A gene expression-based classifier for HER2-low breast cancer

In clinical trials evaluating antibody-conjugated drugs (ADCs), HER2-low breast cancer is defined through protein immunohistochemistry scoring (IHC) 1+ or 2+ without gene amplification. However, in daily practice, the accuracy of IHC is compromised by inter-observer variability. Herein, we aimed to identify HER2-low breast cancer primary tumors by leveraging gene expression profiling. A discovery approach was applied to gene expression profile of institutional INT1 (n = 125) and INT2 (n = 84) datasets. We identified differentially expressed genes (DEGs) in each specific HER2 IHC category 0, 1+, 2+ and 3+. Principal Component Analysis was used to generate a HER2-low signature whose performance was evaluated in the independent INT3 (n = 95), and in the publicly available TCGA and GSE81538 datasets. The association between the HER2-low signature and HER2 IHC categories was evaluated by Kruskal-Wallis test with post hoc pair-wise comparisons. The HER2-low signature discriminatory capability was assessed by estimating the area under the receiver operating characteristic curve (AUC). Gene Ontology and KEGG analyses were performed to evaluate the HER2-low signature genes functional enrichment. A HER2-low signature was computed based on HER2 IHC category-specific DEGs. The twenty genes included in the signature were significantly enriched with lipid and steroid metabolism pathways, peptidase regulation, and humoral immune response. The HER2-low signature values showed a bell-shaped distribution across IHC categories (low values in 0 and 3+; high values in 1+ and 2+), effectively distinguishing HER2-low from 0 (p < 0.001) to 3+ (p < 0.001). Notably, the signature values were higher in tumors scored with 1+ as compared to 0. The HER2-low signature association with IHC categories and its bell-shaped distribution was confirmed in the independent INT3, TCGA and GSE81538 datasets. In the combined INT1 and INT3 datasets, the HER2-low signature achieved an AUC value of 0.74 (95% confidence interval, CI 0.67-0.81) in distinguishing HER2-low vs. the other categories, outperforming the individual ERBB2 mRNA AUC value of 0.52 (95% CI 0.43-0.60). These results represent a proof-of-concept for an observer-independent gene-expression-based classifier of HER2-low status. The herein identified 20-gene signature shows promise in distinguishing between HER2 0 and HER2-low expressing tumors, including those scored as 1+ at IHC, and in developing a selection approach for ADCs candidates.

Alterations in Plasma Lipid Profiles Associated with Melanoma and Therapy Resistance

Dysfunctions of lipid metabolism are associated with tumor progression and treatment resistance of cutaneous melanoma. BRAF/MEK inhibitor resistance is linked to alterations of melanoma lipid pathways. We evaluated whether a specific lipid pattern characterizes plasma from melanoma patients and their response to therapy. Plasma samples from patients and controls were analyzed for FASN and DHCR24 levels and lipidomic profiles. FASN and DHCR24 expression resulted in association with disease condition and related to plasma cholesterol and triglycerides in patients at different disease stages (n = 144) as compared to controls (n = 115). Untargeted lipidomics in plasma (n = 40) from advanced disease patients and controls revealed altered levels of different lipids, including fatty acid derivatives and sphingolipids. Targeted lipidomics identified higher levels of dihydroceramides, ceramides, sphingomyelins, ganglioside GM3, sphingosine, sphingosine-1-phosphate, and dihydrosphingosine, saturated and unsaturated fatty acids. When melanoma patients were stratified based on a long/short-term clinical response to kinase inhibitors, differences in plasma levels were shown for saturated fatty acids (FA 16:0, FA18:0) and oleic acid (FA18:1). Our results associated altered levels of selected lipid species in plasma of melanoma patients with a more favorable prognosis. Although obtained in a small cohort, these results pave the way to lipidomic profiling for melanoma patient stratification.

Superior rectal artery preservation to reduce anastomotic leak rates in familial adenomatous polyposis patients treated with total colectomy and ileorectal anastomosis

BACKGROUND

Total colectomy with ileorectal anastomosis (TC/IRA) is one of the prophylactic surgical options in patients with familial adenomatous polyposis (FAP). This study investigated the effectiveness of superior rectal artery (SRA) preservation during TC/IRA in reducing anastomotic leakage (AL).

METHODS

This retrospective study was based on prospectively collected data (01/2000 - 12/2022) at the National Cancer Institute, Milan, Italy. FAP patients undergoing TC/IRA were enrolled. A 1:1  propensity score matching (PSM) was performed. Associations between SRA preservation and complications were investigated using univariate and multivariate analysis.

RESULTS

The study population included 211 patients undergoing TC/IRA (Sex: 106 Male, 105 Female; Age: median 30 yrs, IQR: 20-48 yrs), 82 with SRA preservation (SRA group) and 129 without SRA preservation (controls). After PSM, 75 patients were considered for each group. SRA preservation was associated with fewer complications (OR 0.331, 95% CI 0.116; 0.942) in univariate logistic regression analysis. AL events were significantly fewer in the SRA group than in the control group (0 vs 12, p = 0.028). The SRA group had fewer overall surgical complication and pelvic sepsis rates (p = 0.020 and p = 0.028, respectively). Median operative time was significantly longer in the SRA group (340 min vs 240 min, p<0.001), and median hospital stay was significantly shorter (6 vs 7 days, p=0.017). Twenty-seven patients in the SRA group experienced intraoperative anastomotic bleeding, which was controlled endoscopically. Superimposable results were obtained analyzing the whole patient cohort.

