Histopathological consensus regarding the diagnosis of progressive GBM in adults

Abigail L.

——Excerpt from the article chapter

【Ref: Goodman AL, et al.

Research background

Results of the study

The new guidelines agree to summarize the problem of molecular detection:

Recommendation: If the tumor is histically similar to the primary tumor and the patient's clinical course is as expected, there is no need to repeat IDH mutation testing

Recommendation: In the event of GBM recurrence, there is no need for repeat testing

Recommendation: For histological features that are difficult to classify as glioblastoma, EGFR amplification testing may be helpful in classification

Recommendation: For patients who are eligible or interested in molecularly guided therapy or clinical trials, first or repeated large panel or whole genome sequencing

Recommendation: If the use of immune checkpoint inhibitors is considered, loss of PD-L1 expression or MMR enzyme activity should be determined, but due to the limited survival benefit of immune checkpoint drugs in primary or progressive glioblastoma, standard testing
is not currently considered necessary.

(Level of evidence: Level III)

Question 6: Is there a valuable bevacizumab reactive biomarker for adult patients with progressive glioblastoma? Can new information be provided for tumor management and prognosis beyond standard histological analysis?

Recommendation: Bevacizumab biomarker testing is currently in the experimental phase and its markers include YKL-40, COL4A2, and FMO4 expression
.

There is currently no established biomarker
of bevacizumab.

(Level of evidence: Level III)