The identification of a small but significant subset of patients still targetable with anti-HER2 inhibitors when affected by triple negative breast carcinoma

Volume change rate before and after neoadjuvant systemic therapy of breast cancer is an efficacious evaluation index to predict pathological complete response

Neoadjuvant systemic therapy (NST) is widely applied in breast cancer treatment, but individuals respond differently to the same NST regimen. It is unclear which patients should adjust their NST regimen and what such an adjustment should be, especially for patients with radiologically partial response (PR). This study aimed to identify a quantitative efficacy evaluation index to evaluate the therapeutic effect of NST. 164 patients were enrolled in this study received four cycles of epirubicin and cyclophosphamide (EC), followed by four cycles of taxanes with trastuzumab [T(H)], if needed. Of patients with a volume change rate of EC treatment (δV1) below 0.80, more than half benefited from subsequent T(H) treatment compared with EC treatment. Importantly, for δV1 of 0.80 and higher, patients' subsequent T(H) treatment was not as efficient as previous EC treatment and they have a lower pathological complete response (pCR) rate. Across all patients, nanoparticle albumin-bound paclitaxel had a numerically higher pCR rate over other taxanes in patients with triple-negative breast cancer. This study showed that the volume change rate is better than the diameter change rate in monitoring the therapeutic effect of NST. Furthermore, δV1 is a good quantitative efficacy evaluation index to distinguish patients resistant to EC treatment and predict the pCR rate and guide the adjustment of individualized NST regimens.

FISH testing of HER2 immunohistochemistry 1+ invasive breast cancer with unfavorable characteristics

Diagnostic assays for human epidermal growth factor receptor 2 (HER2) expression have a high predictive value because patients with HER2-positive tumors could benefit from HER2-targeted therapy. The aim of the present study is to analyze the incidence of HER2 gene amplification in selected tumors with adverse features that scored 1+ by immunohistochemistry (IHC). For that purpose, 331 consecutive invasive breast cancers (IBCs) were tested by IHC for HER2 expression between January and December 2013, 102 of which (31%) scored 1+. Of these 102 women with IBC who underwent surgery, 75 entered the study (73.5%). A total of 48 out of 75 (64%) IBC samples (patients' median age, 60.75 years) were selected according to ≥1 unfavorable tumor characteristics, and tested by fluorescence in situ hybridization (FISH). Of these 48 IBC samples scoring 1+ by IHC, 22 (46%) exhibited high histological grade (G3), 23 (48%) had a high proliferative index (Ki-67, >30%), 27 (56%) showed vascular invasion and 32 out of 41 evaluable cases (78%) were node-positive. Regarding hormone receptor expression, 3 (6%) and 10 (21%) cases were negative for estrogen and progesterone receptors expression, respectively. FISH was performed on 48 IBC cases scoring 1+ by IHC, and 7 infiltrating ductal carcinomas (IDCs) (14.6%) demonstrated HER2 amplification with a high proliferative index. In 42 IDC samples, statistical analysis evidenced a significant association between histological grade and high proliferative index (P=0.0200). In addition, in 48 HER2 scoring 1+ IBCs, Fisher's exact test evidenced a significant association between the presence of gene amplification and high proliferative index (P=0.0033). Based on these biopathological parameters, particularly a high proliferative index, the present results indicate that it is possible to of identify tumors scoring 1+ by IHC with HER2 amplification by FISH, thus aiding the selection of patients who are suitable for HER2-targeted therapy according to an acceptable cost/benefit ratio.

Biomarker testing for breast, lung, and gastroesophageal cancers at NCI designated cancer centers

BACKGROUND

Molecular biomarkers, a cornerstone of precision oncology, are critical in breast, gastroesophageal, and non-small cell lung cancer management (BC, GEC, NSCLC). Testing practices are intensely debated, impacting diagnostic quality and affecting pathologists, oncologists and patients. However, little is known about testing approaches used in practice. Our study described biomarker practices in BC, GEC, and NSCLC at the leading US cancer centers.

METHODS

We conducted a survey of the National Cancer Institute (NCI) designated centers on BC, GEC, and NSCLC biomarker testing. We used simple frequencies to describe practices, two-sided Fisher's exact test and two-sided McNemar's test for cross-cancer comparison. All statistical tests were two-sided.

RESULTS

For BC human epidermal growth factor receptor 2 (HER2), 39% of centers combine guidelines by using in situ hybridization (ISH) and immunohistochemistry (IHC) concurrently, and 21% reflex-test beyond guideline-recommended IHC2+. For GEC HER2, 44% use ISH and IHC concurrently, and 28% reflex-test beyond IHC2+. In NSCLC, the use of IHC is limited to 4% for epidermal growth factor receptor (EGFR) and 7% for anaplastic lymphoma kinase (ALK). 43.5% test NSCLC biomarkers on oncologist order; 34.5% run all biomarkers upfront, and 22% use a sequential protocol. NSCLC external testing is statistically significantly higher than BC (P < .0001) and GEC (P < .0001). NSCLC internally developed tests are statistically significantly more common than BC (P < .0001) and GEC (P < .0001).

CONCLUSIONS

At the NCI cancer centers, biomarker testing practices vary, but exceeding guidelines is a common practice for established biomarkers and emerging practice for newer biomarkers. Use of internally developed tests declines as biomarkers mature. Implementation of multibiomarker protocols is lagging. Our study represents a step toward developing a biomarker testing practice landscape.

Impact of HER2 copy number in IHC2+/FISH-amplified breast cancer on outcome of adjuvant trastuzumab treatment in a large UK cancer network

Background:

Adjuvant trastuzumab with chemotherapy is standard treatment for HER2-positive breast cancer, defined as either HER2 IHC3+ or IHC2+ and FISH amplified. The aim of this study was to investigate the degree to which HER2 amplification in terms of HER2 gene copy numbers in HER2+IHC2+ cancers affected the outcome in a community setting.

Methods:

Case records of 311 consecutive patients with early breast cancer presenting between 1st January 2005 and 31st December 2008 were reviewed. Progression-free survival and overall survival were calculated with the Kaplan–Meier method using STATA 13.

Results:

Among 3+ cases (n=230) 163 received T vs 67 no-T. Among 2+ cases (n=81) 59 received T vs 22 no-T. Among 59 IHC2+-treated cases n=28 had an average of >12, n=13 had >6 to <12, and n=18 had >2 to <6 HER2 gene copies, respectively. The time of progression and overall survival of high and low copy number patients was similar and better than the intermediate copy number and the untreated cohorts.

Conclusions:

High HER2 copy number (>12) appears to be associated with consistently better response compared with patients with intermediate HER2 copy numbers (6–12). In light of emerging data of patients showing insensivity to trastuzumab therapy, we propose that the HER2 gene copy number value should be included as an additional indicator for stratifying both the management and the follow-up of breast cancer patients.