Cancer: Definition and Meaning of Cancer, Hallmarks of Cancer

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Definition and Meaning of Cancer

  • It can be defined as a large family of diseases that involve abnormal cell growth.

  • This cell growth is with the potential to invade or spread to other parts of the body.

  • A tumor or a neoplasm is a group of cells that have undergone unregulated growth.

    • Will often form a mass or lump.

    • May be distributed diffusely.

The Hallmarks of Cancer

  • It consists of six biological capabilities acquired during the multistep development of human tumors.

  • These include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis.

Six Hallmarks of Cancer

Six hallmarks of cancer

Six Hallmarks of Cancer

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Malignant Progression

  • It means progression from normal cells to cells that can form a detectable mass to outright cancer.

  • The multiple steps involved are known as malignant progression.

Signs and Symptoms

Local Symptoms

  • This may occur due to the mass of the tumor or its ulceration.

  • One of the examples is that of mass effects from lung cancer that can block the bronchus resulting in cough or pneumonia.

  • Masses in breasts or testicles may produce observable lumps.

  • It has been observed that some cancers can cause a build-up of fluid within the chest or abdomen.

Cancer Metastasis

Common Sites and Symptoms

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Systemic Symptoms

  • This may occur due to the body’s response to the cancer.

  • They include fatigue, unintentional weight loss, or skin changes.

  • Cachexia is a condition wherein some cancers cause a systemic inflammatory state. This leads to ongoing muscle loss and weakness.

  • Paraneoplastic syndromes are a condition wherein some systemic symptoms of cancer are caused by hormones or other molecules produced by the tumor.

Metastasis

  • Cancer can spread via the blood to distant sites.

  • It can spread from its original site by local spread, lymphatic spread to regional lymph nodes or by hematogenous spread.

Causes of Cancer

Physical Factors

This includes Ionizing radiation for e.g. X-rays and gamma rays.

Chemical Factors

For e.g. tobacco and smoke.

Biological Factors

For e.g. Viral oncogenes and proto-oncogenes.

Diagnosis of Cancer

Diagnosis of Cancer

Diagnosis of Cancer

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