Answer: Staging describes cancer extent: Stage I (localized, small), Stage II (locally advanced), Stage III (regional lymph node involvement), Stage IV (metastatic/distant spread); determines prognosis and guides treatment choice.
- A All diagnosed cancers are considered clinically equivalent and are managed using identical protocols regardless of their assigned stage, with a Stage I tumour treated exactly the same way as a Stage IV metastatic tumour
- B Staging describes cancer extent: Stage I (localized, small), Stage II (locally advanced), Stage III (regional lymph node involvement), Stage IV (metastatic/distant spread); determines prognosis and guides treatment choice
- C Cancer staging protocols are understood by some oncologists to be applicable mainly to lung cancer cases, and are rarely used by clinicians to guide treatment decisions for breast, colon, or skin cancers
- D Cancers that are formally classified as Stage IV are usually considered by clinicians to be readily and largely curable, with metastatic spread to distant organs posing no real challenge to successful treatment
Correct answer: B. Staging describes cancer extent: Stage I (localized, small), Stage II (locally advanced), Stage III (regional lymph node involvement), Stage IV (metastatic/distant spread); determines prognosis and guides treatment choice
Explanation: Cancer staging (TNM system: Tumour size, Node involvement, Metastasis): Stage I - small, localized, best prognosis, often curative; Stage II - larger, still localized; Stage III - regional lymph nodes involved; Stage IV - distant metastases, worst prognosis. Staging guides treatment intensity and predicts survival probability. Early detection (Stage I) dramatically improves outcomes.
The Plasmodium parasite needs both hosts: the female Anopheles mosquito injects sporozoites while biting (infecting the human liver and RBCs, causing the malaria fever cycle), then picks up gametocytes from an infected person's blood, completing the parasite's sexual stage inside the mosquito.
Concept context
Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.