Combining Mass Cytometry Data by CyTOFmerge Reveals Additional Cell Phenotypes in the Heterogeneous Ovarian Cancer Tumor Microenvironment: A Pilot Study

The prognosis of high-grade serous ovarian carcinoma (HGSOC) is poor, and treatment selection is challenging. A heterogeneous tumor microenvironment (TME) characterizes HGSOC and influences tumor growth, progression, and therapy response. Better characterization with multidimensional approaches for simultaneous identification and categorization of the various cell populations is needed to map the TME complexity. While mass cytometry allows the simultaneous detection of around 40 proteins, the CyTOFmerge MATLAB algorithm integrates data sets and extends the phenotyping. This pilot study explored the potential of combining two datasets for improved TME phenotyping by profiling single-cell suspensions from ten chemo-naïve HGSOC tumors by mass cytometry. A 35-marker pan-tumor dataset and a 34-marker pan-immune dataset were analyzed separately and combined with the CyTOFmerge, merging 18 shared markers. While the merged analysis confirmed heterogeneity across patients, it also identified a main tumor cell subset, additionally to the nine identified by the pan-tumor panel. Furthermore, the expression of traditional immune cell markers on tumor and stromal cells was revealed, as were marker combinations that have rarely been examined on individual cells. This study demonstrates the potential of merging mass cytometry data to generate new hypotheses on tumor biology and predictive biomarker research in HGSOC that could improve treatment effectiveness.

A phase I prospective, non-randomized trial of autologous dendritic cell-based cryoimmunotherapy in patients with metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is an immunologically cold disease with dismal outcomes. Cryoablation destroys cancer tissue, releases tumor-associated antigens and creates a pro-inflammatory microenvironment, while dendritic cells (DCs) activate immune responses through processing of antigens. Immunotherapy combinations could enhance the anti-tumor efficacy. This open-label, single-arm, single-center phase I trial determined the safety and tolerability of combining cryoablation and autologous immature DC, without and with checkpoint inhibitors. Immune responses and clinical outcomes were evaluated. Patients with mCRPC, confirmed metastases and intact prostate gland were included. The first participants underwent prostate cryoablation with intratumoral injection of autologous DCs in a 3 + 3 design. In the second part, patients received cryoablation, the highest acceptable DC dose, and checkpoint inhibition with either ipilimumab or pembrolizumab. Sequentially collected information on adverse events, quality of life, blood values and images were analyzed by standard descriptive statistics. Neither dose-limiting toxicities nor adverse events > grade 3 were observed in the 18 participants. Results indicate antitumor activity through altered T cell receptor repertoires, and 33% durable (> 46 weeks) clinical benefit with median 40.7 months overall survival. Post-treatment pain and fatigue were associated with circulating tumor cell (CTC) presence at inclusion, while CTC responses correlated with clinical outcomes. This trial demonstrates that cryoimmunotherapy in mCRPC is safe and well tolerated, also for the highest DC dose (2.0 × 10⁸) combined with checkpoint inhibitors. Further studies focusing on the biologic indications of antitumor activity and immune system activation could be considered through a phase II trial focusing on treatment responses and immunologic biomarkers.

A novel age-related gene expression signature associates with proliferation and disease progression in breast cancer

BACKGROUND AND OBJECTIVE

Breast cancer (BC) diagnosed at ages <40 years presents with more aggressive tumour phenotypes and poorer clinical outcome compared to older BC patients. Here, we explored transcriptional BC alterations to gain a better understanding of age-related tumour biology, also subtype-stratified.

METHODS

We studied publicly available global BC mRNA expression (n = 3999) and proteomics data (n = 113), exploring differentially expressed genes, enriched gene sets, and gene networks in the young compared to older patients.

RESULTS

We identified transcriptional patterns reflecting increased proliferation and oncogenic signalling in BC of the young, also in subtype-stratified analyses. Six up-regulated hub genes built a novel age-related score, significantly associated with aggressive clinicopathologic features. A high 6 Gene Proliferation Score (6GPS) demonstrated independent prognostic value when adjusted for traditional clinicopathologic variables and the molecular subtypes. The 6GPS significantly associated also with disease-specific survival within the luminal, lymph node-negative and Oncotype Dx intermediate subset.

CONCLUSIONS

We here demonstrate evidence of higher tumour cell proliferation in young BC patients, also when adjusting for molecular subtypes, and identified a novel age-based six-gene signature pointing to aggressive tumour features, tumour proliferation, and reduced survival-also in patient subsets with expected good prognosis.

Abstract 3879: High dimensional analysis of tumor microenvironment and heterogeneity in FIGO IB endometrial carcinomas using imaging mass cytometry

Patients with localized endometrial carcinomas (FIGO IA and IB) have a 5-year relative survival rate of &gt; 90%. Still, some patients with an expected good prognosis experience recurrence of disease which dramatically reduces survival rates. Currently, we lack the knowledge to predict which patients will get recurrence. We used Imaging Mass Cytometry to examine 27 proteins in tissue microarrays of 36 primary FIGO IB endometrial carcinomas, of which 17 later recurred. High dimensional images were segmented to extract single-cell information for each tumor. Distinct epithelial-, stromal- and immune cell types of the tumor microenvironment were identified and phenotyped, using protein expression intensities and unsupervised cell clustering. Neighboring cells of CD8+ cells were extracted and phenotyped. In non-recurrent tumors, more cytotoxic T cells were identified adjacent to two epithelial cell populations characterized by high vimentin and progesterone receptor expression (p &lt; 0.01 and p = 0.02). Tumors that were enriched for vimentin showed significantly better recurrence-free survival than tumors with low vimentin or high alpha-smooth muscle actin (a-SMA) signal (p = 0.026). This study reveals distinct characteristics in the microenvironment of low stage tumors that may aid in identifying high-risk patients. Further, the study provides new insight on the pathogenic processes involved in tumor progression of endometrial cancer.

Citation Format: Hilde Eide Lien, Hege Fredriksen Berg, Erling Andre Hoivik, Jone Trovik, Ingfrid Salvesen Haldorsen, Lars Andreas Akslen, Camilla Krakstad. High dimensional analysis of tumor microenvironment and heterogeneity in FIGO IB endometrial carcinomas using imaging mass cytometry [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3879.

Abstract 2695: Identification of an age-related breast cancer gene expression signature with strong prognostic value

Background and Objective: Breast cancer (BC) diagnosed at ages &lt;40 years is known to present more aggressive tumor phenotypes and poorer clinical outcome compared to older BC patients. To gain a better understanding of the possible age-related expression difference in BC promoting genes, we aimed to identify transcriptional alterations supporting cancer progression in BC of the young.

Methods: We studied mRNA gene expression data from METABRIC discovery (n=997), and validation cohort (n=995), and explored the transcriptional patterns associated with BC of the young. We investigated differentially expressed genes (DEGs) between primary BC for patients below and above 40 years at time of diagnosis and explored gene sets (by Gene Set Enrichment Analysis) enriched in BC of the young. Protein-protein interaction (PPI) networks were explored by the STRING database and visualized in Cytoscape software. Hub genes were identified by MCODE and CytoHubba plugins.

Results: Among genes differentially expressed between BC of the young and older, 91 DEGs were commonly (for the two cohorts) upregulated and 99 commonly downregulated in the young (Fold change ≥1.5/≤ -1.5). Oncogenic- and proliferation associated signatures were enriched in the young BC, including signatures reflecting KRAS, MTOR and MYC. Proliferation and cell cycle processes were the dominating enriched gene ontology categories (FDR &lt;10%). Six hub genes presenting highest PPI network connectivity were identified, described to be associated with the cell cycle and cell proliferation. A signature score was made by summarizing the hub genes expression values. High signature score was significantly associated with high tumor size, high histologic grade, lymph node metastasis, ER negativity, basal-like, and HER2 enriched subtypes (P &lt;0.001). The signature score showed strong correlation with the proliferation signatures OncotypeDx and PCNA (ρ=0.90-0.96, P &lt;0.001). Our signature score associated with reduced cancer specific survival (P &lt;0.001), also when adjusted for tumor size, histologic grade, and lymph node status in multivariate analyses in both cohorts (HR: 1.074-1.081, 95% CI: 1.046-1.109, P ≤0.003). The signature score maintained independent, significant association with survival when adjusting for the traditional clinico-pathologic variables in OncotypeDx-low tumors in discovery (HR: 1.077, 95% CI: 1.034-1.122) and validation cohort (HR: 1.154, 95% CI: 1.065-1.251), both P &lt;0.001.

Conclusion: By genome-wide gene expression analyses, the current study provides new insights into age-related gene expression alterations in breast cancer. We demonstrate enrichment of oncogenic signaling and evidence of higher tumor cell proliferation in young BC patients, and identify a gene expression signature reflecting tumor proliferation, aggressive tumor features and reduced survival, also in subsets of low OncotypeDx score.

Citation Format: Lise Martine Ingebriktsen, Lars Andreas Akslen, Elisabeth Wik. Identification of an age-related breast cancer gene expression signature with strong prognostic value [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2695.

Prognostic and predictive impact of stroma cells defined by PDGFRb expression in early breast cancer: results from the randomized SweBCG91RT trial

Purpose

Predictive biomarkers are needed to aid the individualization of radiotherapy (RT) in breast cancer. Cancer-associated fibroblasts have been implicated in tumor radioresistance and can be identified by platelet-derived growth factor receptor-beta (PDGFRb). This study aims to analyze how PDGFRb expression affects RT benefit in a large randomized RT trial.

