Abstract P5-07-08: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Persson E, Gregersson P, Fitzpatrick P, Ståhlberg A, Landberg G. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-08.

Abstract P2-06-11: Sortilin targeted therapy in breast cancer with elevated progranulin expression

Background: A major challenge concerning breast cancer therapy is the occasional lack of effects using drugs that target cancer cells unspecifically. One possible explanation for this treatment failure is the existence of the small subpopulation of breast cancer stem cells that are believed to be more resistant towards conventional therapy and possesses the ability to drive tumor formation and disease progression. Cytokines secreted by nearby cells and other factors in the surrounding tumor microenvironment further stimulate the cancer cells, contributing to a heterogeneous and potentially more treatment resistant tumor. Thus, a more specific treatment approach targeting the breast cancer stem cell niche is crucial in preventing disease recurrences. In a cytokine screen, we identified progranulin as one of the main compounds secreted from cells exposed to hypoxia, leading to cancer stem cell propagation. Progranulin is involved in biological processes such as wound healing, inflammation and cancer progression. Progranulin and its receptor sortilin are known to be highly expressed in subgroups of breast cancer and are further associated with a clinically aggressive phenotype.

Methods/Results: By carrying out a number of in vitro and in vivo like screening assays, we demonstrate that progranulin influences the stem cell population in breast cancer and is responsible for spreading a cancer stem cell promoting signal to normoxic tumor areas. In breast cancer, progranulin induces a dedifferentiation process in the receiving cancer cells and expression of cancer stem cell markers together with an EMT-associated gene expression profile, leading to cancer stem cell expansion. By using siRNA and pharmacological inhibition of sortilin, we show that sortilin is a functional receptor of progranulin and is responsible for driving progranulin induced breast cancer stem cell propagation. Supporting the role of progranulin in cancer progression, administration of progranulin in immunocompromised mice induce lung metastasis in our breast cancer xenograft models. The use of different approaches for blocking sortilin, such as sortilin inhibitors, down-modulators or sortilin-targeted antibodies can prevent this dedifferentiation process, both in vitro and in vivo, making the tumor cells less aggressive and metastatic.

Conclusion: Targeting progranulin through its associated receptors is a potential therapeutic strategy for the treatment of patients with breast tumors having elevated progranulin or sortilin expression. By inhibiting the secretion based breast cancer progression, we could possibly block the formation of metastasis and cancer cell infiltration.

Citation Format: Berger K, Rhost S, Hughes E, Harrison H, Rafnsdottir S, Jacobsson H, Gregersson P, Magnusson Y, Fitzpatrick P, Andersson D, Ståhlberg A, Landberg G. Sortilin targeted therapy in breast cancer with elevated progranulin expression [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-11.

Robotic Mammosphere Assay for High-Throughput Screening in Triple-Negative Breast Cancer

In order to identify novel treatment principles specifically affecting cancer stem cells in triple-negative breast cancer, we have developed a high-throughput screening method based on the mammosphere and anoikis resistance assays allowing us to screen compounds using a functional readout. The assay was validated against manual protocols and through the use of positive controls, such as the response to hypoxia and treatment with the known cancer stem cell-targeting compound salinomycin. Manual and robotic procedures were compared and produced similar results in cell handling, cell cultures, and counting techniques, with no statistically significant difference produced from either method. The variance between samples processed manually versus robotically was no greater than 0.012, while Levene's test of significance was 0.2, indicating no significant difference between mammosphere data produced manually or robotically. Through the screening of 989 FDA-approved drugs and a follow-up screen assessing the antineoplastic subgroup, we have identified three therapeutic compounds with the ability to modulate the breast cancer stem cell fraction in the triple-negative breast cancer cell line MDA-MB-231, highlighting their potential usage as stem cell-specific adjuvant treatments.

PO-21 - Stromal fibroblasts in preinvasive breast cancer (ductal carcinoma in situ, DCIS) demonstrate a cancer-like procoagulant phenotypic switch that may facilitate invasion

INTRODUCTION

Ductal carcinoma in-situ (DCIS) is a preinvasive breast cancer where cancer cells remain confined within the ductal basement membrane. However, genotypic changes have been identified in stroma surrounding DCIS, outside the basement membrane. Stromal fibroblasts undergo phenotypic change in cancer to promote tumour angiogenesis, proliferation, immunosuppression and metastasis and in vivo can induce invasion of DCIS. Phenotypic changes in DCIS stromal fibroblasts may potentially act as a precursor for invasion.

AIM

To determine if stromal fibroblasts in DCIS have procoagulant changes similar to those seen in cancer-associated fibroblasts in invasive breast cancer.

MATERIALS AND METHODS

As part of the prospective cohort study CHAMPion (Cancer induced Hypercoagulabulity as a Marker of Prognosis), patients with DCIS (n=72) and invasive breast cancer (n=292) were recruited. Stromal fibroblasts in tumour and corresponding normal breast tissue (distant from the cancer) were quantified (percentage IHC stained) for tissue factor (TF), thrombin, PAR1 and PAR2. Fibroblasts were identified morphologically, at a minimum distance of 0.2mm from ductal tissue, to avoid myoepithelial scoring. Scoring was performed in duplicate by two independent pathologists.

RESULTS

Fibroblast TF expression was present in normal breast tissue (mean 43% ([SD 27%]) but markedly increased in DCIS (mean 62% [SD 27%], p=0.002). Fibroblast TF expression was further increased in invasive breast cancer (mean 74% [SD 23%], normal vs invasion, p<0.001; DCIS vs invasion, p=0.03). Fibroblast thrombin and PAR2, but not PAR1, expression was increased in DCIS compared to normal (thrombin: 60% vs 42%, p<0.001; PAR2: 58% vs 41%, p=0.002), however no further significant increase was seen in invasive cancer (thrombin 63%, PAR2 61%). Fibroblast tissue factor correlated with fibroblast thrombin expression (p<0.001, r=0.4) and fibroblast PAR2 expression (p<0.001, r=0.5), with thrombin and PAR2 expression also correlating (p<0.001, r=0.4).

CONCLUSIONS

Procoagulant phenotypic changes, in terms of increased TF, thrombin and PAR2 expression, occur in stromal fibroblasts at the preinvasive stage. It needs to be determined if this change is functional and therefore a potential therapeutic target for preventing transition to invasion.

