Cancer Treatment

What is Cancer Treatment?

Cancer treatment is the use of surgery, radiation, medications and other therapies to treat a cancer in the body. The various treatment modalities may be used on its own or in combination.

Depending on the stage of the cancer, the aim of the treatment may be for:

• Cure.
• Control of the cancer, to stop progression.
• Management of symptoms.
• Prevention of complications to improve quality of life.

Cancer treatments may be used as^1,2:

• Primary treatment: The goal of primary treatment is cure, with complete removal of the cancer or death of all cancer cells. This is usually carried out for cancers in the early stages, before they have spread. The most common primary cancer treatment option for most types of cancers is surgery. Radiation therapy or chemotherapy may also be use as primary treatments in cancers that are particularly sensitive to them.
• Adjuvant treatment: The intent of adjuvant therapy is to kill any cancer cells that may remain in the body after primary treatment in order to reduce the chance of the cancer recurring. Common adjuvant therapies include chemotherapy, radiation therapy and hormone therapy. Sometimes these treatments may be used before the primary therapy to increase the effectiveness or ease of the primary treatment – this is known as neoadjuvant treatment.
• Palliative treatment: The aim of palliative treatment is to relieve side effects of treatment or symptoms caused by the cancer itself. Surgery, radiation therapy, chemotherapy and hormone therapy can all be used to relieve symptoms. Other medications may also be used to alleviate symptoms such as pain, nausea and shortness of breath. Palliative care may be given at any stage of your cancer treatment.

Cancer treatments can also be grouped depending on whether they have a localised or widespread (systemic) effect³:

• Local treatment: This involves treatment to a certain part of the body to remove or kill cancer cells without affecting the rest of the body. For example, surgery is used to remove a tumour and radiation therapy can be targeted to the area affected by cancer to kill or damage the cancer cells whilst sparing the rest of the body. Local treatments are typically suitable for early-stage cancers that have not spread.
• Systemic treatment: This usually involves the use of drugs such as chemotherapy that travel throughout the body via the bloodstream to destroy cancer cells that have spread beyond the original tumour to other parts of the body.

In all cases, treatment selection depends on the type of cancer, the characteristics of the tumour (e.g. size, location, type, stage) as well as the person’s overall health and preferences. It is worth noting that your treatment plan may change over time depending on the cancer and your body’s response to current treatment.

Surgery

Surgery is an effective and potentially curative way to remove cancer cells from the body if the cancer is limited to a specific area, especially during the early stages for many types of cancers.

Depending on your type of cancer and how advanced it is, surgery may be used to⁴:

• Remove the entire tumour: Surgery is performed to remove cancer that is contained in one area and may lead to cure.
• Debulk a tumour: This surgery is sometimes done when removal of the entire tumour is not possible as it would cause too much damage to nearby organs or tissues. Surgery removes some, but not all, of the tumour. This is usually followed up with other treatment such as chemotherapy or radiation therapy to treat the remaining cancer.
• Ease cancer symptoms: Surgery may be used to remove tumours that may be causing pain or pressure.

Common surgical methods used to treat cancers include⁵:

• Laparoscopy (keyhole surgery), a minimally invasive procedure.
• Robot-assisted surgery, which provides more precision.
• Open surgery, a more invasive procedure.

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Chemotherapy

Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells or stop them from growing. The drugs enter the bloodstream to affect cancer cells all over the body. An oncologist (cancer specialist) may prescribe chemotherapy for cancers of all stages. It may be given alone or in combination with radiotherapy or surgery to improve treatment outcomes. Chemotherapy plays an important role in “cleaning up” cancer remnants (micrometastases) that are too small to show up on standard imaging tests but are extremely important to eradicate.

Cancer cells tend to grow more quickly than normal cells, thus, cytotoxics are highly effective for killing cancer cells. However, they will also damage normal cells of the body which divide rapidly, causing side effects. Your doctor will work out the balance between killing the cancer cells to achieve cure or control of the cancer, and sparing the normal cells to minimise side effects. The good news is that most normal cells in your body will recover from the cytotoxic effects over time.

Cancer can be treated with a single chemotherapy drug, but often several drugs that work in different ways are used together in a certain order or in particular combinations to kill more cancer cells and also to lower the chance of the cancer developing resistance to any one drug³.

Chemotherapy is generally given in cycles:

• Each cycle consists of a treatment, rest and recovery phase.
• Each cycle usually lasts between one to four weeks (this varies depending on the type of chemotherapy you receive).
• Each course of treatment usually consists of four to six cycles.

