Reducing the risk of late recurrence in hormone-responsive breast cancer

Inhibition of ERK signaling for treatment of ERRα positive TNBC

Breast cancer is the second leading cause of cancer-related deaths in women and triple-negative breast cancer (TNBC), in particular, is an aggressive and highly metastatic type of breast cancer that does not respond to established targeted therapies and is associated with poor prognosis and worse survival. Previous studies identified a subgroup of triple-negative breast cancer patients with high expression of estrogen related receptor alpha (ERRα) that has better prognosis when treated with tamoxifen. We therefore set out to identify common targets of tamoxifen and ERRα in the context of TNBC using phosphoproteomic analysis. In this study, we discovered that phosphorylation of mitogen-activated protein kinase 1 (MAPK1) is regulated by tamoxifen as well as ERRα. Additionally, we showed that inhibition of MAPK signaling together with the use of a selective ERRα inverse agonist, XCT-790, leads to a significant upregulation of apoptosis and paves way for the therapeutic use of MAPK inhibitors for treatment of ERRα expressing TNBC.

Leupaxin is expressed in mammary carcinoma and acts as a transcriptional activator of the estrogen receptor α

Leupaxin belongs to the group of paxillin proteins and was reported to play a major role in the invasion and migration of prostate cancer cells. In the present study we were able to show by using a cDNA cancer profiling array that leupaxin is upregulated in breast and endometrial cancer, whereas downregulation of leupaxin was observed in lung cancer. In addition, immunohistochemical studies using a leupaxin-specific antibody on human breast cancer specimens (n=127) revealed that leupaxin is expressed mainly in invasive ductal carcinomas and ductal carcinoma in situ (40 and 49% respectively), and only in a minority of lobular mammary carcinomas. To further investigate the role of leupaxin in the progression of breast cancer the expression of leupaxin was analysed in six breast cancer cell lines. The estrogen receptor α (ERα)-positive HCC70 and the ERα-negative MDA-MB-231 cells showed leupaxin expression on the RNA and protein level. Leupaxin localizes in these mammary carcinoma cells at focal adhesion sites and shuttles between membrane and nucleus via its LD4 motif as major nuclear export signal. Interaction partners of leupaxin in the nucleus represent the estrogen receptors ERα and ERβ. Both ERα and ERβ bind to the LIM domains of leupaxin via their AF-1/DNA binding domains. Furthermore, leupaxin is able to induce transcriptional activity of ERα independent of the presence of estradiol. The specific downregulation of leupaxin expression using siRNAs in mammary carcinoma cells resulted in reduced migratory capability and diminished invasiveness whereas no effect on proliferation was observed. Collectively, these results show that leupaxin has particular influence on the progression and invasion of breast cancer cells and may therefore represent an interesting candidate protein for diagnosis and therapeutic interventions.

Optimal systemic therapy for premenopausal women with hormone receptor-positive breast cancer

Although systemic therapy is one of the cornerstones of therapy for premenopausal women with early stage breast cancer, there remain many unknowns regarding its optimal use. By accident of clinical trial design, much clinical investigation in premenopausal women has focused on chemotherapy. More recently the value of endocrine therapy (tamoxifen and ovarian suppression/ablation via surgery, LHRH agonists, or chemotherapy-induced menopause) has become apparent, and some form of endocrine therapy is viewed as standard for virtually all premenopausal women with early stage invasive breast cancer that expresses estrogen and/or progesterone receptor. Critical open questions include type and duration of endocrine therapy and the development of prognostic/predictive markers to help identify patients who are likely to benefit from chemotherapy in addition to endocrine therapy. For some years, five years of tamoxifen has been viewed as the standard endocrine therapy for premenopausal hormone-responsive breast cancer, although the ATLAS trial suggests that an additional five years of tamoxifen can be considered. The MA17 trial also suggests that an additional five years of an aromatase inhibitor can be considered for women who become postmenopausal during tamoxifen therapy. Information about the value of ovarian suppression continues to emerge, most recently with the demonstration of excellent outcome with goserelin plus tamoxifen in the ABCSG12 trial. The SOFT and TEXT trials, whose accrual is now complete, should help to define optimal endocrine therapy. In addition, use of the 21-gene recurrence score assay may help to delineate the additional value of chemotherapy for patients with node-negative breast cancer, and its utility in the setting of women with 1-3 positive lymph nodes is under study in the RxPONDER trial. Nonetheless, the need for other predictive biomarkers to select appropriate therapy remains real. Finally, attention to long term benefits and side effects of therapy will continue to be vital for these young women.

