Clinical and Hematological Predictors of High-Grade Immune-Related Adverse Events Associated With Immune Checkpoint Inhibitors

Background

Life-threatening immune-related adverse events (irAEs) that require hospital admission are not uncommon in patients treated with immune checkpoint inhibitors (ICIs). The clinical and hematological parameters are attractive biomarkers as potential predictors of irAE.

Methods

This is a retrospective study of patients with melanoma and lung cancer treated with ICIs between 2015 and 2019 at the University of South Alabama Mitchell Cancer Institute. Fisher’s exact test, Pearson Chi-squared test, log-rank test, and Cox proportional hazard model were used to evaluate clinical and hematological parameters as possible predictors of irAE.

Results

The cohort consisted of 160 patients treated with at least two doses of ICI, of which 54 (33.8%) patients had melanoma and 106 (66.3%) had lung cancer. Incidence of irAE did not have any bearing on the overall survival (OS) or progression-free survival (PFS) of the cohort. The clinical factors associated with irAE were dual-agent therapy (ipilimumab/nivolumab combination) and high disease burden (≥ 2 metastatic sites). The irAE-group had a lower mean platelet-to-lymphocyte ration (PLR, 200 vs. 257, P = 0.04). Although not statistically significant at the level of 0.05, other factors such as type of cancer (lung cancer > melanoma (P = 0.06)), stage at treatment (stage IV > stage II and III disease (P = 0.06)), and higher absolute lymphocyte counts (P = 0.07) showed a considerable association with irAE and warrants further review with different patient data.

Conclusions

Irrespective of ICI used to treat lung cancer and melanoma, patients with high disease burden and dual-agent ICI therapy were more prone to irAE. The only hematological parameter that may predict the incidence of irAE is low baseline PLR.

Predictors of immune-related adverse events associated with checkpoint inhibitors

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Background: Immune-related adverse events (irAE) remain a significant challenge with the expansion of checkpoint inhibitors (ICI) indications. Unlike previous studies published, we investigated risk factors for irAE development, including lymphocytes and neutrophils counts in lung cancer and melanoma treated with all available ICIs in current clinical practice. Methods: This is a retrospective study conducted at the University of South Alabama Mitchell Cancer Institute. Between 2015-2019. A total of 160 patients with a diagnosis of melanoma (N = 54) or lung cancer (N = 106) who received at least two doses of ICI including ipilimumab (15%), nivolumab (32%), pembrolizumab (35%), dual nivolumab/ipilimumab (5%), durvalumab (9%) and atezolizumab (4%). The patient's baseline characteristics were extracted with irAE (grade 3/4) details and survival outcomes. Descriptive statistics were used, Fisher exact test to compare categorical variables, and Wilcoxon rank sum test for continuous variables using JMP software. Results: The median age at diagnosis was 64 years (range 17-93), with 51% females. Race distribution with 76% Caucasians and 26% African Americans. Around 30% of the cohort was treated for recurrence, and 39% did receive prior systemic chemotherapy. Median overall survival (OS) was 13.5 months (m) for melanoma and 16 m for lung cancer with CI 95% [16-24] and [15-23], respectively. Twenty-nine (29%) percent of the cohort (N = 46) had grade 3/4 irAEs. Median of baseline hematological parameters including total white blood count (WBC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), ANC to ALC ratio, and platelet to ALC ratio of these patients were not statistically different from the cohort without grade 3/4 irAEs. Interestingly, if a patient has baseline ALC < 1K/μL, the risk of irAE recurrence is low when ICI is re-initiated, p = .0143 (after symptomatic recovery from irAEs). Conclusions: Irrespective of ICI used, baseline lymphocyte count, and its relation to other blood counts have no clear impact on irAE. Larger cohorts or prospective studies are needed to make stronger conclusions about the relationship between the immune system and the occurrence of irAEs

The pattern of mucin 5AC (MUC5AC) expression using immunohistochemistry and its prognostic significance in patients with pancreatic ductal adenocarcinoma

