Background: Immunohistochemistry (IHC) with mutation-specific antibodies may be an ancillary method of detecting EGFR mutations in lung cancer patients. Methods: EGFR mutation status was analyzed by DNA assays, and compared with IHC results in five non-small-cell lung cancer (NSCLC) cell lines and tumor samples from 78 stage IV NSCLC patients. Results: IHC correctly identified del 19 in the H1650 and PC9 cell lines, L858R in H1975, and wild-type EGFR in H460 and A549, as well as wild-type EGFR in tumor samples from 22 patients. IHC with the mAb against EGFR with del 19 was highly positive for the protein in all 17 patients with a 15-bp (ELREA) deletion in exon 19, whereas in patients with other deletions, IHC was weakly positive in 3 cases and negative in 9 cases. IHC with the mAb against the L858R mutation showed high positivity for the protein in 25/27 (93%) patients with exon 21 EGFR mutations (all with L858R) but did not identify the L861Q mutation in the remaining two patients. Conclusions: IHC with mutation-specific mAbs against EGFR is a promising method for detecting EGFR mutations in NSCLC patients. However these mAbs should be validated with additional studies to clarify their possible role in routine clinical practice for screening EGFR mutations in NSCLC patients.

Small-cell lung cancer (SCLC) accounts for 15% of lung cancers. Only one-third of patients are diagnosed at limited stage. The median survival remains to be around 15–20 months without significative changes in the strategies of treatment for many years. In stage I and IIA, the standard treatment is the surgery followed by adjuvant therapy with platinum–etoposide. In stage IIB–IIIC, the recommended treatment is early concurrent chemotherapy with platinum–etoposide plus thoracic radiotherapy followed by prophylactic cranial irradiation in patients without progression. However, in the extensive stage, significant advances have been observed adding immunotherapy to platinum–etoposide chemotherapy to obtain a significant increase in overall survival, constituting the new recommended standard of care. In the second-line treatment, topotecan remains as the standard treatment. Reinduction with platinum–etoposide is the recommended regimen in patients with sensitive relapse (≥ 3 months) and new drugs such as lurbinectedin and immunotherapy are new treatment options. New biomarkers and new clinical trials designed according to the new classification of SCLC subtypes defined by distinct gene expression profiles are necessary.

In the last decade, important advances have been made in understanding of cancer biology, particularly non-small-cell lung cancer (NSCLC) with the discovery of oncogenic drivers of the disease. The epidermal growth factor receptor (EGFR) gene and its pathways was the first oncogenic driver discovered to be mutated and treatable in lung cancer. Treatment with EGFR tyrosine kinase inhibitors (TKIs) is the standard of care for molecularly selected EGFR-mutant patients, while its role in unselected lung cancer patients is nowadays controversial. This review will provide an overview of the EGFR pathway and options for its treatment of lung cancer.

We investigated the safety and antitumor activity of dalotuzumab, a selective anti-insulin growth factor 1 receptor monoclonal antibody (IGF1R MoAb), plus erlotinib in a sequential phase I/II trial in unselected patients with refractory advanced non-small-cell lung cancer (NSCLC).The phase I trial determined the recommended dose and safety of erlotinib plus dalotuzumab at 5 mg/kg or 10 mg/kg weekly in 20 patients. The phase II trial compared outcomes to erlotinib alone and erlotinib plus dalotuzumab at the mg/kg established in the phase I trial. Erlotinib at 150 mg plus dalotuzumab at 10 mg/kg was safe. The phase II trial included 37 patients in the erlotinib arm and 38 patients in the erlotinib plus dalotuzumab arm. Progression-free survival was 1.6 versus 2.5 months, overall survival was 10.2 and 6.6 months, and the objective response rate was 7.9% and 2.7%, respectively, with no significant differences between the two arms. Grade 3-5 adverse events occurred in 11 (28.9%) versus 13 (35.1%) patients, respectively. The most frequent adverse events were asthenia (36.8% vs. 37.8%), dehydration (5.3% vs. 2.7%), diarrhea (71% vs. 81.1%), hyperglycemia (13.1% vs.18.9%), and skin-related toxicities (92.1% vs. 86.4%). The addition of dalotuzumab to erlotinib did not improve efficacy outcome in patients with refractory advanced NSCLC.