Fear of recurrence in long-term breast cancer survivors-still an issue. Results on prevalence, determinants, and the association with quality of life and depression from the cancer survivorship--a multi-regional population-based study

BACKGROUND

Fear of recurrence (FoR) is a widespread problem among breast cancer survivors. So far, little is known about prevalence, determinants, and consequences of FoR specifically in long-term breast cancer survivors, even though it was found to be one of the most important concerns in this group.

METHODS

Analyses are based on data of several population-based cohorts of long-term breast cancer survivors, recruited by six German cancer registries. Overall, 2671 women were included in the analyses. FoR was assessed using the short form of the Fear of Progression Questionnaire. Potential determinants of moderate/high FoR and the association with depression and quality of life (QoL) were explored via multiple logistic and linear regression.

RESULTS

Even though the majority of women reported low levels of FoR (82%), a substantial percentage experienced moderate (11%) and high (6%) FoR. Younger age (odds ratio = 3.00, confidence intervals = 1.91-4.73 for women below age 55 years) and considering oneself as a tumor patient (odds ratio = 3.36, confidence intervals = 2.66-4.25) were found to exhibit the strongest associations with moderate/high FoR. Overall, psychosocial and sociodemographic factors played a far bigger role in FoR than clinical factors. Higher FoR was associated with higher depression and lower QoL.

CONCLUSION

Fear of recurrence (mostly low levels) is highly prevalent among long-term breast cancer survivors and can negatively affect QoL and well-being. Therefore, it should be given appropriate consideration in research and clinical practice. As specifically younger women tended to be impacted by FoR, it is crucial to be particularly attentive to specific needs of younger survivors.

The difference in prognostic factors between early recurrence and late recurrence in estrogen receptor-positive breast cancer: nodal stage differently impacts early and late recurrence

Background

Probability of recurrence in patients with estrogen receptor (ER)-positive breast cancer remains constant for long periods. We compared tumor burden impact on late versus early recurrence in our cohort with long-term follow-up.

Methods

Five hundred and ninety five patients diagnosed with ER-positive breast cancer between 1989 and 2001 were classified into three groups: early recurrence within 5 years, late recurrence after 5 years, and no recurrence. We identified prognostic factors among the groups using logistic regression analysis.

Results

At median follow-up of 11.7 years, among 595 ER-positive women, 98 (16.4%) had early recurrence and 58 (9.7%) had late recurrence. On multivariate analysis, higher nodal stage (N0 vs. N2, odds ratio [OR] 3.189; N0 vs. N3, OR 9.948), higher histologic grade (grade 1 vs. grade 2, OR 3.896; grade 1 vs. grade 3, OR 5.945), age >35 years (OR 0.295), and receiving endocrine therapy (OR 0.293) affected early recurrence. Compared to no recurrence, receiving endocrine therapy (OR 0.285) was solely related to decreased risk of late recurrence. Increased risk of early recurrence was noted with the higher nodal stage when early and no recurrences were compared. This phenomenon was not found in late recurrence. In the last comparison between the early and late recurrence, higher nodal stage (N0 vs. N3, OR 16.779) and higher histologic grade (grade 1 vs. grade 3, OR 18.111) repeatedly weighted for early recurrence.

Conclusions

Nodal burden had an attenuated influence on late recurrence, which suggests that, unlike early recurrence, tumor biology might have a more important role than tumor load for late recurrence in ER-positive disease.