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Background: Mucin-5AC (MUC5AC) is a secreted form of mucin. Its expression correlates with poor outcome in uterine, ampullary adenocarcinoma and cholangiocarcinoma. Its prognostic significance in pancreatic ductal adenocarcinoma (PDAC) is not well established. Here, we explored the pattern of MUC5AC expression using immunohistochemistry (IHC) and its prognostic significance in patients with PDAC. Methods: This is a retrospective study conducted at the University of South Alabama/Mitchell Cancer Institute. Between 2015-2019, 218 patients with PDAC were identified. Among this cohort, only 45 patients had tissue available for MUC5AC IHC staining. Two pathologists in- dependently scored the expression of MUC5AC. Staining percentage was estimated in 10% increments. Unpaired t test and log-rank Wilcoxon tests were used for statistical analysis. Results: In our cohort, the median age was 65 years (42-85). Males represented 55%. Caucasians, African Americans and other ethnicities (e.g. Asians) represented 71%, 25% and 4% respectively. Twenty patients (44%) had metastatic stage IV disease and 25 patients (56%) had non-metastatic disease. Positive cytoplasmic and apical MUC5AC expression by IHC was seen in 82% and 80% of patients respectively. The median apical MUC5AC expression was higher in metastatic patients compared to non-metastatic patients (67.5 % vs 30%, p = 0.0187 ) while there was no difference in the median cytoplasmic MUC5AC expression between metastatic and non-metastatic patients (13.7 % vs 12.5%, p = 0.3328). In non-metastatic patients, compared to patients with positive apical MUC5AC expression, no expression (0%) was associated with worse overall survival (OS) (43 vs 13 m, p = 0.0322). In metastatic PDAC, there was no difference in OS between patients with positive or no apical MUC5AC expression (18 vs 21 m, p = 0.781). Compared to patients with positive cytoplasmic MUC5AC expression, patients with no cytoplasmic MUC5AC expression (0%) had no difference in OS in both non-metastatic (40 vs 32 m, p = 0.986) and metastatic (36 vs 12.5 m, p = 0.487) patients. Conclusions: MUC5AC expression assessment using IHC is feasible in patients with PDAC. In our cohort, apical, but not cytoplasmic, MUC5AC expression was different between metastatic and non-metatstaic patients and showed prognostic significance in non-metastatic patients. To our knowledge, this is the first study to show prognostic significance of MUC5AC expression in patients with PDAC using IHC.

Exosomal marker CD63 expression pattern using immunohistochemistry (IHC) in patients with rectal adenocarcinoma in comparison with left-sided colon cancer

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Background: Adenocarcinomas arising from the distal one third of the transverse colon, splenic flexure, descending colon, sigmoid colon and rectum are often grouped together due to their hindgut embryologic origin and referred to as left-sided colorectal cancer (CRC). Rectal cancer represents a subset of CRC that has distinct differences in anatomical location, clinical behavior, prognosis and molecular background. In patients with left sided colon cancer (LSCC), the expression of exosomal marker CD63 was reported to be higher in the adjacent normal mucosa (ANM) compared to the tumor (224 vs 154, p = 0.0001). Here, we explored the pattern of CD63 expression using immunohistochemistry in patients with rectal cancer in comparison with patients with LSCC. Methods: Between 2015 and 2018, 53 patients underwent rectal cancer biopsy/resection and had available tissues for CD63 IHC staining. Two pathologists independently scored CD63 expression in the tumor and ANM. Staining intensity was graded from 1-3. Staining percentage was estimated in 10% increments. Mean quick-score (Q-score) was calculated (intensity x percentage). Paired t test was used for statistical analysis. Results: Median age was 60 (range 34-80). Females represented 26%. Caucasians and African Americans represented 74% and 26%, respectively. In patients with rectal cancer, the mean CD63 expression was higher in ANM compared to their expression in the tumor (147 vs 113, p = 0.0012). Compared to patients with LSCC (N = 30), the mean CD63 expression in patients with rectal cancer was lower in the ANM (224 vs 147, p < 0.0001) and in the tumor (154 vs 113, p = 0.01). Conclusions: In our cohort of patients with rectal cancer, exosomal marker CD63 expression was lower in tumor compared to ANM. This observation was similar to our previously reported findings in patients with LSCC. Compared to patients with LSCC, patients with rectal cancer had lower expression of CD63 in the tumor and ANM. To our knowledge, this is the first study to explore exosomal marker CD63 expression using IHC in patients with rectal cancer.

