Efficacy of epidermal growth factor receptor inhibitors

Clinical case

Dr. Renatas Aškinis
Department of Thoracic Surgery and Oncology, Vilnius University Oncology Institute

Medical history
At the end of 2009, a 65-year-old patient developed a fever and started to experience coughing, but only sought medical attention in October 2010. Suspecting pneumonia, the patient was prescribed antibacterial and antipyretic treatment, but her condition did not improve. A chest X-ray was performed, and lung cancer was suspected. To further investigate, refine the diagnosis, and treat, she was referred to the Vilnius University Oncology Institute (VUOI).
At the Oncology Institute, the diagnosis of lung cancer was confirmed by performing a chest X-ray examination (Fig. 1a, b), chest CT scan (Fig. 2). After tumor resection, histological examination revealed lung adenocarcinoma – a malignant glandular tumor (Figs. 3, 4). Molecular tests identified a mutation in exon 19 of the epidermal growth factor receptor (Fig. 5). This was an indication to treat the patient with an epidermal growth factor receptor inhibitor – gefitinib was prescribed in the same month. The medication was effective, and the treatment course was smooth. The patient continues to visit oncologists regularly and subjectively feels well. She takes one gefitinib tablet daily, and the prescription is renewed monthly with state-compensated medication. The patient undergoes periodic blood and radiological tests. Recent radiological tests have shown no disease progression, with a good tumor response to treatment (Figs. 6, 7a, b).

Summary
Since starting treatment with gefitinib, the course of the disease is considered positive: the lung tumor is currently shrinking, stable, without signs of progression. The patient continues to be monitored and treated with this medication at the Šiauliai Oncology Dispensary, as there is no need for her to travel regularly to Vilnius. VUOI follow-up tests are conducted every 6 months.

Commentary on the clinical case

Prof. Saulius Cicėnas
Department of Thoracic Surgery and Oncology, VUOI

Specialists at the Vilnius University Oncology Institute have considerable experience in treating lung cancer with epidermal growth factor receptor inhibitors. Institute oncologists participate in several international multicenter clinical trials involving more than 120 countries, evaluating the effectiveness, safety, and tolerability of these drugs.
Vilnius oncologists became familiar with gefitinib (Iressa) 8 years ago. Initially, we received limited access to this drug for trials, later it was registered and finally began to be reimbursed. We are pleased that treating with Iressa has yielded really good results. However, there have been cases of lung cancer forms resistant to this drug.
Currently, intensive research is ongoing worldwide to determine why there comes a time when lung cancer becomes resistant to treatment with epidermal growth factor receptor inhibitors, and lung cancer begins to progress. It has been found that tumor resistance is influenced by mutations in other receptors, these mutations are affected by other mutations, and so on.
The latest studies on epidermal growth factor receptor mutations were presented at the XV World Oncologists Congress in Sydney in the fall of 2013, discussing and elucidating mechanisms of lung cancer resistance to treatment and other patterns. Although the new drugs do not cure advanced lung cancer, they greatly extend the lives of many patients, inducing long-term remission of the malignant process.
By inhibiting the epidermal growth factor receptors, we have treated about 40 patients with advanced lung cancer, many of whom have managed to stabilize the tumor process and achieve remission. For a patient with advanced cancer, not only years but also several additional months of life are a great achievement. This is also true for the patient's family, loved ones. Previously, as oncologists, we were pleased if we could extend the life of a person with advanced lung cancer by a few months. Now, applying the latest treatment, we can extend the lives of these patients by several years. In the world, and also here, there are already people who, with stage 4 lung cancer, have been living for 5 years or longer. Unfortunately, there are far fewer successful cases than resistant, progressing forms of the disease.
Epidermal growth factor receptor inhibitors are a very promising, often effective treatment for advanced lung cancer, although not all patients can tolerate treatment with these drugs. When we see that due to a severe condition the patient will not be able to undergo treatment or that the treatment may even worsen the condition to a critical state, in such cases, understandably, we do not prescribe these drugs. But if we believe that we can win back at least a few months of the patient's life, then it is definitely worth treating.