World Lung Cancer Awareness Month: New Treatments Are On The Horizon

Lung cancer

Lung cancer tops the list of cancers which can cause death. According to the National Cancer Institute, around 228,190 Americans were diagnosed with lung cancer in 2012 of which an estimated 158,480 succumbed to their illness. 

Lung cancer usually affects people above the age of 60.

Exposure to second hand smoke can also lead to lung cancer. Among other risk factors, genetics also plays an important role with the cancer showing a predisposition to affect family members of patients already suffering from the disease.

Some of the common symptoms of lung cancer are:

• Severe coughing or cough lasting for a long duration

• Pain in the chest, back or shoulders, often as a result of coughing

• Difficulty in breathing in or exhaling of air and in swallowing

• Change in voice often accompanied with hoarseness

• Presence of stridor

• Changes in the color of sputum

• Coughing out of blood tinged sputum

If the cancer has metastasized to areas beyond the lungs, like to the brain or to the bones, additional symptoms are seen depending upon the site of metastasis. There may be swelling and pain of the regional lymph nodes. If the cancer has reached the brain, patient may complain of dizziness, headache, or even seizures. Metastasis to bones often presents as fractures. Metastasis to liver may present as jaundice and enlargement of the liver.

Classification of lung cancer

Lung cancer is broadly classified into:

• Non-small cell lung cancer (NSCLC)
• Small cell lung cancer (SCLC)

NSCLCs can be further divided into four different types depending upon the nature of cells. They are:

• Squamous cell carcinoma: It is also called as epidermoid carcinoma. This type of cancer develops in the lining of the bronchial vessels and is the most common type of lung cancer in men.

• Adenocarcinoma: It develops in the mucus producing glands of the lungs and primarily affects women and non-smokers.

• Bronchioalveolar carcinoma: It is a rare form of lung cancer developing in the terminal bronchioles which open into the air sacs.

• Large cell undifferentiated carcinoma: This type of cancer develops near the outer surface of the lungs.

SCLC are cancers composed of small cells. They proliferate rapidly and metastasize quickly. Almost all of SCLCs are due to smoking.

The different types of lung cancers are staged according to their spread. The treatment and prognosis of these cancers depends upon the stage of the cancer when it is first diagnosed.

New Treatments On The Horizon For Lung Cancer

Conventional therapy has relied upon chemotherapy, surgery and radiation therapy for treating lung cancer. However, because of a vast amount of research going in the field of lung cancer, it is now possible to diagnose the disease early, and to begin the treatment more promptly.

These days, there are newer forms of surgery, new chemotherapeutic agents, and better radiation techniques. Work is being going on to prevent the development of lung cancer. There are better targeted therapies for lung cancer which act specifically at the tumor site preventing damage to the healthy cells. Research is even going on to develop vaccines against lung cancer.

Let us discuss some of these new developments in the treatment of lung cancer.

New medicines for chemotherapy

Researchers are coming up with newer and better chemotherapeutic agents. Some of the most promising ones are:

• Amrubicin: It belongs to the group of anthracyclines which have been used to treat SCLC. However, the currently used medicines of the anthracycline group are associated with marked cardio-toxicity. Amrubicin has been found to be equally effective against SCLC but without the side effect of cardio-toxicity. It has been granted fast track designation for treating SCLC after using first line chemotherapy.

• Nab-paclitaxel: Research is being carries out to find its use in treating NSCLC. Paclitaxel is used for treating lung cancer but nab-paclitaxel has been found to have a quicker action with less side-effects.

Targeted therapies for lung cancer

This is the area of most active research in the field of lung cancer treatment. Many clinical trials are going on to try new targeted therapies for different forms of lung cancer. Some of them are:

• Cetuximab: This drug has shown promising results in treating NSCLC, wherein it improves the survival rate. It is a monoclonal antibody and inhibits the action of epidermal growth factor.

• MetMAb: This is again a monoclonal antibody. When used along with erlotinib, it has been found to be useful in NSCLC.

• Afatinib: Currently used epidermal growth factor receptor (EFGR) inhibitors like erlotinib stop acting after some time as the EFGRs undergo mutation. So, the tumor cells develop resistance against these drugs. Afatinib is a new generation tyrosine kinase inhibitor (TKI) and researchers believe it may overcome the problem of resistance seen with current generation EFGR inhibitors.

• Gilotrif: Gilotrif is also a TKI. It is meant to be used in patients wherein the tumor cells have undergone EGFR exon 19 deletions or exon 21 L858R substitution gene mutations. These mutations develop in 10% of NSCLC cases and the current generation EGFR inhibitors become useless in these cases. The US FDA has approved the use of Gilotrif in patients with late stage NSCLC with EGFR gene mutations. These mutations are detected with the help of an FDA approved test kit called as therascreen EGFR RGQ PCR Kit.

• ALK inhibitors: These are being tested to be used in patients with anaplastic lymphoma kinase (ALK)-positive lung cancer.

Vaccines to treat lung cancer

Research is being carried out to develop vaccines that activate the body’s immune system in a manner that is recognizes the tumor cells and acts against them. For this, the scientists are taking genetic material present in the tumor cells to create the vaccines.

• MAGE A3 ASCI (Antigen-Specific Cancer Immunotherapeutic): Around 30 to 40% of patients suffering from NSCLC test positive for MAGE A3, a tumor antigen. Researchers are trying to use MAGE A3 ASCI in patients of NSCLC which test positive for MAGE A3 antigen.

Chemoprevention

This is again an exciting avenue for research. Scientists are focusing on drugs which have the potential to decrease the risk of lung cancer. One promising agent is oral Iloprost. This medicine is presently used in the treatment of pulmonary hypertension but when used in non-smokers, it was found to limit the damage to lung and reduce the risk of developing lung cancer.

We are living in exciting times where a lot of work is being done to find new ways to treat lung cancer.