Abstract PD04-06: Molecular Phenotypes of DCIS predict Invasive and DCIS recurrence

Introduction: Molecular phenotypes of invasive breast cancer predict early recurrence and survival. DCIS exhibits similar phenotypes but their frequency and clinical significance remain uncertain. To determine whether molecular phenotypes of DCIS predict recurrence, 273 women (median age 57 years) with primary DCIS who were screened for or entered DCIS trials (Iressa/Lapatinib/ERISAC) in one unit from 1990–2010 were studied.

Methods: HER2, oestrogen receptor (ER) and progesterone receptor (PR) expression within primary DCIS were established using immunohistochemistry within the trial protocols. HER2 was scored 0 (absent) to 3 (maximum). Scores ≥2 were taken as positive if amplified on FISH testing. ER and PR scored positive if ≥5% of cells stained. 64.2% patients were ER positive, 43.3% were HER2 positive and 31.8% were high-grade lesions. 94 underwent mastectomy whilst 185 had BCS.

Results: There was an overall recurrence rate of 20.14% after a median follow-up period of 74 months (range 12–240). Of these recurrences, 36.4% were invasive. Conservation surgery (BCS) was used in 185 women who suffered 47 recurrences. Molecular phenotype predicted local recurrence by Log Rank analysis (P &lt; 0.01) and invasive recurrences (P &lt; 0.016) overall and in the BCS group remained predictive of invasive recurrence (p &lt;0.005) and overall recurrence (p &lt; 0.001).

P4-08-04: Preoperative Thrombin Pathway Activation Identifies Node Positive Patients in Early Breast Cancer

Activation of the thrombin pathway (TP) is seen in 50% of cancers and plays a significant role in promoting metastasis. Cancer-induced TP activation is exacerbated by surgery, and this activation may be greater in the presence of metastases.

Our aim was to determine if pre-operative plasma d-dimer, a marker of TP activation, correlated with the presence of LN metastases in early breast cancer. We also examined whether surgery-induced TP activation is affected by tumour-associated factors.

Methods

Plasma d-dimer was measured using automated ELISA pre-operatively and at days 1 and 42 following surgery in 103 prospectively recruited patients undergoing surgery for early breast cancer(87 invasive,13 DCIS). D-dimer values were log-transformed and correlated with LN metastases, tumour size and grade and hormone receptor status using parametric statistical tests.

Results

Median age was 68 years (range 46–82). Mean tumour size was 14.6 mm (range 7.5-40). Seventy invasive cancer patients had wide local excision(WLE) and sentinel node biopsy(SNB) and 17 had mastectomy(MX) +/− axillary clearance(ANC).

Twenty-two patients had positive lymph nodes at primary surgery (MX 8,WLE 14). Of these 3(14%) were ER-ve and 19(86%) were ER+ve.

Mean pre-operative d-dimer was higher (p&lt;0.01) in LN positive (704ng/ml, 95% confidence interval, CI, 455–1088) versus LN node negative invasive cancers (443ng/ml, CI 304–627) or DCIS (366ng/ml, CI 284–471). D-dimer was also higher in patients with lymphovascular invasion (612ng/ml, CI 423–886) than in those without (454ng/ml, CI 385–534) and this approached significance (p=0.084).

Post-operative d-dimer was higher (p&lt;0.05) after MX compared to WLE at all timepoints. Following WLE + SNB for invasive cancer, post-operative d-dimer rose and was higher at day 1 and day 42 in LN positive vs LN negative and in ER negative versus ER positive cancers (see table). Repeated measures ANOVA analysis showed that the change in d-dimer over time was significantly different between subjects according to LN status (p=0.037) or ER status (p=0.015). Only one patient in the ER negative group had LN metastases. There was no association between pre or postoperative d-dimer and tumour size, tumour grade or PR status.

The cocaine- and amphetamine-regulated transcript mediates ligand-independent activation of ERα, and is an independent prognostic factor in node-negative breast cancer

Personalized medicine requires the identification of unambiguous prognostic and predictive biomarkers to inform therapeutic decisions. Within this context, the management of lymph node-negative breast cancer is the subject of much debate with particular emphasis on the requirement for adjuvant chemotherapy. The identification of prognostic and predictive biomarkers in this group of patients is crucial. Here, we demonstrate by tissue microarray and automated image analysis that the cocaine- and amphetamine-regulated transcript (CART) is expressed in primary and metastatic breast cancer and is an independent poor prognostic factor in estrogen receptor (ER)-positive, lymph node-negative tumors in two separate breast cancer cohorts (n=690; P=0.002, 0.013). We also show that CART increases the transcriptional activity of ERα in a ligand-independent manner via the mitogen-activated protein kinase pathway and that CART stimulates an autocrine/paracrine loop within tumor cells to amplify the CART signal. Additionally, we demonstrate that CART expression in ER-positive breast cancer cell lines protects against tamoxifen-mediated cell death and that high CART expression predicts disease outcome in tamoxifen-treated patients in vivo in three independent breast cancer cohorts. We believe that CART profiling will help facilitate stratification of lymph node-negative breast cancer patients into high- and low-risk categories and allow for the personalization of therapy.

Tumour-related factors and prognosis in breast cancer detected by screening

BACKGROUND

Breast cancer detected by screening has an unexplained prognostic advantage beyond stage shift compared with cancers detected clinically. The aim was to investigate biological factors in invasive breast cancer, with reference to mode of detection and rate of death from breast cancer.

METHODS

Histology, oestrogen receptor α and β, progesterone receptor, human epidermal growth factor receptor (HER) 2, cyclin D1, p27, Ki-67 and perinodal growth were analysed in 466 tumours from a prospective cohort, the Malmö Diet and Cancer Study. Using logistic regression, odds ratios were calculated to investigate the relationship between tumour characteristics and mode of detection. The same tumour factors were analysed in relation to standard prognostic features. Death from breast cancer was analysed using Cox regression with adjustments for standard tumour factors; differences following adjustment were analysed by means of Freedman statistics.

