Lung Cancer and Mesothelioma

Lung cancer has two major types:

• non-small cell lung cancer (NSCLC), which makes up 85–90% of cases
• small cell lung cancer (SCLC), which accounts for approximately 10–15% of cases.

Lung cancer is the fifth most common cancer in Australia and claims more lives each year than cancers of the breast, prostate, and colon combined.

Mesothelial cells cover most internal organs. Mesothelioma is a cancer affecting these cells.

There are two types of mesothelioma:

• pleural mesothelioma, which starts in the membranes that cover the lungs and accounts for 90% of cases
• peritoneal mesothelioma, which develops in the lining of the abdomen and accounts for 10% of cases.

The only known risk factor for mesothelioma is exposure to asbestos. In rare cases, mesothelioma can also occur around the heart or reproductive organs.

The most common cause of lung cancer is long-term exposure to tobacco smoke, which causes 80–90% of lung cancers.

Non-smokers account for 10–15% of lung cancer cases. These cases are often attributed to a combination of factors, including:

• genetics
• asbestos exposure
• air pollution, including second-hand smoke.

Although smoking is not the only risk factor, lung cancer is often viewed as a ‘smoker’s disease’. Lung cancer patients face stigma and lack of empathy and speak of being treated as if they ‘deserve’ the disease. This is a significant burden in addition to their cancer diagnosis.

The perception of lung cancer as a smoker’s disease can also prevent non-smokers from seeing a doctor, even if they have symptoms. Anti-tobacco measures have improved survival rates, but they remain low. The five-year survival rate is just 17%.

More men are diagnosed with lung cancer than women. One in every 13 men has been diagnosed with lung cancer in Australia by age 85, compared to one in 21 women.

The symptoms of lung cancer may vary depending on the stage of the disease, but some common signs and symptoms include:

• persistent cough that doesn't go away or worsens over time
• shortness of breath or wheezing
• chest pain that gets worse with deep breathing, coughing, or laughing
• coughing up blood or rust-coloured phlegm
• fatigue and unexplained weight loss
• hoarseness or changes in the voice
• frequent lung infections, such as bronchitis or pneumonia, that don't improve with treatment.

By the time most lung cancer patients develop symptoms, the cancer is at a late stage. For approximately 75% of patients, their cancer has already advanced to stage 3b or 4 when diagnosed. The two key reasons for lung cancer’s high mortality rate are late diagnosis and suboptimal therapies. When lung cancer is at stage 3b or 4, surgery, chemotherapy, and radiation rarely offer a cure. Early detection methods are urgently needed, as well as new treatments.

Treatment depends on the type and stage of the lung cancer.

People with non-small cell lung cancer (NSCLC) can be treated with:

• surgery
• chemotherapy
• radiation therapy
• targeted therapy
• or a combination of these treatments.

Targeted therapies tend to be ineffective for most NSCLC patients, because these tumours generally have no genetic alterations. NSCLC cases usually respond better to immunotherapy alone or in combination with chemotherapy.

People with small cell lung cancer (SCLC) are usually treated with radiation therapy and chemotherapy.