Non-small cell lung cancer (NSCLC) is the most common cancer in the world. Activating epidermal growth factor receptor (EGFR) gene mutations are a positive predictive factor for EGFR tyrosine kinase inhibitors (TKIs). For common EGFR mutations (Del19, L858R), the standard first-line treatment is actually third-generation TKI, osimertinib. In the case of first-line treatment by first (erlotinib, gefitinib)- or second-generation (afatinib) TKIs, osimertinib is approved in second-line treatment for patients with T790M EGFR mutation. Despite the excellent disease control results with EGFR TKIs, acquired resistance inevitably occurs and remains a biological challenge. This leads to the discovery of novel biomarkers and possible drug targets, which vary among the generation/line of EGFR TKIs. Besides EGFR second/third mutations, alternative mechanisms could be involved, such as gene amplification or gene fusion, which could be detected by different molecular techniques on different types of biological samples. Histological transformation is another mechanism of resistance with some biological predictive factors that needs tumor biopsy. The place of liquid biopsy also depends on the generation/line of EGFR TKIs and should be a good candidate for molecular monitoring. This article is based on the literature and proposes actual and future directions in clinical and translational research.

KRAS is the most frequently mutated oncogene in non-small cell lung cancers (NSCLC), with a frequency of around 30%, and encoding a GTPAse that cycles between active form (GTP-bound) to inactive form (GDP-bound). The KRAS mutations favor the active form with inhibition of GTPAse activity. KRAS mutations are often with poor response of EGFR targeted therapies. KRAS mutations are good predictive factor for immunotherapy. The lack of success with direct targeting of KRAS proteins, downstream inhibition of KRAS effector pathways, and other strategies contributed to a focus on developing mutation-specific KRAS inhibitors. KRAS p.G12C mutation is one of the most frequent KRAS mutation in NSCLC, especially in current and former smokers (over 40%), which occurs among approximately 12–14% of NSCLC tumors. The mutated cysteine resides next to a pocket (P2) of the switch II region, and P2 is present only in the inactive GDP-bound KRAS. Small molecules such as sotorasib are now the first targeted drugs for KRAS G12C mutation, preventing conversion of the mutant protein to GTP-bound active state. Little is known about primary or acquired resistance. Acquired resistance does occur and may be due to genetic alterations in the nucleotide exchange function or adaptative mechanisms in either downstream pathways or in newly expressed KRAS G12C mutation.

Breast cancer is the most common cancer among women. Localized breast cancer treatments involve taxanes which are often responsible for acute peripheral neuropathy. The persistence of taxane‐induced peripheral neuropathy (TIPN) is scarcely described among elderly women. A monocenter historical cohort study including all women over 65 years of age treated between 2001 and 2016 with a taxane‐based chemotherapy for localized breast cancer was carried out at the Paul Strauss Regional Comprehensive Cancer Center. All cases included were followed up for at least 2 years, deaths from causes unrelated to TIPN were excluded. We report on the frequency and risk factors and establish a prognostic score of persistent Common Terminology Criteria for Adverse Events (CTCAE) grade 2 and 3 TIPN. Among the 302 included patients, 21% and 9% developed persistent TIPN of grade 2 and 3, respectively. Two patients died from complications of grade 3 TIPN. Risk factors of persistent grade 2 and higher neuropathy included age (P < .0001), body mass index (P < .0001), and diabetes (P = .0093). Persistent TIPN was more frequent with paclitaxel than docetaxel (OR = 5.43; P < .0001). Patients presenting all four major risk factors had a 97.2% probability of developing long‐term symptoms against 1.2% for patients showing no risk factor. We therefore identified 3 prognostic groups. TIPN is a frequent and sometimes severe persistent side effect of breast cancer treatment among elderly women with a major impact on health‐related quality of life. Chemotherapy regimens without taxane could therefore be a valid option in elderly patients with neurotoxicity risk factors.