Lung cancer involves the uncontrolled growth of abnormal cells that form tumors within the lung tissues. While this disease is overwhelmingly associated with older adults due to long-term tobacco use, children can also develop malignant tumors in their lungs. The condition in children is profoundly uncommon, but it presents with different characteristics and causes compared to the disease seen in adults. Understanding this rare diagnosis requires focusing on the unique genetic and environmental factors that affect a developing body.
The Rarity of Pediatric Lung Cancer
Primary lung cancer is an exceptionally rare diagnosis in children, with an estimated incidence of about one case per two million children. This condition accounts for only a fraction of a percent of all childhood cancers, with leukemia and brain tumors being significantly more common malignancies in this age group. The types of lung tumors found in children are fundamentally distinct from the non-small cell lung cancer (NSCLC) often linked to smoking in adults. Pediatric lung cancers frequently include tumor types like carcinoid tumors, pleuropulmonary blastoma, and mucoepidermoid carcinoma. Carcinoid tumors, for instance, arise from the neuroendocrine cells in the lungs and represent a large percentage of primary lung cancers diagnosed in adolescents. These specific tumors exhibit different growth patterns and respond to different treatments than the types commonly found in adults.
Genetic Predispositions and Underlying Conditions
When lung cancer appears in a child, the cause is often rooted in internal, inherited factors rather than the environmental exposures typical of adult cases. Specific genetic mutations can make a child highly susceptible to the development of early-onset tumors, including those in the lungs.
One example is the DICER1 syndrome, which is associated with a significantly increased risk of pleuropulmonary blastoma, a rare and aggressive malignant lung tumor seen in infants and young children. Other inherited conditions, such as Li-Fraumeni syndrome, caused by mutations in the TP53 tumor-suppressor gene, also raise the lifetime risk for numerous cancers, including lung adenocarcinoma. Some pediatric lung tumors are linked to an ALK gene rearrangement, a molecular change that causes cells to divide rapidly. These genetic changes are often present at birth, predisposing the child to tumor development.
A child’s previous medical history can also create a long-term risk for secondary lung malignancies. Survivors of other childhood cancers who received high-dose chemotherapy or radiation therapy to the chest area may face an elevated risk later in life. The cellular damage caused by these treatments can sometimes induce new mutations that lead to a second cancer years after the initial therapy is completed. This risk highlights the need for long-term surveillance in pediatric cancer survivors.
Environmental Exposures and Acquired Risks
While genetic factors play a large part in rare primary tumors, external exposures encountered during childhood are the most common acquired risk factors for lung injury and subsequent cancer. The most significant and preventable environmental risk is exposure to secondhand smoke, which contains over 7,000 chemicals, including dozens of known carcinogens. Because children breathe faster and have developing respiratory systems, they inhale a greater volume of air relative to their body weight, making them particularly vulnerable to these toxins.
Exposure to environmental tobacco smoke is directly linked to an increased risk of respiratory illnesses, which can contribute to chronic lung inflammation and damage over time. Parents and caregivers should ensure that children are never exposed to smoking indoors or in enclosed spaces like vehicles to minimize this hazard. Another environmental factor is radon, a colorless, odorless radioactive gas that naturally seeps into homes from the soil and is the second-leading cause of lung cancer overall. Testing homes for radon and mitigating high levels is an actionable step families can take to reduce this specific risk.
Chronic exposure to outdoor air pollution, specifically fine particulate matter known as PM2.5, is also a recognized risk factor. These microscopic particles penetrate deep into the lungs and can cause long-term cellular damage. Children living near busy roadways or industrial zones may have a slightly elevated risk due to this prolonged inhalation of airborne pollutants. Minimizing a child’s exposure to these external pulmonary irritants is an important preventative focus for overall lung health.
Recognizing Signs and Symptoms
The signs of lung cancer in children are often non-specific and easily mistaken for common pediatric respiratory illnesses, such as asthma or persistent infections. This overlap makes early detection challenging for both parents and healthcare providers. A persistent cough that does not resolve with standard treatments or a cough that changes in character and worsens over time is a symptom that warrants further investigation.
Children may also experience unexplained shortness of breath, wheezing, or recurrent bouts of pneumonia or bronchitis that seem resistant to antibiotics. Other generalized symptoms include chest pain, hoarseness, unexplained weight loss, or fatigue. If a child presents with a combination of these symptoms that persist for a long period, caregivers should consult a pediatrician for a deeper medical evaluation.