Treatment of oncological diseases is not the same for everyone. There are hundreds of different types of malignant tumors and their locations in the human body and they require different treatments and their combinations. Curative treatment is one after which a patient is cured, palliative treatment is used to eliminate and alleviate accompanying symptoms and improve the quality of life of terminal patients in advanced stages of the disease.
Treatment process is always individual. Decisive factors with an impact on decision-making include localization of tumor in terms of organs, its size, histological type, grade of aggression or overall health and performance of the patient. A group of specialists (for example radiologist, surgeon, radiotherapist, chemotherapist, histopathologist and other specialists as needed) decides the most suitable treatment or most optimal combination of treatment methods as well as their succession in time. This kind of approach is called multidisciplinary.
Treatment options used in oncology are divided into systemic treatment, radiation and surgical treatment. Systemic treatment of cancer is administered either orally, most often in the form of tablets, or parenterally – intravenously, intramuscularly or subcutaneously. Radiation therapy uses radiation administered most frequently from the outside by exposing a part of the body to radiation. However, emmiters can be also inserted within a specific organ in order to expose the area to radiation from the inside. Surgical treatment still belongs to the basic treatment options used in oncology.
Chemotherapy
is a systemic tumor treatment by medicaments (so-called cytotoxic drugs) which are intended to eliminate tumor cells. Other healthy cells and tissues are temporarily damaged as well, mainly rapidly dividing cells such as bone marrow, digestive tract and mucosa cells. However, these cells regenerate and survive between treatment cycles, which is why the majority of adverse effects is only temporary, but the tumor cells die on a large scale. This also causes adverse effects of chemotherapy, including drop in white and red blood cell count, drop in platelet count, nausea, vomiting, diarrhea or losing hair. Risk of infection complications increases due to the drop in blood cell counts and mucosa damage by chemotherapy. Drop in platelet count increases bleeding tendency. Besides physical changes, the majority of patients experience a certain degree of emotional changes. This is caused directly by the chemotherapy and its impact on the mood and hormone levels but also indirectly due to fatigue.
Cytotoxic drugs are most often administered in the form of injections, infusions or tablets, either in outpatient or inpatient care. Treatment can be administered during hospital stay or in an outpatient clinic. Some medicaments are administered into body cavities in order to act in a specific area (locally), for example in case of treatment of superficial bladder tumors. The frequency of administration also varies. Some medicaments are administered daily, others once a week or once per two or three weeks, or once a month. This depends on the type of the tumor and the medicament.
Hormone therapy
is used only in case of tumors whose growth depends on hormone levels in the body. These include some types of breast cancer in females and prostate cancer in males. The treatment is intended to either reduce the hormone level in the body or administer a medicament to attenuate the effect of the hormone on tumor growth. Hormone therapy can also be used to prevent breast cancer in women at higher risk of this disease.
Side effects of hormone therapy depend heavily on the specific medicament. Flushes, night sweats and vaginal mucosa dryness are frequent adverse effects of hormone therapy in women. Hormone therapy also impairs menstrual cycle in women before menopause. Men can experience headaches, nausea, vomiting, skin rash, impotence and reduced sex drive. Hormone therapy is administered long-term and during the whole time of effect in case of advanced metastatic disease.
Targeted treatment
is a new modern treatment method for various types of tumors. Targeted treatment is a form of treatment which affects specific molecules essential for the growth and spread of tumor and does not affect all rapidly growing cells, as is the case with chemotherapy. It has been created basically as a result of our growing awareness of processes taking place in the creation and spreading of tumors. On the surface and inside cells are molecules, so-called receptors, which act as a “lock” into which a substance (so-called ligand) fits like a “key”. The substance is meant to signal something to the cell via this key. Turning the “key” thus initiates a signaling pathway.
Biological drugs can act through these receptors or their signaling molecules (ligands) and prevent the tumor cell from growing or trigger processes leading to its death. Since the majority of targeted medications are biological drugs, targeted therapy is sometimes called biological therapy. Biological therapy is sometimes combined with cytostatic therapy in one medicament. In case of biological therapy, the active substance is of biological nature – a product of a living organism or substance taken directly from a living organism (various toxins, antitoxins, serums, plant or animal tissues). Biological sources of medicaments are microorganisms, human cells and animal cells. Some biological medicaments mimic proteins created naturally by the human body. This concerns mainly growth factors which regulate the formation of blood cells. Other types of biological therapy are modified in a laboratory in order to improve their effectiveness and absorptivity.
Targeted therapy focuses on specific targets and adverse events can be derived from the existence of these targets in healthy cells as well. It is necessary to recognize these specific adverse effects (for example high blood pressure, diarrhea, mucosa inflammations, allergic reactions) and ideally manage them early on.
