Non-smokers at greater risk of lung cancer

By Vision Reporter

Added 15th August 2016 05:33 PM

This makes you a secondary smoker and as a secondary smoker you are more prone to suffering from lung cancer.

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This makes you a secondary smoker and as a secondary smoker you are more prone to suffering from lung cancer.

As a non-smoker you might assume that you are living a clean and healthy life, sadly this is far from the truth especially if you keep company with smokers.

This makes you a secondary smoker and as a secondary smoker you are more prone to suffering from lung cancer.

According to experts the risk of lung cancer increases for the non-smoker.

"The primary smoker has a filter in the cigarette and so some of the chemicals might be denied access however the non-smoker does not have this," Dr. Amos Mwaka a medical oncologist at the Rotary cancer treatment center in St. Francis hospital, Nsambya explains.

In Uganda many non-smokers are exposed to tobacco smoke despite the passing of Tobacco Control Bill which was described by international media as the strongest tobacco control law in Africa.

According to the International Agency for Research on cancer (GLOBOCAN), lung cancer has been the most common cancer in the world for several decades. There are estimated to be 1.8 million new cases in 2012, 58 percent of which occurred in the less developed regions.

The disease remains the most common cancer in men worldwide (1.2 million). In women are incidences are generally lower.

"Lung cancer is the most common cause of death from cancer worldwide, estimated to be responsible for nearly one in five (1.59 million deaths, 19.4 percent of the total) because of its high fatality," the research reads.

In Uganda, lung cancer is the tenth most common cancer in men and twelfth most common cancer in women according to a study titled Trends in the incidence of cancer in Kampala, Uganda 1991-2010 by Wabinga et al.

"The rate of new cases is higher in women than men because women today freely smoke," Mwaka adds.

The study shows that there has been a 14.3 percent annual increase in new cases among women and 1.8 percent increase in men since 1991 to 2010.

Lung cancer is divided into two broad groups namely; Small Cell Lung Cancer (SCLC) and Non-Small Cell Lung Cancer (NSCLC).

Dr. Joseph Kigula Mugambe a radiologist and radiation oncologist at Mulago hospital explains that the classification is based on the appearance of the cells under the microscope.

"The SCLC are small in size while the NSCLC are large in size," he says.

There are three common types of NSCLC namely adenocarcinoma, squamous cell carcinomas and large cell carcinomas.

"As far as their behavior is concerned, they can originate from any part of the lung," Kigula says.

An online medical journal explains that the Adenocarcinoma is often found in the outer area of the lung. It accounts for 40 percent of NSCLC and occurs in smokers and non-smokers. This cancer grows slowly.

The other type is the squamous cell carcinomas which are usually found in the center of the lung next to the bronchus. It is linked to a history of smoking and accounts for 25 to 30 percent of NSCLC.

 The third type is the large cell carcinomas that can occur on any part of the lung; tends to grow and spread faster than the other two thus making it difficult to treat. This form of NSCLC accounts for 10 to 15 percent of lung cancers.

The World Health Organisation (WHO) states that NSCLC comprise 85 percent of all lung cancers. Majority of patients with NSCLC present with advanced stage disease and half of the patients treated initially for potentially curable early stage disease will recur with metastatic disease.

Kigula explains that NSCLC is more difficult to treat because it is usually caught late.

"Incidentally you can find that it has spread to the lymph nodes or the opposite lung and you cannot do much," he says.

Kigula explains that this can be due to the fact that there is no available effective screening programme for NSCLC and SCLC.

"Sometimes it is caught incidentally when taking an x-ray of tuberculosis and when you check you see nodules that are tested later only to find cancer," he says.

Mwaka who also has research interest and authority in Cancer awareness and early detection adds that the disease is asymptomatic and manifests with symptoms when it is in its advanced stages. Importantly the symptoms are similar to other diseases.

"Lung cancer manifests with cough, difficulty in breathing like pneumonia, tuberculosis which doctors treat something we term as misattribution of symptoms," he explains.

He adds that there is also difficulty in accessing facilities that can make proper diagnosis as most of them are situated in towns and not rural areas.

"There is also the problem of acceptability of some of the ways we do our diagnosis for example the bronchoscopy which entails putting a tube in someone's mouth to check their chest and lungs," he says.

Kigula says NSCLC more common than the SCLC.

"Most of the SCLC is caught early so they are not referred to us in radiotherapy therefore we see more NSCLC in radiotherapy," Kigula says.


Risk factors

Smokers both primary and secondary are at risk of getting NSCLC and importantly the risk increases for the non-smoker.

Miners, people who live in houses made of asbestos or who work in asbestos companies are prone to suffering from NSCLC because they are exposed to harmful chemicals that accumulate in the lungs.

Exposures to air pollution, diesel, and hydrocarbons from petrol which attach themselves to cells and ruin their DNA also cause lung cancer.

"People who take more than 30 grams of alcohol an equivalent of 8 bottles in a day also are at risk of getting lung cancer," Mwaka says.

Others are consumption of processed foods and a sedentary life style.


Notably lung cancer in its early stages is asymptomatic and that is why most people get diagnosed late.

"NSCLC glows more slowly. It can take about a year or two years growing before symptoms manifest unlike SCLC which takes only months," Kigula notes.

However as the disease progress it manifests with persistent cough that lasts about three weeks.

Kigula adds that the cough can also have blood (hemoptysis). One will also experience chest pain, wheezing because of the mass growing in the airway, difficulty in breathing (dyspnea).

These can be followed by other symptoms related to complications from metastasis (when cancer grows in another part far from the original part).

"One will therefore experience headaches if the cancer has metastasized in the brain," Mwaka explains.



The initial diagnosis of NSCLC is from the patient's complaints of the mentioned symptoms. This is followed by an X-ray; Magnetic Resonance Imaging (MRI) can also be done and costs sh.960,000 while the chest test costs sh.320,000.

One is also subjected to a biopsy which involves the removal of cells or tissues from a peripheral part so that they can be viewed under a microscope by a pathologist to check for signs of cancer.

Kigula adds that if the cancer is centrally located, a tube is pushed in through the mouth into the affected lung and a bronchoscopy is done.

According to the National cancer institute a bronchoscopy is a procedure to look inside the trachea and large airways in the lungs for abnormal areas. The bronchoscope is inserted through the nose or mouth into the trachea and lungs.


Ultimately treatment of lung cancer is hinged on the stage at which the cancer is detected. If NSCLC is detected early the main treatment is surgery.

 "You remove the area which is affected; we make an incision and remove part of the lung (lobe) or the whole lung in some cases," Kigula says.

However if it is not detected early, treatment is the conventional cancer treatment of chemotherapy and radiation.

Mwaka adds that NSCLC can also be treated by targeted therapy where antibodies of single molecules are introduced in the body where they grow into receptors.

"Majority work in the vessels such that they deprive the cancer cells of food like oxygen and glucose which they need to survive," Mwaka explains.

Targeted therapy can be in form of tablets or injections.

However Kigula says chances of curing this type of cancer are few unlike SCLC which can be treated if caught early even without surgery.




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