Letrozole may be a valuable maintenance treatment in high-grade serous ovarian cancer patients

OBJECTIVES

Endocrine therapy is used as maintenance in estrogen receptor (ER) positive breast cancers and has been proposed in low-grade serous ovarian cancers (LGSOC). Here we examine a rationale for its use as maintenance in high-grade serous ovarian cancers (HGSOC).

METHODS

We accessed the TCGA PANCAN dataset to evaluate the expression of ESR1. ESR1 expression data on all cancers (n=8901) and HGSOC (n=527) were followed by investigation of ER expression via immunohistochemistry (IHC) (n=4071). The same was performed in an independent cohort for matched primary and recurrent HGSOC (n=80). Finally, newly diagnosed ER+ HGSOC patients were offered a maintenance therapy with Letrozole.

RESULTS

ESR1 was strongly expressed in similar levels in HGSOC as in breast cancer. We found a strong ER expression via IHC in both the primary and matched recurrent HGSOC, particularly in the Platinum-resistant subgroup. The additional use of Letrozole as maintenance treatment was associated with a significantly prolonged recurrence free interval (after 24months 60% when taking Letrozole versus 38.5% in the control group; p=0.035; RFS: IC₅₀ reached by one subject versus 13.2months). This effect was also present in patients treated additionally with Bevacizumab; 20.8% of patients had no recurrence after 12months compared to 87.5% when taking Letrozole in addition to Bevacizumab (p=0.026).

CONCLUSIONS

Primary HGSOC have a slightly higher ESR1 than and a similar ER expression breast cancer where aromatase inhibitor maintenance is routine for decades. Here we demonstrate evidence for the usefulness of Letrozole in HGSOC, particularly in patients with chemotherapy resistance or residual disease.

Abstract P2-05-12: The ASCO-recommended prognostic factors uPA/PAI-1 in a multicenter cohort study (PiA)

Introduction

The PiA-study (Prognostic assessment in routine Application, NCT 01592825) was designed as a representative cohort of breast cancer patients to estimate the proportions of traditional and modern prognostic factors. The ASCO-recommended biomarkers uPA (urokinase-type plasminogen activator) and its inhibitor PAI-1 were used for biological risk assessment particularly for intermediate risk breast cancer patients and disease-free survival of the patients after 5 yrs of follow-up (F/U) was calculated.

Material & Methods

Between 2009 and 2011, 1,074 non-metastasized, primarily operated breast cancer patients from six centers in Germany were included. From 815 patients, fresh frozen tissue was obtained and processed for central testing uPA/PAI-1 by ELISA (FEMTELLE®, Sekisui Diagnostics GmbH). Low uPA/PAI-1 status is defined by uPA and PAI-1 concentrations below the published cut-offs, high status means one or both were higher than the corresponding cut-offs. Tumor characteristics were based on local pathology. The centers had to follow the national guidelines. In low-risk patients, adjuvant chemotherapy was spared. The median F/U is 56 months (range 0-78).

Results

In the total cohort of 1,074 patients, 166 had G1- and 237 had G3-tumors. Of the 671 patients with a G2-tumor, the following were allocated to the high-risk group: node-positive (n=371), younger than 35 yrs (n=17), and triple-negative (TN) or HER2-positive (n=118). For 253 tumors of the remaining 355 patients with an intermediate risk of recurrence (pN0, G2, HR positive, HER2-negative, ≥35 yrs), uPA/PAI-1 status was available. 126 (49.8%) were allocated to the low-risk group, one patient had a recurrence. At 5 yrs, in the total cohort 90.6% (95% CI, 89.5-91.7) of the patients were free of invasive disease. Of 114 HER2-positive tumors, 94 (82.4 %) had a high uPA/PAI-1 status, only one of the 38 HR negative/HER2 positive tumors had a low uPA/PAI-1 status. In the TN group, the majority of tumors had a high uPA/PAI-1 status (66 of 81; 81.5 %). In 30 patients lymph nodes were involved, 18.5% (n=15) had a low uPA/PAI-1 status, one event was detected. In N pos. patients with an high uPA/PAI-1 6 events were observed.

Conclusion

Testing for uPA/PAI-1 in the daily routine is feasible, fresh frozen tissue has been prepared from 76% of the tumors of the recruited patients, 37% of them had a low risk status. Using uPA/PAI-1, about half of the node-negative patients with an intermediate risk of recurrence were allocated to a group with an extremely low risk of recurrence and thus chemotherapy could be spared. Also in node-positive disease, uPA/PAI-1 has a prognostic impact.