Immunotherapy
It is an innovative process in cancer therapy and two researchers who studied the processes which can be affected in anti-cancer treatment were awarded the Nobel Prize in Physiology or Medicine in 2018. Immune processes are very precisely regulated actions and regulation impairment can lead either to an immune overreaction against the body’s own cells, which happens in case of autoimmune diseases, or to a weakened (insufficient) reaction, which is often present in case of cancer diseases. This knowledge led to the development of a new type of immunotherapy which works with the principle of unblocking the immune system brakes and thus allowing it to function.
At the moment, new immunotherapeutic drugs are in trials for many cancers and their effectiveness has already been proven in case of skin cancer (malignant melanoma), lung cancer, bladder, kidney, breast, head and neck cancer and lymphomas. Immunotherapy works better with certain types of tumors and there has been new intense research of factors which could help predict which patient will benefit from the therapy the most.
Since modern immunotherapy unblocks a blocked immune reaction, it comes with typical adverse effects related to autoimmune action (for example diarrhea, skin reactions, immune inflammations of organs such as the liver, the pituitary gland etc.). Similarly to chemotherapy or targeted biological therapy, it is necessary to recognize the adverse effects and treat them early on if they occur.
Surgical treatment
It is one of the basic treatment methods. It is one of the oldest and most effective ways to treat cancer patients. In case of the majority of oncological diseases, surgical treatment is the fundamental modality of therapy able to potentially cure the patient – based on the scale and character of the disease. Tumor is completely removed with a certain part of the surrounding healthy tissue.
There are two types of treatment in surgical oncology – curative treatment, whose goal is to cure the patient, and palliative treatment, which is used to alleviate accompanying symptoms and improve the quality of life of the patient. Besides the primary disease proper, surgical treatment can also aim to remove metastases (resection) and can be combined with radiotherapy or systemic oncological treatment even during the surgery itself in order to act locally.
Radiotherapy (radiation)
is local tumor treatment using radioactive radiation in order to kill tumor cells. Radiotherapy is most often performed individually or in combination with chemotherapy and targeted biological therapy. Radiation acts in a targeted manner particularly in the area where the tumor is located and as little as possible in the surrounding healthy tissues.
Approximately 60% of cancer patients undergo radiation therapy in the course of their disease. Radiotherapy is used especially when a tumor cannot be completely removed or if it suspected that some tumor cells could have been left in the surgery area. It is intended to reduce the risk of creation of another tumor (recurrence).
The treatment can be administered during hospital stay or in outpatient settings. The advantage of radiotherapy is that in some cases, it allows to keep the affected organ and eliminate the tumor. The intensity and frequency of radiation is determined by radiation oncologist based on several factors (stage and type of tumor, size, sensitivity, location, patient’s age and health condition).
One dose of radiation only lasts several seconds or minutes. The patient doesn't feel anything. Patients usually undergo radiation 5 times per week in the course of several weeks (1 – 6 weeks), but in some cases they can be treated only with one dose (e.g. in case of painful bone metastases). Patient treated by radiotherapy does not have to avoid contact with children or pregnant women. The radiation itself is invisible and people do not feel it. Doses are directed to a specific location and can act only for a precise period of time, which reduces the risk of damage to the surrounding healthy tissue. Radiotherapy does affect healthy cells in our body as well, however, these cells, unlike tumor cells, are able to regenerate.
Even if the treatment is precisely targeted to a specific tumor and solicitously planned, some adverse reactions can occur. Patients might experience listlessness, light fatigue, insomnia, loss of appetite, nausea. However, these global reactions to radiation are only temporary and usually wear off on their own several weeks after the therapy with no consequences. Other local adverse effects can occur at the site of exposure. The development and intensity of these symptoms depend on tumor location, manner of radiation and mental condition of the patient.
Radiotherapy uses two basic types of radiation. External radiation by external beam, where the source of radiation is located outside the patient's body. The instrument is aimed at a precisely determined site in the body and emits a dose of radiation. Internal radiation (brachytherapy), where the source of radiation is inserted directly into the patient’s body (into the tumor or in its immediate vicinity).
Some treatment-related concepts used in oncology:
Adjuvant therapy
could be called “securing” therapy. It is administered when a tumor has been removed surgically but there is a suspicion that tumor cells can still be present in the body. At the moment, we cannot detect some such cells sensitively enough and so we cannot be sure if they are present or not. Adjuvant therapy is most often administered in the form of systemic therapy (chemotherapy, hormonal therapy, biological therapy), but also radiation therapy or a combination of systemic therapy and radiation. The goal of adjuvant therapy is to decrease the risk of recurrence (elimination of the microscopic disease) and prolong life.
Neoadjuvant therapy is a therapy most often administered before surgery in order to reduce the tumor size and allow its complete removal or to be able to remove a smaller part of a healthy organ. For example, in case of breast cancer, a part of mammary gland can be preserved if a tumor shrinks. Since this therapy is most often systemic, it also reduces the risk of tumor spreading to remote parts of the body, which is called a metastasis.