Methods

PDGFRb was assessed by immunohistochemistry on tissue microarrays from 989 tumors of the SweBCG91RT trial, which enrolled lymph node-negative, stage I/IIA breast cancer patients randomized to RT after breast-conserving surgery. Outcomes were analyzed at 10 years for ipsilateral breast tumor recurrence (IBTR) and any recurrence and 15 years for breast cancer specific death (BCSD).

Results

PDGFRb expression correlated with estrogen receptor negativity and younger age. An increased risk for any recurrence was noted in univariable analysis for the medium (HR 1.58, CI 95% 1.11–2.23, p = 0.011) or PDGFRb high group (1.49, 1.06–2.10, p = 0.021) compared to the low group. No differences in IBTR or BCSD risk were detected. RT benefit regarding IBTR risk was significant in the PDGFRb low (0.29, 0.12–0.67, p = 0.004) and medium (0.31, 0.16–0.59, p < 0.001) groups but not the PDGFRb high group (0.64, 0.36–1.11, p = 0.110) in multivariable analysis. Likewise, risk reduction for any recurrence was less pronounced in the PDGFRb high group. No significant interaction between RT and PDGFRb-score could be detected.

Conclusion

A higher PDGFRb-score conferred an increased risk of any recurrence, which partly can be explained by its association with estrogen receptor negativity and young age. Reduced RT benefit was noted among patients with high PDGFRb, however without significant interaction.

The Role of Calcitonin in Predicting the Extent of Surgery in Medullary Thyroid Carcinoma: A Nationwide Population-Based Study in Norway

BACKGROUND

Preoperative predictors for the need of prophylactic lymph node dissection in the lateral neck have been studied in patients with medullary thyroid carcinoma (MTC).

OBJECTIVES

To evaluate the ability of serum calcitonin to predict the extent of surgery needed in the lateral neck.

METHODS

This retrospective population-based cohort study includes data from 94 of 139 patients with MTC surgically treated in Norway from 2003 to 2016. Patients were identified in the 4 regional centers treating MTC and by the Cancer Registry of Norway, and grouped according to calcitonin levels. In 58 patients without distant metastases or disease progression to the next tumor level (NPNL), data were compared in prognostic groups (N0-NPNL), (N1a-NPNL), and (N1b-NPNL).

RESULTS

At calcitonin levels ≤500, 501-1,000, and >1,000 pmol/L, metastatic lymph nodes in the lateral neck were found in 16, 50, and 71% of the patients, respectively. In the prognostic groups, 19% of N0-NPNL patients had calcitonin >500 pmol/L and 17% of N1b-NPNL patients had calcitonin ≤500 pmol/L. In multivariate analysis, factors predicting biochemical cure and calcitonin level ≤500 pmol/L were no metastatic lymph nodes in the lateral neck (p = 0.030) and tumor diameter ≤20 mm (p < 0.001), respectively. Factors related to metastatic lymph nodes in the lateral neck were extrathyroidal extension (p = 0.007) and no biochemical cure (p = 0.028).

CONCLUSIONS

Basal calcitonin cannot predict the need for prophylactic lateral lymph node dissection in patients with MTC. Further prospective, randomized studies are warranted.

Trends in Diagnostics, Surgical Treatment, and Prognostic Factors for Outcomes in Medullary Thyroid Carcinoma in Norway: A Nationwide Population-Based Study

BACKGROUND

Medullary thyroid carcinoma (MTC) is rare. Nationwide population-based studies are important to evaluate its clinical course.

OBJECTIVES

To describe all patients with MTC in Norway during 1994-2016 and compare time-related trends in diagnostics and surgical treatment, including prognostic factors for biochemical cure and disease-specific survival (DSS).

METHODS

This retrospective population-based cohort study includes data for 228 out of 237 patients (96%) with MTC; 201 patients were surgically treated. Patients were identified in the 4 regional centers treating MTC and by the Cancer Registry of Norway. Data were collected from patients' files. Trends were compared over 2 study periods.

RESULTS

MTC accounted for 4.2% of thyroid carcinomas. During the study periods, the incidence increased from 0.18 to 0.25: 100,000 per year, preoperative diagnostics improved with increased use of calcitonin, ultrasound, and fine-needle cytology (p = 0.010, p < 0,001, and p = 0.001), patients were diagnosed at an earlier tumor stage (p = 0.004), and more patients were cured (p = 0.002). Via multivariate analysis of patients with metastatic lymph nodes, independent prognostic factors for cure were: a low ratio of metastatic and total number of dissected lymph nodes (p = 0.021) and no extrathyroidal extension (p = 0.030). Independent prognostic factors for DSS were: no distant metastasis, a younger age, and a low ratio of metastatic and dissected lymph nodes (p = 0.005, p = 0.020, p = 0.022).

CONCLUSIONS

Preoperative diagnostics have improved over time with increased therapeutic control. A low ratio of metastatic and dissected lymph nodes predicts better outcomes in patients with metastatic lymph nodes.

Asparaginase-like protein 1 expression in curettage independently predicts lymph node metastasis in endometrial carcinoma: a multicentre study

OBJECTIVE

Correct preoperative identification of high-risk patients is important to optimise surgical treatment and improve survival. We wanted to explore if asparaginase-like protein 1 (ASRGL1) expression in curettage could predict lymph node metastases and poor outcome, potentially improving preoperative risk stratification.

DESIGN

Multicentre study.

SETTING

Ten hospitals in Norway, Sweden and Belgium.

POPULATION

Women diagnosed with endometrial carcinoma.

METHODS

ASRGL1 expression in curettage specimens from 1144 women was determined by immunohistochemistry.

MAIN OUTCOME MEASURES

ASRGL1 status related to disease-specific survival, lymph node status, preoperative imaging parameters and clinicopathological data.

RESULTS

ASRGL1 expression had independent prognostic value in multivariate survival analyses, both in the whole patient population (hazard ratio (HR) 1.63, 95% CI 1.11-2.37, P = 0.012) and in the low-risk curettage histology subgroup (HR 2.54, 95% CI 1.44-4.47, P = 0.001). Lymph node metastases were more frequent in women with low expression of ASRGL1 compared with women with high ASRGL1 levels (23% versus 10%, P < 0.001), and low ASRGL1 level was found to independently predict lymph node metastases (odds ratio 2.07, 95% CI 1.27-3.38, P = 0.003).

CONCLUSIONS

Low expression of ASRGL1 in curettage independently predicts lymph node metastases and poor disease-specific survival.

TWEETABLE ABSTRACT

Low ASRGL1 expression in curettage predicts lymph node metastasis and poor survival in endometrial carcinoma.

Abstract P4-12-02: Serum-triglycerides among triple negative breast cancer patients as a biomarker of poor outcome

Backgound: Obesity and related metabolic imbalances, including increased activity of free fatty acids, may promote tumor growth and metastasis. Fatty acids are mainly stored as triacylglycerols. Yet, the role of serum-triglycerides on breast cancer prognosis is still undefined.

Methods: A population based survival study among 575 breast cancer patients identified within the Tromsø study during 1979-2008, was conducted. Pre-diagnostic serum triglycerides, high density lipoprotein-cholesterol, total cholesterol, height and weight were measured. Histopathological and clinical data were obtained from medical records, and hormone receptor, HER2 status, and Ki-67 were re-analyzed on tissue microarray blocks. Multivariate Cox proportional Hazard regression models were used to study the associations between patient characteristics including s-triglycerides, and breast cancer survival.

Results: Among 575 women with invasive breast cancer (stage 1-3), a total of 87 women were diagnosed with triple negative breast cancer (TNBC). Patients diagnosed with TNBC, compared to non-TNBC, were likely to be younger at diagnosis (55.3 vs 57.9 years, p=0.061), they had larger tumors (29.7 mm vs 22.5 mm, p=0.001), and higher Ki-67 (31.1% vs 15.9%, p&lt;0.001). After a mean follow-up of 8.4 years, TNBC patients with above median levels of s-triglycerides (&gt; 0.98mmol/L) compared to TNBC patients with below median levels of s-triglycerides (≤ 0.98mmol/L) had 3.0 times higher risk for breast cancer recurrence or breast cancer specific death (HR 3.02, 95% CI 1.21-7.55), and 3.4 times higher overall mortality risk (HR 3.41, 95% CI 1.38-8.45). Among the TNBC patients, women with above median s-triglycerides had 15% lower 5-year disease-free survival (76% vs 91%) and 18% lower 5-year overall survival (74% vs 92%) compared to women with below median s-triglycerides.

Conclusions: Our results strongly support s-triglycerides as an important biomarker for breast cancer outcomes among triple negative breast cancer patients.

Table 1: Multivariable adjusted Hazard Ratios (HRs) for incidence breast cancer recurrence or breast cancer specific death, and incidence overall mortality by pre-diagnostic serum-triglycerides among non-triple negative breast cancer (TNBC) and TNBC patients  Non-TNBC, n=488 TNBC, n=87  Recurrence or breast cancer specific death (n=90)Overall mortality (n=104) Recurrence or breast cancer specific death (n=24)Overall mortality (n=33) nHR (95% CI)HR (95% CI)nHR (95% CI)HR (95% CI)s-Triglycerides      Median      ≤ 0.98 mmol/l2571.001.00431.001.00&gt; 0.98 mmol/l2310.87 (0.56-1.35)1.06 (0.70-1.62)443.02 (1.21-7.55)3.41 (1.38-8.45)       Tertiles      ≤ 0.82 mmol/l1731.001.00261.001.000.83 – 1.22 mmol/l1660.74 (0.44-1.23)0.81 (0.49-1.36)311.37 (0.38-4.98)0.98 (0.31-3.08)≥ 1.23 mmol/l1490.88 (0.50-1.54)1.17 (0.66-1.96)306.63 (1.64-19.3)3.87 (1.52-12.0)p-trend 0.4950.357 0.0050.007       Multivariate Cox proportional Hazard regression model. Adjusted for BMI and age at attendance (continuous), age at diagnosis (continuous), breast cancer stage at diagnosis (categorical), and current smoking (categorical). Abbreviation: CI, confidence interval; n, number of cases; TNBC, triple negative breast cancer

Citation Format: Lofterød T, Mortensen ES, Nalwoga H, Wilsgaard T, Frydenberg H, Risberg T, Eggen AE, McTiernan A, Aziz S, Wist EA, Reitan JB, Akslen LA, Thune I. Serum-triglycerides among triple negative breast cancer patients as a biomarker of poor outcome [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 P4-12-02.

