Lung cancer: a treatment difficult

inevitable consequence of the increase in smoking among women, lung cancer has become the leading cause of cancer death in women in the US and is poised to follow suit in France.

Decreasing the intensity of symptoms, chemotherapy improves the quality of life of patients with lung cancer. But despite the progress made in the terms of administration of combination therapies, the treatment of these tumors remains very difficult.

Overall lung, the survival rate for this cancer five years barely exceeds 10%. If surgery alone can bring healing in the rare cases known as small-cell, when the tumor is spotted at a very limited stage for more advanced tumors, hopes based on the combination of different treatments.

Surgery can easily remove the entire tumor when it is small. However, studies have shown that rather than just removing the tumor, it is necessary to remove the entire lobe to reduce the risk of recurrence. With radiotherapy, chemotherapy improves survival after surgery and to reduce the size of cancer that cannot be removed.

Many trials are conducted to clarify the interest of so-called third generation of agents such as gemcitabine, taxanes, topoisomerase I inhibitors (topotecan and irinotecan) or vinorelbine, with encouraging results. The combination of three agents could be better than the usual dual therapy.

Reduce adverse reactions

Radiation therapy should progress to more intense radiation, to increase efficiency, but also specifically directed to the tumor through modern imaging techniques, to limit the effects of this treatment. One of the major challenges is indeed to achieve limiting toxicity of radiation.

However, tests must be conducted to see if these more targeted radiotherapy does not increase the risk of recurrence.

The tolerance of the treatment could also be improved by the use of cytoprotective drugs that protect cells against the toxicity of chemotherapy and radiotherapy. Thus, amifostine seems to reduce cisplatin toxicity to the kidney. Tests are underway to determine if they can also prevent esophagitis, very common after treatments.

Treatments map

Many studies are underway to try to define the optimal treatment modality for each type of tumor. Thus, in tumors of the upper lung (Pancoast tumor), high survival rate at three years were collected with two chemotherapy cycles and radiation therapy before surgery and two cycles of chemotherapy after surgery. The progress thus come more individualized treatment, taking into account the characteristics of each patient.

Overall, unfortunately current treatments do not increase, at best, a few months survival in the advanced stages of cancer. Some researchers put their hopes in drugs that block the formation of new vessels, to prevent tumor vascularization, or in monoclonal antibodies directed against a protein in malignant cells. But clinical trials are still at the very beginning. As to gene therapy, several trials began, to introduce into the tumor cells a tumor suppressor gene (p53 gene) or a gene capable of enhancing the immune system against the tumor. But many years will certainly be needed before such treatment come in practice.

Faced with therapeutic difficulties, early detection of tumors in smokers could increase the proportion of curable cancers. New tools would achieve this goal of new imaging techniques, such as spiral CT or looking for monoclonal antibodies specific for tumor cells in sputum. Preliminary tests have shown encouraging results. However, the cost of these techniques limits its applications. The future remains, more than ever, the fight against smoking.