RESULTS

None of the biological tumour characteristics varied with mode of detection of breast cancer. After adjustment for age, tumour size, axillary lymph node involvement (ALNI) and grade, women with cancer detected clinically had an increased risk of death from breast cancer (hazard ratio 2·48, 95 per cent confidence interval 1·34 to 4·59), corresponding to a 37·2 per cent difference compared with the unadjusted model. Additional adjustment for biological tumour factors studied caused only minor changes.

CONCLUSION

None of the biological tumour markers investigated explained the improved prognosis in breast cancer detected by screening. None of the factors was related to ALNI, suggesting that other mechanisms may be responsible for tumour spread.

Risk of recurrence following delayed large flap reconstruction after mastectomy for breast cancer

BACKGROUND

The aim of this retrospective matched cohort study was to evaluate the rate of recurrence among women with delayed large flap breast reconstruction after mastectomy for breast cancer. The recurrence rate among women treated at a single hospital was compared with that in an individually matched control group of women with breast cancer who did not have reconstruction after mastectomy.

METHODS

Between 1982 and 2001, 125 women with previous invasive breast carcinoma underwent delayed large flap breast reconstruction with pedicled musculocutaneous or microvascular flaps (a median of 32 months after mastectomy). They were matched individually with 182 women with breast cancer who had a mastectomy but did not undergo breast reconstruction. Matching criteria were year of diagnosis, age at diagnosis and treating hospital. Medical records were evaluated until October 2007. Histopathological specimens for all included women were re-evaluated. The endpoint was locoregional or distant breast cancer recurrence. The risk of recurrent disease was calculated using a Cox proportional hazards analysis, adjusted for established prognostic factors.

RESULTS

Median follow-up for the entire cohort was 146 months. The reconstruction group had a 2·08 (95 per cent confidence interval 1·07 to 4·06) times higher risk of recurrent disease than the mastectomy only group.

CONCLUSION

Women with breast cancer who had delayed reconstruction with a large flap in this study had a higher risk of recurrent disease than those with mastectomy alone.

Abstract P4-05-05: Stromal Response to 14-Day Preoperative Therapy in Postmenopausal Oestrogen Receptor Positive Breast Cancer

Background: Stromal-epithelial interaction is a key factor in tumour progression. Cancer-associated fibroblasts (CAFs) and macrophage infiltration have been associated with early relapse in breast cancer. Bisphosphonates are effective inhibitors of osteoclast activation in metastatic breast cancer but also have a general inhibitory effect on breast cancer progression. In order to monitor a potential tumour stromal response in breast cancer during treatment with an aromatase inhibitor and a bisphosphonate we analysed pre-and post-treatment samples from a neoadjuvant window study and focused on the presence of macrophages and CAFs.

Materials and methods: Tissue microarrays (TMAs) from surgical samples and pre-operative core biopsies were immunohistochemically stained for aSMA (CAF marker), CD68 (macrophages) and epithelial proliferation (Ki67). In order to validate if the presence of macrophages and aSMA could be monitored by the TMA approach, we initially analysed a screening cohort of 144 breast cancer samples. We then studied pre-and post-treatment samples from 110 postmenopausal ER-positive invasive breast cancer patients randomised to receive 14 days of preoperative treatment (placebo, Letrozole, or Letrozole plus Zoledronate). Results: In the screening cohort, we observed significant links between aSMA positive fibroblasts and disease recurrence as well as between CD68 positive macrophages and tumour size, grade, lymph node positivity and recurrence. This validated the use of TMAs for stromal analyses and furthersupported a link with key tumour biological events. In both treatment arms, there was a significant drop in absolute Ki67 value compared to placebo (-9.3% Letrozole and -13.1% combination reduction versus 1% increase, P&lt;0.001). Post-treatment CD68 (median 35, range 3 to 117) was significantly linked to a Ki67 drop (p=0.045). Interestingly, this effect was mainly observed in the combination treatment group (p=0.002). aSMA expression was unaffected during treatment in 52%, increased in 35% and decreased in 13% of cases. Patients with aSMA reduction post treatment had a larger Ki67 fall compared to patients with increase or no change in aSMA (p=0.007).

Conclusion: Short term treatment response in the epithelial component of cancers was paralleled by specific responses in the tumour stromal component. These novel findings suggest that bisphosphonates and aromatase inhibitors have major effects on tumour stroma in vivo which might augment their inhibitory effect on tumour progression.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-05-05.

Abstract P4-06-05: Silencing of Cyclin D1 Increases Breast Cancer Cell Migration through Increased Id1 Expression and Induction of Epithelial-Mesenchymal Transition

Backround: The oncogene cyclin D1 is overexpressed in many breast cancers and despite proliferation activating properties, has been linked to a less malignant phenotype. We have previously shown that down-regulation of cyclin D1 in actively cycling breast cancer cells significantly increased their migratory capacity whilst also decreasing proliferation. Gene expression analysis and animal modeling have highlighted an increase in the inhibitor of differentiation-1 (Id1) gene following cyclin D1 gene (CCND1) silencing. Notably, increased Id1 is associated not only with enhanced migratory and invasive features of breast cancer cells but also with prevention of cell differentiation and induction of an epithelial-mesenchymal-like (EMT) phenotype. Here we sought to determine if the increase in cell motility following cyclin D1 silencing was through increased Id1 expression and induction of an EMT phenotype, and confirm our findings in a large patient cohort.

Materials and Methods: Expression of cyclin D1, Id1 and SNAI2 was determined in MDA-MB-231 and ZR75 cells by qPCR and western blot, whilst cell migration was monitored by transwell assay. Gene expression of CCND1, ID1 and EMT markers was analysed from a pooled cohort of batch-mean centered publically available data sets, with data analysis performed in SPSS.

Results: Silencing of cyclin D1 increased cell migration 1.38 and 1.72 fold in MDA-MB-231 (P&lt;0.001), and ZR75 (P&lt;0.001) cells respectively, an effect abolished by silencing of Id1. qPCR analysis confirmed an increase in Id1 (1.73) and SNAI2 (1.50) expression following siRNA treatment of cyclin D1, an effect reversed following siRNA treatment of Id1. CCND1 gene exression was negatively, while Id1 was positively, associated with the EMT markers Vimentin (P&lt;0.001), SNAI2 (P&lt;0.001) and TWIST1 (P&lt;0.001) in 1,100 breast tumors. In ER+ patients CCND1 was negatively correlated to Id1 expression (0.050) and in CCND1 low patients increasing Id1 expression was predictive of worse cumulative survival (0.027). Conclusion: Decreased CCND1 expression enhances MDA-MB-231 and ZR75 cell migration through increased Id1 expression and induction of EMT. Moreover, both genes are correlated to EMT markers in breast cancer patients and in a subset of the cohort, confer a worse survival. These results may explain the conflicting data regarding cyclin D1 expression in breast carcinomas and solidifies the rationale of the protein as a clinical target.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-06-05.