Compliance to the American Association for the Study of Liver Diseases (AASLD) guidelines and its impact on overall survival in patients with hepatocellular carcinoma

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Background: The Barcelona-Clinic Liver Cancer (BCLC) staging based management proposed by AASLD depends on baseline liver function and performance status of the patient in addition to tumor characteristics. Low adherence to AASLD guidelines, especially in advanced staged tumors, can be ascribed to suboptimal revision/updates of the guidelines reflecting the advancements in hepatocellular carcinoma (HCC) management. Here, in addition to the adherence rate, we explored the overall survival of patients with HCC according to first-line treatment modality compliance to AASLD guidelines. Methods: This is a retrospective study conducted at the University of South Alabama/Mitchell Cancer Institute. Between 2017 and 2019, 148 unique treatment-naïve patients with HCC were identified. Patients were staged according to the BCLC staging system and their compliance with suggested first-line treatment modality according to AASLD guidelines was noted. Overall survival was explored and differences between overall survival rates of compliant and non-complaint patients were compared using the log-rank Wilcoxon test. Results: In our cohort, the median age was 72.5 years (range 38-90). Males represented 80%. Caucasians, African Americans, and other ethnicities (e.g. Asians) represented 68%, 30% and 2% respectively. The overall adherence rate was 83%. The adherence rate according to BCLC stage 0, A, B, C and D was 100%, 97%, 77%, 77% and 38% respectively. Compliance vs. non-compliance to AASLD guidelines showed no significant difference in overall survival of patients with BCLC stage 0-A, B and C. In patients with BCLC stage D (N = 13), compared to patients treated in compliance to AASLD guidelines (N = 5), patients treated in non-compliance (N = 8) had better overall survival (2.2 vs. 5.2 months, p = 0.0012). Conclusions: In our cohort, the adherence rate to AASLD treatment guidelines in patients with BCLC stage D was very low at 38%. Lack of adherence in this group of patients translated into better overall survival. The current AASLD guidelines for the management of HCC have several limitations, especially for advanced stages. In the last few years, the FDA approved several tyrosine kinase inhibitors, immune checkpoint inhibitors and the monoclonal antibody, ramucirumab. This expansion generated the need for periodic updates/revisions of consensus guidelines.

The adherence to The American Association for The Study of Liver Disease (AASLD) guidelines in treating patients with hepatocellular carcinoma: Institutional experience

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Background: The American Association for the Study of Liver Disease (AASLD) guidelines outline an algorithm regarding the treatment modality of choice for patients with hepatocellular carcinoma (HCC) based on Barcelona Clinic Liver Cancer (BCLC) stage. The AASLD guidelines have several limitations and the adherence rate has been reported to be low. The adherence to AASLD guidelines in treating patients with HCC was explored in this study. Methods: Between 2017 and 2019, 106 patients with HCC were identified. In our cohort, 70 patients (66%) were discussed in the multidisciplinary tumor board (MDTB) and their first-line treatment modality was selected based on consensus recommendations from the MDTB team members. The adherence rate of MDTB recommendations to AASLD guidelines was calculated. Results: Median age was 65 (range 42-90). Males represented 84% while females represented 16%. Caucasians, African Americans and Asians represented 69%, 30% and 1% respectively. BCLC stage 0, A, B, C and D represented 7%, 32%, 23%, 27% and 11% respectively. First-line treatment modality of choice recommended by MDTB is summarized in Table. The overall adherence rate of MDTB recommendations to AASLD guidelines is 60%. For BCLC stage 0, A, B, C and D, the adherence rate was 60%, 86%, 44%,58% and 25% respectively. Conclusions: Our MDTB recommendations adherence rate to AASLD guidelines was 60%. The reported low adherence rate to the guidelines suggest that AASLD guidelines would benefit from further refinement and periodic update.