Cutaneous head and neck melanoma (CHNM): A population-based study of the prognostic impact of tumor location

BACKGROUND

Most studies of cutaneous head and neck melanomas (CHNM) have reported poorer survival in CHNM compared with other sites, especially on the scalp/neck.

OBJECTIVE

We sought to compare patient and tumor characteristics between CHNM and cutaneous trunk and extremity melanomas and between CHNM locations (face/ear vs scalp/neck, anterior vs posterior), and to study prognostic factors in patients with CHNM.

METHODS

We studied all CHNM (n = 1074) from 8120 cases of cutaneous melanomas diagnosed in Norway in 2008 to 2012.

RESULTS

Compared with cutaneous trunk and extremity melanomas, CHNM were more frequently found in men, more often nodular and lentigo maligna cutaneous melanomas, and diagnosed at higher T stage (P ≤ .01). CHNM located on posterior sites were diagnosed at significantly higher T stage, and were significantly more often diagnosed with ulceration and at more advanced stage compared with CHNM located on anterior sites (P < .001). T stage and clinical stage were the only significant prognostic factors for melanoma-specific and overall death in the multivariable analysis (P < .001).

LIMITATIONS

Low number of cases and the relatively high frequency of missing values are limitations.

CONCLUSION

More advanced CHNM were diagnosed on posterior compared with anterior locations, but location was not a significant prognostic factor for cutaneous melanoma-specific or overall death in the multivariable models.

A Nationwide Study of Multiple Endocrine Neoplasia Type 2A in Norway: Predictive and Prognostic Factors for the Clinical Course of Medullary Thyroid Carcinoma

BACKGROUND

Multiple endocrine neoplasia type 2A (MEN 2A) is an autosomal dominant syndrome caused by activating germline mutations in the RET (REarranged during Transfection) proto-oncogene. MEN 2A has a strong (>95%) and age-dependent (5-25 years) clinical penetrance of medullary thyroid carcinoma (MTC). Several major studies have analyzed the predictive and prognostic factors for MEN 2A to find indicators that predict the optimal timing of prophylactic thyroidectomy. The aims of this study were to describe all known RET positive MEN 2A patients diagnosed in Norway and to evaluate the clinical course of MTC, as well as its predictive and prognostic factors.

METHODS

This nationwide retrospective cohort study included data for 65 (14 index and 51 screening patients) out of a total of 67 MEN 2A patients with the RET gene mutation who were diagnosed in Norway since 1974. Data were collected by reviewing patient files. The variables analyzed were genotype, phenotype, preoperative basal calcitonin, age at thyroid surgery, central lymph node dissection and nodal status at primary surgery, number of surgical procedures, and biochemical cure. Of the 65 patients, 60 had undergone thyroid surgery. The median follow-up period was 9.9 years. The patients were divided into pre-RET-and RET-era, which included patients who had thyroid surgery before January 1, 1994, and after, respectively.

RESULTS

In index and screening patients, MTC was found, respectively, in 100% and 45% of cases, central lymph node dissection at primary surgery was done for 64% and 52% of patients, and the median total number of surgical procedures was two (range 1-6) and one (range 1-4). At primary surgery, all patients (n = 13) with lymph node metastases had preoperative basal calcitonin levels ≥68 pg/mL, and all patients (n = 17) without central lymph node dissection and preoperative basal calcitonin <40 pg/mL were biochemically cured. Multivariate analysis showed that preoperative basal calcitonin was a significant predictive factor for MTC superior to age at thyroid surgery when analyzing the entire period (p = 0.009) and the RET-era separately (p = 0.021). Prognostic factors for biochemical cure were preoperative basal calcitonin, central lymph node dissection, and nodal status at primary surgery (p = 0.037, p = 0.002, and p = 0.005) when analyzing the entire period, but only nodal status at primary surgery when the RET-era was considered separately (p = 0.006).

CONCLUSIONS

Preoperative basal calcitonin alone can serve as an indicator for optimal timing and the extent of thyroid surgery for MEN 2A patients that could be considered safe. The results are consistent with previously reported data.

Pre-diagnostic high-sensitive C-reactive protein and breast cancer risk, recurrence, and survival

Inflammation may initiate and promote breast cancer development, and be associated with elevated circulating levels of inflammation markers. A total of eight 130 initially healthy women, participated in the population-based Tromsø study (1994-2008). Pre-diagnostic high-sensitivity C-reactive protein (hs-CRP) was assessed. During 14.6 years of follow-up, a total of 192 women developed invasive breast cancer. These cases were followed for additional 7.2 years. Detailed medical records were obtained. We observed an overall positive dose-response relationship between pre-diagnostic hs-CRP and breast cancer risk (hazard ratio (HR) = 1.06, 95 % CI 1.01-1.11). Postmenopausal women with above median levels of hs-CRP (>1.2 mg/l) had a 1.42 (95 % CI 1.01-2.00) higher breast cancer risk compared to postmenopausal women with hs-CRP below median. Postmenopausal women, who were hormone replacement therapy non-users, and were in the middle tertile (0.8-1.9 mg/l), or highest tertile of hs-CRP (>1.9 mg/l), had a 2.31 (95 % CI 1.31-4.03) and 2.08 (95 % CI 1.16-3.76) higher breast cancer risk, respectively, compared with women in the lowest tertile. For each unit increase in pre-diagnostic hs-CRP levels (mg/l), we observed an 18 % increase in disease-free interval (95 % CI 0.70-0.97), and a 22 % reduction in overall mortality (95 % CI 0.62-0.98). Our study supports a positive association between pre-diagnostic hs-CRP and breast cancer risk. In contrast, increased pre-diagnostic hs-CRP was associated with improved overall mortality, but our findings are based on a small sample size, and should be interpreted with caution.

Abstract 4207: Secreted proteins from breast cancer cell lines as a source of cancer biomarkers

Introduction:

Breast cancer is a heterogeneous disease whose molecular diversity is not well reflected in clinical and microscopic markers used for prognostic information and treatment decisions. Traditionally, most biomarkers are based on tissue samples. To increase efficiency, precise liquid biopsies are needed to detect breast cancer at an early stage including its molecular phenotype, to monitor disease progression, and to predict treatment response. Cell line secretomes are enriched with proteins already linked to tumorigenesis, many of which will be present in biological fluids.

Methods:

Here, we studied the secreted proteins in conditioned media (CM) from two basal-like (HS-578, MB-231) and two luminal-like breast cancer cell lines (MCF-7, BT-474), using liquid chromatography-tandem mass spectrometry. The resulting data were analyzed using SearchGUI, PeptideShaker, Progenesis software and DAVID.

Results:

In total, 954 proteins were identified, of which 93 significantly differentially abundant (P-value ≤ 0.05 Mann-Whitney U, two or more peptides quantified) in the CM between basal-like and luminal-like cell lines. 76 proteins were more abundant in the CM from basal-like cell lines, including several proteins related to angiogenesis and extra-cellular matrix remodeling.

Conclusion:

This study shows the potential for using the secretome of breast cancer cell lines combined with mass-spectrometry for biomarker discovery.

Citation Format: Even Birkeland, Monica Mannelqvist, Lars Andreas Akslen. Secreted proteins from breast cancer cell lines as a source of cancer biomarkers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4207. doi:10.1158/1538-7445.AM2015-4207

Abstract 5285: Ki-67 expression and mitotic count in lymph node metastasis and their association with clinico-pathologic features and survival in aggressive breast carcinoma

Background: Proliferation markers in breast cancer are prognostic and might be predictive for therapy response. However, their prognostic and predictive power in lymph node metastasis is not well established. The aim of our study was to examine the prognostic role of these markers in lymph node metastasis in comparison with the matched primary tumor.

Study design: A retrospective series of node-positive breast cancers (n = 111) was used, as a part of the Norwegian Breast Cancer Screening Program (1996-2003). Sections from the largest node with metastasis (&gt; 2mm) were used. The percentage of Ki-67 staining per 500 tumor cells was counted in hot-spot areas. The mitotic count was determined in the most active areas, using 10 consecutive high power fields (x400), and the number of mitotic figures per mm2 was calculated. Assessment of Ki-67 expression and mitotic count was performed on corresponding primary tumors.

Results: The two proliferation markers were highly correlated between metastasis and their matched primary tumors (r = 0.58, 0.46 for Ki-67 and mitotic count, respectively). Ki-67% in metastasis was slightly but significantly lower than in their primary tumors (median = 15.8 vs 17.2, P = 0.013). In contrast, mitotic count in metastasis was slightly but significantly higher than in their primary lesions (median = 1.4 vs 1.2, P = 0.02). The proliferation markers in metastasis showed a significant association with known unfavorable prognostic features in the primary tumor, including tumor diameter, histologic grade, hormone receptor status, HER2 status and molecular subtype.

A subgroup of concordant cases with high proliferation (in matched metastasis and primary tumors) was significantly associated with large tumor diameter (&gt;2 cm), negative hormone receptors, positivity for Her2 status, as well as the triple negative molecular subtype.