Abstract P2-09-34: ERK Phosphorylation in Fibroblasts within Breast Cancer Stroma Is Associated with an Improved Tamoxifen Response

Background. Extra-cellular signal-regulated kinase (ERK) 1/2 is an integral part of the mitogen-activated protein kinase (MAPK) pathway, transmitting signals involved in cell proliferation and cell death upon binding of extracellular growth factors to their receptors. Whereas its role in tumour cells has been linked to key events in cell transformation, its role in tumour-associated fibroblasts, a component of the tumour stroma, is largely unknown.

Material and methods. Tissue microarrays (TMAs) of two cohorts including invasive breast cancer patients were stained for ERK phosphorylation level (pERK) and SMA-alpha expression (SMAa) which were scored and analysed in regard to clinico-pathological, prognostic and molecular markers and recurrence-free survival.

Results. In both clinical materials we show a significant correlation between stromal ERK phosphorylation and the marker for activated fibroblasts SMAa. SMAa expression was not linked to treatment-predictive information but instead had prognostic qualities (P=0.034, multivariate Cox regression). By analysing the unique randomised tamoxifen trial including patients receiving no adjuvant treatment we show for the first time that ERK phosphorylation in cancer-associated fibroblasts (CAF) was associated with an improved outcome upon tamoxifen treatment. In contrast, patients having ERα-positive tumours but lacking ERK phosphorylation in the stroma did not respond to tamoxifen treatment (P=0.015, multivariate interaction analyses).

Discussion. This suggests that only a subpopulation of activated fibroblasts, defined by phosphorylation of ERK, is linked to a response to tamoxifen treatment illustrating the importance of the stroma for monitoring and potentially mediating treatment effects in premenopausal breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-09-34.

Abstract P4-07-06: Yes-Associated Protein, a Proposed Tumour Suppressor, Is Inversely Correlated to Cyclin D1 in Breast Tumours and Associated with a Worse Prognosis

Background: In breast cancer, cyclin D1 over-expression and CCND1 (11q13) gene amplification have been linked to a worse prognosis. Conversely, lower levels of cyclin D1 have also been correlated to an unfavourable outcome. In a microarray analysis of cyclin D1 silenced MDA-MB-231 cells we identified Yes-associated protein (YAP), located at 11q22, as one of the most down-regulated genes. As such, we aimed to determine the importance of YAP in relation to cyclin D1 in breast cancer biology.

Material and methods: Validation of cyclin D1, YAP antibodies and protein levels were performed in MDA-MB-231, MDA-MB-468 and MCF-7 by western blot. YAP protein expression was examined by screening 144 breast tumours and gene expression assessed by meta-analysis of six previously published breast cancer datasets totalling 1107 tumours with clinical follow-up. Subsequent data analysis was performed in SPSS. Results: YAP protein levels were down-regulated in cyclin D1 silenced MDA-MB-231, MDA-MB-468 and MCF-7 cell lines as predicted by microarray analysis. Surprisingly, YAP and cyclin D1 were inversely correlated at both protein and gene level in primary tumours (p=0.004 and P&lt;0.001). Amplification of the CCND1 gene was correlated to low YAP protein expression (P&lt;0.001) in the screening tumour material. Low YAP mRNA was an independent prognostic factor of recurrence (HR= 1.30, 95% CI 1.009-1.678, p=0.043) in the gene expression dataset. This effect was particularly pronounced in the luminal A subtype of breast tumours. Discussion: The independent prognostic value of YAP strengthens the notion of this protein as a tumour suppressor in breast cancer. The regulation of YAP by cyclin D1 appears to occur on both the protein level as seen in cell lines, and on the chromosomal level in terms of 11q aberrations. The inverse correlation observed in the tumour materials between cyclin D1 and YAP may be partly explained by chromosomal rearrangements; the amplification of the CCND1 gene (11q13) is often accompanied by loss of the 11q22 region of the chromosome, harbouring the YAP locus. Further studies are ongoing to clarify the link between YAP and cyclin D1 in breast cancer biology.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-07-06.

Abstract PD05-06: Is ERα a Tamoxifen Predictive Factor in ERα Negative Breast Cancer in Premenopausal Women?

Background: The majority of breast cancers are hormone receptor positive, defined as estrogen receptor (ERα) and/or progesterone receptor (PR) positive. Adjuvant tamoxifen decreases the risk of recurrence and improves survival in hormone positive breast cancer, irrespective of age. Still some do not respond to tamoxifen. The clinical significance of ERα is still unclear, even if studies indicate that ERα might be of importance. The aim of this study was to investigate the tumor expression of ERα in premenopausal women with breast cancer and the relationship to other clinical and pathological parameters and if there is any prognostic or predictive value. This is the first study of ERα based on a randomized study including only premenopausal women.

Material and Methods: Premenopausal women (n=564) with breast cancer, Stage II (UICC), were randomized to either two years of adjuvant tamoxifen (n=276) or no tamoxifen (n=288). The median follow-up was 13.9 years. The expression of ERα (n=303) and ERα (n=309) was analyzed by immunohistochemistry (IHC) using tissue microarrays (TMA). ERα was considered positive if more than 50% of the cells were stained (n=174). ERα was scored according to number of positive cells and the intensity of the staining. ERα negative (n=70) score 0, 1-49% (n=137) score 1, 50-100% (n=102) score 2 and the intensity negative (n=70) score 0, weak (n=119) score 1, strong (n=120) score 2. ERα summary score 4 was considered positive (n=118).

Results: ERα was correlated with lymph node status (p=0.024), ERα (p=0.00016), PR (p=0.0084), Ki67 (p=0.035), cyclin D1 (P&gt;0.00001) but showed a negative correlation to HER2 (p=0.042). Patients with ERα+/ERα- tumors showed significant benefit from 2 years of tamoxifen compared to those with ERα-/ERα — tumors (table1). In the control group ERα showed no prognostic value.

