2 %) Luminal A-like in 18 cases (35 %), Luminal B-like (HER2negative) in 23 cases (45 %), Luminal B--like (HER2 positive) in 6 cases (12 %), HER2-positive (non-luminal) in 1 case (2 %) and triple negative (ductal) breast cancer in 2 cases (4 %). Notably, 5/16 cases classified as Luminal A-like in the core needle biopsy were reclassified as Luminal B-like (HER2-negative) in the surgical specimen, whereas 9/26 cases classified as Luminal B-like (HER2-negative) in the core needle biopsy were reclassified as either Luminal A-like (7 cases) or Luminal B-like (HER2 positive) (2 cases) in the surgical specimen. In all instances, except one, transition between Luminal A-like and Luminal B-like was due to recorded Ki67 expression. One case that was classified as a DCIS in the core needle was reclassified as Luminal B-like (HER2 negative) at time of surgery.

Discussion: In this limited material, discordance between evaluations regarding Luminal A-like and Luminal B-like was considerable. Especially the misclassification of primary HER2-positive breast cancer needs further evaluation. These findings may be caused by tumor heterogeneity, and highlight the risk of both over- and under-treatment upon biomarker assessment from core needle biopsies. Data from gene expression based subtype classifications will be presented during the meeting.

Citation Format: Morgan G, Larsson C, Tahin B, Vallon-Christersson J, Häkkinen J, Ehinger A, Malmberg M, Hegardt C, Borg Å, Rydén L, Saal LH, Hedenfalk I, Loman N. Concordance between immunohistochemical and gene-expression based subtyping of early breast cancer using core needle biopsies and surgical specimens - experices from SCAN-B [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-02-02.

Abstract P1-06-01: Putting multigene signatures to the test: Prognostic assessment in population-based contemporary clinical breast cancer

Background

Gene expression signatures hold promise for a molecularly driven division of primary breast cancer with clinical implications. A gap still remains in the application/validation of such signatures in actual clinical treatment groups from unselected, population-based, primary breast cancer receiving current standard of care therapy. We analyzed classification proportions and overall survival (OS) of 14 reported gene expression phenotypes (GEPs) and risk predictors (RPs) in seven clinical treatments groups from an 3273-sample breast cancer cohort representative of population-based disease in the South Swedish healthcare region.

Patients and methods

Between 2010-09-01 to 2015-03-31, 5101 (87%) of 5892 patients with invasive primary disease in the healthcare region were included in the SCAN-B study (ClinicalTrials.gov ID: NCT02306096). Inclusion criteria included no generalized/prior contralateral disease and known surgery/treatment status (neo- or adjuvant). 3273 tumors were profiled by RNA sequencing and matched to clinicopathological patient data from the National Breast Cancer Register, with distribution of clinicopathological characteristics reflecting proportions in the catchment region. RNA profiles were classified according to 14 reported gene signatures featuring both GEPs (PAM50, IC10, CIT, TNBCtype) and specific risk predictors (e.g. Oncotype Dx, 70-gene, 76-gene, ROR-variants, genomic grade index). Classifications were investigated for association with patient OS by univariate and multivariate analyses in seven adjuvant clinical treatment groups: TNBC-ACT (adjuvant chemotherapy, n=228), TNBC-untreated (n=83), HER2+/ER- with trastuzumab + ACT treatment (n=101), HER2+/ER+ with trastuzumab + ACT + endocrine treatment (n=210), ER+/HER2- with endocrine treatment (n=1477), ER+/HER2- with endocrine + ACT treatment (n=637), and ER+/HER2- untreated (n=216).

Results

For the majority of signatures, analysis of classification demonstrated prognostic value limited to ER+/HER2- tumors given follow-up time. Several signatures (including Oncotype Dx, 70-gene, ROR-variants) showed strong predictive value in identifying a subset of ER+/HER2- patients receiving a combination of endocrine and ACT therapy with excellent overall survival (>96%), indicating appropriate therapy selection. In addition, for both ER+/HER2- treatment groups signature analysis identified high-risk groups of patients in clear need of additional treatment beyond standard therapeutic regimes, even with less than 5-years of follow-up.

Conclusions

Our results support the prognostic association of gene expression signatures in large unselected population-based primary breast cancer cohorts even with a short follow-up of OS.Importantly, prognostic associations are limited to specific subgroups for different classifiers and in population-based breast cancer some clinically important subgroups constitute a small proportion of cases. In this context, continued population-based inclusion and broad transcriptional profiling of breast cancer patients provides an opportunity for application to broader patient groups (e.g. TNBC and HER2+), and for consensus classification of individual risk assessments that could potentially provide more stable predictions.

Citation Format: Staaf J, Vallon-Christersson J, Häkkinen J, Saal LH, Hegardt C, Larsson C, Ehinger A, Ryden L, Loman N, Malmberg M, Borg Å. Putting multigene signatures to the test: Prognostic assessment in population-based contemporary clinical breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-06-01.

Abstract P2-02-09: Breast cancer subtype distribution and circulating tumor DNA in response to neoadjuvant chemotherapy: Experiences from a preoperative cohort within SCAN-B

Introduction: Preoperative chemotherapy in early breast cancer increases the rate of breast preservation and provides prognostic information. In the case of residual disease, a change in subtypes may be observed. Sensitive and reproducible biomarkers predicting treatment response early during the treatment course are needed in order to better exploit the potential benefit of an individualized preoperative treatment.

Material and Methods: In an ongoing prospective study within the population-based SCAN-B project (NCT02306096), patients undergoing preoperative chemotherapy for early or locally recurrent breast cancer have been treated with iv Epirubicin and Cyclophosphamide q3w x 3 in sequence with either Docetaxel q3w x 3 or Paclitaxel q1w x 9 with a preoperative intent. HER2-positive cases also received HER2-directed treatment. At baseline, patients were staged using sentinel node biopsy for clinically node-negative patients and CT scan for cytologically confirmed node-positive cases. A clinical core needle biopsy as well as tissue from the surgical specimen was collected for determination of conventional biomarkers including ER, PgR, HER2 and Ki67. Tumor biopsies for biomolecule-extraction and RNA-sequencing were taken using ultrasound guidance and collected fresh in RNAlater at baseline, after 2 treatment cycles, as well as at surgery. Blood plasma samples were collected at baseline, after one-, three-, and six- 3w treatment cycles, and post-surgery. Using RNA-sequencing data, somatic mutations were identified in the tumor biopsies and personalized analyses for circulating tumor DNA (ctDNA) were performed. A pathological complete remission (pCR) was defined as the complete disappearance of invasive breast cancer in the breast and axilla at time of definitive surgery. Subtyping was performed using modified St Gallen criteria (2013).

