ABSTRACTS

From breast implants to squamous cell carcinoma

Squamous cell carcinoma is a malignant neoplasm of squamous cell of the epidermis, it has the potential for rapid growth and a low but significant risk of metsastasis and death. Chronically injured skin is one of the risk factors for the development of cutaneous Squamous cell carcinoma.

Hereby, we describe the case of a 44-year old woman who had a right breast prosthesis with many surgical re-interventions for aesthetic reasons, at least eight operations were done over nine years complicated each time by superimposed infections at the site of the interventions.

During the last procedure, skin biopsies revealed keratinizing, well-differentiated squamous cell carcinoma, tumor was infiltrating the lower quadrants of the breast, and deeply infiltrating the 3^rd, 4^th and 5^th ribs along with lymph nodes involvement (axillary and internal mammary chain).

Six cycles of Carboplatine with Paclitaxel were received as neoadjuvant chemotherapy but unfortunately the fluorodeoxyglucose (FDG)-positron emission tomography (PET) showed a disease progression; subsequently we decided to go for surgical resection planned in the upcoming two weeks.

A rare tumor of the parotid gland

Epithelial-myoepithelial carcinoma (EMC) is a rare type of malignant tumor, accounting for about 1% of all salivary gland tumors arising most commonly in the parotid gland, but it has also been described in the submandibular gland as well as in minor salivary glands and palate. A biphasic cell arrangement formed by an inner layer of duct-forming epithelial cells and an outer layer of myoepithelial cells is the histological hallmark

Herein, we describe the case of a 44 year old patient diagnosed with an epithelial-myoepithelial carcinoma of the right parotid treated surgically with positive margins, followed by adjuvant radiotherapy; a next generation sequencing showed a HRAS Q61R mutation; three years and a half later he relapsed with lung metastasis treated by surgical excisions along with a platinum based therapy coupled with 5-FU but two years later new lung lesions were seen and the platinum based therapy coupled with 5-FU was adopted again with a stable disease; hence he was started on oral cyclophosphamide for one year; once again, those lung lesions kept on increasing in size and number and once again the platinum based therapy coupled with 5-FU was prescribed but stopped after 6 months for intolerance and major asthenia, and a we decided to stop the treatment . After a median follow up of three years, the disease is always stable and there’s no evidence of loco-regional recurrence.

Genomic profiling of patients with metastatic castration-resistant prostate cancer (mCRPC) for the evaluation of rucaparib: next-generation sequencing (NGS) of tumour tissue and cell-free DNA (cfDNA)

Background

The phase 2 TRITON2 (NCT02952534) and phase 3 TRITON3 (NCT02975934) studies are evaluating the poly(ADP-ribose) polymerase inhibitor rucaparib in patients with mCRPC who have a deleterious germline or somatic mutation in BRCA1, BRCA2, ATM, or other DNA damage repair (DDR) gene. Here we present interim results of central genomic screening of tissue samples and plasma cfDNA in TRITON2 and TRITON3.

Methods

Formalin-fixed paraffin-embedded (FFPE) tumour tissue samples were profiled for genomic alterations in 395 genes, and plasma samples were profiled for genomic alterations in 70 genes, using Foundation Medicine, Inc., NGS assays.

Results

As of 2 July 2018, 1311 tumour tissue blocks (73%) and slides (27%) from primary prostate cancer tumours (84%) and metastases (16%) of 1214 patients with mCRPC were processed. The median sample age was 2.8 years (range, 4 days to 21 years). The NGS tissue test failure rate was 32%, mainly (18%) due to insufficient tumour content or DNA. In total, samples from 872 patients were sequenced successfully. Deleterious genomic alterations in BRCA1, BRCA2, and/or ATM were observed in 15% of patients with successfully sequenced samples: BRCA1 (2%), BRCA2 (7%), and ATM (6%).

In parallel, a total of 638 plasma samples from 606 patients with mCRPC progressing on prior therapy were sequenced. The median sample age was 2 days (range, 1-10 days). NGS was successful for 97% of the plasma samples, and in 93% of those, a genomic alteration was detected in at least 1 assayed gene. Deleterious genomic alterations in BRCA1, BRCA2, and/or ATM were observed in 19% of patients with successfully sequenced samples: BRCA1 (2%), BRCA2 (9%), and ATM (12%).

Conclusions

Genomic profiling of both FFPE tumour tissue samples and cfDNA using NGS successfully identified patients with a genomic alteration in a DDR gene for the evaluation of rucaparib in mCRPC. Additional genomic analyses will be presented.

O.01 IDENTIFICATION, CLINICAL CHARACTERISTICS AND TREATMENT OUTCOMES OF SOMATIC HUMAN EPIDERMAL GROWTH FACTOR RECEPTOR 2 (HER2) MUTATIONS IN METASTATIC BREAST CANCER PATIENTS

O.02 REAL-LIFE TREATMENT PRACTICE FOR MALIGNANT PLEURAL MESOTHELIOMA IN BELGIUM

O.03 DETECTION OF AR PERTURBATIONS IN CIRCULATING TUMOUR CELLS AND CELL-FREE DNA FROM PATIENTS WITH METASTATIC CASTRATION-RESISTANT PROSTATE CANCER PREDICTS RESISTANCE TO ENDOCRINE THERAPY

O.04 PLOCABULIN, A TUBULIN INHIBITOR, HAS ANTITUMOR ACTIVITY IN PATIENT-DERIVED XENOGRAFT (PDX) MODELS OF GASTROINTESTINAL STROMAL TUMOR (GIST)