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Radiation Therapy (Radiotherapy)

Radiation therapy or radiotherapy uses high-powered energy beams or waves, such as x-rays, gamma rays, electron beams, and protons, to destroy or damage cancer cells as well as to shrink tumours. High doses of radiation cause damage to the cancer cells’ DNA. Cancer cells with DNA that is damaged beyond repair stop dividing or die and are subsequently broken down and removed by the body⁶.

Radiation therapy does not kill cancer cells immediately. It requires repeated days or weeks of treatment before DNA is damaged enough for the cancer cells to die. They then continue to die for weeks or months after radiation therapy is completed⁶.

Radiation treatment can come from a machine outside your body (external beam radiation), or it can be placed inside your body (brachytherapy)¹. The type of radiation therapy that you may have depends on many factors, including⁶:

• The type of cancer.
• The size of the cancer.
• The location of the cancer in the body.
• Proximity of the cancer to normal tissues that are sensitive to radiation.
• Whether you will have other types of cancer treatment.
• Your age, general health and other medical conditions.

With recent medical advances, treatments such as proton beam therapy and intensity-modulated radiation therapy (IMRT) can selectively target a high dose of radiation directly onto the cancer cells⁵. The surrounding healthy tissue is exposed to a minimal amount of radiation, thereby greatly reducing unwanted ill-effects from the treatment.

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Immunotherapy

Cancer cells have the ability to ‘camouflage’ themselves in such a way that our body’s immune system is unable to detect these ‘rogue cells’ to destroy them. Immunotherapy is treatment that boosts the body’s immune system to find and destroy cancer cells. This can be done by⁷:

• Stimulating, or enhancing, the immune system’s natural defences so it works more effectively to find and attack cancer cells.
• Making materials in a laboratory that are similar to specific immune system components and using them to help restore or improve the immune system’s ability to find and fight cancer cells.

Whilst chemotherapy drugs exerts its effect directly on the cancer cells, immunotherapy drugs work indirectly on the patients’ immune system. Cancers may respond to chemotherapy very quickly, but it may take longer to see the effects if you receive immunotherapy alone.

It is important to understand that not all cancer patients are eligible for immunotherapy, and not all cancers can be treated with immunotherapy currently. The good news, however, is that advancements in this area of cancer treatment is gaining pace rapidly. New immunotherapy treatments are being discovered that will expand and improve the treatment of cancer in the future⁷.

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Targeted therapy

Targeted therapy is a tailored form of treatment (sometimes called precision medicine) that targets specific changes or substances in cancer cells that are driving the cancer cells’ growth. Targeted drugs can stop or switch off signals that make cancer cells grow, or can instruct the cancer cells to destroy themselves. Because of their targeted action on the cancer cells, these drugs mostly leave normal, healthy cells unaffected⁸.

Some targeted therapies only work in people whose cancer cells have certain genetic mutations. Your cancer cells may be tested in a laboratory to look for specific genes or changes in protein structure on the cancer cells that can be acted upon by medications. Finding a specific target allows patients to be matched with more precise or personalized treatment⁸.

There has been an exponential growth in the discovery of new cancer cell targets in recent years. This has led to the development and approval of more cancer drugs than ever before. The role of targeted therapy in the treatment of cancer will continue to expand in the near future.

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Hormone therapy

Certain cancers are fuelled by your body's hormones. Removing these hormones from the body or blocking their effects may therefore cause the cancer cells to stop growing¹.

Hormone therapy circulates throughout the body to find and target hormones. Different types of hormone therapy work in different ways, including⁹:

• Stopping the body from making the hormone
• Blocking the hormone from attaching to cancer cells
• Altering the hormone so it does not work like it should

Hormone therapy is mostly used to slow the growth of certain breast, prostate, and endometrial (uterine) cancers, which normally grow in response to natural sex hormones in the body⁹.

Bone marrow (or stem cell) transplantation

A transplant of blood-forming stem cells allows a person to receive high doses of chemotherapy and/or radiation therapy. The high treatment doses destroy both cancer cells and healthy blood cells in the bone marrow and this is followed by the transplant of new, healthy stem cells that allow the body to “start over”¹⁰.

The stem cells may come from the patient (known as autologous stem cell transplantation) or from a healthy, matched donor (known as allogenic stem cell transplantation)¹¹.

Bone marrow transplantation is most commonly used to treat blood cancers and cancers that start in the lymph nodes².

Tailoring the right cancer treatment is often a fine balancing act. It is normal to feel overwhelmed and confused by all the information. Here at Parkway Cancer Centre, we have a well-established team of dedicated and esteemed cancer specialists who are ready to support you through your cancer journey with state-of-the-art care. Together, you and your doctor can weigh the benefits and risks of each cancer treatment to determine which is best for you.

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