Results: Thus far, 45 patients aged 24-74 years have been included, of which 34 (76 %) were clinical stage 2 and 11 (24%) were stage 3. The subtype distribution at baseline was five Luminal A-like (11 %), 21 Luminal B-like (HER2 negative) (47 %), 8 HER2-positive (18 %) and 11 Triple-negative (ductal) (24 %). The rates of pCR in 38 operated cases to date were 0/3 Luminal A-like, 3/19 Luminal B-like (HER2 negative), 2/8 HER2-positive, and 4/7 Triple-negative (overall 24 % pCR rate). One patient did not undergo surgery due to clinically progressive disease. In 25 cases with evaluable residual disease at surgery, there was a shift in the subtype in 13 (52 %), the majority of which represented a transition from Luminal B to Luminal A. No Triple-negative cases underwent a change in subtype during treatment. Results of the ctDNA analyses will be presented at the meeting.

Discussion: We have established an infrastructure allowing for an extensive evaluation of preoperative chemotherapy in early breast cancer. The goal is to develop methods to refine response-guided treatment in early breast cancer using molecular responses in the tumor as well as in the blood circulation. The patients continue to be prospectively monitored with iterative ctDNA analyses during follow-up.

Citation Format: Loman N, Chen Y, Aaltonen K, Brueffer C, George AM, Zander L, Vallon-Christersson J, Häkkinen J, Förnvik D, Rigo R, Ehinger A, Malmberg M, Larsson C, Hegardt C, Borg Å, Rydén L, Saal LH. Breast cancer subtype distribution and circulating tumor DNA in response to neoadjuvant chemotherapy: Experiences from a preoperative cohort within SCAN-B [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-02-09.

Abstract P4-09-03: On the development and clinical value of RNA-sequencing-based classifiers for prediction of the five conventional breast cancer biomarkers: A report from the population-based multicenter SCAN-B study

Background:

In early breast cancer, five histopathological biomarkers are part of current clinical routines and used for determining prognosis and treatment: estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (ERBB2/HER2), Ki67, and Nottingham histological grade (NHG). We aimed to develop classifiers for these biomarkers based on tumor mRNA-sequencing (RNA-seq), compare classification performance to conventional histopathology, and test whether RNA-seq-based predictors could add value for patient risk-stratification.

Patients and Methods:

In total, 3678 breast tumors were studied. For 405 breast tumors in the training cohort, a comprehensive histopathological biomarker evaluation was performed by three pathology readings to estimate inter-pathologist variability on the original diagnostic slides as well as on repeat immunostains for this study, and the consensus biomarker status for all five conventional biomarkers was determined. Whole transcriptome gene expression profiling was performed by RNA-sequencing on the Illumina platform. Using RNA-seq-derived tumor gene expression data as input, single-gene classifiers (SGC) and multi-gene classifiers (MGC) were trained on the consensus pathology biomarker labels. The trained classifiers were tested on an independent prospective population-based series of 3273 primary breast cancer cases from the multicenter SCAN-B study with median 41 months follow-up (ClinicalTrials.gov identifier NCT02306096), and classifications were evaluated by agreement statistics and by Kaplan-Meier and Cox regression survival analyses.

Results:

For the histopathological evaluation, pathologist evaluation concordance was high for ER, PgR, and HER2 (average kappa values of .920, .891, and .899, respectively), but moderate for Ki67 and NHG (.734 and .581). Classification concordance between RNA-seq classifiers and histopathology for the independent 3273-cohort was similar to that within histopathology assessments, with SGCs slightly outperforming MGCs. Importantly, patients with discordant results, classified as hormone responsive (HoR+) by histopathology but non-hormone responsive by MGC, presented with significantly inferior overall survival compared to patients with concordant results. These results extended to patients with no adjuvant systemic therapy (hazard ratio, HR, 4.54; 95% confidence interval, CI, 1.42-14.5), endocrine therapy alone (HR 3.46; 95% CI, 2.01-5.95), or receiving chemotherapy (HR 2.57; 95% CI 1.13-5.86). For HoR+ cases receiving endocrine therapy alone, the MGC HoR classifier remained significant after multivariable adjustment (HR 3.14; 95% CI, 1.75-5.65).

Conclusions:

RNA-seq-based classifiers for the five key early breast cancer biomarkers were generally equivalent to conventional histopathology with regards to classification error rate. However, when benchmarked using overall survival, our RNA-seq classifiers provided added clinical value in particular for cases that are determined by histopathology to be hormone-responsive but by RNA-seq appear hormone-insensitive and have a significantly poorer outcome when treated with endocrine therapy alone.

Citation Format: Brueffer C, Vallon-Christersson J, Grabau D, Ehinger A, Häkkinen J, Hegardt C, Malina J, Chen Y, Bendahl P-O, Manjer J, Malmberg M, Larsson C, Loman N, Ryden L, Borg Å, Saal LH. On the development and clinical value of RNA-sequencing-based classifiers for prediction of the five conventional breast cancer biomarkers: A report from the population-based multicenter SCAN-B study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-09-03.

Abstract P1-07-16: Multi-level gene expression signatures provide significant prognostic information in metastatic breast cancer patients

Background: We have previously demonstrated how transcriptional pathway activity and the molecular subtypes of breast cancer metastases significantly influence patient post-relapse survival. Here we extend our analysis to determine whether the prognostic information provided by gene expression signatures in primary breast tumours is also relevant in the metastatic setting. Specifically, we test the research versions of the Genomic Grade Index (GGI), Mammaprint, Recurrence score (RS) and PAM50 gene signatures along with our own cell-cycle based classifier (CCS).

