Breast cancer
Breast cancer remains a significant health concern
The female breast cancer is the second leading cause of cancer incidence and the fourth leading cause of mortality worldwide, with estimated 2.3 million new cases (11.6% of all cancer) and 666,000 deaths (6.9% of all cancer deaths) in 2022.1
The 5-year relative survival rate is over 99% for localized breast cancer, when treatment is typically more effective and less extensive, but drops to 87% and 32% for regional and distant-stage disease, respectively.2
HER2 gene amplification (15%–20% of invasive breast cancers) leading to HER2 protein overexpression is a poor prognostic factor associated with a high rate of recurrence and mortality; however, on the other hand, HER2 overexpression is the most important indicator of the efficacy of anty-HER2 targeted therapy.3
The Problem
The current standard tests for HER2 determination include immunohistochemistry (IHC) and different methods of in situ hybridization (ISH); however, different studies have reported varying levels of IHC accuracy in breast cancer diagnostics.3,4
The 2007 ASCO/CAP guidelines stated that HER2 status should be initially assessed by IHC using a semi-quantitative scoring system, and confirmed by FISH in all IHC score 2+ equivocal cases.5 In the updated 2018 ASCO/CAP guideline, HER2 status, as determined by ISH, is categorized to positive or negative with no equivocal results.6
Patients with HER2+ breast cancer, i.e. IHC score 3+ or ISH-positive IHC score 2+ are eligible for anti-HER2 targeted therapy;7 however, recently, some clinical trials demonstrated that patients with metastatic breast cancer showing low levels of HER2 expression, i.e. IHC score 1+ or ISH-negative IHC score 2+ could also significantly benefit from targeting HER2.8
Accurate and reproducible testing strategies and techniques are the key aspects to identifying patients who may benefit from modern therapies, including antibody-drug conjugate (ADC).9
The Solution
inPROBE® is a new, innovative tool for real-time, quantitative assessment of HER2 expression on breast cancer cells, based on merging molecular biology with photonics technology.
In clinical trial with HER2-positive breast cancer patients, HER2 expression levels ranges detected with inPROBE® corresponding to HER2 receptor status identified by IHC/FISH has been determined, with statistically significant differences between minimum values for HER2-negative vs HER2-positive BC (P-value based on Wilcoxon rank sum exact test = 0.041).10
inPROBE® technology shows promise of becoming a tool providing the oncologist with new, modern, real-time, in vivo diagnostic method.11
