Context
Studies show blood-based tests for cancer screening could save lives.
About Cancer
- Group of diseases where abnormal cells grow uncontrollably, potentially invading other body parts.
- Also known as malignant tumours or neoplasms.
- 2nd leading cause of death in India
- Naming: Named after their origin, even if they spread elsewhere.
- Types of Cancer
- Carcinomas: Start in the skin or internal organ linings, forming solid tumours. Common examples include prostate, breast, lung, and colorectal cancers.
- Sarcomas: Develop in connective tissues like fat, muscles, and bones.
- Leukaemia: Cancer of the blood, where abnormal blood cells grow uncontrollably.
- Lymphomas: Begin in the lymphatic system, with two main types: Hodgkin and non-Hodgkin lymphoma.
- Other Types: Include cancers affecting the central nervous system and others outside the main categories.
- Causes of Cancer
- Multi-Stage Process: Develops from normal cells through stages, ending in a malignant tumour.
- Genetic and External Factors: Includes genetic factors and external agents like physical, chemical, and biological carcinogens.
- Risk Factors: Tobacco use, alcohol, poor diet, physical inactivity, and air pollution increase cancer risk.
- Cancer Treatment: Typically includes surgery, radiotherapy, and systemic therapy (like chemotherapy or targeted therapies).
About Blood-Based Cancer Screening
- Used to detect cancer signals in the blood, offering a less invasive screening method.
- Multi-Cancer Early Detection (MCED) Tests:
- Identifies specific biomarkers such as circulating tumour DNA (ctDNA) or circulating tumour cells (CTCs).
- Capable of identifying up to 50 different types of cancers, including those without reliable early screening methods.
- Current Challenges
- Not yet fully approved by regulatory bodies like the FDA; they are offered as Laboratory-Developed Tests (LDTs).
- Expensive, with prices up to ₹15,000 per test in India.
- Risk of false positives, though it can be mitigated by combining MCED tests with traditional screening methods.
Source:
TH
Previous Year Question
With reference to the treatment of cancerous tumours, a tool called cyberknife has been making the news. In this context, which one of the following statements is not correct?
[UPSC Civil Services Exam – 2010 Prelims]
(a) It is a robotic image guided system
(b) It delivers an extremely precise dose of radiation
(c) It has the capability of achieving sub-millimetre accuracy
(d) It can map the spread of tumour in the body
Answer: (d)