Methods: 287 patients with morphologically confirmed loco-regional or distant breast cancer relapse were enrolled in the Swedish multicenter TEX trial from December 2002 until June 2007. Of these, sufficient tumour RNA for gene expression profiling was obtained from metastatic tissue by fine needle aspiration from 111 patients (totalling 120 relapse biopsies). Gene signatures were applied as described in the original research articles and their relationship to short (1.5 year) and long-term (5 year) post-relapse survival was assessed using likelihood ratio, Kaplan-Meier and Cox regression analysis.

Results: As anticipated from an aggressive metastatic cohort, the majority of samples (> 70%) were classified into intermediate or high risk groups by all signatures. In both short and long-term survival analysis only PAM50 provided statistically significant prognostic information (short: LRχ2 = 14.7, p = 0.005 and long: LRχ2 = 13.2, p = 0.010), with the cell cycle score signature displaying a prognostic trend in long-term survival only (LRχ2 = 5.2, p = 0.074). Kaplan-Meier curves and Cox regression analysis suggest that the strength of both signatures resides in their ability to select a group of low-risk patients with better long-term survival.

Conclusions: Our findings demonstrate the prognostic utility of the multi-level PAM50 and to a lesser extent, cell cycle score signatures in predicting survival of patients with metastatic breast cancer. Simpler binary gene expression signatures (GGI and Mammaprint) do not appear to capture the same prognostic information and as such may have limited utility in a metastatic setting.

Short and long term survival Likehood Ratios for five gene expression signatures in metastatic breast cancer Short term survival (1.5 year)Long term survival (5 year)Gene SignatureLRχ2P-valueLRχ2P-valueGGI1.30.2510.50.500Mammaprint1.70.1900.60.427RS3.90.1434.40.110CCS2.80.2425.20.074PAM5014.70.00513.20.010GGI: Genomic grade index; RS: Recurrence score; CCS: Cell cycle score

Citation Format: Tobin NP, Lundberg A, Lindström LS, Harrell JC, Egyhazi Brage S, Frostvik Stolt M, Einbeigi Z, Loman N, Malmberg M, Perou CM, Bergh J, Hatschek T. Multi-level gene expression signatures provide significant prognostic information in metastatic breast cancer patients [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 P1-07-16.

Abstract P1-07-17: The SCAN-B study: 5-year summary of a large-scale population-based prospective breast cancer translational genomics platform covering a wide geography of Sweden (NCT02306096)

Background:

Breast cancer exhibits significant molecular, pathological, and clinical heterogeneity. Current clinicopathological evaluation is imperfect for predicting outcome, which results in overtreatment for many patients, and for others, leads to death from recurrent disease. Therefore, additional criteria are needed to better personalize care and maximize treatment effectiveness and survival. To address these challenges, large-scale population-based studies are needed to develop and evaluate new predictive biomarker tests under real-world conditions.

Methods:

In 2010 we initiated the Sweden Cancerome Analysis Network - Breast (SCAN-B) multicenter prospective study (ClinicalTrials.gov identifier NCT02306096) with longsighted aims to 1) analyze breast cancers with next-generation genomic technologies for translational research in a population-based manner and integrated with healthcare; 2) decipher fundamental tumor biology from these analyses; 3) utilize genomic data to develop and validate new clinically-actionable biomarker assays; and 4) establish real-time clinical implementation of molecular diagnostic and treatment-predictive tests. Eligibility criteria are suspicion or confirmed diagnosis of primary breast cancer. Eligibility will be extended to recurrent breast cancer in late 2016. For all patients, tumor biopsy and/or surgical tumor specimen and baseline blood samples are collected, as well as follow-up blood samples at defined intervals, and clinical data are obtained from regional and national databases. From all samples, DNA, RNA, and protein fractions are isolated, and tissue arrays are constructed. In the first phase, we focus on molecular profiling of tumor tissue by next-generation RNA-sequencing.

Results:

From August 2010 through May 2016, we have consented and enrolled 8,669 patients with primary breast cancer at 9 hospital sites in Sweden, representing approximately 85% of eligible patients in the catchment area. Preoperative blood samples have been collected for 8,288 (96%) patients and primary fresh-frozen tumor specimens collected for 6,129 (71%) patients. All tumors have been RNA-sequenced, and newly enrolled cases are analyzed in “real-time” within an average of 7 days after biopsy/surgery. Herein we describe the study infrastructure and protocols and present initial proof of concept results from prospective RNA-sequencing including tumor molecular subtyping, detection of driver gene mutations, and determination of ER, PgR, HER2, Ki67, and tumor grade from RNA-seq data. Prospective patient enrollment is ongoing and pilot clinical reports are being evaluated at multidisciplinary breast cancer conferences.

Conclusions:

We demonstrate that population-based collection and real-time RNA-sequencing analysis of breast cancer is feasible at large-scale. The SCAN-B Study should significantly reduce the time to discovery, validation, and clinical implementation of novel molecular diagnostic and predictive tests. We welcome the participation of additional comprehensive cancer treatment centers.

Citation Format: Saal LH, Hegardt C, Vallon-Christersson J, Häkkinen J, Ehinger A, Manjer J, Larsson C, Loman N, Rydén L, Malmberg M, Borg Å. The SCAN-B study: 5-year summary of a large-scale population-based prospective breast cancer translational genomics platform covering a wide geography of Sweden (NCT02306096) [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 P1-07-17.

Targeted sequencing of BRCA1 and BRCA2 across a large unselected breast cancer cohort suggests that one-third of mutations are somatic

We carried out targeted sequencing of BRCA1/2 in an unselected cohort of patients diagnosed with primary breast cancer within a population without strong founder mutations. Eleven percent of cases harbored a germline or somatic BRCA1/2 mutation, and the ratio of germline versus somatic mutation was 2 : 1. This has implications for treatment, genetic counseling, and interpretation of tumor-only testing.

Background

A mutation found in the BRCA1 or BRCA2 gene of a breast tumor could be either germline or somatically acquired. The prevalence of somatic BRCA1/2 mutations and the ratio between somatic and germline BRCA1/2 mutations in unselected breast cancer patients are currently unclear.

