Somatic copy number changes in DPYD are associated with lower risk of recurrence in triple-negative breast cancers

BACKGROUND

Genomic rearrangements at the fragile site FRA1E may disrupt the dihydropyrimidine dehydrogenase gene (DPYD) which is involved in 5-fluorouracil (5-FU) catabolism. In triple-negative breast cancer (TNBC), a subtype of breast cancer frequently deficient in DNA repair, we have investigated the susceptibility to acquire copy number variations (CNVs) in DPYD and evaluated their impact on standard adjuvant treatment.

METHODS

DPYD CNVs were analysed in 106 TNBC tumour specimens using multiplex ligation-dependent probe amplification (MLPA) analysis. Dihydropyrimidine dehydrogenase (DPD) expression was determined by immunohistochemistry in 146 tumour tissues.

RESULTS

In TNBC, we detected 43 (41%) tumour specimens with genomic deletions and/or duplications within DPYD which were associated with higher histological grade (P=0.006) and with rearrangements in the DNA repair gene BRCA1 (P=0.007). Immunohistochemical analysis revealed low, moderate and high DPD expression in 64%, 29% and 7% of all TNBCs, and in 40%, 53% and 7% of TNBCs with DPYD CNVs, respectively. Irrespective of DPD protein levels, the presence of CNVs was significantly related to longer time to progression in patients who had received 5-FU- and/or anthracycline-based polychemotherapy (hazard ratio=0.26 (95% CI: 0.07-0.91), log-rank P=0.023; adjusted for tumour stage: P=0.037).

CONCLUSION

Genomic rearrangements in DPYD, rather than aberrant DPD protein levels, reflect a distinct tumour profile associated with prolonged time to progression upon first-line chemotherapy in TNBC.

Ten-year analysis of the prospective multicentre Chemo-N0 trial validates American Society of Clinical Oncology (ASCO)-recommended biomarkers uPA and PAI-1 for therapy decision making in node-negative breast cancer patients

AIM

Final 10-year analysis of the prospective randomised Chemo-N0 trial is presented. Based on the Chemo-N0 interim results and an European Organisation for Research and Treatment of Cancer (EORTC) pooled analysis (n=8377), American Society of Clinical Oncology (ASCO) and Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) guidelines recommend invasion and metastasis markers urokinase-type plasminogen activator (uPA)/plasminogen activator inhibitor-1 (PAI-1) for risk assessment and treatment decision in node-negative (N0) breast cancer (BC).

METHODS

The final Chemo-N0 trial analysis (recruitment 1993-1998; n=647; 12 centres) comprises 113 (5-167) months of median follow-up. Patients with low-uPA and PAI-1 tumour tissue levels (n=283) were observed. External quality assurance guaranteed uPA/PAI-1 enzyme-linked immunosorbent assay (ELISA) standardisation. Of 364 high uPA and/or PAI-1 patients, 242 agreed to randomisation for CMF chemotherapy (n=117) versus observation (n=125).

RESULTS

Actuarial 10-year recurrence rate (without any adjuvant systemic therapy) for high-uPA/PAI-1 observation group patients (randomised and non-randomised) was 23.0%, in contrast to only 12.9% for low-uPA/PAI-1 patients (plog-rank=0.011). High-risk patients randomised to cyclophosphamide-methotrexate-5-fluorouracil (CMF) therapy had a 26.0% lower estimated probability of disease recurrence than those randomised for observation (intention-to-treat (ITT)-analysis: hazard ratio (HR) 0.74 (0.44-1.27); plog-rank=0.28). Per-protocol analysis demonstrated significant treatment benefit: HR 0.48 (0.26-0.88), p=0.019, disease-free survival (DFS) Cox regression, adjusted for tumour stage and grade.

CONCLUSIONS

Chemo-N0 is the first prospective biomarker-based therapy trial in early BC defining patients reaching good long-term DFS without adjuvant systemic therapy. Using a standardised uPA/PAI-1 ELISA, almost half of N0-patients could be spared chemotherapy, while high-risk patients benefit from adjuvant chemotherapy. These 10-year results validate the long-term prognostic impact of uPA/PAI-1 and the benefit from adjuvant chemotherapy in the high-uPA/PAI-1 group at highest level of evidence. They thus support the guideline-based routine use of uPA/PAI-1 for risk-adapted individualised therapy decisions in N0 breast cancer.

