Biomarker prediction of clinical outcome in operable breast cancer patients treated with tamoxifen

Cell proliferation of the primary tumor predicts ipsilateral axillary node disease in elderly breast cancer patients

The present study investigated whether tumor markers such as cell proliferation and steroid receptor status, which have been shown to have relevance for important endpoints (relapse-free and overall survival), can also predict axillary disease in elderly patients with breast cancer. We evaluated 351 consecutive elderly women with breast cancer ≥70 years of age with estrogen receptor (ER)‑positive tumors with no palpable axillary nodes, for whom information on cell proliferation determined by the 3H-thymidine labeling index (TLI) and progesterone receptor (PgR) was available. Patients underwent quadrantectomy (70.1%) or quadrantectomy plus radiotherapy (29.9%) without axillary node dissection, followed by adjuvant tamoxifen for at least 2 years. Univariable (cumulative incidence curves) and multivariable analyses (Fine and Gray models) were carried out. After a median follow-up of 16 years, ipsilateral axillary relapse was not related to PgR status but was strongly associated with tumor cell proliferation in both small (pT1) and large (pT2-4b) tumors. Axillary relapse cumulative incidence increased from 1% in patients with low-TLI (≤3%), PgR-positive and pT1 tumors to a maximum of 20% in patients with high-TLI, PgR-negative and pT2-4b tumors. Tumor cell proliferation, determined by TLI at primary surgery, is an important predictor of axillary relapse in elderly ER-positive breast cancer patients and could help to identify patients who should undergo axillary surgery.

Proliferation markers and survival in early breast cancer: a systematic review and meta-analysis of 85 studies in 32,825 patients

We have performed a systematic review and meta-analysis of proliferation markers (Ki-67, mitotic index (MI), proliferating cell nuclear antigen (PCNA) and thymidine or bromodeoxyuridine labelling index (LI)) with respect to survival in early breast cancer. Eighty-five studies involving 32,825 patients were analysed. Ki-67 (43 studies, 15,790 patients), MI (20 studies, 7021 patients), and LI (11 studies, 7337 patients) were associated with significantly shorter overall and disease free survival, using results from univariate and multivariate analyses from the individual studies. PCNA (11 studies, 2677 patients) was associated with shorter overall survival by multivariate analysis only, because of lack of data. There was some evidence for publication bias, but all markers remained significant after allowing for this. Ki-67, MI, PCNA and LI are associated with worse survival outcomes in early breast cancer. However, whether these proliferation markers provide additional prognostic information to commonly used prognostic indices remains unclear.

Development of New Rabbit Monoclonal Antibody to Progesterone Receptor (Clone SP2)

Evaluation of estrogen and progesterone receptor (ER, PgR) status in breast cancer is widely used for the prediction of the response to endocrine therapy and as a biologic parameter closely related to disease prognosis. The IHC method is considered to be a specific, sensitive, and economical method for determining ER and PgR status. The authors developed the first rabbit anti-PgR mAb (clone SP2) used in IHC on formalin-fixed, paraffin-embedded tissue sections from breast carcinomas. This new antibody, compared with currently available anti-PgR antibodies, has important advantages, including its reactivity even without heat-based antigen retrieval of fixed-embedded tissue sections in IHC and the predominance of nuclear immunostaining with only very low cytoplasmic signal. A comparative study of IHC on 107 histologic specimens from breast cancer cases showed that SP2 yields the same results as the wellknown mouse mAb to PgR (clone 1A6). The antibody affinity of SP2 is 12 times higher than that of 1A6. Thus, SP2 may prove of great value in the assessment of PgR status in human breast cancer.

The role of surrogate markers in the clinical development of antiretroviral therapy: a model for early evaluation of targeted cancer drugs

Both CD4 cell counts and measurements of plasma HIV-1 RNA (i.e. viral load) have become established surrogate markers for predicting treatment and disease outcome in HIV infection, and are instrumental for the evaluation of new antiretroviral drugs in clinical trials. Recently, HIV drug-resistance testing has also become available and has been shown to have prognostic value in providing guidance with antiretroviral therapy. The identification of robust surrogate markers is also an essential requirement for the clinical development of targeted anticancer agents, which unlike their cytotoxic counterparts, are often devoid of the toxicities that have been traditionally used to monitor the efficacy of chemotherapy. In particular, biological or molecular markers that are predictive of a drug effect need to be integrated into early efficacy trials of targeted therapies in order to confirm that the drug is in fact "hitting" the intended target. The full clinical significance of many of the altered cell types or polymorphisms, which are selected by cytostatic agents, remains to be elucidated. However, molecular genotyping of these targets, akin to drug resistance testing for HIV infection, may constitute an important strategy to assist with the selection and monitoring of targeted chemotherapy in cancer patients. Thus, lessons from HIV/AIDS on the value of surrogate makers may assist with the development and optimization of targeted cancer therapy.

CD44 expression and tumour cell density correlate with response to tamoxifen/carboplatin chemotherapy in glioblastomas

In order to identify response predictors for a post-operative glioblastoma therapy consisting of tamoxifen, carboplatin and radiotherapy, expression of 12 antigens was evaluated in 36 newly diagnosed tumours and 13 recurrences. Results were correlated with the clinical course of the disease. Antigen expression was assessed immunohistochemically for CD44s, TGF-beta2, TGF-alpha, progesterone receptor, estrogen receptor, EGFR, urokinase, urokinase inhibitor 1, CD87, p53 protein and Ki-67. Vessel density was determined by labelling of endothelia with von Willebrand factor. Response to chemotherapy correlated positively with cell density (p < 0.05) and negatively with CD44 over-expression (p < 0.02). Further, a positive correlation between age and CD44 expression (p < 0.05) and a negative correlation between age and p53 accumulation (p < 0.01) was found. In tumour recurrences expression of CD44 was significantly higher in local recurrences than in distant multifocal recurrences (p < 0.02), suggesting that CD44 may predominantly be associated with cell adhesion in glioblastomas.

Primary breast cancer in elderly women: biological profile and relation with clinical outcome

A biological characterisation carried out on 14,007 primary breast cancers provided evidence in favour of a relation between advanced age and favourable features (positivity for oestrogen/progesterone receptors, low proliferative rate, absence of p53 accumulation, bcl-2 overexpression, diploid DNA content), showed a similar pattern of association between patho-biological variables regardless of patient age, and demonstrated a relation between biological variables and disease outcome in the elderly, comparable to that already reported for younger patients. In fact, oestrogen receptor and proliferative activity provided independent prognostic information either in node-negative or in node-positive tumours treated with radical or conservative surgery plus radiotherapy, alone or followed by adjuvant hormonal therapy. It would be thus reasonable to use biomarkers as a complement to clinico-pathological features in a 'risk-factor profile system' even for elderly patients, upon their validation in prospective studies and after assessing the cost-benefit of treatments planned on the basis of biological information.