Patients and methods

Paired normal and tumor DNA was analyzed for BRCA1/2 mutations by massively parallel sequencing in an unselected cohort of 273 breast cancer patients from south Sweden.

Results

Deleterious germline mutations in BRCA1 (n = 10) or BRCA2 (n = 10) were detected in 20 patients (7%). Deleterious somatic mutations in BRCA1 (n = 4) or BRCA2 (n = 5) were detected in 9 patients (3%). Accordingly, about 1 in 9 breast carcinomas (11%) in our cohort harbor a BRCA1/2 mutation. For each gene, the tumor phenotypes were very similar regardless of the mutation being germline or somatically acquired, whereas the tumor phenotypes differed significantly between wild-type and mutated cases. For age at diagnosis, the patients with somatic BRCA1/2 mutations resembled the wild-type patients (median age at diagnosis, germline BRCA1: 41.5 years; germline BRCA2: 49.5 years; somatic BRCA1/2: 65 years; wild-type BRCA1/2: 62.5 years).

Conclusions

In a population without strong germline founder mutations, the likelihood of a BRCA1/2 mutation found in a breast carcinoma being somatic was ∼1/3 and germline 2/3. This may have implications for treatment and genetic counseling.

Molecular subtype and tumor characteristics of breast cancer metastases as assessed by gene expression significantly influence patient post-relapse survival

BACKGROUND

We and others have recently shown that tumor characteristics are altered throughout tumor progression. These findings emphasize the need for re-examination of tumor characteristics at relapse and have led to recommendations from ESMO and the Swedish Breast Cancer group. Here, we aim to determine whether tumor characteristics and molecular subtypes in breast cancer metastases confer clinically relevant prognostic information for patients.

PATIENTS AND METHODS

The translational aspect of the Swedish multicenter randomized trial called TEX included 111 patients with at least one biopsy from a morphologically confirmed locoregional or distant breast cancer metastasis diagnosed from December 2002 until June 2007. All patients had detailed clinical information, complete follow-up, and metastasis gene expression information (Affymetrix array GPL10379). We assessed the previously published gene expression modules describing biological processes [proliferation, apoptosis, human epidermal receptor 2 (HER2) and estrogen (ER) signaling, tumor invasion, immune response, and angiogenesis] and pathways (Ras, MAPK, PTEN, AKT-MTOR, PI3KCA, IGF1, Src, Myc, E2F3, and β-catenin) and the intrinsic subtypes (PAM50). Furthermore, by contrasting genes expressed in the metastases in relation to survival, we derived a poor metastasis survival signature.

RESULTS

A significant reduction in post-relapse breast cancer-specific survival was associated with low-ER receptor signaling and apoptosis gene module scores, and high AKT-MTOR, Ras, and β-catenin module scores. Similarly, intrinsic subtyping of the metastases provided statistically significant post-relapse survival information with the worst survival outcome in the basal-like [hazard ratio (HR) 3.7; 95% confidence interval (CI) 1.3-10.9] and HER2-enriched (HR 4.4; 95% CI 1.5-12.8) subtypes compared with the luminal A subtype. Overall, 25% of the metastases were basal-like, 32% HER2-enriched, 10% luminal A, 28% luminal B, and 5% normal-like.

CONCLUSIONS

We show that tumor characteristics and molecular subtypes of breast cancer metastases significantly influence post-relapse patient survival, emphasizing that molecular investigations at relapse provide prognostic and clinically relevant information. CLINICALTRIALS.GOV: This is the translational part of the Swedish multicenter and randomized trial TEX, clinicaltrials.gov identifier nct01433614 (http://www.clinicaltrials.gov/ct2/show/nct01433614).

Serum thymidine kinase activity compared with CA 15-3 in locally advanced and metastatic breast cancer within a randomized trial

The primary objective was to estimate serum thymidine kinase 1 (TK1) activity, reflecting total body cell proliferation rate including cancer cell proliferation, in women with loco regional inoperable or metastatic breast cancer participating in a prospective and randomized study. Secondary objectives were to analyze TK1 in relation to progression-free survival (PFS), overall survival (OS), therapy response and other tumour characteristics, including CA 15-3, widely used as a standard serum marker for disease progression. TK1 and CA 15-3 were analysed in 198 serum samples collected prospectively from women included in the randomized TEX trial between December 2002 and June 2007. TK1 activity was determined by the ELISA based DiviTum™ assay, and CA 15-3 analyses was generated with the electrochemiluminescence immunoassay Cobas Elecsys CA 15-3 II. High pre-treatment TK1 activity predicted shorter PFS (10 vs. 15 months p = 0.02) and OS (21 vs. 38 months, p < 0.0001), respectively. After adjustment for age, metastatic site and study treatment TK1 showed a trend as predictor of PFS (p = 0.059) and was an independent prognostic factor for OS, (HR 1.81, 95 % confidence interval (CI) 1.26-2.61, p = 0.001). There was a trend of shortened OS for women with high CA 15-3 (p = 0.054) in univariate analysis, but not after adjustment for the above mentioned covariates. Both TK1 (p = 0.0011) and CA 15-3 (p = 0.0004) predicted response to treatment. There were statistically different distributions of TK1 and CA 15-3 in relation to the site of metastases. TK1 activity measured by DiviTum™ predicted therapy response, PFS and OS in loco regional inoperable or disseminated breast cancer. These results suggest that this factor is a useful serum marker. In the present material, a prognostic value of CA 15-3 could not be proven.