Survival analysis (Kaplan-Meier method, log-rank test) for Ki-67 and mitosis alone in lymph node metastasis showed no statistical significant association with breast cancer specific survival. However, this association was significant when comparing the subgroup with concordant high proliferation to all other subgroups with different proliferation patterns (P = 0.01, 0.01 for Ki-67 and mitosis, respectively). In multivariate analysis, the subgroup with concordant high proliferation for Ki67, and tumor diameter, were the only prognostic factors of independent importance.

Conclusion: Proliferation markers in lymph node metastasis are strongly associated with the most unfavorable features of the primary tumors. Combined high proliferation in metastases and primary lesions is associated with reduced breast cancer specific survival. In multivariate analysis, combined high Ki67 was prognostic together with tumor diameter.

Citation Format: Sura M. Aziz, Elisabeth Wik, Gøril Knutsvik, Karin Collett, Lars Andreas Akslen. Ki-67 expression and mitotic count in lymph node metastasis and their association with clinico-pathologic features and survival in aggressive breast carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5285. doi:10.1158/1538-7445.AM2015-5285

Women treated with breast conserving surgery do better than those with mastectomy independent of detection mode, prognostic and predictive tumor characteristics

BACKGROUND

Primary breast conserving treatment (BCT) is well known to have similar long-term survival as mastectomy in breast cancer patients. However, recent studies are suggesting better survival among women treated with BCT compared with mastectomy. More knowledge is needed to understand how disease specific survival is influenced by detection mode, prognostic and predictive tumor characteristics. We aimed to investigate this issue among women targeted by the Norwegian Breast Cancer Screening Program.

METHOD

Information about 9547 women aged 50-69 years diagnosed with primary invasive breast cancer without distant metastasis, who underwent either BCT or mastectomy, 2005-2011, were included in the study. Kaplan-Meier plots were used to estimate six years survival, while Cox proportional hazards models were used to estimate the hazard ratio (HR) of breast cancer death associated with surgical treatment. Information about molecular subtype, detection mode, age at diagnosis, tumor size, lymph node involvement, and histologic grade, in addition to radiation treatment, chemotherapy and endocrine therapy were included in adjusted analyses.

RESULTS

BCT was performed among 61.9% of the women included in the study. Women treated with BCT had prognostic and predictive favorable tumor characteristics compared to women treated with mastectomy. Adjusted analyses revealed a 1.7 (95% CI: 1.3-2.4) higher risk of breast cancer death among women who underwent mastectomy compared with BCT.

CONCLUSION

Women treated with BCT have significantly better breast cancer-specific survival and a lower risk of dying from breast cancer compared to women treated with mastectomy, independent of detection mode, prognostic and predictive tumor characteristic.

Endometrial Carcinoma Recurrence Score (ECARS) validates to identify aggressive disease and associates with markers of epithelial-mesenchymal transition and PI3K alterations

PURPOSE

Our previously reported 29-gene expression signature identified an aggressive subgroup of endometrial cancer patients with PI3K activation. We here wanted to validate these findings by independent patient series.

PATIENTS AND METHODS

The 29-gene expression signature was assessed in fresh frozen tumor tissue from 280 primary endometrial carcinomas (three independent cohorts), 19 metastatic lesions and in 333 primary endometrial carcinomas using TCGA data, and expression was related to clinico-pathologic features and survival. The 29-gene signature was assessed by real-time quantitative PCR, DNA oligonucleotide microarrays, or RNA sequencing. PI3K alterations were assessed by immunohistochemistry, DNA microarrays, DNA sequencing, SNP arrays or fluorescence in situ hybridization. A panel of markers of epithelial-mesenchymal transition (EMT) was also correlated to the 29-gene signature score.

RESULTS

High 29-gene Endometrial Carcinoma Recurrence Score (ECARS) values consistently validated to identify patients with aggressive clinico-pathologic phenotype and reduced survival. Within the presumed favorable subgroups of low grade, endometrioid tumors confined to the uterus, high ECARS still predicted a poor prognosis. The score was higher in metastatic compared to primary lesions (P<0.001) and was significantly associated with potential measures of PI3K activation, markers of EMT and vascular invasion as an indicator of metastatic spread (all P<0.001).

CONCLUSIONS

ECARS validates to identify aggressive endometrial carcinomas in multiple, independent patients cohorts. The higher signature score in metastatic compared to primary lesions, and the potential link to PI3K activation and EMT, support further studies of ECARS in relation to response to PI3K and EMT inhibitors in clinical trials of metastatic endometrial carcinoma.

Increased microvascular proliferation is negatively correlated to tumour blood flow and is associated with unfavourable outcome in endometrial carcinomas

Background:

We aimed to study the angiogenic profile based on histomorphological markers in endometrial carcinomas in relation to imaging parameters obtained from preoperative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) and to explore the potential value of these markers to identify patients with poor outcome.

Methods:

In fifty-four surgically staged endometrial carcinoma patients, immunohistochemical staining with factor VIII and Ki67 allowed assessment of microvessel density (MVD) and microvascular proliferation reflecting tumour angiogenesis. In the same patients, preoperative pelvic DCE-MRI and DWI allowed the calculation of parameters describing tumour microvasculature and microstructure in vivo.

Results:

Microvascular proliferation was negatively correlated to tumour blood flow (Fb) (r=−0.36, P=0.008), capillary permeability surface area product (PS) (r=−0.39, P=0.004) and transfer from the blood to extravascular extracellular space (EES) (Ktrans) (r=−0.40, P=0.003), and was positively correlated to tumour volume (r=0.34; P=0.004). High-tumour microvascular proliferation, low Fb and low Ktrans were all significantly associated with reduced progression/recurrence-free survival (P<0.05).

Conclusion:

Disorganised angiogenesis with coexisting microvascular proliferation and low tumour blood flow is a poor prognostic factor supporting that hypoxia is associated with progression and metastatic spread in endometrial carcinomas.

Molecular subtypes, histopathological grade and survival in a historic cohort of breast cancer patients

Molecular subtyping of breast cancer may provide additional prognostic information regarding patient outcome. However, its clinical significance remains to be established. In this study, the main aims were to discover whether reclassification of breast cancer into molecular subtypes provides more precise information regarding outcome compared to conventional histopathological grading and to study breast cancer-specific survival in the different molecular subtypes. Cases of breast cancer occurring in a cohort of women born between 1886 and 1928 with long-term follow-up were included in the study. Tissue microarrays were constructed from archival formalin-fixed, paraffin-embedded tissue from 909 cases. Using immunohistochemistry and in situ hybridisation as surrogates for gene expression analyses, all cases were reclassified into the following molecular subtypes: Luminal A; Luminal B (HER2−); Luminal B (HER2+); HER2 subtype; Basal phenotype; and five negative phenotype. Kaplan–Meier survival curves and Cox proportional hazards models were used in the analyses. During the first 5 years after diagnosis, there were significant differences in prognosis according to molecular subtypes with the best survival for the Luminal A subtype and the worst for HER2 and five negative phenotype. In this historic cohort of women with breast cancer, differences in breast cancer-specific survival according to subtype occur almost exclusively amongst the histopathological grade 2 tumours. From 5 years after time of diagnosis until the end of follow-up, there appears to be no difference in survival according to molecular subtype or histopathological grade.

KRAS gene amplification and overexpression but not mutation associates with aggressive and metastatic endometrial cancer

BACKGROUND

Three quarter of endometrial carcinomas are treated at early stage. Still, 15 to 20% of these patients experience recurrence, with little effect from systemic therapies. Homo sapiens v-Ki-ras2 Kirsten rat sarcoma viral oncogenes homologue (KRAS) mutations have been reported to have an important role in tumorigenesis for human cancers, but there is limited knowledge regarding clinical relevance of KRAS status in endometrial carcinomas.

METHODS

We have performed a comprehensive and integrated characterisation of genome-wide expression related to KRAS mutations and copy-number alterations in primary- and metastatic endometrial carcinoma lesions in relation to clinical and histopathological data. A primary investigation set and clinical validation set was applied, consisting of 414 primary tumours and 61 metastatic lesions totally.

RESULTS

Amplification and gain of KRAS present in 3% of the primary lesions and 18% of metastatic lesions correlated significantly with poor outcome, high International Federation of Gynaecology and Obstetrics stage, non-endometrioid subtype, high grade, aneuploidy, receptor loss and high KRAS mRNA levels, also found to be associated with aggressive phenotype. In contrast, KRAS mutations were present in 14.7% of primary lesions with no increase in metastatic lesions, and did not influence outcome, but was significantly associated with endometrioid subtype, low grade and obesity.

CONCLUSION

These results support that KRAS amplification and KRAS mRNA expression, both increasing from primary to metastatic lesions, are relevant for endometrial carcinoma disease progression.

Peritoneal carcinosis in apparently benign cortisol producing adrenal adenoma ≥ 5 cm in diameter: the need of regular postoperative surveillance

BACKGROUND

Clinical and histopathological distinction between benign and malignant adrenocortical tumors can be a challenge.Report on 2 patients with cortisol producing apparently benign adrenal adenomas ≥ 5 cm in diameter with local malignant recurrence and peritoneal carcinomatosis after endoscopic surgery.

