Agents targeting programmed death-1 receptor (PD-1) and its ligand (PD-L1) are showing promising results in non-small-cell lung cancer (NSCLC). It is unknown whether PD-1/PD-L1 are differently expressed in oncogene-addicted NSCLC. We analysed a cohort of 125 NSCLC patients, including 56 EGFR mutated, 29 KRAS mutated, 10 ALK translocated and 30 EGFR/KRAS/ALK wild type. PD-L1 and PD-1 expression were assessed by immunohistochemistry. All cases with moderate or strong staining (2+/3+) in >5% of tumour cells were considered as positive. PD-1 positive (+) was significantly associated with current smoking status (P=0.02) and with the presence of KRAS mutations (P=0.006), whereas PD-L1+ was significantly associated to adenocarcinoma histology (P=0.005) and with presence of EGFR mutations (P=0.001). In patients treated with EGFR tyrosine kinase inhibitors (N=95), sensitivity to gefitinib or erlotinib was higher in PD-L1+ vs PD-L1 negative in terms of the response rate (RR: P=0.01) time to progression (TTP: P<0.0001) and survival (OS: P=0.09), with no difference in PD1+ vs PD-1 negative. In the subset of 54 EGFR mutated patients, TTP was significantly longer in PD-L1+ than in PD-L1 negative (P=0.01). PD-1 and PD-L1 are differentially expressed in oncogene-addicted NSCLC supporting further investigation of specific checkpoint inhibitors in combination with targeted therapies.

Background: KRAS codons 12 and 13 mutations predict resistance to anti-EGFR monoclonal antibodies (moAbs) in metastatic colorectal cancer. Also, BRAF V600E mutation has been associated with resistance. Additional KRAS mutations are described in CRC. Methods: We investigated the role of KRAS codons 61 and 146 and BRAF V600E mutations in predicting resistance to cetuximab plus irinotecan in a cohort of KRAS codons 12 and 13 wild-type patients. Results: Among 87 KRAS codons 12 and 13 wild-type patients, KRAS codons 61 and 146 were mutated in 7 and 1 case, respectively. None of mutated patients responded vs 22 of 68 wild type (P=0.096). Eleven patients were not evaluable. KRAS mutations were associated with shorter progression-free survival (PFS, HR: 0.46, P=0.028). None of 13 BRAF-mutated patients responded vs 24 of 74 BRAF wild type (P=0.016). BRAF mutation was associated with a trend towards shorter PFS (HR: 0.59, P=0.073). In the subgroup of BRAF wild-type patients, KRAS codons 61/146 mutations determined a lower response rate (0 vs 37%, P=0.047) and worse PFS (HR: 0.45, P=0.023). Patients bearing KRAS or BRAF mutations had poorer response rate (0 vs 37%, P=0.0005) and PFS (HR: 0.51, P=0.006) compared with KRAS and BRAF wild-type patients. Conclusion: Assessing KRAS codons 61/146 and BRAF V600E mutations might help optimising the selection of the candidate patients to receive anti-EGFR moAbs.

Background: Tumors acquire nutrients that are essential for continued growth and an avenue for dissemination to the rest of the body by inducing angiogenesis (i.e., the formation of new blood vessels). Preliminary studies involving a number of different kinds of cancer have indicated that an assessment of tumor angiogenesis may be useful in predicting disease outcome. Purpose: In a prospective study, we evaluated the relationship between tumor angiogenesis and survival for 407 patients with nonsmall- cell lung carcinoma who were treated with potentially curative surgery. Methods: The study population consisted of 360 male and 47 female patients who underwent surgery consecutively at the Department of Surgery, University of Pisa, Italy, from March 1991 through December 1994. Followup lasted through February 1996, with a median follow-up for living patients of 29 months (range, 15-60 months). An anti-CD34 monoclonal antibody, which is specific for endothelial cells, and standard immunohistochemical techniques were used to measure angiogenesis in tumor samples. Angiogenesis was quantified in terms of microvessel counts; the counts for single, highpower microscopic fields (magnification ×250) in the three most intense areas of blood vessel growth for each sample were averaged. The median microvessel count in this series was 20, and the counts were categorized as follows: 1) low versus high (⩽20 versus >20 microvessels) or 2) in five categories (1-10, 11-20, 21-30, 31-40, and ⩾41 microvessels). Disease-free and overall survival during follow-up were assessed. Kaplan-Meier survival curves were modeled in a univariate analysis of patient and tumor characteristics; the Cox proportional hazards model was used in multivariate analysis. Reported P values are two-sided. Results and Conclusions: In the univariate analysis, patients with larger tumors ( P for trend <.00001), a more advanced tumor stage ( P for trend <.00001), a greater degree of regional lymph node involvement (P for trend <.00001), or more vascularized tumors (high versus low microvessel count, P <.00001) experienced significantly reduced overall survival. When microvessel counts were analyzed in five categories, a highly significant trend ( P <.00001) toward worse prognosis was observed with increasing tumor vascularity. In multivariate analysis, tumor microvessel count ( P <.00001), tumor size ( P = .0006), and regional lymph node status ( P <.00001) retained independent prognostic value with respect to overall survival; among these variables, tumor microvessel count, considered as a continuous variable, was the most important, with a relative hazard of death of 8.38 (95% confidence interval = 4.19- 16.78) associated with the highest microvessel counts. Implications: An evaluation of tumor angiogenesis may be useful in the postsurgical staging of patients with non-small-cell lung carcinoma and in identifying subsets of patients who may benefit from different postsurgical treatments.