Abstract P1-05-07: Prognostic relevance of Claudin-2 expression in metastatic breast cancer

The site of relapse is known to be a strong prognostic factor of survival from metastatic breast cancer. The liver is the third most frequent site affected and patients with hepatic metastases have an inferior prognosis relative to patients with bone and lung metastases. Predicting the likelihood of liver metastasis after adjuvant therapy of primary breast cancer is challenging. The aim of this study was to identify and characterize genes associated with breast cancer liver metastases. We thus performed global transcriptional profiling of 120 metastatic lesions from different anatomical sites from breast cancer patients enrolled in a randomized clinical trial1 and found that while the expression of other matrix remodelling and tight-junction molecules was down-regulated in liver metastases, Claudin-2 (CLDN2) was significantly up-regulated (p = 0.001). Furthermore, high expression of CLDN2 was also observed amongst patients diagnosed with a liver metastasis, irrespective of the specific site of the metastasis that was profiled, compared to patients without hepatic metastases (p = 0.001). We further investigated the prognostic significance of CLDN2 protein expression by immunohistochemical staining of primary tumours and matched lymph node metastases from a larger cohort of patients (n∼200) with metastatic breast cancer. We found CLDN2 to be significantly more frequently expressed in lymph node metastases compared to primary tumours (p = 0.013). Also, consistent with mRNA expression levels, more frequent expression of CLDN2 protein was observed in the primary tumours of patients who eventually developed a liver metastasis (p = 0.027). Interestingly, high expression of CLDN2 in the primary tumour was associated with a shorter time to recurrence (p = 0.032). Specifically, high expression of CLDN2 in the primary tumour was associated with a shorter progression to liver metastasis (p = 0.002). These data highlight a potential role of CLDN2 in the development and prognosis of breast cancer liver metastases.

1. Hatschek, T., et al. Individually tailored treatment with epirubicin and paclitaxel with or without capecitabine as first-line chemotherapy in metastatic breast cancer: a randomized multicenter trial. Breast Cancer Res Treat. 2012, 131(3):939–47.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-05-07.

Cardiomyocyte apoptosis after cardioplegic ischemia: comparison to unprotected regional ischemia-reperfusion

BACKGROUND

Cardiomyocyte apoptosis might contribute to left ventricular (LV) dysfunction following cardiac surgery. Magnetic resonance imaging is considered the most accurate method of determining LV function. We compared apoptosis (by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, TUNEL, staining and detection of caspase 3 activation) and LV function after regional ischemia-reperfusion (I-R) and global cardioplegic ischemia.

METHODS

Pigs were randomized to undergo regional myocardial I-R for 20 + 20 min, global myocardial ischemia with cardiopulmonary bypass (CPB) for 40 min or CPB without ischemia (control), followed by 274 min of reperfusion.

RESULTS

Compared with the control group, the number of TUNEL-positive cardiomyocytes was higher in the global ischemia group with CPB (0.024 ± 0.014%; p = 0.02) and further increased in areas of unprotected regional I-R (0.444 ± 0.562%; p = 0.003, vs. control). Myocytes with active caspase 3 were detected after global and regional ischemia. The global ejection fraction did not differ between CPB and regional I-R groups.

CONCLUSIONS

The use of cardioplegia and CPB efficiently protects the heart from global I-R-induced cardiomyocyte apoptosis during open heart surgery.

Validation of the predictive value of tissue inhibitor of metalloproteinases-1 for the response to first-line chemotherapy in metastatic breast cancer

Abstract #6057

*Würtz SØ and Klintman M contributed equally, Malström P and Brünner N shares the senior authorship.&#x2028; Background. Predictive markers are scarcely represented in breast cancer. TIMP-1 has in a previous study (n = 173) performed in our laboratory been shown to carry predictive information for the response to chemotherapy in metastatic breast cancer as high tumor tissue levels of TIMP-1 were significantly associated with a low objective response rate to treatment with the most frequently used chemotherapeutic drugs (CMF or anthracyclines). The purpose of the present study was to validate these previous results with a new independent patient population.&#x2028; Methods. The TIMP-1 level was measured using a validated ELISA in 168 primary tumor extracts from patients with metastatic breast cancer and levels were associated with the objective response to CMF and anthracyclines. Patients were included in the study provided that they had received chemotherapy for their metastatic disease and that frozen tumor tissue as well as data on their objective response to chemotherapy was available.&#x2028; Results. The median TIMP-1 level in responders was 17.3 (2.9 – 75.8) ng TIMP-1/mg protein and in non-responders it was 19.6 (0-190.3) ng TIMP-1/mg protein. When analysed as a continuous log-transformed variable, increasing tumor levels of TIMP-1 were associated with a decreasing probability of objective response to CMF or anthracyclines (OR = 1.59, 95% CI: 0.97 – 2.62, p = 0.07). This is very similar to the original study and thus supporting previous data. Next, we used a more clinically relevant approach for analysing the data from the validation study. For this analysis, objective response was scored as complete or partial response versus stable disease lasting at least six months (clinical benefit) versus progressive disease (non-response). This analysis showed that increasing levels of TIMP-1 were associated with a poor clinical benefit rate from chemotherapy (OR = 1.56, 95% CI: 0.98 - 2.51, p=0.06). The original study has not previously been analysed using this endpoint. When performing this analysis, similar results were found (OR = 1.62, 95% CI: 1.06 - 2.48, p = 0.02). Combining the new population and the original population in a pooled analysis (n = 341) using a random effects model showed that high levels of TIMP-1 were highly significantly associated with a poor clinical benefit rate from chemotherapy compared with patients with low levels (OR = 1.59, 95% CI: 1.16 - 2.18, p=0.003).&#x2028; Conclusion. The present validation study supports previous findings that primary tumor tissue levels of TIMP-1 carries predictive information in metastatic breast cancer treated with chemotherapy.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6057.

Paclitaxel, Epirubicin and Capecitabine (TEX) as First-Line Treatment for Metastatic Breast Cancer: a Pilot Phase I/II Feasibility Study

Thirteen patients with untreated metastatic breast cancer received epirubicin 60 mg/m(2), paclitaxel 155 mg/m(2) (both day 1) and capecitabine 665 mg/m(2) twice daily (days 1-14) every 21 days, with intra-patient dose escalation/reduction. Grade 3/4 events were infrequent. Nine patients (69%) achieved an objective response. Median time to progression and overall survival were 6.6 and 23.5 months, respectively.

Dog allergen in indoor air and dust during dog shows

BACKGROUND AND METHODS

Dog dander is one of the most important indoor allergens in Nordic countries. Due to the population flow into cities, the number of dogs in urban areas has increased. Dog allergens can be found practically everywhere indoors. We measured allergen content in indoor air and dust during dog shows.