Recurrence free survival (RFS) at 10 years tamoxifen vs control

Discussion: ERα might be a tamoxifen predictive factor in ERα negative premenopausal breast cancer. If so, further studies are motivated to explore whether a subset of patients with triple negative breast cancer could benefit from endocrine therapy.

Randomised Placebo Controlled Trial Studying Short Term Biological Effects of the Combination of Letrozole and Zoledronic Acid on Invasive Breast Cancer

To determine whether the addition of Zoledronic Acid to endocrine therapy increases apoptosis or decreases proliferation in early invasive breast cancer, a placebo controlled randomised trial comparing 14 days treatment with Letrozole or Letrozole and Zoledronic Acid pre-operatively was performed.PatientsIn total 109 postmenopausal women with early invasive hormone receptor positive breast cancer were randomised (1:1:1) to either placebo, Letrozole 2.5mg/day or Letrozole with Zoledronic Acid 4mg single dose intravenously 2-4 days before definitive surgical excision. Epithelial proliferation and apoptosis were measured on paired baseline and surgical biopsy specimens (after 14 days of treatment) using Ki67 and Activated Caspase 3 immunohistochemistry. Alterations in angiogenic markers (VCAM/VEGF and CD31) were also studied. The primary endpoint was fall in Ki67 between diagnosis and surgical excision.ResultsOverall 109 women were enrolled but paired biopsies were only available for 101 patients. PlaceboLetrozoleLet + Zoln323435Absolute Ki67 change (median,range)-0.8 (-12,12)8.6 (-14,37)12.9 (-12,29)    Caspase 3 change (median,range)0.1 (-3.8, 9.3)0.4 (-2.7, -4.1)0.2 (-10.9, -14.4)    Absolute change (Cell turnover index)-0.3 (-142, -59)18.9 (-201, 192)17.7 (-14, 379) Statistically significant reductions in Ki67 and Cell Turnover Index were seen with Letrozole and Let & Zol (p ≤ 0.001) but there was no significant different between Letrozole and Letrozole plus Zoledronic Acid groups (p = 0.26). Apoptosis did not change between the three groups.ConclusionLetrozole reduces proliferation by 70% when used for 14 days prior to surgery. Zoledronic Acid administration prior to surgery is safe but when administered as a single dose at a median of 3 days before surgery did not significantly increase apoptosis or decrease proliferation compared to Letrozole alone.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2009.

Short-term biological effects of zoledronic acid combined with letrozole in postmenopausal women with estrogen receptor-positive invasive breast cancer

e11625

Background: Aromatase inhibitors (AIs) reduce tumor cell proliferation and improve breast cancer survival. Recent evidence from in vivo models and the ABCSG-12 Trial suggests that bisphosphonates such as zoledronic acid add to the inhibitory effect of AIs but the mechanism is unclear. We assessed the effect of letrozole alone and in combination with zoledronic acid in a 14 day pre-surgical study in women with primary breast cancer. Methods: Postmenopausal women (n=109) aged 50–75 years with untreated estrogen receptor positive invasive breast cancer (no prior hormonal therapy) gave written informed consent to the study and were randomized to letrozole (2.5mg) or placebo tablets (2:1). Letrozole treated patients were randomized further to zoledronic acid 4mg intravenously or no treatment 2–4 days prior to surgery. Epithelial proliferation and apoptosis was measured pre and post treatment by immunohistochemistry for Ki67 and activated caspase 3 respectively counting at least 1,000 cells. Smooth Muscle Actin immunohistochemistry was also assessed pre and post treatment to determine fibroblast activation. Results: The study is powered to detect a 10% difference in epithelial proliferation with the combination arm (80% chance) compared to the letrozole alone arm. Conclusions: This preoperative biological study should provide important insight into the cellular mechanism or action of zoledronic acid in addition to AIs on primary breast cancer.

[Table: see text]

Phosphorylation of the oestrogen receptor alpha at serine 305 and prediction of tamoxifen resistance in breast cancer

Phosphorylation of oestrogen receptor alpha at serine 305 (ERalphaS305-P) induces tamoxifen resistance in experimental studies, but does not influence response to other endocrine agents, such as fulvestrant. We evaluated ERalphaS305-P using immunohistochemistry in 377 breast carcinomas from premenopausal participants of a randomized trial (n=248) and patients with advanced disease (n=129). Among the premenopausal patients, adjuvant tamoxifen improved recurrence-free survival (RFS) for ERalphaS305-P-negative tumours (multivariate HR=0.53, 95% CI 0.32-0.86, p=0.010), but not for ERalphaS305-P-positive tumours (multivariate HR=1.01, 95% CI 0.33-3.05, p=0.99) (interaction p=0.131). Notably, ERalphaS305-P was not significantly associated with RFS in patients not treated with tamoxifen (multivariate HR=0.64, 95% CI 0.30-1.37, p=0.248), indicating that ERalphaS305-P is a marker for treatment outcome rather than tumour progression. Given the direct experimental link between ERalphaS305-P and tamoxifen resistance and these first clinical data suggesting that premenopausal patients with ERalphaS305-P-positive breast cancer are resistant to adjuvant tamoxifen, further research is encouraged to study whether alternative endocrine treatment should be considered for this subgroup.

Oestrogen receptors alpha and beta show different associations to clinicopathological parameters and their co-expression might predict a better response to endocrine treatment in breast cancer

AIMS

The majority of all breast cancers are hormone responsive, traditionally defined by the expression of oestrogen receptor (ER) alpha and/or progesterone receptors. In contrast to ERalpha, the clinical significance of the relatively recently identified ERbeta is still unclear. This study aimed to define the relationship between ERbeta and clinicopathological parameters in a mixed cohort of breast cancer and, furthermore, to investigate the impact of ERbeta expression on disease outcome.

METHODS

The immunohistochemical expression of ERalpha and ERbeta was analysed in tissue microarrays containing a total number of 512 tumours with all incident breast cancers diagnosed at the Malmö University Hospital between 1988 and 1992.

