BackgroundTrastuzumab is a humanized monoclonal antibody (mAb) currently used for the treatment of breast cancer (BC) patients with HER-2 overexpressing tumor subtype. Previous data reported the involvement of FcγRIIIA/IIA gene polymorphisms and/or antibody-dependent cellular cytotoxicity (ADCC) in the therapeutic efficacy of trastuzumab, although results on these issues are still controversial. This study was aimed to evaluate in vitro the functional relationships among FcγRIIIA/IIA polymorphisms, ADCC intensity and HER-2 expression on tumor target cells and to correlate them with response to trastuzumab.Patients and methodsTwenty-five patients with HER-2 overexpressing BC, receiving trastuzumab in a neoadjuvant (NEO) or metastatic (MTS) setting, were genotyped for the FcγRIIIA 158V>F and FcγRIIA 131H>R polymorphisms by a newly developed pyrosequencing assay and by multiplex Tetra-primer-ARMS PCR, respectively. Trastuzumab-mediated ADCC of patients’ peripheral blood mononuclear cells (PBMCs) was evaluated prior to therapy and measured by 51Chromium release using as targets three human BC cell lines showing different levels of reactivity with trastuzumab.ResultsWe found that the FcγRIIIA 158F and/or the FcγRIIA 131R variants, commonly reported as unfavorable in BC, may actually behave as ADCC favorable genotypes, in both the NEO (P ranging from 0.009 to 0.039 and from 0.007 to 0.047, respectively) and MTS (P ranging from 0.009 to 0.032 and P = 0.034, respectively) patients. The ADCC intensity was affected by different levels of trastuzumab reactivity with BC target cells. In this context, the MCF-7 cell line, showing the lowest reactivity with trastuzumab, resulted the most suitable cell line for evaluating ADCC and response to trastuzumab. Indeed, we found a statistically significant correlation between an increased frequency of patients showing ADCC of MCF-7 and complete response to trastuzumab in the NEO setting (P = 0.006).ConclusionsAlthough this study was performed in a limited number of patients, it would indicate a correlation of FcγR gene polymorphisms to the ADCC extent in combination with the HER-2 expression levels on tumor target cells in BC patients. However, to confirm our findings further experimental evidences obtained from a larger cohort of BC patients are mandatory.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0680-0) contains supplementary material, which is available to authorized users.
Trastuzumab is a humanized monoclonal antibody against the extracellular domain of hEGF receptor-2 (HER2). Trastuzumab in combination with chemotherapy has proven efficacy in treating both early and metastatic HER2-positive breast cancer. In the metastatic setting, the addition of trastuzumab to chemotherapy is associated with a statistically significant longer time to disease progression, higher rate of objective response and improvement in overall survival. Trastuzumab efficacy is not influenced by hormone receptor status, but differences in median overall survival exist between HER2-positive and HER2-negative states. Reassessment of the benefit of re-exposing patients with metastatic breast cancer to trastuzumab following relapse in the adjuvant setting is necessary. Ongoing research into new HER2-targeted therapies and trials involving combination anti-HER2 drug therapy without chemotherapy show promise. This review is focused on the available results obtained with the use of trastuzumab in the subset of HER2-positive breast cancer patients with metastatic disease.
The use of chemotherapy in premenopausal cancer patients may lead to chemotherapy-induced premature ovarian failure. Pharmacological temporary ovarian suppression obtained with the gonadotropin-releasing hormone agonist (GnRHa) administered concomitantly with chemotherapy has been investigated as a technique capable to reduce the gonadotoxicity, reducing the risk of developing premature menopause. In recent years, important evidence has become available on the efficacy and safety of this strategy that should now be considered a standard option for ovarian function preservation in premenopausal breast cancer patients. However, in women interested in fertility preservation, this is not an alternative to cryopreservation strategies, which remains the first option to be proposed. The purpose of this review is to summarize the mechanisms of GnRHa in the preservation of fertility in premenopausal cancer patient candidates to receive chemotherapy, highlighting the areas of doubt that require further investigation.
BackgroundRadiation therapy after lumpectomy is a standard part of breast conserving therapy for invasive breast carcinoma. The most frequently used schedule worldwide is 60 Gy in 30 fractions in 6 weeks, a time commitment that sporadically may dissuade some otherwise eligible women from undertaking treatment. The purpose and primary endpoint of this perspective study is to evaluate feasibility and short-term late toxicity in a hypofractionated whole breast irradiation schedule.MethodsBetween February and October 2008 we treated 65 consecutive patients with operable invasive early-stage breast cancer with a hypofractionated schedule of external beam radiation therapy. All patients were assigned to 39 Gy in 13 fractions in 3 weeks to the whole breast plus a concomitant weekly boost dose to the lumpectomy cavity of 3 Gy in 3 fractions.ResultsAll the patients had achieved a median follow up of 24 months (range 21-29 months). At the end of treatment 52% presented grade 0 acute toxicity 39% had grade 1 and 9% had grade 2. At 6 months with all the patients assessed there were 34% case of grade 1 subacute toxicity and 6% of grade 2. At 12 months 43% and 3% of patients presented with clinical grade 1 and grade 2 fibrosis respectively and 5% presented grade 1 hyperpigmentation. The remaining patients were free of side effects. At 24 months, with 56 assessed, just 2 patients (3%) showed grade 2 of late fibrosis.ConclusionsThe clinical results observed showed a reasonably good feasibility of the accelerated hypofractionated schedule in terms of acute, subacute and short-term late toxicity. This useful 13 fractions with a concomitant boost schedule seems, in selected patients, a biologically acceptable alternative to the traditional 30 days regime.
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