RESULTS

In facilities used for dog shows, the dog allergen content was exceptionally high, up to 2,100,000 ng Can f 1/g dust, but it can be reduced by proper cleaning. The efficiency of cleaning will remain poor if furniture and textiles are not cleaned or the distribution of airborne allergen cannot be prevented.

CONCLUSIONS

Dog shows should not be held in public facilities, such as schools, where a significant proportion of occupants are hypersensitive to dog allergens and may therefore suffer symptoms due to the exposure to dog dander.

A pharmacokinetic study of 5-FU/leucovorin and alpha-interferon in advanced cancer

The present study was designed to study 5-FU pharmacokinetics after interferon. Weekly bolus 5-FU (500 mg/m2), immediately followed by leucovorin (60 mg/m2) was given in 14 weekly cycles to 55 gastrointestinal and breast cancer patients. Interferon-alpha was given on days 2, 4 and 6, starting from cycle 2 at a dose of 0.5 million units (MU) and stepwise increased to 12 MU in cycles 12 and 13. Five patients could not tolerate the treatment even at the lowest dose of interferon and 22 patients were unavailable for the pharmacokinetic analysis because of dose reductions of 5-FU. Five patients were able to follow the protocol to 12 MU, whereas most patients were unable to continue owing to toxicity. 5-FU pharmacokinetics was analysed every second cycle. Peak concentration and AUC were increased after 12 MU of interferon, but no other significant influence of interferon on pharmacokinetic parameters of 5-FU was observed.

Computerized image-analysis quantitation of heterogeneity of response in k562 human leukemia-cells after methotrexate exposure

Methotrexate (MTX) induces a concentration-dependent accumulation of cells in S-phase, an increase in average cell size and RNA and protein content ('unbalanced growth') and finally induces cell death. Even after high-dose MTX treatment, however, some cells escape the drug effect and this heterogeneity in response may play a major role in therapeutic outcome. We investigated heterogeneity in the response of K562 human leukemia cells, which exhibited population characteristics of unbalanced growth when treated with MTX, including a concentration-dependent increase in average-cell size and a block in S-phase of the cell cycle that correlated with growth inhibition. To investigate for the first time the response to MTX at the individual cell level, an individual colony formation assay (iCFA) was used. The iCFA revealed marked heterogeneity in both untreated K562 cells and their response to MTX treatment, as well as distinctive features of the response. Colonies of untreated K562 cells grew logarithmically with modal doubling times of 21.9 h (compared to 18.8+/-1.1 h in suspension culture), but there was over a 2-fold range of doubling times for individual cells. In addition, there was heterogeneity in the size of individual untreated K562 cells. Following MTX treatment, the iCFA detected shifts in the growth rate that were not detected in suspension culture and also drug-induced increased heterogeneity in growth rates at relatively nontoxic MTX concentrations. More importantly, the iCFA demonstrated that at a MTX concentration where no cells reproduced sufficiently to reach the threshold necessary to be counted as a colony, continued slow, logarithmic growth of a number of individual cells was observed. Thus, in addition to cytotoxicity, growth slow-down was a major effect exhibited in K562 cells treated with MTX. There was no correlation between MTX-induced unbalanced growth (as indicated by an increase in individual cell size) and the proliferative capacity of each cell. At cytotoxic MTX concentrations, there were individual cells that showed dramatically increased cell size but continued to proliferate, while other cells did not enlarge, but were still killed. These data show directly for the first time that the increase in cell size following MTX treatment is not likely to be the primary mechanism of cell kill. Similar changes were observed with gamma-fluoromethotrexate (FMTX), an MTX analog which is deficient in polyglutamylation. Since FMTX caused similar effects to MTX, we conclude that under these conditions poly(gamma-glutamate) synthesis is not the most significant factor in producing the observed effects in K562 cells. These results point out the utility of this approach as an alternative to the plating efficiency assay in order to identify approaches to arrest the growth of cells escaping primary drug effects.

Effect of doxorubicin, daunorubicin, and idarubicin on the growth rate of human leukemia cells (K562) studied with image analysis

The effects of doxorubicin, daunorubicin, and idarubicin on the growth of K562 cells were investigated by monitoring the formation of individual colonies in semi-solid culture employing an automated image analysis system. Drug effects were evaluated using short-term exposure (2 h) at clinically achievable drug plasma concentrations. Following drug exposure, heterogeneity in growth patterns was observed which was categorized into three distinct types; (1) continuous growth at a decreased growth rate; (2) limited growth; (3) no growth. In addition to a concentration-dependent decrease of the growth fraction, a reduction of the growth rate of the continuously growing colonies was observed. At equitoxic drug concentrations, comparable changes in growth rate were observed for each of the three anthracyclines studied. It is demonstrated that the fraction of cells which escape drug-induced growth arrest with therapeutically achievable drug concentrations display a significant decrease in growth rate.

Growth slow-down and growth arrest of human colon carcinoma cells HCT-8 in vitro after exposure to 5-fluoro-2'-deoxyuridine

Cellular heterogeneity in drug response denotes a mixed response among individual cells in a drug treated population. Individual cell responses may be more complex than 'cell kill' and 'no response'. In this study we employed a colony formation assay and high-resolution image analysis to detect the various responses such as immediate and delayed cessation of growth, growth delay and growth slow-down, at the level of the individual colony. The evaluation was carried out using a human ileocaecal adenocarcinoma cell line (HCT-8) and the anti-tumour agent 5-fluoro-2'-deoxyuridine (FdUrd). In the presence of a drug concentration which, in standard monolayer assays, inhibits the growth to about 50% (IC50) only about 20% of the colonies ceased to grow and the remaining colonies grew at a growth rate of about 70% of control. At an FdUrd concentration which, in standard monolayer assays, reduced growth by > 90% (> IC90), about 50% of the cells grew, with growth rates of about 30% of control. The slowing of growth, most prominent at lower drug concentrations, should be considered in determining mechanisms of drug action at the individual cell level. In clinical situations in which high drug doses are precluded by toxicity to normal tissues, growth slow-down may play a significant role in tumour response.