[Table: see text]

A practice transformation model to improve lung cancer care

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Background: Lung cancer has the highest cause of cancer death, treatment of which is both complicated and expensive. Emerging actionable biomarkers and treatments provide both opportunity and treatment challenges. Adherence to evidence-based treatment and advanced care discussions add value to care. Oncology practices need to document the above to participate in value-based care reimbursement models. A Practice Transformation (PT) model was implemented to address quality and cost issues. Methods: After IRB approval, baseline data on lung cancer patients diagnosed during a 6-month period (Jul-Dec 2017) were collected through chart abstraction and treatment planning surveys. Rates of molecular testing ordered, results available at time of treatment decision-making, guideline concordant treatment decisions, and documentation of advanced care discussions were presented to the PT team. After education on recent clinical trial results and NCCN treatment guidelines, the PT team determined strategies for change. The PT team met after two 3-month periods of PT for education updates and progress reports. Data was compared on newly diagnosed patients during a 6-month period (Jul-Dec 2018), one year after the baseline period. Results: A total of forty-two patients were diagnosed in two 6-month periods, baseline and study period. Average age was 65 years, 57% male, 71% Caucasian, 95% ever smokers, 71% adenocarcinoma histology. Rate of ordering any molecular testing was (16/19) 84% in the baseline period vs (20/23) 86% in the study period. However, extended molecular testing increased from 16% (3/19) to 60% (12/20), p = .05 Fishers exact test. At treatment initiation, evidence-based treatment selections went from 47% to 52%. Documentation of advanced care discussions, 42% (8/19) to 56% (13/23), did not change significantly. Conclusions: A PT model that included education, and two cycles of implementation and feedback, resulted in increased molecular testing to inform evidence-based treatment selections. Increased awareness of the lack of documentation of advanced care discussions provides opportunity for continued improvement to effect quality care.

Using Airborne Digital Imagery for Detecting Oak Wilt Disease

Color-infrared (CIR) digital imagery was evaluated as a remote sensing tool for detecting oak wilt disease in live oak (Quercus fusiformis). Aerial CIR digital imagery and CIR photography were obtained concurrently of a live oak forested area in south-central Texas affected by oak wilt. Dead, diseased, and healthy live oak trees could generally be delineated as well in the digital imagery as in the CIR photography. Light reflectance measurements obtained in the field showed that dead, diseased, and healthy trees had different visible and near-infrared reflectance values.

Effect of RotyIenchulus reniformis on reflectance of cotton plant leaves

Differences between light reflectance from leaves of cotton (Gossypiurn hirsutum) plants grown with a low- or no-nematode (Rotylenchulus reniformis) population (nonstressed), and from leaves grown with a high nematode population (stressed) were measured in field and greenhouse experiments. Reflectance was measured spectrophotometrically in the laboratory on single leaves and spectroradiometrically in the field on plant canopies. Nematode-stressed cotton plants were stunted with fewer, smaller, and darker-green leaves than nonstressed plants. Over the 0.5- to 2.5-/microm waveband, stressed leaves had lower reflectance than nonstressed leaves of the same chronological age for both field- and greenhouse-grown plants. Reflectance differences between stressed and nonstressed leaves in the visible (0.5 to 0.75 microm), near-infrared (0.75 to 1.35 mum) and infrared water absorption (1.35 to 2.5 microm) regions were primarily caused by differences in leaf chlorophyll concentration, mesophyll structure, and water content, respectively. Results indicate the potential for remotely sensing nematode-infested plants to distinguish them from normal plants.

Refractive index of plant cell walls

Air was replaced with media of higher refractive indices by vacuum infiltration in leaves of cucumber, blackeye pea, tomato, and string bean plants, and reflectance of noninfiltrated and infiltrated leaves was spectrophotometrically measured. Infiltrated leaves reflected less light than noninfiltrated leaves over the 500-2500-nm wavelength interval because cell wall-air interfaces were partly eliminated. Minimal reflectance should occur when the average refractive index of plant cell walls was matched by the infiltrating fluid. Although refractive indices that resulted in minimal reflectance differed among the four plant genera, an average value of 1.425 approximates the refractive index of plant cell walls for the four plant genera.