Presentation management and outcome of phlegmonous and inflammed appendicitis in children in Ethiopia: retrospective review

BACKGROUND

Acute appendicitis is the leading cause of emergency pediatric surgical admissions in the world. The diagnosis is may be difficult and is often dependent on clinical parameters. This study was aimed at reviewing the clinical presentations, the management and outcomes in children with inflamed and phlegmonous appendicitis with reference to the operative findings.

METHODS

The records of 211 children 5 to 15 years of age who were operated for acute appendicitis with intra operative findings of inflamed or phlegmonous appendicitis who met inclusion criteria were entered and analyzed using SPSS (IBM) V.26. Descriptive and regression tests were done with p < 0.05 considered statistically significant.

RESULTS

Of 211 children with inflamed and phlegmonous appendicitis, the M: F was 1.48:1 with a median age of 11 years. 58.3% of them presented within 24 h with the commonest symptoms being right lower abdominal pain, anorexia, and vomiting (96.2%,96.2%, 85.3%,) respectively. 96.7% of them had right lower abdominal tenderness. 73% had neutrophils ≥ 75%, and of 171 patients who had abdominal ultrasound scan, 97.7% showed appendiceal diameter ≥ 6 mm. Intraoperatively 56.4% of them were found to have phlegmonous appendicitis. In a retrospective Pediatric Appendiceal Score, only 52.6% of patients fall into the high-risk category, who could be confirmed on preoperative clinical assessment. Postoperatively 90% of them discharged improved with a mean hospital stay of 2.26(SD = 0.9) days. There was no association between the sex of the child and the intraoperative finding of inflamed or phlegmonous appendicitis (p = 0.77).

CONCLUSION

Pediatric appendicitis affects more male children in their second decade of life. Most had phlegmonous appendicitis and presented within 24 h. Duration of illness has little effect on the progress of appendicitis. Surgical management is safe for inflamed and phlegmonous appendicitis with a reasonable hospital stay and a low rate of complications.

Integration of tumor inflammation, cell proliferation, and traditional biomarkers improves prediction of immunotherapy resistance and response

BACKGROUND

Contemporary to the rapidly evolving landscape of cancer immunotherapy is the equally changing understanding of immune tumor microenvironments (TMEs) which is crucial to the success of these therapies. Their reliance on a robust host immune response necessitates clinical grade measurements of immune TMEs at diagnosis. In this study, we describe a stable tumor immunogenic profile describing immune TMEs in multiple tumor types with ability to predict clinical benefit from immune checkpoint inhibitors (ICIs).

METHODS

A tumor immunogenic signature (TIGS) was derived from targeted RNA-sequencing (RNA-seq) and gene expression analysis of 1323 clinical solid tumor cases spanning 35 histologies using unsupervised analysis. TIGS correlation with ICI response and survival was assessed in a retrospective cohort of NSCLC, melanoma and RCC tumor blocks, alone and combined with TMB, PD-L1 IHC and cell proliferation biomarkers.

RESULTS

Unsupervised clustering of RNA-seq profiles uncovered a 161 gene signature where T cell and B cell activation, IFNg, chemokine, cytokine and interleukin pathways are over-represented. Mean expression of these genes produced three distinct TIGS score categories: strong (n = 384/1323; 29.02%), moderate (n = 354/1323; 26.76%), and weak (n = 585/1323; 44.22%). Strong TIGS tumors presented an improved ICI response rate of 37% (30/81); with highest response rate advantage occurring in NSCLC (ORR = 36.6%; 16/44; p = 0.051). Similarly, overall survival for strong TIGS tumors trended upward (median = 25 months; p = 0.19). Integrating the TIGS score categories with neoplastic influence quantified via cell proliferation showed highly proliferative and strong TIGS tumors correlate with significantly higher ICI ORR than poorly proliferative and weak TIGS tumors [14.28%; p = 0.0006]. Importantly, we noted that strong TIGS and highly [median = not achieved; p = 0.025] or moderately [median = 16.2 months; p = 0.025] proliferative tumors had significantly better survival compared to weak TIGS, highly proliferative tumors [median = 7.03 months]. Importantly, TIGS discriminates subpopulations of potential ICI responders that were considered negative for response by TMB and PD-L1.

CONCLUSIONS

TIGS is a comprehensive and informative measurement of immune TME that effectively characterizes host immune response to ICIs in multiple tumors. The results indicate that when combined with PD-L1, TMB and cell proliferation, TIGS provides greater context of both immune and neoplastic influences on the TME for implementation into clinical practice.

Predicting response to checkpoint inhibitors in melanoma beyond PD-L1 and mutational burden

BACKGROUND

Immune checkpoint inhibitors (ICIs) have changed the clinical management of melanoma. However, not all patients respond, and current biomarkers including PD-L1 and mutational burden show incomplete predictive performance. The clinical validity and utility of complex biomarkers have not been studied in melanoma.

METHODS

Cutaneous metastatic melanoma patients at eight institutions were evaluated for PD-L1 expression, CD8+ T-cell infiltration pattern, mutational burden, and 394 immune transcript expression. PD-L1 IHC and mutational burden were assessed for association with overall survival (OS) in 94 patients treated prior to ICI approval by the FDA (historical-controls), and in 137 patients treated with ICIs. Unsupervised analysis revealed distinct immune-clusters with separate response rates. This comprehensive immune profiling data were then integrated to generate a continuous Response Score (RS) based upon response criteria (RECIST v.1.1). RS was developed using a single institution training cohort (n = 48) and subsequently tested in a separate eight institution validation cohort (n = 29) to mimic a real-world clinical scenario.

RESULTS

PD-L1 positivity ≥1% correlated with response and OS in ICI-treated patients, but demonstrated limited predictive performance. High mutational burden was associated with response in ICI-treated patients, but not with OS. Comprehensive immune profiling using RS demonstrated higher sensitivity (72.2%) compared to PD-L1 IHC (34.25%) and tumor mutational burden (32.5%), but with similar specificity.

CONCLUSIONS

In this study, the response score derived from comprehensive immune profiling in a limited melanoma cohort showed improved predictive performance as compared to PD-L1 IHC and tumor mutational burden.