With a very low survival rate and almost always a late diagnosis, the battle against lung cancer remains unsurmountable.
IT is the most frequently-occurring cancer and yet the diagnosis and treatments of lung cancer remain an unsurmountable obstacle. Early detection is almost impossible since there is no screening for lung cancer. Only about 15 per cent of cases are detected early. The remaining are diagnosed at advanced stages.
Late diagnosis, therefore, is a major obstacle in improving lung cancer prognosis. Due to this, it remains the world’s biggest cancer killer with one in five cancer death due to lung cancer.
Unfortunately, lung cancer is one of the most aggressive cancers. Out of 100 patients, only 10 to 15 patients survive for five years upon diagnosis. Things look even bleaker for those diagnosed with stage four with only two out of 100 patients living up to five years.
Subang Jaya Medical Centre clinical oncologist Dr Matin Mellor says early diagnosis for lung cancer is difficult as there are no symptoms to indicate the presence of the disease.
Every time patients complain about coughing or chest pain, they almost always co-relate with an advanced stage of the disease. Some of the cases are diagnosed incidentally when patients come in with a different health issue.
“It is difficult to detect it early because the lungs have a big capacity. There are two lungs, so if there is any issue, there will not be any symptoms. Even if half of the lung is destroyed, you can still function normally.
“It is only when the tumour grows to a certain size or reaches a critical level that the symptoms manifest persistently, something you can no longer ignore. If the cancer blocks the main function of the lungs, then you may have early symptoms such as a cough.
“But if it is peripheral, you may not have any symptoms. Only when it grows more central will you get the symptoms. But by then the cancer will have moved to an advanced stage.”
COMMON SYMPTOMS
Dr Matin says that while it may be difficult to detect it early, patients need to be aware when they have persistent health issues such as a cough, a common symptom of lung cancer.
“A cough does not always mean it is lung cancer. But in general if a condition is related to cancer, it will persist. If the cough persists for two weeks, after you have been to a physician and taken medication, then something is wrong.
“When the condition continues, even with treatment, you need to go for further investigation. It is also not a good idea to change doctors if the condition continues. You must see the same physician who has your history and is familiar with your issues,” he says during a roundtable discussion on lung cancer.
In Malaysia, 90 per cent of cases are presented at stage three and four where possibility of being cured is extremely low. Every day, 10 Malaysians die of lung cancer.
Smoking is by far the leading risk factor for lung cancer and the main cause for 80 per cent of lung cancer deaths.
University Malaya Medical Centre consultant respiratory Professor Dr Liam Chong Kin says cough is a sign that something is wrong with the respiratory system. In addition, patients may also suffer from other symptoms including shortness of breath, unexplained weight loss and fatigue.
“When you suffer from these symptoms persistently, seek medical attention immediately. The worry is that there is an increased number of younger lung cancer patients and mostly female who are nonsmokers. There is certainly a risk of lung cancer due to secondhand smoke.
“Studies have shown that secondhand smokers have between 20 and 30 per cent chance of developing lung cancer compared to those who are not exposed to it,” says Dr Liam.
While there are still uncertainties on the impact of shisha and e-cigarettes, it is believed that they may be harmful in the long term.
“There is no tar in shisha or e-cigarettes but you don’t know the ingredients in the liquid. There can be side effects which we do not know yet. People are promoting e-cigarettes as a tool to stop smoking, which is fine if you can stop smoking. But what is frightening is that young people are taking up e-cigarette smoking because they think it is trendy.”
TREATMENT OPTIONS
With the late diagnosis, treatment options for lung cancer are also limited. Surgery and radiotherapy are usually not recommended, leaving patients with only chemotherapy. But at an advanced stage of the disease, many patients may not be able to withstand the treatment.
However, over the last few years, targeted therapy is another choice for lung cancer patients. Targeted therapy is mainly for non–small cell lung cancer that has spread to other parts of the body, cancer that has come back after chemotherapy or has not responded to chemotherapy.
Targeted therapy works with the identification of a biomarker, which is determined through a biopsy of the cancer cells. Cancer biomarkers refer to proteins, genes, and other molecules that affect how cancer cells grow, multiply, die, and respond to other compounds in the body.
Dr Matin says biomarkers can help doctors detect and diagnose the disease, evaluate the likely outcome or course of the disease, choose the appropriate course of treatment and monitor the response to the treatment.
Some common biomarkers include the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), ROS proto-oncogene 1 (ROS1) and programmed death-ligand 1 (PD-L1).
Dr Matin says the ALK, EGFR and ROS-1 are changes in genes of a tumour cell that can cause cancer cells to grow and divide. The PD-L1 allows some cancers to avoid being detected by the immune system.
He says with targeted therapy, lung cancer patients can survive much longer compared to before. There are stage four patients who survive for more than 12 years with targeted therapy.
“It is not unusual for patients to refuse treatment if the only choice is chemotherapy especially at an advanced stage. But when we opt for targeted therapy, we need to take into account the patients’ understanding of the disease.
“We also need to consider the pathology, the stage and the biomarker status of the cancer. Only then can we decide on how best to manage the disease and ensure a positive outcome for the patient.”
While targeted therapy works better compared to traditional cancer treatment, it is expensive and it does not work on everyone, says Dr Matin.
The cost is RM4,000 a month and patients may need treatment for a longer period of time. Two pharmaceutical companies provide free anti EGFR medication but only for patients who have gone through treatments for 10 months.
“Unfortunately, targeted therapy does not bring out the same result for every patient. For some patients who are EGFR positive, studies have shown that the treatments may fail after 10 to 12 months as the cancer cells mutate.
“When this happens, we need another biopsy to determine the biomarker and then choose a different targeted therapy. Unfortunately this often happens because there are still a lot of things that we don’t understand about cancer. There are new drugs for cancer but at the same time there are new mutations. This is the challenge in treatments for lung cancer, and other types of cancers.”
FAST FACTS
* Lung cancer is a disease in which certain cells in the lungs become abnormal and multiply uncontrollably to form a tumour.
* Lung cancer is most common in older people and the risk increases with age. It's rare in people younger than 40.
* It is generally divided into two types — small cell lung cancer and non-small cell lung cancer, based on the size of the affected cells.
* Non-small cell lung cancer accounts for 85 per cent of lung cancer, while small cell lung cancer accounts for the remaining 15 per cent.
* Small cell lung cancer grows quickly and often metastasises, most commonly to the liver, brain, bones, and adrenal glands (small hormone-producing glands located on top of each kidney). After diagnosis, most people with small cell lung cancer survive for about one year; less than seven per cent survive five years.
* Non-small cell lung cancer is divided into three subtypes: adenocarcinoma, squamous cell carcinoma, and large cell lung carcinoma.
* The five-year survival rate for people with non-small cell lung cancer is usually between 11 and 17 per cent. It can be lower or higher depending on the subtype and stage of the cancer.
* Lung carcinoid tumours are rare, grow very slowly and usually do not spread.
* Lung cancer is hard to find in its early stages. It may take years for the cancer to grow and there usually are no symptoms early on.
* Researchers are working to develop tests that can find lung cancer in its early stages. New studies have shown that low-dose CT screening for high-risk individuals who meet certain guidelines can save lives.
Source : US National Library of Medicine, American Lung Association