RESULTS

78% of the tumours were ERalpha positive and 50% were ERbeta positive. ERbeta correlated positively with ERalpha (p = 0.001). In contrast to ERalpha, ERbeta was not associated with any important clinicopathological variables. Furthermore, no overall prognostic significance could be demonstrated for ERbeta. In the ERalpha-positive subgroup, however, a low expression of ERbeta correlated with a decreased disease-free survival in patients receiving endocrine treatment (p = 0.003).

CONCLUSIONS

Although interrelated, ERalpha and ERbeta seem to be differentially associated to clinicopathological parameters, and this would support the fact that they might have different functions in vivo. Furthermore, ERbeta might be a predictive marker of response to endocrine therapy, although this needs to be confirmed in additional studies, preferably randomised trials.

Cyclin E confers a prognostic value in premenopausal breast cancer patients with tumours exhibiting an infiltrative growth pattern

AIMS

To investigate the prognostic value of cyclin E in relation to tumour growth pattern by analysing stage II primary breast cancers from premenopausal women not subjected to any further adjuvant treatment. To analyse the value of cyclin E as a predictor of tamoxifen response, by comparing untreated and treated patients with oestrogen receptor positive tumours.

METHODS

Breast cancer samples, assembled in tissue microarrays, were immunohistochemically stained for cyclin E and evaluated regarding the presence of nuclear staining. The overall growth characteristics of each tumour were assessed using whole tissue sections.

RESULTS

Tumours displaying a pushing margin phenotype were strongly associated with high cyclin E levels, lymph node negative disease, a high histological grade and oestrogen receptor negativity, and exhibited a better prognosis compared to tumours with an infiltrative growth pattern. In the total cohort of non-treated patients (n = 187), cyclin E was not associated with recurrence free survival (RFS). However, when analysing the subgroup of tumours lacking a pushing growth pattern (n = 141), cyclin E was significantly associated with RFS, independent of histological grade and node status. There was no significant difference in tamoxifen response with regard to different cyclin E levels.

CONCLUSION

The prognostic value of cyclin E in premenopausal breast cancer is limited to patients with breast carcinomas exhibiting an exclusively infiltrative growth pattern. This limitation could be explained by the presence of a small but distinct subgroup of cyclin E-high breast cancers with a pushing margin phenotype and a more favourable outcome.

Transcriptional upregulation and unmethylation of the promoter region of p16 in invasive basal cell carcinoma cells and partial co-localization with the gamma 2 chain of laminin-332

Basal cell carcinoma cells show low proliferation rates at the invasive front and a concordant upregulation of the cdk-inhibitor p16, limiting proliferative capacity. Little is known about the mechanisms of p16 regulation in normal and malignant cells apart from that many transcription factors such as Ets1, Ets2, SP1, SP3, JunB and the polycomb protein Bmi1 have the potential to induce or repress p16 expression. Therefore, the aim of this study was to determine how p16 is regulated in basal cell carcinoma with special focus on its upregulation in invasive cells. By analysing various microdissected areas of basal cell carcinoma using real-time quantitative PCR we observed upregulation of p16 mRNA in invasive tumour cells compared to centrally localized tumour cells. The methylation status of the p16 promoter, analysed by methylation-specific PCR, also showed diminished methylation in tumour cells at the invasive front, supporting the hypothesis that promoter methylation can affect the transcriptional activation of p16 in vivo. There was only sporadic co-localization of Ets, or ERK1/2 phosphorylation with p16 upregulation at the invasive front, suggesting that these factors were not directly involved in the regulation of p16. Furthermore, the gamma 2 chain of laminin-332 has been reported to be increased at the invasive front compared to the central areas of many tumours. Interestingly, in basal cell carcinoma we observed partial co-localization between p16 and the gamma 2 chain of laminin-332 in tumour cells towards areas of ulceration and in the majority of clearly infiltrative tumour cells but not in p16 positive tumour cells with a more pushing invasive growth pattern. These data suggest that concurrent p16 upregulation and decreased proliferation are more general phenomena in different types of invasive growth patterns in basal cell carcinomas and that these only partially overlap with the gamma 2 chain of laminin-332 associated invasion patterns.

Pathology parameters and adjuvant tamoxifen response in a randomised premenopausal breast cancer trial

BACKGROUND

Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment.

AIMS

To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer.

MATERIALS/METHODS

Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression.

RESULTS

Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly.

CONCLUSIONS

Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.

Ki67 and p53 immunohistochemistry reduces interobserver variation in assessment of Barrett's oesophagus

AIMS

To devise clinically applicable methods for assessing p53 and Ki67 immunohistochemical (IHC) reactivity in Barrett's oesophagus (BE) and to compare the interobserver agreement between these methods and routine haematoxylin and eosin (H&E) evaluation.

METHODS AND RESULTS

One hundred and fifteen biopsies diagnosed as BE, selected from the files of the University Hospital MAS, Malmo, were re-evaluated for dysplasia by three pathologists. For IHC analysis areas with the most prominent positivity were evaluated. The mean of p53+ epithelial nuclei/high-power field (HPF) was obtained by counting between 1 and 5 HPFs/biopsy. A proliferation quotient (PQ) was obtained by dividing the number of Ki67+ epithelial nuclei in the upper half by the lower half of the mucosa, using two HPFs. Mean kappa values were 0.24, 0.71 and 0.52 for H&E, p53 and Ki67 evaluations, respectively. There was a correlation between increasing severity of dysplasia, IHC measurable overexpression of p53 and shift of the mucosal proliferation zone towards the surface, measured as PQ.

CONCLUSIONS

The described methods for p53 and Ki67 evaluation are more reproducible than routine H&E evaluation of BE. Furthermore, the IHC methods correlate with the severity of dysplasia and are useful supplementary prognostic markers.

