Marjukka Nykänen

Predicting aggressive outcome in T1N0M0 breast cancer.

Despite the excellent overall prognosis, unpredictable breast cancer recurrences and deaths also occur among T1N0M0 patients. We have evaluated clinically applicable methods for identifying aggressive outcome in T1N0M0 breast cancer. The material is based on aggressive T1N0M0 invasive ductal and lobular carcinomas diagnosed in Turku University Hospital and Jyväskylä Central Hospital, Finland, during 1987–1997. We studied all the T1N0M0 breast cancers that had led to recurrency or death (n=21, 95% T1cN0M0) during the follow-up period (4–14 years). The study is based on statistical analyses of matched case–control data in which the prognostic factors of each individual patient with aggressive disease were compared with control patients (n=45) individually matched by tumour size, age at diagnosis, histological type of tumour and length of follow-up. The cancer cases were examined for clinically applicable conventional and immunohistochemical pathologic prognostic factors. High Ki-67 immunopositivity was the strongest prognosticator of breast cancer death or recurrence in T1N0M0 breast cancer. Also, high p53 immunopositivity, low oestrogen receptor immunopositivity and Her-2/neu oncogene amplification by chromogen in situ hybridisation were reliable indicators of unfavourable outcome. Our statistical methods also allowed us to determine for the present material a range of clinical significance for each immunohistochemical prognostic feature with the associated relative risk for breast cancer death and recurrence. The paper suggests guidelines for predicting aggressive outcome in T1N0M0 breast cancer.

Securin predicts aneuploidy and survival in breast cancer

Karra H, Pitkänen R, Nykänen M, Talvinen K, Kuopio T, Söderström M & Kronqvist P 
(2012) Histopathology 60, 586–596
Securin predicts aneuploidy and survival in breast cancer

Securin promotes the identification of favourable outcome in invasive breast cancer

Background:Securin is a recently recognised oncogene with multiple known functions in initiation, progression and cell cycle regulation in several malignant diseases, including breast carcinoma.Methods:In this paper, the prognostic value of securin is evaluated by immunohistochemistry in 310 patients diagnosed with invasive breast cancer during a mammographic screening programme in Central Finland. All patients were directed to modern surgical and oncological treatments and were followed up for a maximum of 20 years.Results:Our results suggest that securin immunopositivity is an independent prognosticator of invasive breast cancer. In our study, securin predicted breast cancer-specific survival among all cases of invasive breast cancer and subgroups divided according to histological type, Ki-67 proliferation status and tumour size. Especially in a multivariate analysis standardised for axillary lymph node status, patients age and tumour size at the time of diagnosis, securin immunopositivity indicated a 13.1-fold risk of breast cancer death (P=0.024) among invasive ductal breast carcinomas with low Ki-67 positivity.Conclusion:Our present and previous results suggest that securin could be useful in clinical pathology to intensify the power of the established prognosticators of invasive breast cancer and, especially, to assist in identifying patients with a more favourable outcome than that indicated by Ki-67 alone.

Low cdc27 and high securin expression predict short survival for breast cancer patients.

Cell cycle regulators cdc27 and securin participate in control of the mitotic checkpoint and survey the mitotic spindle to maintain chromosomal integrity. This is achieved by their functions in metaphase–anaphase transition, DNA damage repair, enhancement of mitotic arrest and apoptosis. We report on the roles of cdc27 and securin in aneuploidy and prognosis of breast cancer. The study comprises 429 breast cancer patients with up to 22 years of follow‐up. DNA content was determined by image cytometry, and immunopositivity for cdc27 and securin was based on tissue microarrays. An inverse association between cdc27 and securin expression was observed in both image cytometric and immunohistochemical analyses. Low cdc27 and high securin expression identified patients with significant difference in disease outcome. Cdc27 and securin immunoexpression identified patients at risk of early cancer death within five years from diagnosis. In multivariate analysis, the combination of cdc27 and securin immunohistochemistry was the strongest predictor of cancer death after lymph node status. We demonstrate, for the first time in human breast cancer, the prognostic value of cdc27 and securin immunohistochemistry. Cdc27 and securin appear promising biomarkers for applications in predicting disease progression, prognostication of individual patients and potential in anti‐mitotic drug development.

Protein and gene expression of estrogen receptor alpha and nuclear morphology of two breast cancer cell lines after different fixation methods

We assessed morphology and ERalpha protein and gene expression of two breast cancer cell lines after three different fixatives: neutral-buffered 10% formaldehyde, LN-FIX and FineFIX and varying fixation times. We found that the cell morphology was best preserved in cells fixed with LN-FIX. Two commercial fixatives used in this study shrank cells less than formalin. In immunohistochemical assay samples were stained with two different ERalpha antibodies, clone 1D5 and clone SP1. All tested fixatives were suitable for immunohistochemistry. Staining was more intensive and the number of stained cells was larger with the clone 1D5 than with the clone SP1. Our gene expression analysis showed that formalin and LN-FIX preserve the ERalpha better than FineFIX, which is advertised to be optimal for molecular analysis. Our study suggests that tissues fixed with formalin are suitable also for molecular biology assays. This makes possible to research formalin-fixed paraffin-embedded archival tissues also with molecular techniques.

