Type I Diabetes Mellitus Suppresses Experimental Skin Carcinogenesis

This study explores the previously uncharted territory of the effects of ultraviolet (UV) radiation on diabetic skin, compared to its well-documented impact on normal skin, particularly focusing on carcinogenesis and aging. Employing hairless SKH-hr2, Type 1 and 2 diabetic, and nondiabetic male mice, the research subjected these to UV radiation thrice weekly for eight months. The investigation included comprehensive assessments of photoaging and photocarcinogenesis in diabetic versus normal skin, measuring factors such as hydration, trans-epidermal water loss, elasticity, skin thickness, melanin, sebum content, stratum corneum exfoliation and body weight, alongside photo documentation. Additionally, oxidative stress and the presence of hydrophilic antioxidants (uric acid and glutathione) in the stratum corneum were evaluated. Histopathological examination post-sacrifice provided insights into the morphological changes. Findings reveal that under UV exposure, Type 1 diabetic skin showed heightened dehydration, thinning, and signs of accelerated aging. Remarkably, Type 1 diabetic mice did not develop squamous cell carcinoma or pigmented nevi, contrary to normal and Type 2 diabetic skin. This unexpected resistance to UV-induced skin cancers in Type 1 diabetic skin prompts a crucial need for further research to uncover the underlying mechanisms providing this resistance.

Clinical features and outcomes of advanced HER2+ esophageal/GEJ cancer with brain metastasis

BACKGROUND

Brain metastasis (BRM) is uncommon in gastroesophageal cancer. As such, clinicopathologic and molecular determinants of BRM and impact on clinical outcome remain incompletely understood.

METHODS

We retrospectively analyzed clinicopathologic data from advanced esophageal/gastroesophageal junction (E/GEJ) patients at Johns Hopkins from 2003 to 2021. We investigated the association between several clinical and molecular features and the occurrence of BRM, with particular focus on human epidermal growth factor receptor 2 (HER2) overexpression. Survival outcomes and time to BRM onset were also evaluated.

RESULTS

We included 515 patients with advanced E/GEJ cancer. Tumors were 78.3% esophageal primary, 82.9% adenocarcinoma, 31.0% HER2 positive. Cumulative incidence of BRM in the overall cohort and within HER2+ subgroup was 13.8% and 24.3%, respectively. HER2 overexpression was associated with increased risk of BRM [odds ratio 2.45; 95% confidence interval (CI) 1.10-5.46]. On initial presentation with BRM, 50.7% had a solitary brain lesion and 11.3% were asymptomatic. HER2+ status was associated with longer median time to onset of BRM (14.0 versus 6.3 months, P < 0.01), improved median progression free survival on first-line systemic therapy (hazard ratio 0.35, 95% CI 0.16-0.80), and improved median overall survival (hazard ratio 0.20, 95% CI 0.08-0.54) in patients with BRM.

CONCLUSION

HER2 overexpression identifies a gastroesophageal cancer molecular subtype that is significantly associated with increased risk of BRM, though with later onset of BRM and improved survival likely reflecting the impact of central nervous system-penetrant HER2-directed therapy. The prevalence of asymptomatic and solitary brain lesions suggests that brain surveillance for HER2+ patients warrants prospective investigation.

HLA class II immunogenic mutation burden predicts response to immune checkpoint blockade

BACKGROUND

Whereas human leukocyte antigen (HLA) class I mutation-associated neoantigen burden has been linked with response to immune checkpoint blockade (ICB), the role of HLA class II-restricted neoantigens in clinical responses to ICB is less studied. We used computational approaches to assess HLA class II immunogenic mutation (IMM) burden in patients with melanoma and lung cancer treated with ICB.

