What is lung cancer?

Lung cancer, over the years has evolved rapidly and is one of the commonest cancer affecting both men and women. Men have a slightly higher rate of incidence. The increased intake of illegal drugs, cigarette smoking and air pollution are some of the most common causes of this disease. It is a tumor that starts in cells of the lung and can spread to the other parts of the body.

The most common are of two main types
1. Non-small cell lung cancer (NSCLC). These are further of main 02 types.
The one that starts in glandular cells on the outer part of the lung is called adenocarcinoma. The other main type (other types exist too) can start within the flat, thin airways lining cells called squamous cells and this type of cancer is called squamous cell carcinoma of the lung. Squamous cell carcinoma can start in central areas of the lung and airways.

2. Small Cell Lung Cancer (SSLC)
It starts in cells that line the bronchi in the central airways so is usually more centrally located in the lung.

Non-Small Cell Lung Cancer is the most common one and approximately 85% of people who are diagnosed with lung cancer have this type. SCLC affects about 10-15% of patients with lung cancer.

Cancer of the lung might begin in an unsuspecting individual, usually with one or more risk factors and spread to destroy the lung tissue causing difficulty in breathing/ breathlessness/ blood while coughing.

Symptoms of Lung Cancer

Symptoms of lung cancer are similar to that of tuberculosis, but there are some fine line of differences between them.

  • A coughing problem that persists for more than two to three weeks.
  • Persistent pain in the chest.
  • Experiencing shortness of breath
  • Coughing out blood
  • Unexpected loss of weight
  • Headaches that last long maybe cancer spread to brain
  • Loss of memory maybe an early sign of metastasis (spread) to brain.

Lung Cancer Diagnosis

Imaging Tests –MRI, CT or PET scan helps in detecting the presence of abnormal masses in the lungs.
Sputum Cytology –It helps to examine the people who spit mucus when cough. This mucus when examined under a microscope can help detect cancer cells which maybe thrown out.
Biopsy –Biopsy or FNAC (fine needle aspiration cytology sample obtained at Bronchoscopy, Mediastinoscopy etc) and further examination of these under a microscope by a pathologist help to diagnose the cancer. A fine needle aspiration biopsy is done by a pathologist of a peripheral lesion but bronchoscopy/ thoracoscopy and other procedures are done by a pulmonologist who would further submit the sample to a pathologist. There should be immediate dispatch of these samples to the pathologist or else these deteriorate once outside the human body and cannot be appropriately assessed by a pathologist. The final diagnosis of cancer is given by a pathologist.
While imaging tests are done by Radiology centers; FNAC (fine needle aspiration cytology), biopsy or tissue diagnosis of tissue sampled at bronchoscopy, cytology of a bronchoalveolar lavage sample are done by all the major pathology labs.

Lung Cancer Treatment

It depends on the type of lung cancer detected. The pathologist, with his or her expertise and knowledge shall type the cancer as small cell type or non small cell type and possibly into certain other more well defined types. Depending upon the pathologist’s report, the oncologist (he is an MD in medicine and further specialised in cancer medical treatment) will decide on the treatment. Small cell cancer responds to chemotherapy better than radiotherapy and squamous cell carcinoma (non small cell type) does better with radiotherapy. Some decisions maybe required depending on the size of the cancer. If small and resectable, the oncologist may further refer to an oncosurgeon (he is an MS in surgery and further specialized in cancer surgery) for resection of the tumor. This resected tumor should again be sent to the pathologist for assessment and a diagnosis. This sample would be larger and help a better assessment of the type and grade of the tumor, whether margins of tissue resected are clear of the tumor. If any lymph nodes have been removed as well by the surgeon, a pathologist would be able to tell whether these are involved by the tumor. Today there are much better targeted therapies available for lung cancers. The most important fact is their early detected and correct diagnosis.

American Cancer society has now laid down screening protocols by low dose CT scans in high risk patients. Please check www.amulyalabs.com for these.