RESULTS

Case 1: The 59-year-old male presented with adrenal hypercortisolism due to a 5.0 cm large adrenal tumor on the left side. A retroperitoneoscopic total adrenalectomy was performed. Histologically, a benign adrenal adenoma (Weiss score 1, Ki-67 < 2%) was found. 6 months later, the patient developed clinically and biochemically recurrent disease with recurrent tumor in the left adrenal region and peritoneal carcinomatosis. The patient died 5 months after second surgery. Case 2: The 32-year-old female was pregnant in 27th week when presenting with adrenal hypercortisolism due to a 5.5 cm large adrenal tumor on the left side. She was operated on using a laparoscopic approach and a total adrenalectomy was carried out. Histological examination revealed a benign adrenocortical adenoma (Weiss score 1, Ki-67 < 5%). 4 years later, the patient came back with clinically and biochemically recurrent disease. Imaging showed a 10 cm large tumor in the left retroperitoneum and a diffuse peritoneal carcinomatosis. The patient died 2 months after diagnosis.

CONCLUSION

Cortisol producing adrenal tumors ≥ 5 cm in diameter are at risk to be misdiagnosed as apparently benign. Regular surveillance should be considered in patients presenting with large cortisol producing tumors.

Microvessel proliferation by co-expression of endothelial nestin and Ki-67 is associated with a basal-like phenotype and aggressive features in breast cancer

BACKGROUND

To quantify tumour angiogenesis, microvessel density (MVD) has been widely used. We here present a novel angiogenesis marker, microvessel proliferation (MVP), based on dual immunohistochemical staining of nestin and Ki-67. Immature endothelial cells express nestin, and when co-expressed with the proliferation marker Ki-67, the number of proliferating immature blood vessels can be measured.

MATERIALS AND METHODS

Microvessel proliferation was evaluated in 178 breast cancer samples and estimated by vascular proliferation index (VPI), the ratio between the number of vessels containing proliferating endothelial cells and the total number of immature vessels.

RESULTS

High VPI was strongly associated with several markers of aggressive breast cancer, such as negative oestrogen receptor (ER) status (p = 0.003), high tumour cell proliferation by Ki-67 (p = 0.004), high p53 expression (p = 0.001), and five profiles for the basal-like phenotype (odds ratios (OR); range 3.4-6.3). Also, high VPI was significantly associated with interval detected breast cancer compared with screening detected lesions (p < 0.0005), and adverse outcome in univariate and multivariate survival analysis (p = 0.034 and p = 0.022, respectively).

CONCLUSION

Microvessel proliferation is a novel marker of ongoing angiogenesis and was associated with aggressive tumour features, basal-like phenotypes, interval presentation, and prognosis in this series of breast cancer.

Abstract 1372: Microvessel proliferation by co-expression of endothelial nestin and Ki-67 is associated with a basal-like phenotype and aggressive features in breast cancer

Angiogenesis, the formation of new blood vessels from pre-existing ones, is essential in tumour growth and metastasis. Microvessel density (MVD) is the most widely used method for quantification of tumour angiogenesis. We here present a novel angiogenesis marker, microvessel proliferation (MVP) based on a dual immunohistochemical stain of nestin and Ki-67. Nestin is an intermediate filament protein expressed in a variety of undifferentiated cells, including newly synthesized endothelial cells (1-3), and used in this study to stain the vasculature. Proliferating cells were recognized by their Ki-67 positivity, and immature microvessels were recognized by their nestin positivity combined with their morphology. Proliferating microvessels contains endothelial cells co-expressing nestin and Ki-67. Microvessel proliferation was estimated by vascular proliferation index (VPI), the ratio of vessels containing immature proliferating endothelial cells, and the total number of immature vessels. VPI was evaluated in 178 breast cancer tissue sections. High VPI showed significant association to several markers of aggressive breast cancer, including negative estrogen receptor (ER) status (p=0.003), high tumour cell proliferation by Ki-67 (p=0.004), high p53 expression (p=0.001), five immunohistochemical profiles for the basal-like phenotype (odds ratios (OR); range 2.8-6.3), and the triple negative phenotype (TNP)(p=0.040). Concerning the mode of detection, high VPI was three times more likely to be presented in an interval detected breast cancer compared with a screening detected (OR: 3.0, p&lt;0.0005). Both in univariate and multivariate analysis, high VPI was significantly associated with poor survival (p=0.034 and p=0.022, respectively). In conclusion, activated angiogenesis, estimated by microvessel proliferation, is associated with several markers of aggressive breast cancer phenotype, basal-like breast cancer, interval detection, and a significant predictor of prognosis in this series of breast cancer. 1. Lendahl U, Zimmerman LB, McKay RD. CNS stem cells express a new class of intermediate filament protein. Cell. 1990 Feb 23;60(4):585-95. 2. Mokry J, Cizkova D, Filip S, Ehrmann J, Osterreicher J, Kolar Z, et al. Nestin expression by newly formed human blood vessels. Stem Cells Dev. 2004 Dec;13(6):658-64. 3. Mokry J, Ehrmann J, Karbanova J, Cizkova D, Soukup T, Suchanek J, et al. Expression of intermediate filament nestin in blood vessels of neural and non-neural tissues. Acta Medica (Hradec Kralove). 2008;51(3):173-9.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1372. doi:1538-7445.AM2012-1372

Loss of GPER identifies new targets for therapy among a subgroup of ERα-positive endometrial cancer patients with poor outcome

BACKGROUND

The G protein-coupled oestrogen receptor, GPER, has been suggested as an alternative oestrogen receptor. Our purpose was to investigate the potential of GPER as a prognostic and predictive marker in endometrial carcinoma and to search for new drug candidates to improve treatment of aggressive disease.

MATERIALS AND METHOD

A total of 767 primary endometrial carcinomas derived from three patient series, including an external dataset, were studied for protein and mRNA expression levels to investigate and validate if GPER loss identifies poor prognosis and new targets for therapy in endometrial carcinoma. Gene expression levels, according to ERα/GPER status, were used to search the connectivity map database for small molecular inhibitors with potential for treatment of metastatic disease for receptor status subgroups.

RESULTS

Loss of GPER protein is significantly correlated with low GPER mRNA, high FIGO stage, non-endometrioid histology, high grade, aneuploidy and ERα loss (all P-values ≤0.05). Loss of GPER among ERα-positive patients identifies a subgroup with poor prognosis that until now has been unrecognised, with reduced 5-year survival from 93% to 76% (P=0.003). Additional loss of GPER from primary to metastatic lesion counterparts further supports that loss of GPER is associated with disease progression.

CONCLUSION

These results support that GPER status adds clinically relevant information to ERα status in endometrial carcinoma and suggest a potential for new inhibitors in the treatment of metastatic endometrial cancers with ERα expression and GPER loss.

High BMI is significantly associated with positive progesterone receptor status and clinico-pathological markers for non-aggressive disease in endometrial cancer

BACKGROUND

Endometrial cancer incidence is increasing in industrialised countries. High body mass index (BMI, kg  m(-2)) is associated with higher risk for disease. We wanted to investigate if BMI is related to clinico-pathological characteristics, hormone receptor status in primary tumour, and disease outcome in endometrial cancer.

PATIENTS AND METHODS

In total, 1129 women primarily treated for endometrial carcinoma at Haukeland University Hospital during 1981-2009 were studied. Body mass index was available for 949 patients and related to comprehensive clinical and histopathological data, hormone receptor status in tumour, treatment, and follow-up.

RESULTS

High BMI was significantly associated with low International Federation of Gynaecology and Obstetrics (FIGO) stage, endometrioid histology, low/intermediate grade, and high level of progesterone receptor (PR) mRNA by qPCR (n=150; P=0.02) and protein expression by immunohistochemistry (n=433; P=0.003). In contrast, oestrogen receptor (ERα) status was not associated with BMI. Overweight/obese women had significantly better disease-specific survival (DSS) than normal/underweight women in univariate analysis (P=0.035). In multivariate analysis of DSS adjusting for age, FIGO stage, histological subtype, and grade, BMI showed no independent prognostic impact.

CONCLUSION

High BMI was significantly associated with markers of non-aggressive disease and positive PR status in a large population-based study of endometrial carcinoma. Women with high BMI had significantly better prognosis in univariate analysis of DSS, an effect that disappeared in multivariate analysis adjusting for established prognostic markers. The role of PR in endometrial carcinogenesis needs to be further studied.

Hyperoxic treatment induces mesenchymal-to-epithelial transition in a rat adenocarcinoma model

Tumor hypoxia is relevant for tumor growth, metabolism and epithelial-to-mesenchymal transition (EMT). We report that hyperbaric oxygen (HBO) treatment induced mesenchymal-to-epithelial transition (MET) in a dimetyl-α-benzantracene induced mammary rat adenocarcinoma model, and the MET was associated with extensive coordinated gene expression changes and less aggressive tumors. One group of tumor bearing rats was exposed to HBO (2 bar, pO₂ = 2 bar, 4 exposures à 90 minutes), whereas the control group was housed under normal atmosphere (1 bar, pO₂ = 0.2 bar). Treatment effects were determined by assessment of tumor growth, tumor vascularisation, tumor cell proliferation, cell death, collagen fibrils and gene expression profile. Tumor growth was significantly reduced (∼16%) after HBO treatment compared to day 1 levels, whereas control tumors increased almost 100% in volume. Significant decreases in tumor cell proliferation, tumor blood vessels and collagen fibrils, together with an increase in cell death, are consistent with tumor growth reduction and tumor stroma influence after hyperoxic treatment. Gene expression profiling showed that HBO induced MET. In conclusion, hyperoxia induced MET with coordinated expression of gene modules involved in cell junctions and attachments together with a shift towards non-tumorigenic metabolism. This leads to more differentiated and less aggressive tumors, and indicates that oxygen per se might be an important factor in the “switches” of EMT and MET in vivo. HBO treatment also attenuated tumor growth and changed tumor stroma, by targeting the vascular system, having anti-proliferative and pro-apoptotic effects.

