Cancer is a neoplasm of a malignant nature that can affect any organ of the human body.
What causes cancer?
The causes of cancer are not always fully understood, and the causes of some varieties of this disease are completely unknown. It is not clear why one person gets cancer, and another does not.
But in some cases, doctors and scientists understand what caused cancer. For example, smoking is the main cause of lung cancer, and the sunlight is the main cause of skin cancer.
However, although the causes of many types of cancer are not clear, there are many risk factors associated with cancer. A risk factor is exposure or influence that increases the likelihood of developing cancer.
The main risk factors for cancer in the world are tobacco use, alcohol consumption, unhealthy diet and lack of physical activity; they also represent the four main common risk factors for other noncommunicable diseases.
Some chronic infections are risk factors for cancer, especially in low- and middle-income countries. Carcinogenic infections, including Helicobacter pylori, human papillomavirus (HPV), hepatitis B virus, hepatitis C virus and Epstein-Barr virus, were identified as the cause of approximately 15% of cancer cases diagnosed in 2012.
Hepatitis B and C virus and some types of HPV increase the risk of liver and cervical cancer, respectively. HIV infection significantly increases the risk of developing cancer, such as cervical cancer.
What are the symptoms of cancer?
Cancer can have many different symptoms. Some varieties of this disease are asymptomatic, while in others only many symptoms appear after the cancer has begun to develop and become dangerous. Cancer symptoms can look and manifest in the body in very different ways.
General change in well-being:
- Fever, chills, night sweats;
- Unexpected weight change;
- Constant pain;
- General feeling that a person is sick, or a constant feeling of ill health;
- Persistent muscle or joint pain;
- Constant feeling of tiredness or fatigue;
- Difficulty sleeping.
Changes in the skin:
- Swelling under the skin;
- Changes in moles or skin color, the appearance of sores;
- Bleeding or frequent bruising.
Changes related to breathing, nutrition and digestion:
- Loss of appetite;
- Changes in bowel or bladder function;
- Persistent cough or shortness of breath;
- Hard to swallow;
- Persistent indigestion or discomfort after eating;
- Constant diarrhea, or constipation, or blood in the stool.
If you observe any of these symptoms or other symptoms that cause you anxiety, consult your doctor!
For diagnostic purposes, the patient should seek the advice and conduct of the necessary medical research from an oncologist. For diagnostic purposes, they use the methods of ultrasound diagnostics, radiography, computed tomography, magnetic resonance imaging, fibroscopy, biopsy. The tactics and methods of research and treatment are determined by the attending physician individually for each patient.
Types of cancer
Malignant neoplasms are classified according to various criteria, one of which is the localization of the primary tumor. In this regard, cancer of a specific organ in which the tumor is diagnosed is isolated, for example:
- kidney cancer;
- bladder/gall bladder cancer;
- esophageal carcinoma;
- thyroid cancer;
- blood cancer (leukemia);
- liver cancer;
- throat cancer and so on.
The prevalence of each of the diseases varies significantly depending on the country, gender, age. In men, the structure of the incidence of cancer (in%) is as follows:
- lung cancer – 25.2%;
- stomach – 14.1%;
- skin – melanoma, Kaposi’s sarcoma – 7.9%;
- prostates – 6.1%;
- rectum – 4.9%.
In women, the prevalence is completely different:
- breast cancer – 18.2%;
- skin – 12.9%;
- cervix uteri – 9.9%;
- intestines – 5.2%;
- ovary – 1.8%.
Such types of cancer are much less common:
- lymphoid tissue disease – lymphogranulomatosis.
In the treatment of a cancerous tumor, combinations of various methods are used, which allows to achieve the highest possible efficiency and increase the median survival of patients. Surgery is the leading treatment for the vast majority of malignant neoplasms. Its volume is determined by the stage of cancer. In some cases, not only complete/partial removal of the tumor with surrounding tissues or metastases is performed, but complete removal of the organ (uterus, ovaries, mammary gland). Such operations, despite the violation/exclusion of certain functions in the body, are the most effective. Often, they can be the only way to save lives.
In the advanced stages of cancer (or early in inoperable patients), radiation therapy is widely used in the treatment of oncology. It can either be preceded by surgery or be carried out after it, it can also be used in combination with chemotherapy and surgery. Modern methods of radiotherapy are SBRT, IGRT, IMRT, TomoTherapy HD system, proton radiation therapy. They allow specialists to effectively influence any neoplasm in all parts of the body with:
- high precision;
- various dose loads;
- the possibility of simultaneous irradiation of several or extended targets without changing the position of the patient.
There is another leading method of treating cancer, especially in patients with an unresectable stage (it is technically impossible to remove the formation). This is chemotherapy, used both as monotherapy and in combination with radiation therapy. In practice, a wide range of cytostatics is used, including preparations based on platinum with a relatively low toxic effect and good tolerance. The choice of the optimal chemotherapy regimen for cancer and specific drugs is carried out taking into account the general condition of the patient. Specialists evaluate the functional reserves of his/her body and the cytotoxic effect of the drugs.
Modern approaches to chemotherapy in oncology also include the use of “targeted” drugs (Tarceva, Bevacizumab, Neovastat, Beksarotin, Trastuzumab, etc.). They act selectively on certain targets, the expression of which helps to stabilize the tumor process. The basis of their mechanism of action is a cytostatic effect that contributes to the inhibition of tumor growth.
There are also other treatment methods:
- hormone therapy (for cancer of the reproductive system);
- immunotherapy, based on the introduction into the body of biologically active drugs with antitumor activity (monoclonal antibodies, T-helpers, cytokines, TIL cells).
Given the level of modern knowledge, including the main risk factors for cancer, a significant part of cancer can be prevented. This requires high alertness regarding cancer.
Cancer prevention should be carried out at various levels:
- minimizing the effects of carcinogenic factors – smoking, adverse environmental factors (work/living in a potentially dangerous area, contact with carcinogens);
- normalization of lifestyle – the fight against obesity, abuse of alcohol-containing drinks, physical inactivity, unhealthy diets, avoiding stress;
- competent contraception;
- timely treatment of precancerous diseases;
- limitation of exposure to sunlight;
- regular examination of various organs and systems of the body.
In fact, cancer prevention is about maintaining a healthy lifestyle. A balanced rational diet with a high content of natural products is equally important for oncology. Fat and fried foods, trans fats, fast food, sweets, foods containing food additives (colorants, flavor enhancers, preservatives, nitrates) are subject to restrictions.
The role of medical institutions in the secondary prevention of oncology is no less important. They provide increased public awareness of oncology, quality control of risk groups, diagnosis and timely treatment of benign tumors and precancerous conditions.
Given the particular importance of detecting cancer in the early stages, you should immediately consult an oncologist if you notice any negative symptoms associated with malignant diseases. Timely treatment is the key to effective cancer treatment.