PATIENTS AND METHODS

We analyzed whole-exome sequence data from four cohorts of ICB-treated patients with melanoma (n = 110) and non-small-cell lung cancer (NSCLC) (n = 123). MHCnuggets, a neural network-based model, was applied to estimate HLA class II IMM burdens and cellular fractions of IMMs were calculated to assess mutation clonality. We evaluated the combined impact of HLA class II germline genetic variation and class II IMM burden on clinical outcomes. Correlations between HLA class II IMM burden and density of tumor-infiltrating lymphocytes were computed from expression data.

RESULTS

Responding tumors harbored a significantly higher HLA class II IMM burden for both melanoma and NSCLC (P ≤ 9.6e-3). HLA class II IMM burden was correlated with longer survival, particularly in the NSCLC cohort and in the context of low intratumoral IMM heterogeneity (P < 0.001). HLA class I and II IMM landscapes were largely distinct suggesting a complementary role for class II IMMs in tumor rejection. A higher HLA class II IMM burden was associated with CD4+ T-cell infiltration and programmed death-ligand 1 expression. Transcriptomic analyses revealed an inflamed tumor microenvironment for tumors harboring a high HLA class II IMM burden.

CONCLUSIONS

HLA class II IMM burden identified patients with NSCLC and melanoma that attained longer survival after ICB treatment. Our findings suggest that HLA class II IMMs may impact responses to ICB in a manner that is distinct and complementary to HLA class I-mediated responses.

Pathologic features of response to neoadjuvant anti-PD-1 in resected non-small-cell lung carcinoma: a proposal for quantitative immune-related pathologic response criteria (irPRC)

Background

Neoadjuvant anti-PD-1 may improve outcomes for patients with resectable NSCLC and provides a critical window for examining pathologic features associated with response. Resections showing major pathologic response to neoadjuvant therapy, defined as ≤10% residual viable tumor (RVT), may predict improved long-term patient outcome. However, %RVT calculations were developed in the context of chemotherapy (%cRVT). An immune-related %RVT (%irRVT) has yet to be developed.

Patients and methods

The first trial of neoadjuvant anti-PD-1 (nivolumab, NCT02259621) was just reported. We analyzed hematoxylin and eosin-stained slides from the post-treatment resection specimens of the 20 patients with non-small-cell lung carcinoma who underwent definitive surgery. Pretreatment tumor biopsies and preresection radiographic 'tumor' measurements were also assessed.

Results

We found that the regression bed (the area of immune-mediated tumor clearance) accounts for the previously noted discrepancy between CT imaging and pathologic assessment of residual tumor. The regression bed is characterized by (i) immune activation-dense tumor infiltrating lymphocytes with macrophages and tertiary lymphoid structures; (ii) massive tumor cell death-cholesterol clefts; and (iii) tissue repair-neovascularization and proliferative fibrosis (each feature enriched in major pathologic responders versus nonresponders, P < 0.05). This distinct constellation of histologic findings was not identified in any pretreatment specimens. Histopathologic features of the regression bed were used to develop 'Immune-Related Pathologic Response Criteria' (irPRC), and these criteria were shown to be reproducible amongst pathologists. Specifically, %irRVT had improved interobserver consistency compared with %cRVT [median per-case %RVT variability 5% (0%-29%) versus 10% (0%-58%), P = 0.007] and a twofold decrease in median standard deviation across pathologists within a sample (4.6 versus 2.2, P = 0.002).

Conclusions

irPRC may be used to standardize pathologic assessment of immunotherapeutic efficacy. Long-term follow-up is needed to determine irPRC reliability as a surrogate for recurrence-free and overall survival.

P1-07-03: Preanalytical Variables Affect Protein Expression in Formalin Fixed Paraffin Embedded Tissue – Assessment of Intrinsic Controls To Define Tissue Quality for Immunohistochemical Analysis

Background: Recently it has been shown that biospecimen handling and pre-analytical variables can dramatically affect biomarker assays of protein expression in tumor tissue. Phospho-proteins and even labile unmodified proteins have been suggested to show significant loss of expression due to prolonged time to formalin fixation. Here we assess 4 clinically relevant proteins (ER, PR, HER2 and Ki67) and 20 other proteins for changes as a function to the key preanalytic variables of ischemic time. The ultimate goal of our effort is to find a method to monitor the degradative effect of these variables by construction of a Tissue Quality Index (TQI).