Characterization of tumor cell heterogeneity of a murine leukemia cell line (L1210) in response to arabinosylcytosine: quantitation using a computerized image analysis system

Cytosine arabinoside (Ara-C) is one of the most effective drugs in inducing remission in acute nonlymphocytic leukemia (ANLL) patients. However, the high recurrence rate indicates that a subpopulation of leukemic cells escapes drug effect. This cellular heterogeneity in drug response may play a major role in chemotherapeutic outcome. We have recently developed the individual colony-formation assay (ICFA) to study drug effects on the kinetics of proliferation of individual cells and their progeny. Thus parameters of proliferation are calculated for individual colonies. Three categories of drug responses were defined, including immediate growth cessation, delayed growth cessation (growth stops several days after drug exposure) and growth slowdown (logarithmic growth at a reduced rate compared to control). In the experiments included in this report, murine leukemia (L1210) cells were exposed to various concentrations of Ara-C for 1, 6 or 24 hours, and their responses quantified. Regardless of the Ara-C concentration or exposure time, subpopulations of cells were observed in each of the three response categories: immediate or delayed arrest or growth slowdown. As expected, the fraction of cells exhibiting immediate growth cessation generally increased with increasing drug dose and was markedly increased with longer exposure time. Delayed arrest was most prevalent at intermediate drug concentrations at all exposure times. If exposure was limited to 1 hour, at least 30% of cells continued to grow, although at a reduced rate (71% control rate after exposure to 1 mM Ara-C). This limited effect was paralleled by saturation of Ara-C triphosphate (Ara-CTP) formation. Six-hour exposure left at least 6.4% of cells growing, with an average rate of 45% of control. Under these conditions, no saturation in Ara-CTP formation was observed. Even 24-hour exposure to 5 microM Ara-C left 4.8% of colonies growing, at 42% of control rate. Thus a subpopulation of cells continued to grow even after 24-hour exposure to a relatively high concentration of Ara-C. Surviving, but slowly growing, cells may represent a previously unrecognized population that may contribute to therapeutic failure.

Isolation and characterization of a human ileocecal carcinoma cell line (HCT-8) subclone resistant to fluorodeoxyuridine

A 5-fluoro-2'-deoxyuridine (FdUrd)-resistant subclone (Fd9XR) of HCT-8 (human ileocecal carcinoma) cells was established by two schedules of drug exposure. Initially, cells were exposed to short-term (3 hr) 100 nM FdUrd repeatedly (9 cycles over 8 months), and cells were then exposed to 10 nM FdUrd continuously. During this latter stage, a colony (Fd9XR) with fast growth rate was isolated, expanded, and characterized with respect to mechanisms of resistance to FdUrd and cross-resistance to other chemotherapeutic agents. Fd9XR cells were 1000-fold resistant to FdURD, but 3-fold more sensitive to 5-fluorouracil (FUra) than HCT-8 cells. After a 3-hr treatment with FdUrd, Fd9XR cells accumulated 6630-, 69-, and 3.7-fold less fluorodeoxyuridylate (FdUMP), fluorouridine triphosphate (FUTP) and acid-insoluble materials, respectively, than HCT-8 cells. However, when FUra was substituted for FdUrd, Fd9XR cells accumulated 9.2-, 3.1-, and 2.3-fold more FdUMP, FUTP and acid-insoluble materials, respectively, than HCT-8 cells. Fd9XR and HCT-8 were similar in their growth rates, combined pools of 5,10-methylenetetrahydrofolates (5,10-CH2H4PteGlun) and tetrahydrofolates (H4PTeGlun), thymidine phosphorylase (TP) activity, and level and activity of thymidylate synthase (TS). In contrast, thymidine kinase (TK) activity of Fd9XR was 0.23 and 0.35% of that of HCT-8, for thymidine (dThd) and FdUrd as substrates, respectively. Furthermore, Fd9XR cells exhibited greater sensitivity to the antifolate TS inhibitor ICI D1694 and to methotrexate (MTX) than HCT-8 cells. In addition, dThd alone and in combination with hypoxanthine did not offer any protection against the cytotoxic effect of ICI D1694 in Fd9XR cells. These results indicate that in Fd9XR cells (1) TK deficiency is the primary mechanism of resistance to FdUrd; (2) the greater sensitivity to FUra was associated with higher pools of FdUMP and FUTP with a subsequently higher level of incorporation into cellular RNA; and (3) antifolate compounds, e.g. ICI D1694 and MTX, could be useful agents in the treatment of FdUrd-resistant tumors associated with decreased TK activity and decreased capacity of utilizing dThd.

Phase II study of high dose toremifene in advanced breast cancer progressing during tamoxifene treatment

Thirty-five (34 evaluable) consecutive postmenopausal women with estrogen receptor positive (greater than or equal to 10 fmol/mg) or unknown advanced breast cancer were treated with high dose toremifene in a phase II study. All patients had progressed during prior adjuvant or palliativ antiestrogen treatment. The dose of toremifene was 240 mg per day. No complete or partial responders were registered. Nine patients (26%) were considered to have stable disease (NC). The time to progression for these patients was 5-27+ months with a mean time of twelve months and median time of eight months. Two patients are still on treatment after twelve and 24 months respectively. There seems to be a relationship with receptor value; however, there are two few patients for a safe statistical analysis. The side effects were insignificant. The conclusion is that the efficiency of toremifene as second line hormonal treatment is restricted, although it may be one additional choice.

Weekly dose adriamycin as first line chemotherapy in advanced breast cancer

Weekly dose Adriamycin was given prospectively as first line chemotherapy in a phase II study including 76 patients with evaluable advanced breast cancer. The response rate (CR+PR) was 24 percent (18/76) and a further 41 per cent (31/76) of the patients achieved stable disease (NC). Mean time to progression for responders was 17 months and for those with stabilized disease 10 months. Mean time to progression for all patients was 8.8 months and overall mean survival time 16 months (2-55+). Side effects were well tolerable; myelosuppression was registered in 27 percent and alopecia requiring a wig in 24 percent. In three patients cardiotoxicity was registered after 1,190 mg, 1,480 mg and 1,780 mg respectively. This low dose regimen seems effective and well comparable regarding time to progression with multidrug regimens, including doxorubicin.