Expression of epidermal growth factor receptor in relation to BRCA1 status, basal-like markers and prognosis in breast cancer

AIMS

BRCA1-related breast cancer is associated with a basal-like phenotype, and is frequently oestrogen receptor (ER) and HER2 negative. The expression of epidermal growth factor receptor (EGFR) has been considered to be one component of the basal-like phenotype, but no standard criteria exist. This study investigates the relationship between EGFR expression, BRCA1 status and basal markers with respect to clinicopathological associations and prognosis, in addition to evaluating different criteria for EGFR assessment by immunohistochemistry.

METHODS

A tissue microarray comprising 230 available cases, from a series of primary invasive breast cancer diagnosed in Ashkenazi Jewish women during 1980-1995, was stained for EGFR using the Dako PharmDX kit, and evaluated by Webslide virtual microscopy.

RESULTS

EGFR was positive in 9-19% according to different criteria. Expression was associated with BRCA1 carrier status and basal-like markers as negative ER, positive cytokeratin 5/6 and positive P-cadherin staining. EGFR was prognostically significant by univariate and multivariate analysis within the group carrying germ-line BRCA1 mutations. Histological grade, axillary lymph node status and P-cadherin status had significant independent value in the final multivariate model including all cases, whereas EGFR was not significant in this model. All five scoring systems gave comparable results concerning clinicopathological associations and patient outcome, although the most restrictive criteria (EGFR-HI) tended to be most sensitive in predicting BRCA1 status, a basal phenotype, and patient prognosis.

CONCLUSIONS

EGFR expression, being present in 9-19% of the cases, was prognostically significant among BRCA1 mutated cases only. In multivariate survival analysis of all cases, no independent effect was seen. However, EGFR immunostaining might be relevant to predict the response to targeted therapy, and this should be studied further.

Low BMI-1 expression is associated with an activated BMI-1-driven signature, vascular invasion, and hormone receptor loss in endometrial carcinoma

We studied the expression of polycomb group (PcG) protein BMI-1 in a large population-based patient series of endometrial carcinomas in relation to clinical and molecular phenotype. Also, 57 fresh frozen endometrial carcinomas were studied for the relationship between BMI-1 protein expression, BMI-1 mRNA level, and activation of an 11-gene signature reported to represent a BMI-1-driven pathway. BMI-1 protein expression was significantly weaker in tumours with vascular invasion (P<0.0001), deep myometrial infiltration (P=0.004), and loss of oestrogen receptor (ER) (P<0.0001) and progesterone receptors (PR) (P=0.03). Low BMI-1 protein expression was highly associated with low BMI-1 mRNA expression (P=0.002), and similarly low BMI-1 mRNA expression correlated significantly with vascular invasion, ER and PR loss, and histologic grade 3. In contrast, activation of the reported 11-gene signature, supposed to represent a BMI-1-driven pathway, correlated with low mRNA expression of BMI-1 (P<0.001), hormone receptor loss, presence of vascular invasion, and poor prognosis. We conclude that BMI-1 protein and mRNA expression are significantly correlated and that BMI-1 expression is inversely associated with activation of the 11-gene signature. Loss of BMI-1 seems to be associated with an aggressive phenotype in endometrial carcinomas.

Independent prognostic value of the basal-like phenotype of breast cancer and associations with EGFR and candidate stem cell marker BMI-1

AIMS

To study the relationship between basal-like breast cancers, epidermal growth factor receptor (EGFR) and candidate stem cell markers (BMI-1, EZH2, Oct-4) in a population-based setting.

METHODS AND RESULTS

Immunohistochemistry was evaluated in a series of 190 breast cancers. Basal-like phenotype (BLP) 1-5 was found in 4.3-14.3% of cases. EGFR was expressed in 9% of cases and associated with cytokeratin (CK) 5 and P-cadherin positivity, but not with survival; 28% of CK5+ cases were EGFR+. On multivariate analysis, basal-like differentiation and lymph node status were independent prognostic factors of comparable strength. BMI-1 positivity (42.6%) was associated with absence of basal-like features, oestrogen receptor positivity and low Ki67, but not related to survival. BMI was not associated with EZH2 expression, and these markers tended to show opposite associations with other variables, suggesting different roles in breast cancer. Oct-4 expression was not detected in this series.

CONCLUSIONS

Basal-like features and lymph node status were strong and independent prognostic factors in this population-based series of breast cancer. Neither EGFR nor BMI-1 had significant prognostic impact, whereas EZH2 expression was associated with decreased survival. BMI-1 was inversely related to basal-like factors, and a stem cell phenotype of the basal-like subgroup could not be verified by this marker.

Comparison of nucleic acid targets prepared from total RNA or poly(A) RNA for DNA oligonucleotide microarray hybridization

The aim of this work was to compare DNA microarray results using either total RNA or affinity-purified poly(A) RNA from the same biological sample for target preparation. The high-density oligonucleotide microarrays of both Agilent Technologies (based on two-color detection) and Applied Biosystems (based on single-color detection) were evaluated. Real-time quantitative PCR was used to quantify messenger RNA (mRNA) and ribosomal RNA (rRNA) at different stages of target preparations. Poly(A) RNA versus total RNA target hybridizations exhibited slightly lower correlation coefficients than did self versus self hybridizations (i.e., poly(A) RNA targets vs. poly(A) RNA targets or total RNA targets vs. total RNA targets). Only a small fraction of all transcripts appeared to be significantly over- or underrepresented when total RNA targets or poly(A) RNA targets from the same biological sample were compared. Therefore, the conclusion is that poly(A) affinity purification from total RNA can be omitted during target preparation for routine mRNA expression analysis using high-density oligonucleotide microarrays. Among consistently overrepresented transcripts in total RNA targets were histone mRNAs known to lack poly(A) tails. Therefore, structurally exceptional RNA species can be identified by comparing targets derived from either poly(A) RNA or total RNA using microarray hybridization.

Increased Expression of SIM2-s Protein Is a Novel Marker of Aggressive Prostate Cancer

PURPOSE

The human SIM2 gene is located within the Down's syndrome critical region of chromosome 21 and encodes transcription factors involved in brain development and neuronal differentiation. SIM2 has been assigned a possible role in the pathogenesis of solid tumors, and the SIM2-short isoform (SIM2-s) was recently proposed as a molecular target for cancer therapy. We previously reported SIM2 among the highly up-regulated genes in 29 prostate cancers, and the purpose of our present study was to examine the expression status of SIM2 at the transcriptional and protein level as related to outcome in prostate cancer.

EXPERIMENTAL DESIGN

By quantitative PCR, mRNA in situ hybridization, and immunohistochemistry, we evaluated the expression and significance of SIM2 isoforms in 39 patients with clinically localized prostate cancer and validated the expression of SIM2-s protein in an independent cohort of 103 radical prostatectomies from patients with long and complete follow-up.

RESULTS

The SIM2 isoforms (SIM2-s and SIM2-l) were significantly coexpressed and increased in prostate cancer. Tumor cell expression of SIM2-s protein was associated with adverse clinicopathologic factors like increased preoperative serum prostate-specific antigen, high histologic grade, invasive tumor growth with extra-prostatic extension, and increased tumor cell proliferation by Ki-67 expression. SIM2-s protein expression was significantly associated with reduced cancer-specific survival in multivariate analyses.

CONCLUSIONS

These novel findings indicate for the first time that SIM2 expression might be important for clinical progress of human cancer and support the recent proposal of SIM2-s as a candidate for targeted therapy in prostate cancer.

ERG upregulation and related ETS transcription factors in prostate cancer

The aim of this study was to identify and validate differentially expressed genes in matched pairs of benign and malignant prostate tissue. Samples included 29 histologically verified primary tumors and 23 benign controls. Microarray analysis was initially performed using a sequence verified set of 40,000 human cDNA clones. Among the genes most consistently and highly upregulated in prostate cancer was the ETS family transcription factor ERG (ETS related gene). This finding was validated in an expanded patient series (37 tumors and 38 benign samples) using DNA oligonucleotide microarray and real-time quantitative PCR assays. ERG was 20- to more than 100-fold overexpressed in prostate cancer compared with benign prostate tissue in more than 50% of patients according to quantitative PCR. Surprisingly, ERG mRNA levels were found to be significantly higher in the endothelial cell line, HUVEC, than in the prostate cell lines PC3, DU145 and LNCaP. In situ hybridization of prostate cancer tissue revealed that ERG was abundantly expressed in both prostate cancer cells and associated endothelial cells. The consistency and magnitude of ERG overexpression in prostate cancer appeared unique, but several related ETS transcription factors were also overexpressed in matched pairs of tumor and benign samples, whereas ETS2 was significantly underexpressed. Our findings support the hypothesis that ERG overexpression and related ETS transcription factors are important for early prostate carcinogenesis.

Body size and thyroid cancer in two million Norwegian men and women

We investigated relations between measured body mass index (BMI) and stature and thyroid cancer (3046 cases) in a large Norwegian cohort of more than two million individuals. The risk of thyroid cancer, especially of the papillary and follicular types, increased moderately with increasing BMI and height in both sexes.

