Lung cancer and smoking: It’s never too late to quit

IN Sarawak, lung cancer is our third most common cancer as statistics from the public Radiotherapy and Oncology Unit (RTU) at the Sarawak General Hospital (SGH) indicate it represents around 10 to 11 per cent of all new cancer cases in the state each year.

And coming as no surprise, an estimated 85 per cent of all lung cancer patients are smokers.

According to Dr Voon Pei Jye, an oncologist at SGH, and the Sarawak committee chair of the Malaysian Oncological Society (MOS), tobacco smoking and second-hand smoke exposure are classified by the International Agency for Research on Cancer (IARC) as one of the leading causes of lung cancer worldwide.

“Smoking is a top source of carcinogens, meaning it is toxic. Athough it causes almost all types of cancer and even other diseases like cardiovascular disease, yet people still smoke.

“And these people are 15 to 30 times more likely to develop lung cancer or die from it than people who do not smoke. So I cannot stop stressing how important it is to stop smoking,” he declares.

The information that lung cancer and smoking are heavily linked is not new as the link was discovered over 60 years ago, and since then, heavy regulations and measures have been sanctioned worldwide to deter smoking and inform the public of its dangers.

Globally, the effects of this can be observed in the implementation of heavy taxes on tobacco products and the banning of smoking in most public areas, and in our own backyard, you’d be hard pressed to find a packet of cigarettes that isn’t embossed with warning labels and graphic images of lung cancer and other associated diseases.

But even with such serious warnings and deterrents, a good portion of us still continues to smoke.

According to the National Health and Morbidity Survey (NHMS), an estimated five million Malaysians or 22.8 per cent of the population, are smokers.

In Sarawak, that proportion is even higher with an estimated 25.4 per cent of the people being smokers.

This is an extremely worrying figure because other than one

fifth of our population actively putting themselves at risk of developing lung cancer and various other cancers and disease, Dr Voon shares that tobacco smoke does not just affect the person smoking, but also everyone exposed to it.

“Three per cent of lung cancer is developed due to second-hand smoke exposure in non-smokers. While this figure may sound small, it’s actually not because the total number of lung cancer cases is very large.

“And these are innocent people who did not choose to smoke but yet are suffering because of smokers around them.”

Based on information from the World Health Organisation, the effects of second-hand smoke is estimated to cause 600,000 deaths annually, with one third of those killed being children often exposed to smoke in their homes.

If the thought of potentially harming a child isn’t enough to deter the idea of smoking, Dr Voon adds that tobacco smoke has also been found to be associated with a large number of other cancers such as those of the mouth and throat, oesophagus, stomach, colon, rectum, liver, pancreas, larynx, trachea, bronchus, kidney and renal pelvis, urinary bladder, cervix and some forms of leukaemia.

In addition, it also causes a multitude of other health issues ranging from increased risk of having a stroke to fertility issues.

“Cancer is such a dangerous disease, why go and spend money to try and get it,” he queries.

Too little to matter or too late to quit

While Dr Voon’s question is a rhetorical one, meant to emphasise the dangers of smoking and the severity of cancer, it is still worth answering as it can help us understand the motivation behind smoking and the reluctance our communities to quit this toxic habit.

Obviously, the first thing to note is that tobacco smoke is an addictive substance due to presence of nicotine that gives smokers a temporary ‘high.’

Smokers will find themselves craving for cigarettes while heavy smokers, attempting to quit, will find themselves having withdrawal symptoms from the sudden absence of nicotine in their bodies.

Because of this, it may be very hard for smokers to quit without proper support from physicians in the form of nicotine replace therapy (NRT) — a treatment where smokers are given low dosages of nicotine to help curb their craving and withdrawals.

While NRT is widely available at all government clinics and hospitals for free to any smokers looking to kick their habit, their utilisation rates are still low as evidenced by the high number of smokers.

Sharing his own experiences, Dr Voon points out that smokers’ reluctance to even try to quit is due to the misconception it may already be too late or their smoking habits will not put them at too much risk due to it being fairly light.

