Lung cancer is the leading cause of death worldwide and is more common in smokers, but it is observed even in non-smokers or Never smokers(10-20%), which has a separate cohort called LCINS (lung cancer in never smokers). Never smoker means a person who smokes cigarettes <100 in his or her lifetime. Lung cancer in nerve smokers is the 7th leading cause of death worldwide. The main reason for this cohort/group is, in this group of patients with Lung cancer, ‘Symptoms are minimal’, most of them diagnosed cancer on simple health checkups. According to Dr. Ugandhar Bhattu. C, Consultant Interventional Pulmonologist, Yashoda Hospitals, Hyderabad, the main reason for less symptoms as it Involves Distal Airways, so no recurrent/non-resolving obstructive pneumonia, no blood in sputum(NO HEMOPTYSIS), and no difficulty breathing.
These patients are young when compared to lung cancer in smokers, and they are more common in females, unlike lung cancer in smokers was predominantly in males. So this group has an easy chance to miss the screening.
The genetic mutations in their group are different from smokers group, and it’s more amenable for targeted therapy. Hence lung cancer in the never smokers group needs active screening methods to detect early-stage Lung cancer for effective outcomes.
The most common types of lung cancer in these groups are:
- Adenocarcinoma (50 - 60 %),
- Squamous cell carcinoma (10-20%),
- carcinoid ,
- small cell lung cancers are rare (6-8%).
Causes
- 1. Passive smoking (Ex: housewife and children in a smoker’s house) = 15%
- 2. Occupational carcinogen -in male = 20.5%, In females = 4.3%
- 3. X Ray Radiation exposure =0.8%
- 4. Radon exposure (Radon is a decay product of uranium- 238 and radium- 226) seen in soil, rock, groundwater, and homes is 0.5%
- 5. Outdoor pollution =8%(Ex:Asbestosis)
- 6. Viral Infections (Ex: HPV-Human Papillomavirus, EBV)
- 7. Old pulmonary kochs (Ex: scar carcinoma)
- 8. Genetic Mutations
Symptoms
- Unexplained or persistent cough
- 10% Loss of weight or loss of Appetite or wheezing.
- Fever not responding to antibiotics (Ex: more common in lepidic carcinoma) this may be commonly diagnosed as Pneumonia.
- Easy fatigability, change of voice, chest Pain
- Bony pain or bone fracture with trivial injury (pathological fracture)
- Seizures ( In case of cerebral metastasis)
- Low back ache is a common complaint.
The last two symptoms are notorious in these groups representing stage IV (metastatic stage).
Also Read: Can Tobacco Cause Lung Cancer? Oncologist Explains Risk Factors
Diagnosis
- Chest X-ray PA view
- CBP (Complete Blood Picture)
- CT chest (with or without IV contrast)
- Bronchoscopic guided (+/- Radial ebus) or
- CT guided Biopsy of lesion in lungs.
- EBUS guided FNAC of Lymphodes for Staging of cancer,Restating of treated lung cancer.
- PET scan of the whole body for Staging or follow up.
- Biopsy subjected for IHC & mutations
Treatment
It depends on two things:
- Type of cancer-Adenocarcinoma, Squamous cell carcinoma
- Stage of tumour – for metastatic Chemotherapy or without metastatic surgical resection, Radiotherapy for palliative care
Targeted therapy with EGFR tyrosine kinase inhibitors:
- Erlotinib
- Gefitinib
- Afatinib
- Osimertinib
Takeaway
Lung cancer is not uncommon in non smokers so screening, active medical attention needed in symptomatic or patients with family history of cancer,which will pick up early and treat effectively otherwise Late stage presentation is common in this non smokers group.
Image credits- freepik
