PD-L1 expression comparison between primary and relapsed non-small cell lung carcinoma using whole sections and clone SP263

We assessed the concordance, in terms of PD-L1 expression, between primary and metastatic non-small cell lung carcinoma (NSCLC) of different histotypes using validated SP263 clone. A few samples of local recurrences have also been analyzed.

Whole sections of consecutive cases of primary NSCLC and paired relapses undergone surgical resection have been stained with PD-L1 clone SP263; for scoring purposes, a three-tiered system was applied using the following thresholds: <1%, 1–49% and ≥50%.

Eighty-four cases of paired primary and relapsed tumors from 83 patients were analyzed, including 75 metastases and 9 local recurrences. Regarding metastases, when considering a cutoff of 1%, discrepancy in PD-L1 expression occurred in 9/75 (12%) paired samples (kappa value = 0.75); at 50% cutoff, discrepancy in PD-L1 expression was detected in 7/75 (9.3%) of paired samples (kappa value = 0.61). Regarding recurrences, at 1% cutoff, the discrepancy in PD-L1 expression was seen in 3/9 (33%) paired samples and in all cases there was a gained PD-L1 expression; at 50% cutoff, 1/9 (11%) paired samples showed gained PD-L1 expression.

Our data provide important information regarding the concordance between primary and relapsed NSCLC and the degree of reliability of metastatic sites in terms of PD-L1 expression evaluation.

PD-L1 Expression Heterogeneity in Non-Small Cell Lung Cancer: Defining Criteria for Harmonization between Biopsy Specimens and Whole Sections

INTRODUCTION

Determination of programmed death ligand 1 (PD-L1) expression defines eligibility for treatment with pembrolizumab in patients with advanced NSCLC. This study was designed to better define which value across core biopsy specimens from the same case more closely reflects the PD-L1 expression status on whole sections and how many core biopsy specimens are needed for confident classification of tumors in terms of PD-L1 expression.

METHODS

We built tissue microarrays as surrogates of biopsies collecting five cores per case from 268 cases and compared PD-L1 staining results obtained by using the validated clone SP263 with the results obtained by using whole tumor sections.

RESULTS

We found an overall positivity in 39% of cases at a cutoff of 1% and in 10% of cases at a cutoff of 50%. The maximum value across cores was associated with high concordance between cores and whole sections and the lowest number of false-negative cases overall. To reach high concordance with whole sections, four and three cores are necessary at cutoffs of 1% and 50%, respectively. Importantly, with 20% as the cutoff for core biopsy specimens, fewer than three cores showed high sensitivity and specificity in identifying cases with 50% or more of tumor cells positive for PD-L1 on whole sections. Specifically, for PD-L1 expression values of 20% to 49% on cores, the probabilities of a tumor specimen expressing PD-L1 in at least 50% of cells on a whole section were 46% and 24% with one and two biopsy specimens, respectively.

CONCLUSIONS

An accurate definition of the criteria to determine the PD-L1 status of a given tumor may greatly help in selecting those patients who could benefit from anti-programmed cell death 1/PD-L1 treatment.

Prognostic role of circulating tumor cells-CTCs in metastatic renal cell carcinoma

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Background: CTCs can be isolated in peripheral blood of cancer pts and have demonstrated to have prognostic role in several metastatic tumors such as breast, colorectal and prostate cancer. Few data are available for Renal Cell Carcinoma-RCC. Methods: We designed a multicenter prospective observational trial aiming to assess the association between CTC counts and PFS of RCC pts treated with an antiangiogenic tyrosine-kinase inhibitors as a first-line regimen for metastatic disease. OS and response rate were secondary objectives. Both basal and sequential counts were enumerated by Cellsearch system at 4 time points: day 0 of treatment, +1 mo, +3 mo, at progression or 12 mo in the absence of progression. Ethics Committee approval was obtained. Results: Among 246 pts, 195 are eligible for the present analysis, 71.4% males, median age 69 yrs (range, 27 to 91), 81% with previous partial/total nephrectomy. Treatment was sunitinib (77.5%), pazopanib (21%) or sorafenib (1.5%). According to Heng criteria there were 24.6% good, 62.6% intermediate and 24.6% poor prognosis pts. After a median follow-up of 31.5 mo, median PFS is 13.6 mo (23% censored), 49.2% of pts are still alive. Investigator-assessed best response was 3.8% complete, 37.3% partial response, 33% stable, 25.9% progression. At baseline 91 pts had 1 or more CTCs, median 2, range 1 to 263. Pts with at least 1 CTC had a significantly shorter PFS compared to negative pts (8.8 vs 16.6 mo, p = 0.03), HR = 1.41 (95%CI 1.02-1.9). Thirty pts had > = 3 CTCs, with a median PFS of 5.8 vs 15 mo in the remaining pts (p = 0.002), HR = 1.99 (CI 1.28-3.03). Percentage of pts with > = 3 CTCs increased from 6.6% of good, 18.4% intermediate and 38.9% poor Heng score pts (p = 0.042). Pts with > = 3 CTCs had a shorter estimated OS of 13.8 mo vs 52.8 mo (p = 0.003), HR = 1.99 (CI 1,17-3.2). Correlation between CTC positivity and response rate was not significant. Conclusions: In this robust multicenter prospective cohort of first-line metastatic RCC pts, the presence of 3 or more CTCs predicts a significantly shorter PFS and OS. Further analyses are ongoing on apoptotic markers of CTCs and concomitant counts of endothelial cells collected in the same cohort.

Clinical outcomes in a contemporary series of "young" patients with castration-resistant prostate cancer who were 60 years and younger

BACKGROUND

The prognosis of younger patients with prostate cancer is unclear, and the very few studies assessing those with metastatic castration-resistant prostate cancer (mCRPC) have mainly involved patients treated with older therapies. The aim of this observational study was to evaluate the clinical outcomes of a contemporary series of docetaxel-treated patients with mCRPC who were 60 years and younger.

PATIENTS AND METHODS

We retrospectively identified 134 patients who were 60 years and younger who were treated with docetaxel in 25 Italian hospitals and recorded their predocetaxel history of prostate cancer, their characteristics at the start of chemotherapy, and their postdocetaxel treatment history and outcomes.

RESULTS

Most of the 134 consecutive patients with mCRPC received the standard 3-week docetaxel schedule; median progression-free survival (PFS) was 7 months, and 90 patients underwent further therapies after progression. The median overall survival (OS) from the start of docetaxel treatment was 21 months, but OS was significantly prolonged by the postprogression treatments, particularly those based on the new agents such as cabazitaxel, abiraterone acetate, or enzalutamide. OS was significantly shorter in the patients with a shorter interval between the diagnosis of prostate cancer and the start of docetaxel treatment; those who received hormonal treatment for a shorter period; those with shorter prostate-specific antigen doubling times; and those with lower hemoglobin levels, a worse performance status, and higher lactate dehydrogenase levels before starting treatment with docetaxel.

CONCLUSIONS

The findings of this first study of clinical outcomes in a contemporary series of younger patients with mCRPC showed that their survival is similar to that expected in unselected patients with mCRPC who were of any age.