Abstract PS7-35: Geicam/2014-03 (registem): A prospective registry of advanced breast cancer: A subset of triple negative breast cancer patients with her2 low expression

Background: The RegistEM study will provide prospective data from advanced breast cancer (ABC) patients (pts). Understanding the real distribution of BC subtypes is its primary objective. A new nomenclature has been proposed for those cases with HER2 1+ or 2+ by immunohistochemistry and negative in situ hybridization, HER2-low BC. In clinical practice, these tumors are reported as HER2 negative. Methods: This is a non-interventional study that will enroll approximately 1,867 pts with ABC diagnosed from January 2016 to December 2019, either after recurrence or as 1st diagnosis, in 38 Spanish sites. Biological samples (primary and/or metastatic tumor lesions, and blood) collection is part of its procedures. In this analysis (cut-off date 01/April/2020, database ongoing), we describe the characteristics of pts with Triple Negative (TN) subtype and HER2-low expression (as mentioned above). Biomarkers, including HER2, were determined in either primary tumor (PT), M1 or in both, PT and M1. Results: This subset of pts make up 37.4% (n=49) of TN pts considered for this analysis (n=131). Their distribution within the three groups (PT, M1 and PT/M1), was 46.9% (n=23), 42.9% (n=21) and 10.2% (n=5), respectively. These pts were diagnosed with early BC (EBC) and at recurrence, 91.7% presented distant metastases. Median time from EBC diagnosis until recurrent disease in terms of ABC was 29.8 months (mo), with the majority of pts recurring at >12 mo (95.9%), similar to the whole TN subset. Most pts were Caucasian (98%), and at diagnosis of ABC, the median age was 60 years (range 31-84) and 65.3% were postmenopausal. A change of BC subtype was documented in 15/49 (30.6%) pts, with the higher rate in M1 group (52.4%); as opposed to the TN subset, a change to HER2+ disease was reported in 6/15 (40.0%) pts and just after the TN subtype in all cases. Family history of BC and/or ovarian cancer was reported in 42.9% pts and any genetic test to assess the hereditary risk was performed in 30.6% pts. Similarly to TN subset, lung (36.7%), lymph nodes and bone (34.7% each) and liver (24.5%) were the most frequent metastatic locations; central nervous system metastases were developed by 14.3% pts. Visceral involvement was present in 66.7% pts, being this rate lower in M1 compared to PT and PT/M1 groups. The most frequent 1st-line therapies were chemotherapy (CT) (44.9%) and CT/biological therapy (BT) (36.7%). Type of CT mainly included capecitabine (36.4%), taxanes (27.3%), eribulin (13.6%) and platinum-based combinations (13.6%). Most pts received CT as monotherapy (86.4%). Bevacizumab (BVZ) was the most frequent BT associated to CT (77.8%), mainly with capecitabine and/or paclitaxel (72.2%). Progressive disease to 1st-line therapy in the whole group was reported in 73.5% pts (higher than in TN subset), with a median time to progression (TTP) of 5.7 mo (range 1.7-15.0); PT was the group with a higher PD rate. A 2nd-line therapy was reported in 63.3% pts. Similarly to 1st-line setting, the most frequent 2nd-line therapies were CT (74.2%) and CT/BT (12.9%) (with BVZ in 75.0% pts). CT in monotherapy was reported in 69.6% pts (capecitabine 31.3%, eribulin 25.0%). Median duration of this line therapy was 3.0 mo (range 0.6-15.8), PD has been reported in 96.8% pts (similar between groups), and 3rd-line therapy in 25/49 (51.0%) pts.

Conclusions: In TN/HER2-low ABC pts, lung, lymph nodes and bone were the most frequent metastatic locations. As opposed to TN subset, HER2+ disease is part of the subtype changes reported. Although the main 1st- and 2nd-line therapies were CT and CT/BT, similarly to TN subset, the rate of pts with PD to 1st- and 2nd-line therapies is higher, and also those pts treated in the 3rd-line setting.

Citation Format: Carlos Jara, Isabel Álvarez, César A Rodríguez, Purificación Martínez, Raquel Andrés, Álvaro Rodríguez-Lescure, Diego Malón, Jose Luis Alonso, Encarna Adrover, María José Echarri, Mireia Margeli, Ariadna Tibau, Judith Ramírez, Silvia Antolín, Ruth Campo, Juan José Miralles, Susana Bezares, Federico Rojo, Sara López-Tarruella, Angel Guerrero-Zotano. Geicam/2014-03 (registem): A prospective registry of advanced breast cancer: A subset of triple negative breast cancer patients with her2 low expression [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-35.