CONCLUSIONS

SRA preservation can be considered an advantage in this patient population, despite adding a further technical step during surgery and thereby prolonging the operative time. Intraoperative endoscopic checking of possible anastomotic bleeding sites is recommended.

Quality of life after prophylactic surgery for colorectal adenomatous polyposis

PURPOSE

Colorectal adenomatous polyposis is characterized by the onset of tens to thousands of adenomas in the colorectal epithelium and, if not treated, leads to a lifetime increased risk of developing colorectal cancer compared to the general population. Thus, prophylactic surgery is recommended. This study aims to investigate the quality of life of colorectal adenomatous polyposis patients following prophylactic surgery and indirectly compares these findings with those of healthy adults of the normative sample.

METHODS

All patients who underwent prophylactic surgery for polyposis and were in follow-up at the hereditary digestive tract tumors outpatient department of our institute were eligible for the study. The Short Form-36 questionnaire and 21 ad hoc items were used at the time of clinical evaluation.

RESULTS

A total of 102 patients were enrolled. For the SF-36 domains, mean values ranged from 64.18 for vitality to 88.49 for physical functioning, with the highest variability for role-physical limitations; the minimum value of functioning was reached for role-physical limitations, role-emotional limitations, and social functioning. The maximum value of functioning was reached for role-emotional limitations (73.96%) and role-physical limitations (60.42%). In total, 48.96% and 90.63% of patients reported no fecal or urinary incontinence episodes, respectively; 69.79% of patients did not have problems in work/school resumption or the personal sexual sphere.

CONCLUSION

Quality of life following prophylactic surgery for these patients seems to be good when indirectly compared to HP-normative samples'. Young adult patients appear to quickly manage and adapt to changes in bowel functioning. A minority of patients may experience social and sexual issues.

Abstract 5506: Circulating immature neutrophils early detect hyperprogressive disease upon first-line PD-1/PD-L1 inhibitors in non-small cell lung cancer patients selecting best candidates for platinum-based chemotherapy and PD-1/PD-L1 inhibitors combinations

Background: Hyperprogressive disease (HPD) has been described in ≃14-25% of pretreated non-small cell lung cancer (NSCLC) patients upon single-agent (SA) PD-1/PD-L1 inhibitors (ICI) and has not been reported upon platinum-based chemotherapy (PCT) and ICI combinations. So far, no predictive biomarkers are available for HPD early detection.

Methods: NSCLC patients treated with 1st line SA-ICI or PCT-ICI were assessed for HPD and circulating neutrophils. HPD was defined as delta tumor growth rate (TGR) &gt;50% and/or TGR ratio ≥2. Circulating low density neutrophils (LDNs) were assessed by flow cytometry on peripheral blood mononuclear cells (PMBCs). LDNs were defined as CD66b+CD15+ cells among CD11b+ PBMCs and immature subtypes as CD10− LDNs. The LDNs predictive role was assessed by penalized model-based tests.

Results: 144 NSCLC patients were included: 75 treated with SA-ICI, 69 with PCT-ICI. In the SA-ICI cohort, HPD occurred in 8 (11%) patients, while progressive disease (PD) and response or stable disease (PR/SD) occurred in 33 (44%) and 34 (45%) of patients respectively. Immature circulating CD10− LDNs were significantly higher in baseline blood samples of HPD patients [median (ME): 39.3, interquartile range (IQR): 28.7] compared to PD [ME: 7.4, IQR: 14.9, p&lt;0.01] or PR/SD patients [ME: 3.7, IQR: 12.6, p&lt;0.01]. Circulating CD10− LDNs were associated with HPD [odds ratio (OR): 1.17, 95% CI: 1.06; 1.29], with a good prediction capability [cross-validated AUC 0.97 (95%CI: 0.94;1.00)]. A 30.5% cut-off value for CD10− LDNs circulating neutrophils was identified by Younden index to discriminate HPD from others. In the PCT-ICI cohort, 14 patients had circulating CD10− LDNs ≥30.5%, being at high risk of HPD. However, no HPD was observed in PCT-ICI cohort and dynamic LDNs evaluation in high HPD risk patients showed 52.3% (IQR: 28.4) median reduction in CD10− LDNs upon PCT-ICI, versus only 8.9% (IQR: 34.6) reduction in HPD patients upon SA-ICI, suggesting that PCT prevents HPD by reducing selectively immature LDNs.

Conclusions: Baseline circulating immature neutrophils characterize HPD upon 1st line SA-ICI and a 30.5% cut-off of immature neutrophils could select NSCLC patients to be addressed to PCT-ICI combinations.

Citation Format: Roberto Ferrara, Giuseppe Lo Russo, Chiara Maura Ciniselli, Annamaria Piva, Barbara Bassani, Elena Jachetti, Giuseppina Calareso, Valeria Duroni, Settimio Di Gregorio, Claudia Proto, Arsela Prelaj, Alessandro De Toma, Mario Occhipinti, Marta Brambilla, Sara Manglaviti, Laura Mazzeo, Arturo Rinaldi, Teresa Beninato, Monica Ganzinelli, Filippo De Braud, Marina Chiara Garassino, Paolo Verderio, Mario Paolo Colombo, Sabina Sangaletti. Circulating immature neutrophils early detect hyperprogressive disease upon first-line PD-1/PD-L1 inhibitors in non-small cell lung cancer patients selecting best candidates for platinum-based chemotherapy and PD-1/PD-L1 inhibitors combinations. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5506.