“While ex-smokers still have an increased risk of developing cancers compared to never-smokers, it does not mean that quitting will be useless.

“Actually, people who quit smoking have a much lower risk of lung cancer than if they had continued.

“It also doesn’t matter how old you are as quitting smoking at any age can significantly reduce your risk of lung cancer,” he explains.

For light and social smokers, Dr Voon emphasises that any amount of tobacco smoke will heighten the risk of developing lung cancer.

“So, even smoking a few cigarettes a day or occasionally increases the risk of lung cancer, and the more years a person smokes and the more cigarettes smoked each day, the more the risk of developing lung cancer will go up.

“It’s unnecessary and it affects not only yourself but also your loved ones. So my advice is to quit now if you’re a smoker because it’s the best chance to lower the chance of developing lung cancer.

“And if you’re a non-smoker, never start — it is very difficult to quit.”

Other causes

It is also important to understand there are other environmental factors linked to causing lung cancer. These are prolonged exposures to air pollution and toxic chemicals such as asbestos, nickel, arsenic and gas radon.

Fortunately, these chemicals are usually restricted to a select few industrial industries and thanks to improvements in our occupational work health and safety guidelines, it is unlikely exposure to these chemicals will occur.

Dr Voon also adds that lung cancer may be inherited but inherited mutations are not thought to cause very many cases of lung cancer.

“So at the end of the day, the main thing you can do to reduce your risk of lung cancer is to stop smoking.”

Late diagnosis and low survival rates

Adding to the argument of not smoking, lung cancer is a particularly dangerous cancer type as it is difficult to detect in early stages (1 &2), causing a large portion to only be diagnosed in advance stages (3 & 4) when the disease has already spread and is very hard to cure.

“Lung cancer is abysmal because it can be asymptomatic in early stages, meaning that common symptoms like coughing may not even present at all in early stages and only present in advance stages.

“Locally, around 50 per cent of new cancer cases are diagnosed at Stage 4 where the disease already spread to other parts of the body and is very hard to treat,” Dr Voon explains.

 

Screening

Coming this far, it’s clear that best way to decrease the risk of developing this serious disease is stay far away from tobacco smoke.

But as mentioned, smokers who quit now will still have a higher risk of developing the disease compared to non-smokers.

To address this issue, Dr Voon guides that there is a screening process that heavy smokers or heavy ex-smokers can undergo to help them pick up the disease earlier if does develops.

The screening process is called a low-dose computed tomography scan (LDCT) which involves taking cross-sectional images of the chest that are so detailed that it can reveal any lung abnormalities the size of a grain of rice, allowing for earlier detection of potential lung cancer tumours.

“LDCT is usually given to high-risk lung cancer patients annually and is a better tool to screen for lung cancer compared to the conventional chest x-ray.

“This is because it has been proven that high-risk patients utilising LDCT have a 20 per cent lower chance of dying from lung cancer compared to patients who use X-rays as screening tool,” he reveals.

However, he also points out  that LDCT is not for everybody — only high-risk patients.

The reasoning behind this is that LDCT has its own risks such as false positives, and due to a lack of clinical trials, it has not yet been determined that the screening tool will yield the same benefits in lower-risk patients as it does in high-risk patients.

Currently, LDCT screening is being offered at the SGH but only for heavy smokers — those who have smoked 30 pack years (a pack of cigarettes every day for 30 years) or more and are between the ages of 55 and 80.

 

Dr Voon Pei Jye

Dr Voon is born and raised in Sarawak. His interest and dedication to medicine have always been a guiding light in his life. After graduating from University Malaysia Sarawak in 2001, he left home for the first time to Singapore where he obtained his masters in internal medicine from the National University of Singapore and completed his advanced specialist training in Medical Oncology from the National University Hospital Singapore. Since then, he has returned home to continue serving as a consultant medical oncologist at SGH. But beyond just treating patients, Dr Voon’s passion also lies in the area of medical research. Sitting as the local committee chair of the MOS, he is the principal investigator and co-investigator for several international multi-centre cancer trials, and has published and co-authored numerous presentations in national international scientific meetings.