Detection and quantification of EGFR T790M mutation in liquid biopsies by droplet digital PCR.

BACKGROUND: Liquid biopsy allows the identification of targetable cancer mutations in a minimally invasive manner. In patients with advanced non-small cell lung cancer (NSCLC), droplet digital PCR (ddPCR) is increasingly used to genotype the epidermal growth factor receptor (EGFR) gene in circulating cell-free DNA (cfDNA). However, the sensitivity of this method is still under debate. The aim of this study was to implement and assess the performance of a ddPCR assay for detecting the EGFR T790M mutation in liquid biopsies. METHODS: A ddPCR assay was optimized to detect the EGFR T790M mutation in plasma samples from 77 patients with NSCLC in progression. RESULTS: Our ddPCR assay enabled the detection and quantification of the EGFR T790M mutation at cfDNA allele frequency as low as 0.5%. The mutation was detected in 40 plasma samples, corresponding to a positivity rate of 52%. The number of mutant molecules per mL of plasma ranged from 1 to 6,000. A re-biopsy was analyzed for 12 patients that had a negative plasma test and the mutation was detected in 2 cases. A second liquid biopsy was performed for 6 patients and the mutation was detected in 3 cases. CONCLUSIONS: This study highlights the value of ddPCR to detect and quantify the EGFR T790M mutation in liquid biopsies in a real-world clinical setting. Our results suggest that repeated ddPCR tests in cfDNA may obviate tissue re-biopsy in patients unable to provide a tumor tissue sample suitable for molecular analysis.

Loss of HER2 and disease prognosis after neoadjuvant treatment of HER2+ breast cancer.

INTRODUCTION: HER2 overexpression/amplification occurs in 15-20% breast cancers (BC) and is associated with worse prognosis. The addition of anti-HER2 treatment to neoadjuvant chemotherapy significantly improves the pathological complete response (pCR) rate. Changes in HER2 status after neoadjuvant treatment (NAT) have been reported and may affect prognosis. The aim of this study was to assess the efficacy of NAT in patients with HER2+ BC and its influence on HER2 status and associated prognostic impact. METHODS: Retrospective chart review and pathologic evaluation of all consecutive patients with HER2+ BC (defined as IHC 3+ or IHC 2+ confirmed by SISH) submitted to NAT between 2010-2015 in three Portuguese Hospitals. RESULTS: One hundred eight female patients were included; 40 with stage II, 68 with stage III. Hormone receptors were positive in 70. pCR (ypT0/isN0) was achieved in 48 patients (44%). With a median follow-up of 52 months, there were 5 disease free survival (DFS) events among pCR patients and 19 among non-pCR (P = 0.02). Of the 60 patients with residual disease at surgery, 52 remained HER2+ and 8 (13%) lost HER2 overexpression/amplification. 5y-DFS and 5y-OS was 70% and 84%, respectively, for patients whose residual tumors remained HER2+, and 21% and 50% for patients whose residual tumors became HER2 negative (P = 0.02 and < 0.001). DISCUSSION: We confirmed the negative prognostic impact of NAT-induced HER2 loss on residual tumor leading to worse DFS and OS. Despite the retrospective design and small sample size, these results suggest that it is important to retest HER2 after NAT, to better refine patient outcome.

Vaginal Endosalpingiosis Case Report: A Rare Entity Presenting as Intermenstrual Bleeding.

Endosalpingiosis is a benign and rare entity whose pathophysiology remains unknown. It has been described in pelvic organs, the abdomen, or axillar lymph nodes. Its underrecognition has occasionally led to its misinterpretation for an adenocarcinoma. This case reports the treatment and follow-up of vaginal endosalpingiosis, presenting as a vaginal polyp in a premenopausal women with intermenstrual bleeding. To our knowledge this is the first reported case of vaginal endosalpingiosis and the second mucosal localization after bladder endosalpingiosis.

Inflammatory Breast Cancer: A Case Report.

BACKGROUND: Inflammatory breast cancer is a rare, yet controversial, syndrome of invasive breast cancer. CASE REPORT: A female, Caucasian, 57-year-old patient presented at the emergency department with complaints suggestive of inflammatory breast cancer. CONCLUSIONS: Inflammatory breast cancer, besides the advances on its molecular profile, still remains a clinical entity difficult to diagnose, especially in the primary health care setting.