LUNG CANCER PART-2
(All the articles published in past are available at www.shyamhemoncclinic.com/blog/)
Question: Thank you Chiragbhai for explaining role of tobacco as etiology of lung cancer, and other factors like pollution, role of diet. Importance of avoiding passive smoking, especially in children, role of measures to quit or reduce tobacco, and impact of quitting tobacco.
You have nicely covered cancer prevention in your book also, titled “Cancer Can Be Cured” or in Gujarati “Cancer Mati Shake Che”. Now, can you tell us why most patients are diagnosed so late, resulting in about 80-90% mortality rate overall for lung cancers. And how to make early diagnosis?
Ans: Thank you. Yes lung cancer is one of the deadliest cancers. Symptoms are often vague initially, resulting in late diagnosis. Also, culturally, and probably due to economic reasons, most Indians avoid tests like chest x ray or CT scan. There is also a big overlap of symptoms of lung cancer and Tuberculosis. This results in false diagnosis of tuberculosis based on symptoms and chest xray. Patients are then treated empirically for tuberculosis, without confirmation of diagnosis, and lung cancer diagnosis is made after few months when there is obvious progression. In fact, after seeing so many such patients with misdiagnosis of tuberculosis, me and my colleagues did a symposium on this specific subject, several years ago.
Most common symptoms of lung cancer are cough, lack of appetite, weight loss, low grade fever, hemoptysis. These are essentially the symptoms of tuberculosis as well. On top of this, chest x ray can also have many overlapping features, especially hilar mass/lymphadenopathy, pleural effusion. A simple effort to establish firm diagnosis will differentiate both of these diseases. This includes a CT scan of chest, followed by bronchoscopy OR CT scan guided FNAC or biopsy OR pleural effusion cytology. This small effort can save one life, and also save a lot of concerns for both patient and doctor, by making early diagnosis.
Few patients present with more typical features, like chest pain, signs of SVC (superior vena cava) syndrome, bone pain due to metastases, hoarseness of voice (due to recurrent laryngeal nerve involvement)…chest xray showing obvious mass or invasion of spine/rib…Ocassional patients present with paraneoplastic syndrome. Later means symptoms not directly due to tumor, but indirectly due to release of chemicals/cytokines. Commonest are hypercalcemia, hypertrophic pulmonary osteoarthropathy (clubbing), hyponatremia, cushing syndrome, cerebellar degeneration…
It is important to remember that a new cough or above noted symptoms lasting for over 3-4 weeks, must include a simple chest xray in evaluation. It is so common to find such patients undergoing several forms of treatment, including various home remedies/allpathy medicines etc for many months, without a chest xray or sometimes even without any blood tests. Patients and doctors both need to have low threshold for basic screening type of tests for symptoms lasting over 3-4 weeks, for early diagnosis of most cancers, and even other serious illnesses.
Que: What are the common types of lung cancer?
Ans: Once lung cancer is suspected, it needs a biopsy or cytology to confirm diagnosis. In most cases, a larger biopsy should be performed, such as Trucut, rather than FNAC (fine needle aspiration cytology). FNAC was sufficient earlier, but nowadays, it is important to have more tissue for several advance tests. These tests are important in deciding what type of therapy to choose.
Sometimes, bronchoscopy or CT guided biopsy both are not feasible, for example, with some centrally located tumors or with peripherally located/pleural based nodules. Additional methods helpful to obtain biopsy in such cases include TBNA (transbronchial needle aspiration/biopsy), EBUS (endobronchial ultrasound guided biopsy), VATS (video assisted thoracic surgery), mediastinoscopy.
Commonest histology used to be squamous cell or small cell. However, now adenocarcinoma is most common, followed by squamous cell, and even less is small cell, large cell varieties. Small cell and non-small cell are the two broad varieties. Later includes everything except small cell cancer. Reasons for this changing pattern in histology is not clear, but probably related to changes in smoking pattern.
Once the type is established, nowadays a number of tests are frequently done from biopsy to establish molecular pattern of the tumor. Some of these tests are very useful in determination of treatment options, such as EGFR, ALK, ROS1…the list is getting longer day by day.
Second most important step is staging. PET-CT is preferred in general. However, a CT scan of chest, abdomen and bone scan is also alternative. MRI brain is also recommended, in advance cases.
April 15th 2016.
Dr. Chirag A. Shah; M.D. Oncology/Hematology (USA), 079 26754001. Diplomate American Board of Oncology and Hematology. Ahmedabad. email@example.com Shyam Hem-Onc Clinic. 402 Galaxy, Near Shivranjani, Opp Jhansi ki Rani BRTS, Ahmedabad. www.shyamhemoncclinic.com