Cyclin D1 overexpression is a negative predictive factor for tamoxifen response in postmenopausal breast cancer patients

Antioestrogen treatment by tamoxifen is a well-established adjuvant therapy for oestrogen receptor-alpha (ERα) positive breast cancer. Despite ERα expression some tumours do not respond to tamoxifen and we therefore delineated the potential link between the cell cycle regulator and ERα co-factor, cyclin D1, and tamoxifen response in a material of 167 postmenopausal breast cancers arranged in a tissue array. The patients had been randomised to 2 years of tamoxifen treatment or no treatment and the median follow-up time was 18 years. Interestingly in the 55 strongly ERα positive samples with moderate or low cyclin D1 levels, patients responded to tamoxifen treatment whereas the 46 patients with highly ERα positive and cyclin D1 overexpressing tumours did not show any difference in survival between tamoxifen and no treatment. Survival in untreated patients with cyclin D1 high tumours was slightly better than for patients with cyclin D1 low/moderate tumours. However, there was a clearly increased risk of death in the cyclin D1 high group compared to an age-matched control population. Our results suggest that cyclin D1 overexpression predicts for tamoxifen treatment resistance in breast cancer, which is line with recent experimental data using breast cancer cell lines and overexpression systems.

Expression of vascular endothelial growth factor protein in human renal cell carcinoma

OBJECTIVE

To evaluate the effect of vascular endothelial growth factor (VEGF, one of the most important angiogenetic factors) in renal cell carcinoma (RCC) by analysing many RCCs for the expression of immunohistochemical (IHC) VEGF-staining related to clinicopathological findings and survival.

PATIENTS AND METHODS

VEGF immunostaining was examined with the tissue microarray (TMA) method on tumour samples from 229 patients and validated in 71 by ordinary tissue sections (TS). IHC VEGF expression was quantified by estimating the volume density and staining intensity on a three-grade scale.

RESULTS

In most RCCs there was VEGF staining in the cell cytoplasm and membrane. In cell membranes the VEGF expression declined with storage time. IHC VEGF expression analysed by TMA and TS gave corresponding results. There was no difference in VEGF expression among conventional, papillary and chromophobe RCCs. There were significant correlations between VEGF expression and tumour size and stage. In univariate analysis VEGF expression correlated with survival, especially in conventional RCCs; this prognostic information was lost in multivariate analysis. The VEGF staining intensity correlated only with VEGF expression but not with any clinicopathological factors.

CONCLUSIONS

VEGF protein was present in most RCC cells. There was no difference in VEGF expression among the different RCC types. The correlation between VEGF expression and tumour stage and with prognosis indicates the significance of VEGF within tumour growth and progression in RCC.

Tissue microarray analyses of G1/S-regulatory proteins in ductal carcinoma in situ of the breast indicate that low cyclin D1 is associated with local recurrence

Ductal carcinoma in situ (DCIS) of the breast constitutes about 10% of all diagnosed breast cancers and, despite surgical removal, it may recur, either as DCIS or invasive breast cancer. Nuclear grade and growth pattern according to Andersen et al as well as surgical margins are factors that have been used to predict local recurrence, but ideally a set of tumour-specific factors should be identified and used as prognostic markers. Many cell cycle regulatory gene products have been shown to be involved in the formation of tumours and are either oncogenes or suppressor genes and involved in key processes in the transformation. We therefore characterised the cell cycle regulators cyclin E, cyclin D1, p27 and p16 in a material of DCIS cases arranged in a tissue microarray. With a manual tissue arrayer, 52% of the initial 177 DCIS samples were successfully targeted allowing immunohistochemical analyses of all four proteins in 92 cases of DCIS. As also observed in invasive breast cancer, there was a trend indicating that DCIS cases with high cyclin D1 were cyclin E low and oestrogen receptor-positive, whereas cyclin E high DCIS cases were cyclin D1 low and oestrogen receptor-negative. For the 64 patients that did not receive postoperative radiotherapy, there were 16 local recurrences (eight DCIS and eight invasive breast cancer) during a mean follow-up time of 63 months. Cyclin E, p27 or p16 were not associated with local recurrence, but interestingly cyclin D1 was significantly and inversely associated with local recurrence, both using univariate and multivariate analyses. In summary, using a tissue array approach we have shown that cyclin D1, besides growth pattern, is a prognostic marker for local recurrence in DCIS.

Expression of cyclin D1, D3, E, and p27 in human renal cell carcinoma analysed by tissue microarray

Aberrations in the G1/S transition of the cell cycle have been observed in many malignancies and seem to be critical in the transformation process. Few studies have delineated the presence of G1/S regulatory defects and their clinical relevance in renal cell carcinoma (RCC). Therefore, we have examined the protein contents of cyclin D1, D3, E, and p27 in 218 RCCs, using tissue microarray and immunohistochemistry. The results from a subset of tumours were confirmed by Western blotting and immunohistochemical staining of regular tissue sections. Interestingly, low protein contents of cyclin D1 and p27 were associated with high nuclear grade, large tumour size, and poor prognosis for patients with conventional tumours. We further observed substantial differences in the pattern of G1/S regulatory defects between the different RCC subtypes. The majority of both conventional and papillary cases expressed p27; however, chromophobe tumours generally lacked p27 staining. In addition, conventional RCCs often expressed high cyclin D1 protein levels, while papillary RCCs exhibited high cyclin E. In summary, we have shown that G1/S regulatory defects are present in RCC and are associated with clinico-pathological parameters. The pattern of cell cycle regulatory defects also differed between RCC subtypes.

Downregulation of the potential suppressor gene IGFBP-rP1 in human breast cancer is associated with inactivation of the retinoblastoma protein, cyclin E overexpression and increased proliferation in estrogen receptor negative tumors

The complex insulin-like growth factor network of ligands, receptors and binding proteins has been shown to be disturbed in breast cancer. In addition to defects in proteins controlling cell cycle checkpoints, this type of aberrations could affect tumor growth and survival thereby influencing both tumor aggressiveness and potential response to treatments. We have previously identified the T1A12/mac25 protein, which is identical to the IGFBP-rP1, as a differentially expressed gene product in breast cancer cells compared with normal cells. Here we compare the expression of IGFBP-rP1 in 106 tumor samples with known status of cell cycle aberrations and other clinicopathological data. This was done using a tumor tissue section array system that allows for simultaneous immunohistochemical staining of all samples in parallel. Cytoplasmic staining of variable intensity was observed in most tumors, 15% lacked IGFBP-rP1 staining completely, 20% had weak staining, 32% intermediate and 33% showed strong staining. Low IGFBP-rP1 was associated with high cyclin E protein content, retinoblastoma protein (pRb) inactivation, low bcl-2 protein, poorly differentiated tumors and higher stage. There was a significantly impaired prognosis for patients with low IGFBP-rP1 protein tumors. Interestingly, IGFBP-rP1 showed an inverse association with proliferation (Ki-67%) in estrogen receptor negative tumors as well as in cyclin E high tumors suggesting a separate cell cycle regulatory function for IGFBP-rP1 independent of interaction with the estrogen receptor or the pRb pathway.

