Awareness key to surviving lung cancer

OUR risk of developing a cancer of any sort before 75 years of age is approximately one in 10 for men and one in nine for women.

The cause for most cancers is often multifactorial with unhealthy lifestyle habits, environmental pollutants, stress and genetic predisposition the usual culprits.

 

The stage of any cancer (based on an international classification) refers to the extent of spread and is determined by an array of investigations.

The cancer stage in turn determines the most appropriate treatment to be given and thus determines the outcome or prognosis.

 

Cancer outcomes are universally quantified in terms of a five-year survival. This provides useful but limited statistics to suggest what proportion of patients will still be alive in five years from their initial diagnosis.

Alarmingly, between 89% and 91% of Malaysians are only diagnosed with lung cancer in the advanced stage.

Data just released from the Health Ministry’s inaugural Malaysian Study on Cancer Survival confirmed that lung cancer has by far the worst survival of all local cancers with a five-year relative survival of just 11 months and a median survival time of only 6.8 months.

In other words, due to late stage advanced disease presentation, half of all lung cancer patients in Malaysia will die within seven months of their initial diagnosis.

Broadly speaking, lung cancer has four stages: I to IV. The diagnostic work-up will typically involve a chest x-ray, contrast (dye) CT chest scan and a metabolic PET scan.

A tissue sample (biopsy) is usually required for a histological diagnosis to confirm if the growth is indeed a cancer and to subtype it.

Sometimes the patient may require an ultrasound-guided scope (endobronchial or endoscopic) to further sample suspicious nearby lymph nodes in the chest.

Early (stages I and II and selected cases of IIIA) lung cancers are best treated with surgery to remove that part of the lung where the tumour resides, provided the patient is fit enough to undergo the required surgical procedure.

The treatment goal is to achieve a cure but all survivors will require surveillance with an annual CT scan for a minimum of five years after successful surgery.

Some patients may also require adjuvant or post-operative chemo-radiotherapy to minimise any future recurrence.

Advanced disease (stages III and IV) is usually best treated with combinations of chemotherapy, radiation, immunotherapy or targeted therapy, depending on the molecular characteristics and biology of the lung tumour.

In advanced stage disease, the cancer has spread to nearby (regional) lymph nodes or to a distant site (commonly bone or the brain) via the bloodstream or lymphatics by a process known as metastasis hence surgery is usually not appropriate, with a few exceptions.

Despite tremendous recent advances in chemotherapy, targeted therapy and immunotherapy, treatment for advanced disease still remains non-curative.

The goal of treatment here is to palliate symptoms and may sometimes confer improvement in disease progression free survival. Alarmingly, NCR data confirms that 90% of Malaysians have locally advanced or distant metastatic disease (stage III or IV) at initial diagnosis.

This immediately precludes curative therapy. In other words, these unfortunate individuals will eventually die soon from the cancer as evinced by alarming local contemporary data.

Unfortunately, by the time a person develops signs and symptoms of lung cancer (eg. unexplained weight loss, shortness of breath, persistent cough, coughing up blood-stained phlegm, recurrent chest infections or chest pains), the disease is often at an advanced stage.

Hence, it is imperative that the disease is detected at an earlier stage and this can only be achieved through screening.

Two major landmark international clinical trials (National Lung Screening Trial USA 2011 and the recently concluded Dutch-Belgian NELSON trial) provide compelling unequivocal evidence on the health and survival benefits of screening for lung cancer in at risk individuals with the use of a low dose CT (LDCT) scan.

Screening is advocated for male and female chronic smokers and ex-smokers aged approximately 50 to 75 years.

Others who may benefit include individuals with a family history of lung cancer, a personal history of any cancer, those with chronic lung diseases like Chronic Obstructive Pulmonary Disease, previous lung tuberculosis infection and chronic exposure to environmental pollutants like second-hand smoking, asbestos and radon gas.

Screening for lung cancer is a process and not an isolated test. The LDCT is a quick, painless single-breath scan that requires no prior preparation or fasting and has minimal radiation as no contrast or dye is required unlike a conventional CT scan.

Most individuals will have a normal scan and should be advised to stop smoking and do a follow-up scan at an interval to be determined by their doctor based on their clinical risk profile.

A suspicious-looking scan mandates at the very least, close surveillance with a subsequent scan three to four months later, or in some instances, a biopsy to confirm or exclude an early stage lung cancer.

If carefully instituted, LDCT screening has the potential to save lives with detection of earlier stage disease amenable for curative surgery.

Traditionally, lung cancer has been a male smokers’ disease but alarmingly, an increasing number of non- or never smokers are now being diagnosed with lung cancers, particularly Chinese women, many of whom have an increased expression of a genetic driver mutation (eg. EGFR, ROS or ALK) in their tumours.

Genes aside, chronic exposure to cooking or diesel fumes, and second- or third-hand smoke (passive smoking) may also be a factor.

Smoking, including passive smoking remains the single most preventable and modifiable risk factor in the pathogenesis of lung cancer.

The recent announcement by the Government to ban outdoor smoking at open-air eateries nationwide as of Jan 1, 2019 is most welcome.

Legislation to create more smoke-free zones and efforts to promote smoking cessation including increased taxation on cigarettes must be sustained.

Dr Anand Sachithanandan is a consultant cardiothoracic surgeon and passionate advocate for increased lung cancer awareness and screening.