A model for mimicking the pharmacokinetics of chemotherapy drugs for evaluation of drug effects in a soft agar colony formation assay system

Colony formation assay systems are an important part of in vitro drug evaluation. It would be useful if the in vitro drug cytotoxicity could be carried out under conditions mimicking those employed clinically. We have developed an individual colony formation assay system that would allow monitoring and quantitation of the growth of individual colonies (9) in the presence of the drug under conditions of continuous and/or short-term exposure, after plating of the cells in the agarose. In this brief report, we established the pharmacokinetic profile of four drugs, cytosine arabinoside (araC), Doxorubicin (Dox), 5-fluorouracil (5-FUra) and 5-fluoro-2'-deoxyuridine (FdUrd) in agarose mimicking those that are achieved when these agents were administered in vivo as an i.v. push. The results show that short-term treatment in agarose is possible and that the washing procedure of the drugs decreased the drug concentrations 3-4 logs over 44 hours.

Variability of measurements of cranial growth in the rabbit

This study concerns techniques used in experimental cranial growth research: roentgen cephalometry, roentgen stereophotogrammetry, and gross measurements (osteometry). A comparison of the precision of these methods has not been found in the literature. Computation of technical errors is fundamental to the sound evaluation of registered findings, and such a presentation must be obligatory in all biometric reports. We compared the measurement error of roentgen cephalometric and osteometric data with that obtained by roentgen stereophotogrammetry (RSA). RSA demonstrates a superior replicability, and this technique gives possibilities for kinematic and volumetric determinations simultaneously with distance evaluation. Roentgen cephalometry has the advantage of enabling distance and angular measurements between any well-defined skeletal points or lines. This technique, preferably after implantation of bone markers, is a reliable alternative, but optimal results necessitates calculations of the magnification factor for each bone segment involved. Direct osteometry does not contribute additional information, but problems of image magnification are omitted. Preferably, one individual should perform all measurements regardless of the method used. Growth rates and values calculated by one technique cannot be directly transformed to some other approach. In all probability, assessments of distance changes would gain substantially by using one technical approach consistently throughout actual age intervals. The least variable measurements of sutural growth are made for sutures growing primarily in one plane and with substantial growth rates. One must realize that differences among studies may be due to the limitations of, in particular, the cephalometric and osteometric techniques.

The determination of growth rates of individual colonies in agarose using high-resolution automated image analysis

This paper describes the evaluation of a colony formation assay using automated image analysis, which permits the tracking of growth at the individual colony level, such that a growth rate can be estimated for each colony followed. In principle, this will permit quantitative characterization of cellular heterogeneity in growth rate and cellular heterogeneity in response to proliferation-modifying agents. In addition, we have demonstrated the possibility of using correlative microscopy to relate growth rate to other parameters, using metabolic viability as an example. This should be useful for determining cellular characteristics associated with proliferative behavior and response to proliferation-modifying agents.

Body weight gain as related to craniofacial and calvarial volumetric changes in growing rabbits

This investigation was conducted to evaluate the relationship between calvarial and craniofacial volumetric growth relative to body weight gain. Ten male New Zealand white rabbits received spherical tantalum bone markers in the nasal, frontal, parietal, and temporal bones: a minimum of two in each bone segment. The animals were followed from age 32 to 144 days using a roentgen stereophotogrammetric system and an accurate scale. Implant stability was checked at each stereometric examination. Sutural growth and volumetric changes were computed and correlated to weight increase. Successive calvarial and craniofacial polyhedron expansion, as well as weight, showed considerable variability and interindividual variation throughout the observation period. Calculated coefficients of determination, linear regressions, and the correlation coefficients for each age interval demonstrated weak correlations, especially for calvarial to weight data. Consequently, this study suggests a low dependence of calvarial volumetric growth, reflecting the neural mass expansion on body weight development. Thereby, further indications of the low reliability of weight as a parameter of general health evaluation was provided.

Recurrence and survival after anterior resection of the rectum using the end to end anastomotic stapler

With the introduction of the end to end anastomotic stapler there has been an increase in the number of sphincter saving resections for carcinoma of the middle and distal part of the rectum. The results of earlier reports have indicated an increasing number of local recurrences possibly due to less extensive dissection of the lower pelvic area. Ninety-six patients, 46 males and 50 females, with a median age of 68 years (a range in age of 33 to 86 years) were operated upon between 1978 and 1981 for carcinoma of the rectum with anterior resection and stapled anastomosis have been analyzed. All patients were observed for more than three years (a median of 65 months and a range of 36 to 82 months). The hospital mortality rate was 5 per cent. The median distal margin was 2.5 centimeters (a range of 1 to 10 centimeters). Local recurrences occurred in 17 patients. No correlation between the grade of malignant disease and classification according to Dukes' staging and local recurrence was found. The median time between operation and the diagnosis of a local recurrence was 14 months (two to 62 months). Distant metastases developed in 14 of 83 patients who underwent operation for cure. The over-all five year survival rate was 64 per cent. The survival rate for 83 patients who underwent operation for cure was 71 per cent (96 per cent of Dukes' A, 72 per cent for Dukes' B, 45 per cent for Dukes' C and zero per cent for Dukes' D). It is concluded that the use of stapling devices has not been followed by a higher rate of local recurrence or a decreased five year survival rate and that this new technique can be used whenever technically possible.

Hymenolepis diminuta: a comparison between young developing, and small, destrobilated worms in the rat intestine

Newly in vitro excysted tapeworms of Hymenolepis diminuta (Cestoda, Cyclophyllidea), 1- to 3-day-old worms and destrobilated worms from rat intestines were investigated by means of light microscopy (LM) and scanning electron microscopy (SEM). It was found that the scolex of 1- and 2-day-old worms had shallow suckers with smooth brims, while 3-day-old and older worms, including destrobilated worms, had deep suckers with puckered brims. The posterior end of 1- and 2-day-old worms had a central cone-shaped structure not present in 3-day-old and older, or destrobilated worms. The repairing of the posterior end and the protonephridial system after excystation or destrobilation was much the same. Tissue remnants moved into the centre of the posterior end, resulting in an indentation with a pore to the exterior. The indentation and its pore became connected to the emptying canals of the protonephridial system, i.e. they developed into the excretory bladder and pore respectively.