Methylation of the p16(Ink4a) tumor suppressor gene 5'-CpG island in breast cancer

Methylation of the p16(Ink4a) tumor suppressor gene 5'CpG island was analyzed in 104 primary breast cancer specimens using Southern blotting and methylation specific polymerase chain reaction (PCR) (MSP). Eight and four tumors, respectively, showed methylation, and all MSP positive tumors were detected by Southern blotting. To investigate possible methylation not detectable by these methods, bisulphite genomic sequencing was performed in 220 clones from 14 selected tumors. Absent methylation or methylation of single CpG dinucleotides prevailed in all tumors, but of the MSP positive tumors, three contained alleles with methylation of 31 or 32 of the 32 analyzed CpG dinucleotides in the island. Partially methylated alleles were also observed. In a group with low p16(Ink4a) expression determined by Western blotting, four randomly selected tumors contained several identical clones with methylation of 15 CpG dinucleotides by bisulphite genomic sequencing but with a methylation pattern that did not support detection by either Southern blotting or MSP, increasing the potential significance of p16(Ink4a) methylation in breast cancer.

p53 expression in correlation to clinical outcome in patients with renal cell carcinoma

OBJECTIVE

The aim of this study was to evaluate the role of p53 as prognostic factor in renal cell carcinoma (RCC) and its relation to clinicopathological factors.

MATERIAL AND METHODS

The nuclear accumulation of p53 protein was determined by immunohistochemical analysis in RCC specimens from 90 patients and was correlated with clinical stage, grade, DNA ploidy, S-phase fraction and cancer-specific survival.

RESULTS

p53 overexpression was observed in 17 of 90 (19%) tumours. There was a significant correlation to stage (p = 0.016) and grade (p = 0.020) but not to DNA ploidy or S-phase. Patients with high p53 immunoreactivity had shorter cancer-specific survival (p = 0.003) than those with normal p53 protein expression. This difference was found in papillary and chromophobe tumour types (p < 0.0001) but not in conventional RCC.

CONCLUSIONS

In patients with RCC, significant correlations between p53 protein expression and tumour stage, grade and survival time were observed. For patients with chromophobe and papillary tumour types, but not in conventional RCC, p53 immunoreactivity gave prognostic information, suggesting that the prognostic differences in p53 immunoreactivity might be due to disparate genetic abnormalities in the different RCC types.

Prognostic implications of p27 and cyclin E protein contents in malignant lymphomas

The G1/S transition in the cell cycle is one of the checkpoints that can be deregulated in tumor development potentially causing increased proliferation and impaired capacity to arrest genetically damaged cells. The balance between activating and inhibitory molecules acting in the check point area seems to be critical and overexpression of cyclins and/or downregulation of the cdk inhibitors have been observed in many malignancies including lymphomas. In this review we have focused on two of the interplayers in the G1/S transition namely cyclin E and p27, and present the current knowledge of aberrations affecting these proteins in lymphomas as well as associations with clinico-pathological data including survival.

Human colorectal cancers with an intact p16/cyclin D1/pRb pathway have up-regulated p16 expression and decreased proliferation in small invasive tumor clusters

A systematic spatial heterogeneity with high proliferative activity at the luminal border and low activity at the invasive margin is an unexpected behavior that has been observed in colorectal cancer (CRC). To clarify this phenomenon and possible underlying regulatory mechanisms, we have by immunohistochemistry elucidated the proliferative activity and the expression of G1/S regulatory proteins in small and large tumor cell clusters at the invasive margin in 97 CRCs. By identifying small tumor clusters at the tumor front, actually invading cancer cells could be characterized and analyzed separately. These cells could then be compared with the main tumor mass represented by the larger tumor clusters. The proliferation was significantly lower in small tumor clusters compared with larger clusters (P < 0.001) and the decrease in proliferation was correlated with a p16 up-regulation (r(s) = -0.41, P < 0.001). Interestingly, CRCs lacking p16 expression (18%) or tumors with other aberrations in the p16/cyclin D1/pRb pathway had a less pronounced decrease in proliferation between large and small clusters (P < 0.001), further strengthening the association between p16 and ceased proliferation at the invasive margin. This contrasts to tumors with low p27 or abnormal p53 levels showing sustained proliferation in small tumor clusters. Our findings imply that invading CRC cells generally have low proliferative activity, and this phenomenon seems to be mediated through p16 and the p16/cyclin D1/pRb pathway.

Factors of importance for prediction of survival in patients with metastatic renal cell carcinoma, treated with or without nephrectomy

OBJECTIVE

The indications for nephrectomy in patients with metastatic renal cell carcinoma remain controversial. A number of variables were analysed to identify factors that might predict the survival time, and these factors were used to obtain guidance as to which patients might benefit from palliative nephrectomy.

MATERIAL AND METHODS

We reviewed the medical records for 106 consecutive patients with primary metastatic renal cell carcinoma, including clinicopathological factors, routine laboratory data and metastatic spread. The association of the different factors to survival time was evaluated by univariate and multivariate analysis.

RESULTS

A number of factors correlated to survival time in univariate analysis, including solitary versus multiple metastases, serum albumin and DNA ploidy, but after Cox multivariate analysis their significance was lost. The remaining independent prognostic factors were performance status, number of metastatic sites, erythrocyte sedimentation rate (ESR), calcium in serum and vein invasion with tumour thrombus formation. The factors with no association to survival time were the metastatic sites, tumour size and nuclear grade. Patients treated with nephrectomy had a significantly longer survival time than those who did not undergo nephrectomy (p < 0.001). None of the 28 patients who did not undergo nephrectomy survived for 2 years, compared with 38 of the 78 patients who were nephrectomized.

CONCLUSIONS

Patients who can be expected to survive longer, and who might be recommended for nephrectomy despite metastatic disease, would have the following independent factors: a good performance status, metastases limited to one organ, low ESR, normal calcium in serum and no tumour thrombus formation.