Malignant tumor / Cancer

Malignant tumor (cancer) is the most common type of malignant neoplasm; those arising from mesenchymal tissue are collectively called sarcomas, with a few exceptions such as nephroblastoma and malignant teratoma. In common usage "cancer" generally refers to all malignant tumors. A tumor is a new growth formed when local tissue cells lose normal genetic control of growth under oncogenic stimuli, resulting in abnormal proliferation and differentiation; once formed it does not stop growing when the cause is removed, and grows beyond normal physiological regulation, destroying normal tissues and organs — especially in malignancies. Compared with benign tumors, malignancies grow rapidly, are invasive, prone to bleeding, necrosis and ulceration, and often metastasize distally, causing weight loss, weakness, anemia, poor appetite, fever and severe organ dysfunction, eventually leading to death. Clinical manifestations vary by organ, site and stage; early malignancies are often asymptomatic or non-specific, and by the time characteristic symptoms appear the tumor is often already advanced. Manifestations are generally divided into local findings and systemic symptoms.

Common Symptoms

Loss of appetite; progressive weight loss; increased mitotic figures; dysphagia; scaphoid abdomen; dyspepsia

Causes

1. Physical carcinogens, e.g. X-rays, ionizing radiation. 2. Chemical carcinogens, e.g. nitrosamines (commonly in pickled vegetables or leftover dishes), aflatoxin. 3. Viral carcinogens, e.g. hepatitis B virus, herpes viruses. Lifestyle does influence cancer occurrence, including smoking, diet, exercise, alcohol, sun exposure and sexually transmitted diseases. Cancer risk is also related to melatonin levels; people who spend long hours in bright environments (e.g. night-shift workers) have lower melatonin and higher cancer incidence. Most cancers are "spontaneous", but some have a genetic component, especially when inherited defective tumor-suppressor genes are present. Cancer arises from a series of gene mutations, each affecting subsequent cell behavior. Carcinogenesis is a chain process in which DNA damage causes uncontrolled cell division. Cancer is a genetic disease; when growth-regulating genes mutate or become damaged, cells lose control and continuously grow and divide to form a tumor. Cancer cells grow without external regulation — possibly via activation of previously silent proto-oncogenes — but mainly through abnormalities in proteins that control cell division. This may result from DNA mutation that damages the coding sequence, producing an abnormal translated protein. Transforming a normal cell into a malignant one requires many mutations or disruption of gene-to-protein translation. Although tumors can temporarily supply themselves by growing new vessels, rapid growth eventually pushes them to resource and space limits, at which point they spread. This progressively more aggressive growth is called progression: growth accelerates, surrounding normal tissue is invaded (cancerous infiltration), and distant metastases occur through vessels. Some patients develop cancer after receiving transplanted organs that harbored tumor.

Treatment

Surgery; drug therapy; radiotherapy; supportive care

Prevention

Do not hold urine. Studies link bladder cancer to drinking and urination habits: people who urinate 5 times daily are more prone to bladder cancer than those urinating 6+ times. Insufficient drinking and prolonged urine retention concentrate urine, prolong mucosal exposure and promote cancer. Drinking more water and urinating frequently "flushes" the bladder and removes harmful chemicals. Quit smoking. Smoking is a worldwide public health hazard. Reports from the US, UK and Canada show smokers have 10.8 times the lung cancer death rate and 5.4 times the laryngeal cancer death rate of non-smokers. A leading US cancer institute attributes 35% of carcinogenic factors to poor lifestyle and 30% to smoking — together 65%. Smoking is especially harmful to fetuses; children of smokers have a 50% higher cancer risk. Smoking is extremely dangerous at any age and causes cancer. Drink vegetable juice often. Beetroot juice (root and tops), carrot juice (with beta-carotene) and asparagus juice are recommended; a mix of fresh cabbage and carrot is excellent. Grape, cherry and all dark juices including blackcurrant are nutritious, and fresh apple juice is beneficial. Fruit juice is best in the morning; vegetable juice in the afternoon. Drink only mineral or distilled water. Eat raw radish. Interferon, a glycoprotein produced by human white blood cells, inhibits rapid cancer cell division, but endogenous interferon is limited, so scientists developed interferon inducers. Among foods, white radish is most effective; its active double-stranded RNA component has shown clear inhibitory effects on esophageal, gastric, nasopharyngeal and cervical cancer cells. Since this component is heat-labile and destroyed by cooking, eating radish raw is beneficial. Limit high-fat diet. Studies show high-fat diets greatly increase colon and breast cancer risk compared with low-fat diets; high-fat diet is a tumor growth promoter.

Recommended Department

It is recommended to visit the oncology department; before the visit you may first book an appointment and connect with experts through this platform.

Warm reminder: The above information is provided for health education reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek care at a regular hospital in time.