Correlation between biopsy type and insufficient tissue availability for biomarker testing in five solid cancer types.
e22136 Background: Limited tissue availability is a known barrier to conducting biomarker testing on cancer tissue specimens. It has been assumed that the frequency of insufficient tissue being available is correlated with type of tissue biopsy performed, but this has not previously been quantified across multiple cancer types. Methods: A panel of pathologists in the US (N=90) were asked to report on recent cancer tissues they prepared/handled for biomarker testing. The physicians were asked to report on the cancer type, biopsy method, molecular diagnostics tests conducted, and whether sufficient tissue was available for all requested tests. If insufficient tissue was available, they were asked to report on which tests they were unable to perform as a result. All data was collected through an online survey between August and November 2012. Results: In total, 99 breast cancer samples, 85 NSCLC samples, 60 CRC samples, 30 gastric cancer samples and 40 melanoma samples were reported on. Insufficient tissue was available in 5 (6%) of all NSCLC samples, 2 of which were obtained through fine needle aspirations (14% of all FNAs), a further 2 through core biopsies (5%), and a further 1 through a bronchoscopy (8%). Insufficient tissue was available in 1 (1%) of all breast cancer samples (core biopsy, 1% of all core biopsies), 1 (3%) of all melanoma samples (core biopsy, 13% of all core biopsies) and 1 (2%) of all CRC samples (core biopsy, 11% of all core biopsies). Conclusions: Insufficient cancer tissue for biomarker testing occurred across 4 out of 5 cancer types reported on, though was rare (<5%) in cancers other than NSCLC. The majority of tissue samples in which insufficient tissue was present were acquired through core biopsies (67% of all cases) or FNAs (22% of all cases).