Strong expression of ID1 protein is associated with decreased survival, increased expression of ephrin-A1/EPHA2, and reduced thrombospondin-1 in malignant melanoma

The ID1 protein, an inhibitor of basic helix–loop–helix transcription factors, has been involved in multiple cellular processes including cell cycle regulation, apoptosis, and angiogenesis. To evaluate the importance of ID1 in malignant melanoma, tumour cell expression was examined by immunohistochemistry in 119 cases of nodular melanoma using tissue microarray technique, and related to multiple tumour markers including proliferation, p16 expression, angiogenesis and patient survival. Strong ID1 expression was significantly associated with increased tumour thickness, and significantly reduced survival. Also, increased ID1 was associated with loss of thrombospondin-1 (TSP-1) expression, a known inhibitor of angiogenesis, and increased intensity of ephrin-A1 and its receptor EPHA2. Presence of BRAF mutations was related to strong ID1 expression, but there was no relationship with p16 protein expression. Further, no significant correlation was found between ID1 and microvessel density. In conclusion, our study supports a significant role of the ID1 protein in melanoma progression and patient prognosis. The absence of correlation with p16 protein expression and angiogenesis suggests that other regulatory pathways and mechanisms might be influenced by ID1 in melanomas. An inverse relation between ID1 and TSP-1 expression support an important role of ID1 in the regulation of this complex multitarget protein.

Prognostic and predictive value of changes in tumour cell proliferation in locally advanced breast cancer primarily treated with doxorubicin

We previously reported that high tumour cell proliferation evaluated by Ki-67 expression, high mitotic frequency and high histological grade were associated with resistance to primary doxorubicin monotherapy in locally advanced breast cancer harbouring wild-type (wt) TP53. The aim of our present study was to evaluate the predictive and prognostic impact of proliferation parameters assessed in tumour tissue obtained after chemotherapy, and alterations induced in tumour cell proliferation. While we found a significant reduction in Ki-67 expression and mitotic frequency in tumours with wtTP53 (p=0.001 and p=0.008, respectively), no significant change was recorded in tumours expressing mutant TP53. For histological grade there was no significant change in either group. There was a direct correlation between pre- and post-treatment values for Ki-67 and mitotic frequency in tumours harbouring wtTP53 (p=0.0001 for both), but no correlation in tumours harbouring mutated TP53. High post-treatment Ki-67 expression and mitotic frequency were found to predict doxorubicin resistance only in patients with wtTP53 (p=0.04 and p=0.03, respectively). The prognostic importance of proliferation markers and histological grade was found to be similar whether they were determined in the pre- or post-treatment samples (Ki-67; pre: p=0.02; post: p=0.03; mitotic frequency; p=0.002 and p=0.01, respectively; histological grade; p=0.0001 and p=0.002, respectively). While the reduction in mitotic frequency was associated with improved survival (p=0.03), no significant associations between changes in other parameters and outcome were recorded.

PREDICTORS OF PROSTATE CANCER EVALUATED BY RECEIVER OPERATING CHARACTERISTICS PARTIAL AREA INDEX: A PROSPECTIVE INSTITUTIONAL STUDY

PURPOSE

To our knowledge we introduce the ROC partial area under the curve (AUC) index as a method of evaluating the discriminative power of different prostate cancer predictors. Peripheral zone volume and peripheral zone prostate specific antigen (PSA) density are introduced as potential predictors and compared with other known predictors of prostate cancer.

MATERIALS AND METHODS

During 1999, 220 consecutive patients with suspected early prostate cancer were examined using total PSA, free PSA, total prostate volume, transition zone volume and transrectal ultrasonography guided sextant biopsy of the prostate. The free-to-total PSA ratio, PSA density, transition zone PSA density, peripheral zone volume and peripheral zone PSA density were calculated. Usually total AUC is used to evaluate the discriminative power of different parameters. In this study parameters were evaluated by the ROC partial area index, which includes only the AUC in highly sensitivity parts of the ROC curve. Explorative analysis using logistic regression analysis was performed to investigate the ability of combinations of parameters to predict cancer.

RESULTS

Of the 220 patients 75 were diagnosed with cancer. In the subgroup of 160 patients with PSA less than 10 microg/l 44 had cancer. Transition zone PSA density and PSA density had significant discriminative power in the total group, while none of the parameters were discriminative in the subgroup of patients.

CONCLUSIONS

When high sensitivity is demanded, the ROC partial area index seems to be meaningful for evaluating the discriminative power of potential predictors. In our study none of the evaluated parameters had discriminative power in patients with PSA less than 10 microg/l, while transition zone PSA density and PSA density showed discriminative power in the total group of patients.

Gene expression profiles in prostate cancer: association with patient subgroups and tumour differentiation

Prostate carcinoma is the most common cancer of western men and is a markedly heterogeneous disease. The aim of this study was to identify signatures of differentially expressed genes in prostate cancer using DNA microarray technology, evaluating expression profiles in matched pairs of benign and malignant tissue. Samples were collected from 33 radical prostatectomies, and 52 specimens were included, representing 29 histologically verified primary tumours, 19 paired samples of malignant and benign tissue, and 4 non-paired benign tissue samples. Microarray analysis was performed using an expanded sequence verified set of 40,000 human cDNA clones, revealing several genes with significant differences between malignant and benign tissue, including recently reported genes like alpha-methylacyl-CoA racemase (AMACR) and hepsin, as well as genes relevant for tumour development and progression. Leave out cross validation (LOCV) test correctly predicted tumour or benign tissue in 47 (90.3%) out of 52 cases, significantly better than cross validation tests using randomly permuted tissue labels. Unsupervised clustering analysis revealed 3 distinct patient clusters significantly associated with Gleason score, and high grade tumours (Gleason score >/=7) accumulated in cluster 1 (C1). Gene expression profiles correctly predicted 100% of tumour samples segregating to C1, as also validated by LOCV. Gene expression profiles were analysed in filtered and floored datasets with similar results, and a pair-wise design was also tested. Gene expression profiles provided tumour clusters linked to differentiation, and revealed novel markers relevant for molecular classification, grading and therapy of prostate cancer.

Molecular differences between RER+ and RER- sporadic endometrial carcinomas in a large population-based series

Studies, to date, have suggested that there are distinct molecular differences between microsatellite stable (RER(-)) and unstable (RER(+)) solid tumors, such as colorectal carcinoma. We investigated a range of molecular events including mutation frequency of K-ras, microsatellite instability within the coding region of TGF-beta RII, BAX, and IGF-IIR, loss of expression of p53, hMLH1, hMSH2, hMSH6, and PTEN, and methylation of hMLH1, hMSH2, and PTEN within a large population-based series of sporadic endometrial carcinomas to establish whether there are distinct differences between replication error repair (RER(+)) and RER(-) cases. RER(+) endometrial carcinomas tended to be diploid with normal p53 expression, compared with RER(-) cases. Mutations in TGF-beta RII, IGF-IIR, and BAX were rare, but there was a strong association between mutation and RER(+) status. Methylation and loss of hMLH1 expression were significantly more common in RER(+) cases, as was methylation of PTEN. K-ras mutations were equally frequent in RER(+) and RER(-) cases. Despite the absence of distinct clinicopathological differences between RER(+) and RER(-) cases in this series of sporadic endometrial carcinomas, our results confirm that there are molecular differences between RER(+) and RER(-) cases, but the molecular events occurring in RER(+) endometrial carcinomas differ from those seen in RER(+) colorectal carcinomas.

Prognostic impact of histological grade and vascular invasion compared with tumour cell proliferation in endometrial carcinoma of endometrioid type

AIMS

The relative impact of different prognostic factors is important for endometrial carcinoma patients. The aim of our study was to examine the combined value of histological grade [International Federation of Gynaecology and Obstetrics (FIGO)] and vascular invasion in comparison with tumour cell proliferation assessed by mitotic count and Ki67. The recently proposed binary architectural grade was also evaluated, in addition to age, depth of myometrial infiltration and FIGO stage in our population-based series of 237 endometrioid carcinomas.

METHODS AND RESULTS

The tumours were studied for several histological features, including FIGO grade, binary grade, vascular invasion, mitotic count, myometrial invasion and expression of Ki67. FIGO grade was significantly associated with all investigated histological features, including Ki67 expression. Vascular invasion was significantly more frequent in FIGO grade 3 tumours, and was associated with a diffusely infiltrative growth pattern, solid growth, necrosis and deep myometrial invasion. All variables showed a highly significant relationship with patient survival in univariate analysis. In multivariate models, FIGO grade, vascular invasion, and proliferation assessed by Ki67 expression all had independent prognostic influence in this population-based study. Comparing tumour cell proliferation (Ki67) with vascular invasion as a marker of metastatic spread, the latter had a stronger survival impact.

CONCLUSIONS

Vascular invasion and tumour cell proliferation measured by Ki67 both had independent prognostic influence, and should be considered to identify aggressive tumours of the endometrioid subtype.

TP53 gene mutations predict the response to neoadjuvant treatment with 5-fluorouracil and mitomycin in locally advanced breast cancer

PURPOSE

Recent studies have found an association between certain TP53 mutations and resistance to anthracycline-based primary medical therapy in breast cancer. The purpose of this study was to investigate whether TP53 mutational status also might influence the response to a non-anthracycline-containing regimen in primary breast cancer.

EXPERIMENTAL DESIGN

Thirty-five patients with locally advanced breast cancer were investigated for TP53 mutations before receiving combination chemotherapy with 5-fluorouracil (1000 mg/m(2) on days 1 and 2) and mitomycin (6 mg/m(2) on day 2), administered every 3 weeks for 2-10 cycles in the neoadjuvant setting.

RESULTS

Mutations in the TP53 gene, in particular those affecting loop domains L2 or L3 of the p53 protein, were associated with lack of response to chemotherapy (i.e., increase in the diameter product of tumor lesion by >/=25%; P = 0.177 for all mutations and P = 0.006 for those affecting L2/L3 domains, respectively). No statistically significant correlation between TP53 LOH and response to therapy was seen.

