Abstract P3-19-16: Impact of targeted intraoperative (TARGIT-IORT) tumor bed boost during breast conserving surgery for early breast cancer on breast cancer associated and non-breast cancer associated mortality and morbidity

Introduction: Targeted intraoperative radiotherapy (TARGIT - IORT) as a tumor bed boost during breast conserving surgery is an established option for women with early breast cancer. In a previous study our group could demonstrate a beneficial effect of TARGIT-IORT on overall survival after neoadjuvant chemotherapy driven by non-breast cancer mortality, especially from cardiac or pulmonary diseases. This was in line with results of TARGIT-A trial that demonstrated an improved overall survival after TARGIT-IORT that was driven by other causes of death than breast cancer but in our analysis we could not exclude a selection bias because we had no data regarding pulmonary and cardiac co-morbidities. In this study we present an analysis of breast cancer associated and non-breast cancer associated mortality and morbidity in a lower risk population treated with TARGIT-IORT boost or external boost (EBRT) and with a complete dataset of pulmonary and cardiac co-morbidities at baseline. Material/Methods: In this non-randomized cohort study involving 125 patients with early breast cancer we compared outcomes of 59 patients who received a tumor bed boost with IORT (TARGIT-IORT) during lumpectomy versus 66 patients with external (EBRT) boost. All patients received whole breast radiotherapy. Local recurrence rates, distant recurrence rates, mortality, causes of death and incidence of new pulmonary and cardiac morbidity were compared. The small event rate did not allow a formal comparison, so the results are reported descriptively. Results: There were no statistically significant differences between the two groups regarding age, menopausal status, nodal status, ER status, PR status, HER2 status, tumor size, grading, cardiac or pulmonary diseases and hypertension. Median follow up was 60 months. Local recurrence occurred in 3 cases in the EBRT group (4.5%) and 4 cases in the TARGIT-IORT group (6.8%). Distant recurrences were observed in 5 cases in the EBR group (7.6%) and 3 cases in the TARGIT-IORT group (5.1%). 9 patients in the EBRT group (13.6%) died in the follow-up of 60 months and 6 patients (10.2%) in the TARGIT-IORT group. No death from a pulmonary disease occurred and the incidence of new pulmonary and new cardiac diseases showed no difference between both groups with 3 cases in the EBRT group (4.5%) and 2 cases in the TARGIT-IORT group (3.4%). Death from cardiac disease occurred with an incidence of 7 cases in the EBRT group (10.6%) and only 2 cases in the TARGIT-IORT group (3.4%). 2 patients in the EBRT group died of breast cancer (3.0%) whereas this did not happen at all in the TARGIT-IORT group. Conclusion: This analysis of an average risk group of breast cancer patients well balanced for pulmonary and cardiac co-morbidities demonstrates that TARGIT-IORT as an anticipated boost is not inferior to external beam radiotherapy boost. Trends for an improved overall survival after TARGIT-IORT have been reported before. The trend for a lower incidence of death from cardiac disease is in line with earlier considerations that TARGIT-IORT may induce miR-223 in the peritumoral breast tissue resulting in a downregulation of the local expression of epidermal growth factor (EGF) and a decreased activation of epidermal growth factor receptor (EGFR). This mechanism could explain an effect of TARGIT-IORT on the vascular system. In the currently recruiting TARGIT-B study this aspect will be prospectively investigated.

Citation Format: Hans-Christin Kolberg, Stephanie Gutberlet, Jayant S Vaidya, Maja Krajewska, György Lövey, Oliver Hoffmann, Miltiades Stephanou, Cornelia Kolberg-Liedtke. Impact of targeted intraoperative (TARGIT-IORT) tumor bed boost during breast conserving surgery for early breast cancer on breast cancer associated and non-breast cancer associated mortality and morbidity [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-19-16.

Abstract P3-11-07: Factors associated with first line chemotherapy use in patients with hormone receptor positive, HER2 negative metastatic breast cancer – data from the PRAEGNANT breast cancer registry

Background

For breast cancer patients with metastases which are not life threatening national and international guidelines recommend the exhaustion of all antihormonal therapeutic options before recommending chemotherapy. In Germany up to now only everolimus was an additional option to overcome endocrine resistance. CDK4/6 inhibitors recently became available in Germany (Nov 2011). Aim of this analysis was the identification of predictors for a decision against an antihormonal treatment.