Abstract PS7-24: Characteristics of HR+/HER2- patients with recurrent disease by HER2 expression from a prospective registry of unresectable locally advanced or metastatic breast cancer: GEICAM/2014-03 (RegistEM)

Background: The RegistEM study is a non-interventional cohort study that will provide prospective data from >1,800 advanced breast cancer (ABC) patients (pts), either after recurrence or as first diagnosis in 38 Spanish sites. Primary objective is the distribution of BC subtypes. A new nomenclature has been proposed for those cases with immunohistochemistry (IHC) 1+ or 2+ and negative in situ hybridization (ISH), HER2-low BC. In clinical practice these tumors are reported as HER2 negative. This subpopulation has been identified as an interesting group from a clinical perspective. Methods: In this analysis (cut-off date 01/April/2020; database is ongoing) we describe the characteristics of 229 pts with hormone receptor (HR)+/HER2-low BC documented in a metastatic lesion after early disease recurrence and who received adjuvant endocrine therapy (ET). Three subgroups of pts have been considered for this analysis based on HER2 results: HER2 IHC 0, HER2-low, and HER2 ISH- (without IHC). Biological samples collection is part of study procedures. Results: The distribution of HER2 IHC 0, HER2-low, and HER2 ISH- subgroups was 52.4%, 42.8% and 4.8%, respectively. The median time to advance disease was 98.6, 88.8 and 106.9 mo in each group. Almost all pts were female and Caucasian (99%), and at ABC diagnosis, 75.5% were postmenopausal. Median age was 59 years (range 33-88). Fourteen (6.1%) pts had HER2+ (IHC 3+ or ISH amplified) BC subtype during their disease. Family history of BC and/or ovarian cancer was reported in 31.4% pts, an hereditary-risk genetic test was performed in 11.4% (n=26) pts in total and BRCA2 gene mutation (n=6) was the only one reported. The most frequent metastases are included in Table 1. Visceral disease was present in 63.3% pts and 76% pts had ≤2 locations. The most frequent 1st-line therapies were ET/biological therapy (BT) (46.7%) and ET (28.8%), and were equal distributed in the 3 subgroups. The most common ET/BT regimens were aromatase inhibitor (AI)/cyclin-dependent kinase 4/6 inhibitor (CDKi) (49.1%/48.9%/42.9% in each subgroup) and fulvestrant (FUL)/CDKi (35.8%/27.7%/28.6%); AIs (50%/64%/66.7%) and FUL (31.6%/20%/0%) were also the most common drugs for monotherapy ET. A 2nd-line therapy was reported in ~53% pts in HER2 IHC 0 and HER2-low, and in 36% pts in HER2 ISH-. The median time to progression (TTP) to 1st-line therapy was 11.4 mo (1.2-37.0), being similar in pts with HER2 IHC 0 and HER2-low (~11 mo), and higher in pts with HER2 ISH- (16 mo). The most frequent 2nd-line therapies were ET/BT (~34% in HER2 IHC 0 and HER2-low, and 25% in HER2 ISH-) [FUL/CDKi (36.4%/47.1%/100%), AI/CDKi (36.4%/23.5%/0%)], chemotherapy as monotherapy (17 pts out of 63 in HER2 IHC 0, 17 pts out of 53 in HER2-low and 1 pt (capecitabine) out of 4 in HER2 FISH-) (capecitabine 29.4%/52.9% in HER2 IHC 0 and HER2-low). Median duration of 2nd-line therapy was ~5 mo in HER2 IHC 0 and ~8 mo in HER2-low and HER2 ISH-; disease progression was reported in 52.4%/62.3%/50% pts, respectively. Conclusions: In this population of HR+ tumors, the proportion of HER2 IHC 0 and HER2-low groups was similar. Time to advance relapse and the distribution of distant metastases were similar among the groups. The most common first- and second-line therapy was the ET/BT combination, with AI/CDKi and FUL/CDKi, respectively.

Table 1Location of metastatic lesionsIHC 0HER2-lowISH- non IHCN=120 N (%)N=98 N (%)N=11 N (%)Bone74 (61.7)55 (56.1)6 (54.5)Liver36 (30.0)37 (37.8)3 (27.3)Lung27 (22.5)21 (21.4)5 (45.5)Lymph Node27 (22.5)21 (21.4)2 (18.2)Soft Tissue6 (5.0)11 (11.2)0CNS3 (2.5)4 (4.1)0Other43 (35.8)31 (31.6)5 (45.5)

Citation Format: Isabel Álvarez, Angel Guerrero, Sara López-Tarruella, Purificación Martínez, Marta Mori, Catalina Falo, Silvia Antolín, César A Rodríguez, Mireia Margeli, Isabel Garau, Ariadna Tibau, Diana Moreno, Josefina Cruz, María José Echarri, Antonio Antón, Álvaro Rodríguez-Lescure, María José Escudero, Susana Bezares, Federico Rojo, Carlos Jara. Characteristics of HR+/HER2- patients with recurrent disease by HER2 expression from a prospective registry of unresectable locally advanced or metastatic breast cancer: GEICAM/2014-03 (RegistEM) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-24.

