The relationship between the PD-L1 expression of surgically resected and fine-needle aspiration specimens for patients with pancreatic cancer

BACKGROUND

Recently, therapeutic antibodies against programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) have shown promising clinical results for several solid tumors, including pancreatic cancer. In this study, we evaluated the relationship between the PD-L1 expression of surgical resected and fine-needle aspiration (FNA) specimens for patients with pancreatic cancer.

METHODS

Of 121 patients who underwent endoscopic ultrasound-guided (EUS)-FNA before surgery for pancreatic cancer in an academic center, the 94 (78%) with adequate FNA specimens for a histological evaluation were retrospectively analyzed. All the patients had undergone upfront surgery without any chemotherapy or radiotherapy. We performed immunohistochemistry (IHC) staining to investigate the PD-L1 expression in both resected and FNA specimens. The positive-stained cells were counted, and their percentage was used for the investigation.

RESULTS

Of the 94 patients, 16 (17%) and 11 (10%) were defined as positive on resected cancer specimens using cutoff points of 5% and 10% positively stained cancer cell counts, respectively. The concordance rates for the positive frequency of PD-L1 expression between resected and FNA specimens were 44% (7/16) and 55% (6/11) when the positivity was set to ≥ 5% and ≥ 10%, respectively. The concordance rates for the negative frequency of PD-L1 expression between two specimens were 97% (76/78) and 99% (82/83) when the positivity was set to ≥ 5% and ≥ 10%, respectively.

CONCLUSIONS

Approximately, half of the patients with PD-L1 expression positive and almost all the patients with PD-L1 expression negative could be diagnosed on FNA specimens.

Comparison of the Diagnostic Performance of Newly Designed 21-Gauge and Standard 22-Gauge Aspiration Needles in Patients with Solid Pancreatic Masses

BACKGROUND

Although endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been widely used for the diagnosis of pancreatic tumors, the ability to obtain adequate pancreatic tumor tissue needs to be improved.

AIMS

This study was performed to compare a newly designed 21-gauge needle (EUS Sonopsy CY; Hakko Medical, Nagano, Japan) and a standard 22-gauge needle for tissue sampling of solid pancreatic masses.

METHODS

Consecutive patients with solid pancreatic masses who underwent EUS-FNA with either the EUS Sonopsy CY or the 22-gauge needle from June 2014 to December 2016 were enrolled. The primary outcome was comparison of the diagnostic yield of the FNA samples. The secondary outcomes were comparison of technical success, diagnostic ability for malignancy, and complications.

RESULTS

A total of 93 patients (40.9% female; mean age, 70.1 years) underwent EUS-FNA with the EUS Sonopsy CY (n = 47) or the standard 22-gauge needle (n = 46). The technical success rate was 100% in both groups, and the overall diagnostic accuracy for malignancy was similar between the groups (100% in the EUS Sonopsy CY group vs. 95.7% in the 22-gauge needle group, P = 0.242). Nevertheless, the EUS Sonopsy CY resulted in significantly higher scores for cellularity (P = 0.006) and lower scores for blood contamination (P < 0.001). The procedure-related complication rate was comparable between the groups (P = 0.148).

CONCLUSIONS

The EUS Sonopsy CY provided higher-quality specimens for histological evaluation in terms of both sample cellularity and blood contamination for the diagnosis of solid pancreatic masses.

TRIAL REGISTRATION

The study was registered in a clinical trial registry, No. UMIN000032598.