Malignant Tumor (Cancer)

Malignant tumor (cancer) is the most common class of malignancy; mesenchymal-origin malignancies are called sarcomas. A few exceptions (Wilms tumor, malignant teratoma). Colloquially 'cancer' = all malignancies. A tumor is a new growth caused by gene-level loss of normal growth regulation under carcinogenic stimuli, leading to abnormal proliferation/differentiation. Once formed, it does not stop when the stimulus is removed; growth is not physiologically regulated, destroys normal tissue/organs (especially in malignancy). Compared with benign tumors: faster growth, invasive, bleeding/necrosis/ulceration, distant metastasis; causes weight loss, fatigue, anemia, anorexia, fever, organ failure, death. Clinical manifestations vary by organ/site/extent; early disease asymptomatic/non-specific; by the time characteristic symptoms appear, it is often late. Two categories: local manifestations and systemic symptoms.

Common Symptoms

Anorexia; progressive weight loss; increased mitoses; dysphagia; scaphoid abdomen; dyspepsia

Causes and Pathogenesis

(1) Physical: X-rays, ionizing radiation. (2) Chemical: nitrosamines (pickled/overnight food), aflatoxins. (3) Viral: HBV, herpesvirus. Lifestyle: tobacco, diet, exercise, alcohol, sun, STDs. Melatonin: night-shift workers (low melatonin) have higher cancer rates. Most cancers are 'spontaneous'; some genetic (tumor-suppressor mutations). Cancer = series of DNA mutations → uncontrolled cell division. Oncogene activation + cell-cycle protein abnormalities. Invasive growth + angiogenesis + metastasis (invasion/metastasis). Transplant-transmitted cancer also reported.

Treatment

Surgery, drug, radiation, supportive therapy

Preventive Measures

Don't hold urine: 5 voids/day vs >6 = higher bladder cancer risk; drink more, void frequently. Stop smoking: smokers' lung-cancer death = 10.8x non-smokers; laryngeal cancer = 5.4x; lifestyle factors = 35% of carcinogens, smoking = 30%. Maternal smoking raises child's cancer risk by 50%. Drink vegetable juices (beet/carrot/asparagus/grape/cherry/blackcurrant). Eat raw radish (induces interferon, contains ds-RNA; inhibits esophageal/gastric/nasopharyngeal/cervical cancer cells; heat-labile so eat raw). Limit high-fat diet (increases colon/breast cancer risk).

Department to Visit

It is recommended to visit the Medical Oncology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.