Tab 1: Proportion of the subgroups according to IHC, grading and uPA/PAI-1-statusTumor typetotallow uPA/PAI-1 statushigh uPA/PAI-1 statusn=815 (100%)n=304 (37%)n=511 (63%)Luminal A-like tumors:HRpos., HER2neg., G1, G2515 (63.2%)240 (78.9%)275 (53.9%)Luminal B/HER2-negative-like tumors:HRpos., HER2neg., G3104 (12.8%)29 (9.5%)75 (14.7%)Luminal B/HER2-positive-like tumors:HR pos., HER2 pos., all grades77 (9.4%)19 (6.2%)58 (11.4%)HER2-positive (nonluminal) - like tumors:HRneg., HER2pos., all grades38 (4.7%)1 (0.3%)37 (7.3%)TN tumors:HRneg., HER2neg., all grades81 (9.9%)15 (4.9%)66 (12.9%)

Citation Format: Vetter M, Hartung C, Hanf V, Lantzsch T, Uleer C, Peschel S, John J, Buchmann J, Bürrig K-F, Weigert E, Thomssen C, Kantelhardt EJ. The ASCO-recommended prognostic factors uPA/PAI-1 in a multicenter cohort study (PiA) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-12.

Abstract P2-08-22: The ASCO-recommended biomarkers urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 define a subgroup of patients with very low risk of recurrence under routine conditions

Background:

ASCO Tumor Marker Guidelines 2007 recommended clinical routine use of the invasion markers uPA and PAI-1 for risk assessment in node-negative breast cancer patients (Harris et al. JCO 2007; 25:5287), and in some countries, e.g. Germany and France, risk assessment using these markers is broadly used. We wanted to evaluate the impact of uPA/PAI-1 on identifying patients with low risk of recurrence also in the daily routine in order to demonstrate that >25 years since their first description, these markers are still valuable.

Material and Methods:

We identified a cohort of 227 patients who were tested for uPA and PAI-1 in the clinical routine before 2012. Fresh frozen tissue of the primary tumor was obtained at biopsy or operation and processed for testing by a commercially available ELISA (FEMTELLE®, Sekisui Diagnostics GmbH) as previously described (Thomssen et al. JNCI 2009;101:1028). Tumor and patient characteristics were documented and all patients were regularly followed. Tumor concentrations below 3 ng/mg protein for uPA and below 14 ng/mg protein for PAI-1 were considered indicating low risk of recurrence (Harbeck et al. EJC 2013; 49:1825). Disease-free survival was defined as survival free from metastasis and loco-regional recurrence.

Results:

In our cohort, 86 patients had low tumor levels of uPA/PAI-1 (37.9 %). The median follow-up was 38.9 months (0.4 – 113.5 months). Adjuvant chemotherapy was delivered to 25 of 86 patients (29.1%) in the low risk group and to 85 of 141 patients (60.3%) in the high risk group; if steroid hormone receptor status was positive, generally adjuvant endocrine therapy for five years was advised. Using immunohistochemical subtyping, 73 of 86 patients with low uPA/PAI-1 values were luminal-like, 9 patients had a HER2-positive tumor and 3 patients had a triple negative breast cancer (TNBC). In patients with uPA or PAI-1 or both elevated, 105 of 141 patients had a luminal-like cancer, 12 patients were HER2 positive and 22 had TNBC; 1 case unknown. At 60 months of follow-up, patients with low uPA and/or PAI-1 tumor values had not experienced any recurrence, while in the high risk group 7 recurrences were observed although adequate adjuvant therapy was delivered (log-rank p=0.07). In node-negative pts with low uPA/PAI-1 values (n=72; pN0 70, cN0 2), no recurrences were observed, in 104 high risk patients 5 recurrences were observed (p=0.057).

Conclusions:

This observation confirms that also in daily routine, patients with a very low risk of recurrence can be identified by testing for uPA/PAI1. This group of pts comprises nearly 40% of pts and in these patients further evaluation with expensive predictive tests can be avoided and - above all - potentially toxic adjuvant chemotherapy can be spared.

Citation Format: Thomssen C, Kantelhardt E-J, Grosse R, Papendick N, Steer S, Buchmann J, Wickenhauser C, Vetter M. The ASCO-recommended biomarkers urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 define a subgroup of patients with very low risk of recurrence under routine conditions. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-22.

Aggressive Breast Cancer during Pregnancy with a Rare Form of Metastasis in the Maternal Placenta

Breast cancer is the second most common cancer diagnosed during pregnancy. Here we describe a 29-year-old patient with a recurrence of breast cancer with simultaneous brain, pulmonary and placenta metastasis. An overview of the literature on placenta metastases is provided together with a report on the interdisciplinary medical management.