Materials and Methods: Two different breast cancer cohorts were used in order to analyze the biomarkers and their change according to time to formalin fixation. The first cohort consists of 93 breast cancer specimens in 2 fold redundancy on a TMA with cell lines and controls. The time to formalin fixation for each breast cancer specimen was recorded and ranges from 25 to 415 minutes. The second cohort consists of 25 matched pairs of breast cancer biopsies and resections. The time to formalin fixation for the biopsies is minimal while the time to fixation for the resections, though not recorded, averages between 1 and 3 hours. Protein expression was measured using the AQUA method of quantitative immunofluorescence.

Results: ER alpha, PR, HER2 and Ki67 were each analyzed on the time to fixation array with 2 different antibodies commonly used in the clinical setting. Correlation of AQUA scores of these markers with time to formalin fixation revealed a trend towards loss of protein expression as a linear function of time to fixation without reaching statistical significance. Analysis of these 4 proteins on the matched pairs of biopsies and resections showed that tumor heterogeneity predominated over the effects of ischemic time. Toward identification of markers for a TQI, 20 biomarkers were analyzed on the time to fixation array. Both HIF1alpha and AKAP13 show a significant increase as a function of time to fixation, whereas pMAPK, histone 4 and pTyrosine 4G10 revealed a significant loss of expression. These trends were confirmed in the matched pair validation set with the execption of histone 4. A TQI is being built from these variables.

Conclusions: Ischemic time is a critical pre-analytical variable that impacts measurement of protein expression in tumor tissue. The 4 standard markers used clinically in breast cancer appear to show only moderate effects that appear less critical to measurement accuracy than the issue of tumor heterogeneity. We identified 4 proteins which show a significant change with increasing time to formalin fixation and should allow construction of a TQI for assessment of pre-analytic antigenic degradation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-07-03.

Association of expression of bcl-2 with outcome in non-small cell lung cancer

e22039

Background: BCL-2 promotes cell survival by inhibiting adapters needed for the activation and cleavage of caspases thus blocking the proteolytic cascade that ultimately dismantles the cell. It is preferentially expressed in squamous cell carcinomas of the lung and has been investigated as a potential prognostic parameter in lung cancer patients with conflicting results. Here, we quantitatively assessed BCL-2 protein expression in two large and independent data sets to investigate the impact of BCL-2 on patient survival. Methods: AQUA, a fluorescent-based method for analysis of in situ protein expression, was used to measure BCL-2 protein levels and classify tumor by BCL-2 expression in a cohort of 180 lung cancer patients from Yale New Haven Hospital (training set). An independent cohort of 360 lung cancer patients from Sotiria General Hospital and Patras University Hospital in Greece was used to validate BCL-2 classification and evaluate outcome (validation set). Results: Tumors expressed BCL-2 in 57% and 53% of the cases in training and validation cohorts respectively and squamous cell carcinomas expressed higher levels of BCL-2 expression compared to adenocarcinomas (mean AQUA score 42 and 26 respectively, p=0.007); BCL-2 was not associated with other standard clinical or pathological characteristics. Survival analysis showed that patients with high BCL-2 expression had a longer median overall survival compared to the low expressers (20 vs 15 months, log rank p=0.016). Multivariate analysis revealed an independent lower risk of death for lung cancer patients with BCL-2 expressing tumors (HR=0.58, 95% CI 0.39–0.86, p=0.006). Conclusions: BCL-2 expression defines a subgroup of patients with a favorable outcome and may be useful for prognostic stratification of lung cancer patients as well as incorporation of BCL-2 into clinical decisions.

[Table: see text]