Methods

The PRAEGNANT metastatic breast cancer registry (NCT02338167) is a prospective registry for metastatic breast cancer patients. Besides biomarker research the description of real-world treatment data was one of the main study aims. This analysis was restricted to first line metastatic patients who were hormone receptor (HR) positive and HER2 negative. First, predictors were identified with a multiple logistic regression model. Then patients, who received chemo or not ,were compared with regard to overall survival using Cox regression analysis with the predictors for chemotherapy from above and additionally chemo status (yes/no)

Results

A total of 389 HR-positive and HER2-negative patients with detailed treatment information were included during the 1st line therapy into PRAEGNANT. Of those 173 (44.5%) received a chemotherapy, 190 an antihormone therapy (AHT) (48.8%), and 26 (6.7%) everolimus+AHT. In the multiple logistic regression model, older patients, lower graded tumors, bone only disease and previous adjuvant chemotherapy were associated with a lower rate of first line chemotherapies. BMI and number of concomitant diseases had no influence on the choice of first line metastatic therapy. In patients with visceral metastases 58.1% were treated with a 1st line chemo, while in patients with brain metastases or bone only metastases these numbers were 55.6% and 26.9%. Grading had an influence with patients having a G1, G2 and G3 tumor receiving 1st line chemo in 28.0%, 38.4% and 63.2% of the cases respectively. Patients who received chemo seemed to have a worse overall survival than patients who did not receive chemo (adjusted HR 1.58; 95% CI, 0.89 to 2.18). However, this result was not signifcant (p = 0.12). Overall survival was primarily influenced by ECOG and location of metastasis

Conclusion

The usage of chemotherapy can be predicted with age, metastasis pattern, grading and previous use of chemotherapy. However, we could not show that patients benefited from chemotherapy. On contrary, there was a tendency that patients treated with chemotherapy had poorer overall survival. Further studies with larger sample sizes are needed to confirm this claim.

Citation Format: Huober J, Fasching PA, Taran F-A, Volz B, Overkamp F, Kolberg HC, Hadji P, Tesch H, Haeberle L, Ettl J, Hartkopf AD, Lux MP, Lueftner D, Wallwiener M, Mueller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Fersis N, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Janni W, Wallwiener D, Brucker SY, Schneeweiss A, Fehm TN. Factors associated with first line chemotherapy use in patients with hormone receptor positive, HER2 negative metastatic breast cancer – data from the PRAEGNANT breast cancer registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-11-07.

Abstract P5-21-09: Overall survival of metastatic breast cancer patients – data from the PRAEGNANT breast cancer registry

Background

Breast Cancer registries can help to understand how patient groups are treated outside clinical trials and what outcome is to expected for specific patient groups and therapy lines, which are not included into clinical trials. Here we present overall survival data according to therapy lines, patient and tumor characteristics.

Methods

The PRAEGNANT metastatic breast cancer registry (NCT02338167) is a prospective registry for breast cancer patients with focus on molecular biomarkers. Patients of all therapy lines with any kind of treatment are eligible for this registry. Collected data comprises therapies, adverse events, quality of life and other patient reported outcomes. Here we report on the comparison of overall survival data for different patient groups. For that analysis was restricted to patients included in the first therapy line for subgroup comparisons. Only for the analysis of the effect of therapy line on overall survival the complete dataset was used.

Results

A total of 1854 patients took part in this analysis. Of those 1016 were included first line, and 340, 213 and 285 patients 2nd line, 3rd lin4 and 4th line or higher respectively. A total of 339 deaths were observed. Two year survival rates (2Y-OS) for these groups were 75%, 65%, 57% and 36% (p(log-rank)<0.001). All further analyses were done only for the subset of first line treated patients with a total of 127 events. HER2 positive patients had the highest 2Y-OS rate of 84% and TNBC had the worst with 60% (see figure 1). Absolute numbers of deaths for TNBC, luminal A like, luminal B like and HER2 posives were 21, 48, 25, and 21. According to metastastic pattern the following survival rates were seen: brain (48%), other locations (69%), visceral (78%) and bone only (81%). ECOG was another factor that had a large influence on OS with ECOG 0: 83%, ECOG 1: 67% and EGOG 2+: 63% 2Y-OS. Age, BMI, number of concomitant diseases, and primary metastatic status did not have an influence on 2Y-OS.

Conclusion

This breast registry included patients over all therapy lines however mainly during the 1st line of therapy. Simple patient and tumor characteristics can classify patients into patients with differently favourable prognosis. Patients with HER2 positive disease had the best overall survival, while TNBC and luminal B like patients had the worst prognosis. As most of the patients were luminal A like 43% of all deaths occured within the group of luminal A like patients, which will need further focus for therapy development in the future.

Citation Format: Taran F-A, Fasching PA, Volz B, Huober J, Overkamp F, Kolberg HC, Hadji P, Tesch H, Haeberle L, Ettl J, Lux MP, Hartkopf AD, Lueftner D, Wallwiener M, Müller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Fersis N, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Janni W, Fehm TN, Wallwiener D, Brucker SY, Schneeweiss A. Overall survival of metastatic breast cancer patients – data from the PRAEGNANT breast cancer registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-09.

