Recent years have witnessed an unsettling trend: lung cancer diagnoses among non-smokers are increasing at an alarming rate. If you find yourself persistently coughing, accompanied by other symptoms like chest pain, wheezing, hoarseness, unexplained fatigue, or drastic weight loss, it’s time to take heed of your health.

While lung cancer is often dubbed a "smoker's disease," experts stress that non-smokers are also at risk. Dr. Toh Chee Keong, an oncologist at Curie Oncology, notes that lung cancer's association predominantly with smoking has led many to underestimate their own susceptibility. In fact, a 2018 study conducted by the National Cancer Centre Singapore revealed that nearly half of lung cancer patients had never smoked. This statistic marks a worrying increase from a similar study conducted in 2006, signifying a rising trend of lung cancer prevalence among non-smokers.

Lung cancer ranks as the third most common cancer in both men and women in Singapore and is the leading cause of cancer-related deaths, accounting for 25% of all such deaths in males and 15% in females. Alarmingly, the disease often manifests silently in its early stages, making early detection a significant challenge. A recent report highlighted that among 8,955 patients diagnosed with lung cancer between 2017 and 2021, a staggering 60% were already in Stage 4 by the time of diagnosis, indicating that the cancer had potentially spread to other areas of the body.

Understanding Lung Cancer

Lung cancer begins when DNA mutations lead to the rapid production of lung cells, forming masses known as tumors that invade healthy lung tissue. According to the Mayo Clinic, these mutations can be spurred by exposure to various carcinogenic substances, often found in tobacco smoke, but also present in other environments.

There are two primary categories of lung cancer: small cell lung cancer, typically found in long-term heavy smokers, and non-small cell lung cancer, which encompasses various subtypes—including squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.

Why Are Non-Smokers at Risk?

Several factors contribute to the increased lung cancer risk among non-smokers. Genetics can play a significant role, particularly for those with a family history of lung cancer. One surprising study from the Saw Swee Hock School of Public Health has identified cooking oil fumes as a potential risk factor. Women who frequently cook at home exhibited higher levels of carcinogenic agents in their urine compared to those who did not.

Additionally, exposure to radon gas, a naturally occurring radioactive gas produced by the decay of uranium in soil and rock, poses another risk. Even living with a smoker can elevate your risk of developing lung cancer due to second-hand smoke exposure, which studies have shown can increase risk by 20% to 30%.

The Dangers of Second-Hand and Third-Hand Smoke

Second-hand smoke is a well-documented risk, with tobacco smoke containing thousands of harmful compounds. Dr. Toh warns that heavy smoking indoors can significantly spike particulate matter (PM) levels, lingering in the environment for up to five hours and traveling through building ventilation systems.

Less known is the concept of third-hand smoke, which refers to residual nicotine and other toxic substances left on surfaces long after smoking has ceased. This chemical residue clings to clothing, walls, and furniture, continuing to pose health risks, especially to children who are likely to come into contact with these surfaces.

Airing out a room or smoking near a window does little to mitigate these risks, as smoke can still infiltrate indoor environments long after the smoker has reduced ventilation. Dr. Jonathan Tang from the National University Hospital emphasizes that completely eliminating tobacco use is the only effective way to safeguard non-smokers from the dangers of both second-hand and third-hand smoke exposures.

Proactive Measures and Early Detection

Looking to take control of your health? Detecting lung cancer early can drastically improve survival rates. The low-dose computerized tomography (LDCT) scan is a quick and effective screening tool to catch lung cancer in its initial stages. Early detection enhances treatment outcomes significantly, with studies indicating a 63% five-year survival rate for early-diagnosed patients.

If you fall into a high-risk category due to familial lung cancer history or increased exposure to relevant carcinogens, consider participating in screening programs like the 365 Cancer Prevention Society's "Are You At Risk?" campaign for free scans.

Lung cancer in non-smokers is a reality we can no longer ignore. Stay informed, remain vigilant, and take proactive steps to protect yourself and your loved ones from this hidden threat.