There have been encouraging advances made in recent years in the fight against lung cancer, and researchers are investigating potential new treatments or treatment strategies all the time. The following list is a brief sample of some the types of potential anti-cancer agents and technologies under investigation:
New Surgical Techniques
Video-assisted thoracoscopic surgery (VATS): a less invasive surgical technique that may be helpful for people with marginal lung function who cannot tolerate major surgery. VATS allows “keyhole” surgery, enabling the surgeon to perform the necessary surgery through a small incision with the aid of a video camera and television screen.
New Radiation Techniques
- Conformal 3-D radiation therapy is an important new technique that allows the dose of radiation to be increased with a reduction in the exposure time.
- The combination of both primary radiation therapy and chemotherapy is being examined and shows promise.
- Fractionation: the practise of varying the dose, duration and time between radiation treatments.
- Radiation modifiers can be used to change the cellular response to radiation. These agents appear to inhibit cancer cells from repairing the damage caused by a radiation treatment.
- Radiation sensitisers i.e. agents that make cells more sensitive to the effects of radiation.
- Brachytherapy – a technique used to deliver high doses of radiation from very short distances and involves the placement of a small radiation source in the airway next to a tumour.
Epidermal Growth Factor Receptor (EGFR) inhibitors
EGFR inhibitors are designed to stop the uncontrolled growth of cancer cells in certain types of tumour. EGFR inhibitors work by blocking one of the important signalling pathways involved in cancer cell growth in lung tumours. Clinical studies of these agents in advanced lung cancer have demonstrated that significant numbers of patients achieved either tumour shrinkage or stabilised disease and many patients experienced an improvement in their disease related symptoms.
New Chemotherapy Agents
Promising new chemotherapeutic agents are in clinical trials now, either alone, or in a variety of combinations. Timing and dosing of chemotherapeutic agents is under investigation, as are products that could enhance the effectiveness of the drugs or which can protect normal cells during chemotherapy.
There are a variety of treatments under investigation that may inhibit the formation of tumour blood vessels. Solid tumours, such as lung cancer are able to grow and survive in the human body only by developing their own blood vessels to link into the body’s blood supply. By preventing the tumour from thus accessing the body’s blood supply – which brings nutrients and oxygen to the tumour cells, enabling them to survive and grow, and takes waste products away for processing elsewhere in the body – the tumour cells will eventually die.
Gene therapy for cancer uses genetic material as a therapeutic agent. The aim is to insert into cancer cells a regulator gene that has been lost or altered, or to try to block production of a gene whose function is to promote uncontrolled cell growth. For example, half of all NSCLC patients have abnormalities in their p53 gene – the gene responsible for killing abnormal cells. Whether it is this gene, or other genes involved with lung cancer, genetic therapy may hold promise for preventing and treating NSCLC.
Matrix Metalloprotease Inhibitors
Matrix metalloproteases (MMPs) are naturally-occurring enzymes which help to break down the structure between cells in order to make room for new, healthy tissue to grow. These enzymes are important in normal processes like new blood vessel development and wound healing. It is also believed, however, that MMPs can assist tumour cells as they invade surrounding healthy tissue and spread to more distant parts of the body and may help the development of new tumour blood vessels. By inhibiting the action of MMPs, it is hoped that tumour growth and spread may be slowed down.
Therapeutic Monoclonal Antibodies
Monoclonal antibodies are antibodies that are cloned, or artificially reproduced in a laboratory. They bind only to a certain protein that is a “match” for them. This means monoclonal antibodies can be designed to attach to certain tumour cells and destroy only them.