Optimal combination of radiotherapy and endocrine drugs in breast cancer treatment

PURPOSE

Breast cancer is the most common cancer in women. Radiotherapy is considered a standard treatment option after surgery and adjuvant endocrine therapy is also universally used. Tamoxifen and letrozole are the current first-line endocrine therapy drugs. However, information has been scarce about how best to sequence these therapies to maximize their effectiveness and keep toxic effects to a minimum. In this study, we observed the effect of different sequence combination of radiotherapy and endocrine drugs, tamoxifen or letrozole, to get the best treatment sequence.

MATERIALS AND METHODS

The combination effect of radiotherapy and tamoxifen was observed on breast tumour cell line MCF-7, radiotherapy and letrozole on aromatase-expressing breast tumour cell line MCF-7CA. Irradiation was performed with 6Gy, except for doses ranging from 0 to 8Gy for clone formation assay. Tamoxifen or letrozole was added before or after irradiation, respectively. Radiosensitivity was evaluated by clonogenic assay, cell viability by 3-(4,-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. To explore the potential mechanism, cell apoptosis was determined by DNA-binding dye 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) assay, the change of Bcl-2 and Bax expression was by western blot.

RESULTS

Although no significant statistical difference was observed between different sequence, tamoxifen and letrozole both increased radiosensitivity. Furthermore, the above inhibitory effect was related with apoptosis signaling pathway, especially Bcl-2 and Bax.

CONCLUSION

Taken together, these results suggested that endocrine drugs, such as tamoxifen and letrozole, have potential application with radiotherapy.

Current controversies in extended adjuvant endocrine therapy for early breast cancer

PURPOSE OF REVIEW

Hormone receptor positive breast cancer is responsible for the majority of breast cancer deaths. The risk for disease recurrence that is lower in the first 5 years after primary treatment than for hormone receptor negative breast cancer remains relatively high even after 15 years. Late recurrences can be prevented or at least further delayed with extended endocrine therapy. Its optimal duration and treatment tailoring is discussed in the present review.

RECENT FINDINGS

Recently, the results of Adjuvant Tamoxifen, Longer Against Shorter and adjuvant Tamoxifen--To offer more, two very large adjuvant trials exploring the benefit of extending tamoxifen treatment beyond 5 years, were reported, adding controversy to what was believed to be the optimal duration of adjuvant tamoxifen. Aromatase inhibitors have proven to have disease-free survival advantage when used after 5 years of tamoxifen with a delay of up to 2.8 years. Further data on sequencing endocrine agents are eagerly awaited.

SUMMARY

In summary, at least further 4 years of aromatase inhibitor treatment after the first 5 years of adjuvant tamoxifen is recommended in postmenopausal endocrine responsive early breast cancer, nowadays. The value of extended tamoxifen therapy is still controversial, though it might be of interest especially in premenopausal patients. Tailoring treatment according to risk of disease recurrence, patient life expectancy, comorbidity, risk factors for cardiovascular disease or osteoporosis and compliance is necessary.

Endocrine therapy in metastatic breast cancer: data from Breast Cancer Registry of Palermo, 1999-2005

This study compares the survival of breast cancer patients who are metastatic at diagnosis (DMBC) and of recurrent metastatic breast cancer (RMBC) patients. We analyzed retrospectively the population-based data of Breast Cancer Registry of Palermo and collected a total of 4459 breast cancer cases in the years 1999-2005. Survival analysis did not show statistically significant differences between DMBC and RMBC patients (P= 0.882). Endocrine manipulation is the treatment of choice in the case of hormone receptor-positive breast tumors. In 91 receptor-positive DMBC patients the endocrine treatment was associated with a prolonged overall survival (OS) (median survival 33.5 months compared to 29 months for receptor-positive patients who did not receive hormone treatment). Receptor-negative patients who underwent endocrine therapy (76% of cases) survived longer than receptor-negative patients who did not receive hormone treatment (median survival 28.5 months vs. 15 months, respectively). This evidence supports the concept that endocrine therapies impinging upon molecular targets other than hormone receptors may increase survival rates of breast cancer patients.