CONCLUSION

This study revealed a significant association between lack of response to 5-fluorouracil and mitomycin and mutations affecting the L2/L3 domains of the p53 protein. Together with our previous finding that such mutations predict resistance to weekly doxorubicin, our data suggest that mutations affecting this particular domain of the p53 protein may cause resistance to several different cytotoxic compounds applied in breast cancer treatment.

Glomeruloid microvascular proliferation is associated with p53 expression, germline BRCA1 mutations and an adverse outcome following breast cancer

Glomeruloid microvascular proliferation (GMP) in breast cancer independently adversely affected survival (relative risk 1.9, 95% CI: 1.2-3.0), particularly among women who received adjuvant chemotherapy (10-year survival 27 vs 69%, P=0.0003), and was significantly associated with p53 overexpression and BRCA1 germline mutations. The presence of GMP may influence treatment decisions.

Benign growth of different prostate zones in aging men with slightly elevated PSA in whom prostate cancer has been excluded: a prospective study of 510 patients

OBJECTIVES

To study, in a selected series of patients, whether the peripheral/central zone volumes also change with age. The reported normal total prostate volume in the third decade seems not to exceed 25 to 30 cm(3). Benign prostatic hyperplasia is generally accepted to originate in the transition zone and periurethral tissue, which accordingly show substantial growth with age.

METHODS

From January 1997 through December 2000, we performed transrectal ultrasound volume measurements of the different prostate zones in patients admitted for suspected prostate cancer. The information was registered according to a prospectively designed protocol. A total of 872 patients were examined, of whom 360 shown to have prostate cancer were excluded. Two more patients were excluded because of missing volume data, leaving 510 patients with noncancerous prostates for inclusion in this study.

RESULTS

The mean age was 62.8 years and the mean total prostate-specific antigen level was 9.8 microg/L. It was found that 64.9% (331 of 510) had a peripheral/central zone volume larger than 30 cm(3), indicating that some form of growth had occurred also in this zone. A weak but significant correlation was found between age and the peripheral/central zone volume.

CONCLUSIONS

The results of our study indicate that the peripheral/central zone may contribute to the benign growth of the prostate gland in men younger than 70 years old with slightly elevated total prostate-specific antigen levels.

Predictive value of tumour cell proliferation in locally advanced breast cancer treated with neoadjuvant chemotherapy

We previously reported that defects in apoptotic pathways (mutations in the TP53 gene) predicted resistance to doxorubicin monotherapy. The aim of this study was to evaluate whether cell proliferation, as assessed by mitotic frequency and Ki-67 levels, may provide additional predictive information in the same tumours and to assess any potential correlations between these markers and mutations in the TP53 gene and erbB-2 overexpression. Surgical specimens were obtained from ninety locally advanced breast cancers before commencing primary chemotherapy consisting of weekly doxorubicin (14 mg/m2) for 16 weeks. 38% of the patients had a partial response (PR) to therapy, 52% had stable disease (SD) while 10% had progressive disease (PD). Univariate analysis showed a significant association between a high cell proliferation rate (expressed as a high mitotic frequency) and resistance to doxorubicin (P = 0.001). Further analyses revealed this association to be limited to the subgroup of tumour expressing wild-type TP53 (P = 0.016), and TP53 mutation status was the only factor predicting drug resistance in the multivariate analyses. The finding that a high mitotic frequency, as well as a high Ki-67 staining, correlated to TP53 mutations (P = 0.001 for both), suggests TP53 mutations are the key predictor of drug resistance, although cell proliferation may play an additional role in tumours harbouring wild-type TP53. Regarding overall (OS) and relapse-free survival (RFS), multivariate analyses (Cox' proportional hazards regression) revealed a high histological grade and negative oestrogen receptor (ER) status to be the variables that were most strongly related to breast cancer death (P = 0.001 and P = 0.001, respectively). A key reason for this difference with respect to the factors predicting chemotherapy resistance could be due to the adjuvant use of tamoxifen in all patients harbouring ER-positive tumours.

Significant impact of promoter hypermethylation and the 540 C>T polymorphism of CDKN2A in cutaneous melanoma of the vertical growth phase

Promoter hypermethylation, mutations, and loss of heterozygosity in the CDKN2A gene as well as polymorphisms at the 3'-untranslated region were determined in vertical growth phase melanomas. Methylation-specific polymerase chain reaction in soluti and in situ showed that 19% of the cases were hypermethylated at the CDKN2A promoter region, and some of these cases were heterogeneous with both methylated and unmethylated tumor cells. Methylation was associated with increased tumor cell proliferation by Ki-67 expression (P = 0.01) and decreased patient survival (P = 0.025). Point mutations in CDKN2A were found in 4% of the cases, whereas 90% had loss of heterozygosity at one or more of 4 markers studied. Furthermore, presence of the 540 C>T polymorphism at the 3'-untranslated region of CDKN2A (23%) was associated with improved survival in multivariate analysis (hazard ratio, 2.6; P = 0.02). Our results suggest that promoter methylation of the CDKN2A gene is present in a subgroup of the tumors and associated with increased tumor cell proliferation and reduced survival. Further, the 540 C>T polymorphism might define a distinct subgroup of low-grade vertical growth phase melanomas. These findings support a significant role of the CDKN2A gene in melanoma progression.

Importance of vascular phenotype by basic fibroblast growth factor, and influence of the angiogenic factors basic fibroblast growth factor/fibroblast growth factor receptor-1 and ephrin-A1/EphA2 on melanoma progression

The expression of several angiogenic factors and receptors was examined in a series of vertical growth phase cutaneous melanomas using high-throughput tissue microarray technology and immunohistochemistry. The results were correlated with microvessel density, clinicopathological features, and patient survival. Expression of basic fibroblast growth factor (bFGF) was significantly associated with increased microvessel density. Also, we found an independent prognostic importance of vascular phenotype by endothelial cell expression of bFGF; cases with positive vessels had the best prognosis and these tumors revealed a low frequency of vascular invasion (14%) when compared with bFGF-negative vessels (47%). This bFGF-negative phenotype was significantly increased in metastatic lesions. Strong tumor cell expression of FLT-4, ephrin-A1, and EphA2 was associated with increased melanoma thickness, and ephrin-A1 staining was related to decreased survival (P = 0.039). Expression of EphA2 in tumor cells was associated with increased tumor cell proliferation (Ki-67 positivity), indicating possible autocrine growth stimulation. Thus, our findings indicate the presence of phenotypic diversity among tumor-associated vessels, and subgroups defined by bFGF expression may be of clinical importance. bFGF was associated with microvessel density, whereas the ephrin-A1/EphA2 pathway might also be important for tumor cell proliferation and patient survival.

A single nucleotide polymorphism in the 3'untranslated region of the CDKN2A gene is common in sporadic primary melanomas but mutations in the CDKN2B, CDKN2C, CDK4 and p53 genes are rare

In this report we present the results of mutational analysis of the CDKN2B, CDKN2C, CDK4, p53 genes and 5'UTR of the CDKN2A gene in a set of 44 sporadic primary melanomas, which had been earlier analysed for mutations in the CDKN2A (p16/p14(ARF)) gene. No tumour-associated mutations were detected except in 1 melanoma where we found a CC>T* deletion-mutation in the codon 151-152 (exon 5) of the p53 gene. On the basis of our preliminary results, we did extended genotyping of the 500 C>G and 540 C>T polymorphisms in the 3'UTR of the CDKN2A gene in 229 melanoma cases and 235 controls. The T-allele frequency (for 540 C>T polymorphism) in melanomas was significantly higher than in controls (0.14 vs. 0.08; chi(2) = 5.95, p = 0.01; OR = 1.71, 95%CI = 1.11-2.66). The heterozygote frequency for this polymorphism was 0.26 (59/229) in melanomas compared to 0.13 (30/235) in healthy controls (chi(2) = 11.4; p = 0.0007; OR = 2.34, 95% CI = 1.40-3.92). The frequency of the 500 C>G polymorphism in the 3'UTR in the CDKN2A gene was not significantly higher in melanomas compared to healthy controls. The 500 C>G polymorphism, however, was in linkage disequilibrium with approximately 50 kb apart the C>A intronic polymorphism in the CDKN2B gene (determined in 44 melanomas and 90 controls; Fisher exact test, p<0.0001). Finally, the sequence analysis of genomic DNA isolated from T cell lymphocytes of healthy individuals exhibited that the codon reported as last of exon 2 of the CDKN2C gene is rather the first codon of exon 3.

Maximum Ki-67 staining in prostate cancer provides independent prognostic information after radical prostatectomy

BACKGROUND

We have evaluated the prognostic value of Ki-67 growth fraction after radical prostatectomy, especially focusing on intermediate grade carcinomas.

MATERIALS AND METHODS

104 patients treated by radical prostatectomy for clinically localized prostate cancer were studied. The area of highest tumour grade was selected from the prostatectomy specimens and used for Ki-67 immunostaining The fraction of Ki-67 positive tumour nuclei in the area of most intense proliferation ("hot spot") was estimated, and related to biochemical failure.

RESULTS

Ki-67 expression (median 6.7%, range 1.2-42.6%) was significantly associated with WHO histological grade. In univariate analysis of all 104 carcinomas, Ki-67 expression was associated with time to biochemical failure as were age, tumour dimension, WHO histological grade, pathological stage, positive surgical margins and pre-operative s-PSA. In multivariate Cox' analysis, Ki-67 expression, pathological stage and pre-operative s-PSA remained as independent predictors of time to biochemical failure. Ki-67 expression (HR 4.8, p < 0.001) was also found to be an independent predictor among moderately-differentiated carcinomas.

CONCLUSION

Estimates of Ki-67 growth fraction in areas of highest tumour grade may prove to be a useful prognostic biomarker after radical prostatectomy.