As per the World Health Organization (WHO), approximately two million deaths occurred in 2020 due to lung cancer, responsible for the highest number of cancer-related deaths in that year. In India, a high prevalence of lung cancer has been reported and the disease has accounted for 5.9% of all cancer cases and 8.1% of all cancer-associated deaths.
The word ‘lung cancer’ immediately creates visuals of smoking in our minds. Indeed, tobacco smoke (active and passive/second-hand smoke) is the biggest cause of lung cancer (70%) cases. Other causes include excessive exposure to industrial fumes, chemicals, and air pollutants and genetic and familial history. Such etiological agents cause an uncontrolled and uncoordinated proliferation of modified cells leading to the formation of a malignant neoplasm or tumor in the pulmonary (lung) tissues which is referred to as lung cancer.
A recent study conducted on >70,000 individuals has also demonstrated a positive correlation between vitamin B consumption and an increased risk of lung cancer. The study findings have been published in the Journal of Clinical Oncology and showed that 10-year usage of vitamin B6 and B12 from individual supplements, but not from multivitamins was associated with 30% to 40% increases in the risk of lung cancer among male smokers aged 50 to 70 years residing in Washington.
On the other hand, supplemental folate, vitamins B6, and B12 were not associated with lung cancer risk among women. Most of the individuals exceeded recommended dietary allowances (RDA) for each B vitamin which led to deoxyribonucleic acid (DNA) methylation of several genes that could be reactivated or deregulated during carcinogenesis (the process of cancer formation).
Cancer Research has revealed that prompt diagnosis and timely treatment could improve the likelihood of lung cancer patients. Therefore, it is important to identify the signs and symptoms of lung cancer at the earliest.
Symptoms of Lung Cancer
Persistent cough lasting beyond three weeks and getting worse with time should be considered a red flag for lung cancer. Likewise, unexplainable breathlessness and recurrent chest infections could also indicate lung cancer development. A few patients may exhibit blood in their cough (hemoptysis) and wheezing (chest crackles) and/or hoarseness of voice while talking.
Other symptoms of lung cancer may include:
- Difficulty or pain in swallowing
- Finger clubbing
- Shoulder and/or chest pain
- Face or neck swelling
- Loss of appetite
- Unexplained weight loss
- Back pain
- Bone pain
- Enlarged lymph nodes (lymphadenopathy)
It has been reported that persistent cough, hemoptysis, wheezing, back pain, bone pain, fatigue and unexplained weight loss were substantially associated with lung cancer six months prior to the diagnosis, of which, all symptoms except weight loss were also significantly associated with cases one year before the diagnosis.
Other signs and symptoms significantly associated with lung cancer cases closer to the diagnosis data include chest pain and shortness of breath (three months before diagnosis), finger clubbing and lymphadenopathy (one month before diagnosis).
In the majority of the cases, lung cancer symptoms are not prominent enough in the initial stages thereby hampering or delaying timely diagnosis as in the initial stage, lung cancer could only present as flu or cold until it begins to worsen over time.
Furthermore, cough could also be a presenting symptom of coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); therefore; appropriate testing and accurate diagnosis are important.