Lung cancer in Hong Kong: risk factors and prevention

The original article cites Department of Health and cancer charity figures recording 3,910 lung cancer deaths in 2022, exceeding colorectal cancer deaths. Although breast cancer is especially common in women and colorectal cancer in men, lung cancer is a leading cause of cancer death in both sexes. Early tumours are often small and symptom-free; symptoms may emerge only after nearby organs have been affected or the cancer has spread. The original page also presented age-standardised lung cancer mortality by sex for 1981–2020.

A young non-smoker’s experience Overseas media reported that a 22-year-old medical student, Mohamad Hazman, studying at Universiti Teknologi MARA in Sungai Buloh, Kuala Lumpur, described on TikTok being diagnosed with stage 3 lung cancer in January. He had felt well in November, but developed fever and chest pain in December and was initially diagnosed with pneumonia. An unusual X-ray raised concern, and CT imaging and biopsy confirmed lung cancer.

Why early recognition is difficult Early lung cancer may cause no discomfort. As it progresses, symptoms can include fatigue, persistent cough, breathlessness and chest pain. More advanced symptoms can include coughing blood, hoarseness, chest, shoulder or bone pain and repeated chest infections.

Risk factors Smoking is a principal cause. The source article cites historical estimates that 90% of male patients smoked, around 80% of deaths were smoking-related, 10% of smokers eventually developed lung cancer, and smokers had 20 times the risk of non-smokers. It also cites a 30% increase in risk for spouses exposed to second-hand smoke and an association between paternal smoking and nearly one fifth of childhood cancer cases.

Men over 40 and long-term smokers are highlighted as higher-risk groups. Other exposures listed include asbestos, nickel, uranium, chromium compounds, arsenic, radon, hydrocarbons and chloromethyl ethers; cooking fumes; frequent barbecued or preserved food; incense smoke; low intake of fresh vegetables, fruit or vitamin A-rich foods; and ethnic or inherited factors.

Lung cancer is not contagious It is caused by malignant cellular changes, not an ordinary respiratory infection. However, chemotherapy may reduce white blood cells and weaken immunity. Family members who are ill should wear masks to help protect the patient. Patients should practise hand hygiene and avoid crowded places and inadequately cooked food to reduce infection risk, which can otherwise worsen their condition or delay chemotherapy.

Smoking myths Carcinogens in tobacco damage the respiratory tract’s defence mechanisms, including the cilia that normally clear harmful substances, bacteria and viruses. Greater exposure and longer smoking duration increase risk. “Light” or menthol cigarettes do not offer protection: the cooling sensation may encourage deeper inhalation and make quitting harder. Pipes and cigars also increase oral, oesophageal and lung cancer risk.

It is never too late to quit Stopping smoking can improve circulation and breathing, recovery after lung surgery, treatment side effects and the risk of a second cancer—even after a lung cancer diagnosis.

The article’s prevention suggestions Quit smoking; avoid second-hand smoke; reduce alcohol and eat more fruit and vegetables; exercise regularly; and discuss appropriate cancer screening. The original article notes that annual lung screening may benefit current or former heavy smokers and cites a 20% mortality reduction from earlier detection. Screening does not prevent cancer itself.