Participation in the SUCCESS-A Trial Improves Intensity and Quality of Care for Patients with Primary Breast Cancer

The SUCCESS-A trial is a prospective, multicenter, phase III clinical trial for high-risk primary breast cancer. It compares disease-free survival after randomization in patients treated with fluorouracil, epirubicin and cyclophosphamide followed by 3 cycles of docetaxel (FEC-D) with that of patients treated with 3 cycles of FEC followed by 3 cycles of gemcitabine and docetaxel (FEC-DG). After a second randomization patients were treated with zoledronate for 2 or 5 years. A total of 251 centers took part in the trial and 3754 patients were recruited over a period of 18 months which ended in March 2007. In a questionnaire-based survey we investigated the impact of enrollment in the trial on patient care, the choice of chemotherapy protocol and access to current oncologic information as well as overall satisfaction in the respective centers. Analysis of the 78 questionnaires returned showed that 40 % of the centers had never previously enrolled patients with these indications in clinical studies. Prior to participating in the study, 4 % of the centers prescribed CMF or other protocols in patients with high-primary breast cancer risk, 46 % administered anthracycline-based chemotherapy and 50 % gave taxane-based chemotherapy. Around half of the participating centers noted that intensity of care and overall quality of care became even better and that access to breast cancer-specific information improved through participation in the trial. After their experience with the SUCCESS-A trial, all of the centers stated that they were prepared to enroll patients in clinical phase III trials again in the future. These data indicate that both patients and physicians benefit from clinical trials, as enrollment improves treatment strategies and individual patient care, irrespective of study endpoints.

Abstract P5-15-04: CTX and CTX-related direct medication costs saved by testing biomarkers uPA and PAI-1 in primary breast cancer: Results of a prospective multi-center study at Certified Breast Centers in Germany

Background: Biomarkers uPA and PAI-1 are guideline recommended by ASCO, USA, and AGO, Germany, to be used in primary breast cancer to avoid unnecessary CTX in medium risk recurrence patients [G2, N−, HR+, HER2neu−, >35 years]. This study was performed to verify in normal clinical settings how many CTX cycles and how much CTX-related direct medication costs can be avoided by uPA/PAI-1 testing.

Methods: Prospective, non-interventional, multi-center study over two years among six Certified Breast Centers in Germany to analyze application of uPA/PAI-1 and consecutive decision making in the clinical setting for AOK Bayern-insured patients. CTX regimen and cycles avoided were identified for each case and direct costs for CTX and CTX-related medication costs for concomitant medication calculated for each patient individually according to body weight and body surface as well as potential FN prophylaxis according to physicians' decision. All medication costs were taken from the pharmaceutical price list for Germany Rote Liste of 2012. EURO [€] to US Dollar conversion rate as of June 12 2012: € 1.00 = US$ 1.25.

Results: In n=93 breast cancers n=35 CTX (37.6%; FEC n=25, FEC+DOC n=8 and TC n=2) were avoided according to uPA/PAI-1 test result. Consecutively 210 CTX cycles or 12.1 years of CTX application were saved improving patients' quality of life. uPA/PAI-1 testing saved direct medication costs for avoided CTX of US$ 221.816, CTX-related concomitant medication of US$ 34.353 and G-CSF prophylaxis of US$ 25.749, overall US$ 281.918. At process costs for a single uPA/PAI-1 test calculated at US$ 359, uPA/PAI-1 testing resulted in additional costs of US$ 33.387 for all breast cancer cases. Overall, testing of uPA/PAI-1 has been proven to be cost-effective regarding direct medication costs alone at a return-on-investment ratio of 8.4:1. Indirect cost savings further increase this ROI.

Conclusions: Innovative and individual cancer diagnostics like biomarkers uPA/PAI-1 can decrease need of CTX and increase patients' quality of life and thereby reduce costs for health care systems. Since application of this test is inadequate at present time measures are suggested to fully implement such cost-effective diagnostics.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-15-04.

Risk-reducing Surgery in Women at Risk for Familial Breast or Ovarian Cancer

An estimated 5 % of breast cancers and 10 % of ovarian cancers may be due to inherited autosomal dominant breast and ovarian cancer alleles BRCA1 und BRCA2. According to population-based studies 1 or 2 women per 1000 carry such a risk allele. The cumulative cancer risk for healthy women with a BRCA-mutation is between 60 and 85 % for breast cancer and between 20 and 60 % for ovarian cancer. Recent studies have reported an increased risk for contralateral breast cancer in women after unilateral breast cancer. Since 1997 the German Cancer Aid has supported an interdisciplinary approach for high-risk women consisting of genetic testing, counselling and prevention in 12 specialised centres. Since 2005 this concept has received additional support from health insurance companies, and results have been assessed with regard to outcomes (e.g. reduced mortality due to more intensive early diagnosis). The number of centres has increased to 15 at various university hospitals. These interdisciplinary centres offer women the opportunity to participate in a structured screening programme for the early diagnosis of breast cancer and provide non-directive counselling on the options for risk-reducing surgery, e.g., prophylactic bilateral salpingo-oophorectomy, prophylactic bilateral mastectomy or contralateral prophylactic mastectomy after unilateral breast cancer. Such surgical interventions can significantly reduce the risk of disease, the respective disease-specific mortality and - particularly prophylactic bilateral salpingo-oophorectomy - total mortality in BRCA-mutation carriers.