Characterisation of the promoter region of the human DNA-repair gene Rad51

PURPOSE OF INVESTIGATION

Regulatory elements of the 5'-flanking region of the DNA-repair gene Rad51 were analysed to characterise pathological alterations of Rad51 mRNA expression during tumour development.

METHODS

Various fragments of the Rad51 promoter were cloned into the pGL3 reporter vector and the respective promoter activity was determined by luciferase assays in transfected U2-OS cells. Transcription factor binding was identified using Protein/DNA arrays.

RESULTS

The region encompassing base pairs -204 to -58 was identified as crucial for Rad51 gene transcription. Down regulator sequences are present upstream (-305 to -204) and downstream (-48 and +204) of this core promoter element. Promoter activity is significantly enhanced by substituting G at the polymorphic positions +135 and +172 for C and T, respectively. Transcription factors Ets1/PEA3, E2F1, p53, EGR1, and Stat5 were identified as relevant for regulating expression of Rad51.

CONCLUSION

We identified three separate cis-sequence elements within the Rad51 transcriptional promoter, one ensuring basal levels of expression and two elements limiting expression to relatively low levels. The characterisation of transcription factor binding might help to explain high-level expression of Rad51 in a variety of solid tumours. The polymorphic sites appear important for the increased risk of breast and/or ovarian cancer for BRCA2 mutation carriers.

Relationship between chemotherapy with paclitaxel, cisplatin, vinorelbine and titanocene dichloride and expression of proliferation markers and tumour suppressor gene p53 in human ovarian cancer xenografts in nude mice

PURPOSE

In this study the relationship between therapy with paclitaxel, cisplatin, vinorelbine and titanocene dichloride and of the expression of proliferation markers (ki67 and S-phase fraction) and tumour suppressor gene p53 was analyzed using a human ovarian cancer xenograft model.

METHODS

Biopsy material from one human ovarian cancer was expanded and transplanted into 102 nude mice. The mice were divided into six groups with different intraperitoneal treatments with paclitaxel, cisplatin, vinorelbine, titanocene dichloride and a control group treated with 0.9% saline solution. After the observation period the tumours were extracted and immunohistochemically stained with monoclonal antibodies against ki67 and p53. The S-phase-fraction was identified by flow cytometry.

RESULTS

There where no statistically significant differences. Regarding the treatment groups, the vinorelbine-group showed the highest percentage (53.3%) and the titanocene dichloride-3x40 mg/kg-group the lowest percentage (7.1%) of ki67-positive specimens, whereas in the control group 35.7% of the specimens were positively stained for ki67. The results for the expression of p53 were similar. The vinorelbine-group had the highest percentage of p53-positive specimens (60%), in both titanocene-groups no specimen showed a positive staining for p53 and in the control group 7.1% of the specimens were positively stained for p53. The mean S-phase-fraction was 14.48% (SD +/- 3.98), no statistically significant relation between S-phase-fraction and expression of p53 (p = 0.883) or of ki67 (p = 0.351) could be shown. The change of tumour volume was independent of the results for ki67, p53 and the S-phase-fraction.

CONCLUSION

Although, as previously published, a significant difference of tumour volume change occurred between the treatment groups, in this study we could not find a relation between this change of tumour volume and the expression of p53 or ki67. The absolute number of p53- and ki67-positive staining specimens was too small for statistical analysis, therefore the relevance of the differences between the different treatment groups and the control remains unclear. The results for the S-phase-fraction showed no correlation between the change of tumour volume, different treatment protocols or the expression of p53- and ki67. Our findings contribute to the controversy of the influence of chemotherapy on the expression of proliferation markers and p53.

Taxanes in the first-line chemotherapy of metastatic breast cancer: review

Taxanes belong to the most effective agents in the treatment of advanced and non-hormone responsive breast cancer. Several recently published phase III studies have examined the role of taxane-anthracycline combinations in the first line treatment of metastatic breast cancer. Especially, patients with symptomatic visceral spread seem to benefit from taxanes containing polychemotherapy that is adequately dosed. Polychemotherapy with taxanes appears to be more effective than monotherapy. But at present, there are no adequate data concerning the comparison of taxane-monotherapy and anthracycline-containing polychemotherapy. New hopeful results with respect to efficacy and toxicity are reported from the docetaxel-capecitabine polychemotherapy. Thus, the combination of anthracyclines (adriamycin, doxorubicin) and taxanes (docetaxel, paclitaxel) is a promising tool in the treatment of metastatic breast cancer. New interesting combinations are under investigation.