Targeted Therapy in Locally Advanced and Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma (LA-R/M HNSCC)

Surgery and radiotherapy are the standard treatment options for patients with squamous cell carcinoma of the head and neck (SCCHN). Chemoradiotherapy is an alternative for patients with locally advanced disease. In recurrent/metastatic disease and after progression to platin-based regimens, no standard treatments other than best supportive care are currently available. Most SCCHN tumours overexpress the epidermal growth factor receptor (EGFR). This receptor is a tyrosine-kinase membrane receptor that has been implicated in angiogenesis, tumour progression and resistance to different cancer treatments. In this review, we analysed the different drugs and pathways under development to treat SCCHN, especially recurrent/metastatic disease. Until now, the EGFR signalling pathway has been considered the most important target with respect to new drugs; however, new drugs, such as immunotherapies, are currently under study. As new treatments for SCCHN are developed, the influence of therapies with respect to overall survival, progression free survival and quality of life in patients with this disease is changing.

The NER-related gene GTF2H5 predicts survival in high-grade serous ovarian cancer patients

OBJECTIVE

We aimed to evaluate the prognostic and predictive value of the nucleotide excision repair-related gene GTF2H5, which is localized at the 6q24.2-26 deletion previously reported by our group to predict longer survival of high-grade serous ovarian cancer patients.

METHODS

In order to test if protein levels of GTF2H5 are associated with patients' outcome, we performed GTF2H5 immunohistochemical staining in 139 high-grade serous ovarian carcinomas included in tissue microarrays. Upon stratification of cases into high- and low-GTF2H5 staining categories (> and ≤ median staining, respectively) Kaplan-Meier and log-rank test were used to estimate patients' survival and assess statistical differences. We also evaluated the association of GTF2H5 with survival at the transcriptional level by using the on-line Kaplan-Meier plotter tool, which includes gene expression and survival data of 855 high-grade serous ovarian cancer patients from 13 different datasets. Finally, we determined whether stable short hairpin RNA-mediated GTF2H5 downregulation modulates cisplatin sensitivity in the SKOV3 and COV504 cell lines by using cytotoxicity assays.

RESULTS

Low expression of GTF2H5 was associated with longer 5-year survival of patients at the protein (hazard ratio [HR], 0.52; 95% CI, 0.29 to 0.93; p=0.024) and transcriptional level (HR, 0.80; 95% CI, 0.65 to 0.97; p=0.023) in high-grade serous ovarian cancer patients. We confirmed the association with 5-year overall survival (HR, 0.55; 95% CI, 0.38 to 0.78; p=0.0007) and also found an association with progression-free survival (HR, 0.72; 95% CI, 0.54 to 0.96; p=0.026) in a homogenous group of 388 high-stage (stages III-IV using the International Federation of Gynecology and Obstetrics staging system), optimally debulked high-grade serous ovarian cancer patients. GTF2H5-silencing induced a decrease of the half maximal inhibitory concentration upon cisplatin treatment in GTF2H5-silenced ovarian cancer cells.

CONCLUSION

Low levels of GTF2H5 are associated with enhanced prognosis in high-grade serous ovarian cancer patients and may contribute to cisplatin sensitization.

Use of bevacizumab as a first-line treatment for metastatic breast cancer

OBJECTIVE

During clinical practice, it can be challenging, given the lack of response biomarkers, to identify the patients with metastatic breast cancer (mbca) who would benefit most from the addition of bevacizumab to first-line standard chemotherapy. The aim of the present review was to summarize the relevant scientific evidence and to discuss the experience of a group of experts in using bevacizumab to treat mbca.

METHODS

A panel of 17 Spanish oncology experts met to discuss the literature and their experience in the use of bevacizumab as first-line treatment for mbca. During the meeting, discussions focused on three main issues: the profile of the patients who could benefit most from bevacizumab, the optimal bevacizumab treatment duration, and the safety profile of bevacizumab.

RESULTS

The subset of mbca patients who would benefit the most from the addition of bevacizumab to first-line standard chemotherapy are those with clinically defined aggressive disease. Treatment with bevacizumab should be maintained until disease progression or the appearance of unacceptable toxicity. In the mbca setting, the toxicity profile of bevacizumab is well known and can be managed in clinical practice after adequate training.

CONCLUSIONS

This expert group recommends administering bevacizumab as first-line treatment in patients with clinically aggressive disease.

Molecular biology in head and neck cancer

Major changes in the treatment of head and neck cancer are possible today because of the knowledge that we have on the molecular biology of these tumors. Different pathways are active in the development of this cancer and field cancerization is a major problem for the cure in early stage disease. Epidermal growth factor signal transduction pathway is now the principal target for this disease. New therapeutic strategies such as monoclonal antibodies and small molecules have appeared, however no more than 20% of the patients have objective responses with these therapies. Consequently, new alternatives of treatment in the basis of the understanding of molecular biology are necessary to increase the number of patients that can be cured in the future.