Separase is a marker for prognosis and mitotic activity in breast cancer

Background:Cancer cell proliferation is a critical feature in classifying and predicting the outcome of breast carcinoma. Separase has a central role in cell cycle progression in unleashing sister-chromatids at anaphase onset. Abnormally functioning separase is known to lead to chromosomal instability.Methods:The study comprises 349 breast carcinoma patients treated in Central Hospital of Central Finland. The prognostic value, role as a proliferation marker and regulatory interactions of separase are evaluated by immunohistochemical and double- and triple-immunofluorescence (IF) detections based on complete clinical data and >22-year follow-up of the patient material.Results:In our material, abnormal separase expression predicted doubled risk of breast cancer death (P<0.001). Up to 11.3-year survival difference was observed when comparing patients with and without separase expressing cancer cell mitoses. Particularly, abnormal separase expression predicted impaired survival for luminal breast carcinoma (P<0.001, respectively). In multivariate analyses, abnormal separase expression showed independent prognostic value. The complex inhibitory interactions involving securin and cyclin B1 were investigated in double- and triple-IFs and revealed patient subgroups with aberrant regulation and expression patterns of separase.Conclusions:In our experience, separase is a promising and clinically applicable proliferation marker. Separase expression shows strong and independent prognostic value and could be developed into a biomarker for treatment decisions in breast carcinoma, particularly defining prognostic subgroups among luminal carcinomas.

The Expression of Cohesin Subunit SA2 Predicts Breast Cancer Survival.

Cohesin is one of the main regulators of sister chromatid separation during the metaphase/anaphase transition. It is a multiprotein complex consisting of 4 core subunits, one of those being the SA2 subunit. SA2 plays the final role in dismantling the cohesion complex from the sister chromatids and also functions in DNA double-strand break repair and gene regulation. There is increasing evidence regarding the involvement of both overexpression and underexpression of cohesin in cancer. Here, we present expression patterns of SA2 in different types of human breast tissue, and the prognostic analysis in the material from breast cancer patients with long-term follow-up. SA2 immunoexpression was evaluated in benign, precancerous, and malignant breast tissue, and was classified into low-intensity or high-intensity groups. The DNA content was determined by image cytometry on breast cancer cell imprints. Prognostic analyses were based on 445 breast cancer patients with upto 20 years’ follow-up. SA2 immunoexpression was equally high in both benign and precancerous breast tissue. Instead, 72% of the invasive breast cancers showed deficient SA2 expression. These patients were also associated with an unfavorable outcome as indicated by a 1.6-fold risk of breast cancer death (P=0.0208). The majority (75%) of the patients with low SA2 expression were alive 6.0 years after the diagnosis, whereas the majority of the patients with high SA2 expression survived 17.6 years after the diagnosis. No statistically significant association could be detected between SA2 immunoexpression and DNA aneuploidy. Our results and previous literature indicate that decreased SA2 immunoexpression is associated with malignant breast disease and a particularly unfavorable course of disease.

Proliferation-associated miRNAs-494, -205, -21 and -126 detected by in situ hybridization: expression and prognostic potential in breast carcinoma patients

PurposeTo visualize by in situ hybridization (ISH) the levels of a set of proliferation-associated miRNAs and to evaluate their impact and clinical applicability in prognostication of invasive breast carcinoma.MethodsTissue specimen from breast carcinoma patients were investigated for miRNAs-494, -205, -21 and -126. Prognostic associations for levels of miRNAs were analyzed based on complete clinical data and up to 22.5-year follow-up of the patient material (n = 285). For detection of the miRNAs, an automated sensitive protocol applying in situ hybridization was developed.ResultsMiRNA-494 indicated prognostic value for patients with invasive breast carcinoma. Among node-negative disease reduced level of miRNA-494 predicted 8.5-fold risk of breast cancer death (p = 0.04). Altered levels and expression patterns of the studied miRNAs were observed in breast carcinomas as compared to benign breast tissue.ConclusionsThe present paper reports for the first time on the prognostic value of miRNA-494 in invasive breast cancer. Particularly, detection of miRNA-494 could benefit patients with node-negative breast cancer in identifying subgroups with aggressive disease. Based on our experience, the developed automatic ISH method to visualize altered levels of miRNAs-494, -205, -21 and -126 could be applied to routine pathology diagnostics providing that conditions of tissue treatment, especially fixation delays, are managed.