An Overview of Cancer Treatments
What treatment options are available for cancer, and how do these methods work? What is the goal of these treatments, and when are they used?
Choosing a Cancer Treatment Plan
If you or a loved one have recently been diagnosed with cancer, you may be feeling anxious and overwhelmed. Cancer or the “C word” can instill a sense of fear and dread in even the bravest of people. Many advances have been made in the treatment of cancer, often allowing several different options for care. How can you make the choices that are best for you as an individual?
Thankfully it is not only possible to make these decisions, but people with cancer are taking a more active role than ever in choosing their treatments. These choices will depend on many factors, including your age, the specific type and stage of cancer you have, and the possible side effects of treatment you are willing to tolerate. Similarly, every cancer is different from a molecular standpoint, and a treatment which works well for one person with a specific type of cancer may not work as well for another person with the same type of cancer.
Let’s take a look at the cancer therapies currently available, the different goals of treatment, and what you can do yourself in order to make the best decisions for your care.
Local vs. Systemic Cancer Treatments
There are several different methods by which cancer is treated, but it’s helpful to first break these down into two major approaches: local treatments and systemic treatments for cancer.
Local Treatments – Local treatments address a cancer where it originates locally. Both surgery and radiation therapy are considered local treatments. They treat or remove a primary cancer but are unable to treat cancer cells which may have spread to other regions of the body.
Systemic treatments – Systemic treatments include those which treat cancer cells wherever they happen to be in the body. Methods which provide “systemic coverage” of cancer include chemotherapy, targeted therapies, hormonal therapies, and immunotherapy. If a cancer has spread or if there is a chance it has spread, a systemic therapy such as chemotherapy is often needed to remove these vagrant cells. Since blood-related cancers such as leukemia affect cells in the bloodstream—cells that travel throughout the body—systemic treatments are the primary method of treatment.
Goals of Cancer Treatment
It is extremely important to consider the goals of your cancer treatment before beginning cancer therapy. Studies suggest that people with cancer often have significantly different expectations than those of their physicians with regard to the effectiveness of various therapies. Goals may include:
- To cure cancer – The goal in treating some cancers is to eradicate the cancer, so it is gone forever. Unfortunately, due to the fact that cancer cells from solid tumors may sometimes “hide” for years or decades, other goals are often considered (even if the likelihood that the cancer will come back is small.)
- To extend life or reduce the risk of recurrence – Many cancer treatments offer the chance to increase the length of time someone can live with cancer, or live in remission from cancer.
- Adjuvant therapy – Adjuvant therapy is a treatment approach in which a treatment (usually chemotherapy or radiation therapy) is used to kill cancer cells which have spread to other regions of the body (micrometastases) but cannot yet be picked up on radiological studies. Adjuvant therapy is often used after surgery to decrease the likelihood that a cancer will recur.
- Neoadjuvant therapy – Neoadjuvant treatments include those (usually chemotherapy or radiation therapy) which are used to decrease the size of a tumor so that surgery is then possible.
- Palliative therapy – Palliative care or “supportive therapy” refers to a treatment approach which addresses all parts of a person: body, mind, and spirit. These treatments are designed to improve the quality of life for people with cancer but are not designed to treat the cancer itself. It’s important to note that palliative care is different than hospice. Palliative care may be used to improve quality of life even for people who have cancers that are likely to be cured.
Can Cancer Be Cured With Treatment?
In reviewing the goals of treatment may people wonder why the word “cure” is rarely used with solid tumors and why cancers sometimes come back. There are several theories on why cancers may recur, even decades later. This is important to keep in mind in that even if there is little chance your cancer will recur after treatment, there is also little chance your oncologist will use the word “cured” if you have a solid tumor. Instead, you are likely to hear terms such as “complete remission” and “no evidence of disease.”
Cancers that can be “cured” with treatment include some leukemias and lymphomas, early stage ovarian cancer, and solid tumors which are discovered when a tumor is still considered carcinoma in situ. Carcinoma in situ refers to a cancer which is clearly malignant (it is not made up of precancerous cells) but does not extend into the basement membrane. In other words, it is not an “invasive” cancer. The majority of cancers, even those that are stage I, are still considered invasive in that they extend beyond the basement membrane.
Overview of Cancer Treatment Methods and Options
There are many ways in which cancer is treated. Keep in mind that within any of these options there may be multiple different approaches and variations and that these different options may be recommended with different goals in mind. For example, one form of radiation therapy may be used as a curative therapy while another type of radiation may be used as palliative therapy, even with the same type of cancer. Each of these methods will be expanded on further below. Treatment methods include:
- radiation therapy
- targeted therapies
- hormonal therapies
- stem cell transplants
- clinical trials
- alternative cancer treatments
Surgery as a Cancer Treatment
With a few exceptions, such as blood-related cancers like leukemia, surgery offers the best chance to cure a cancer or at least significantly reduce the chance that it could recur. The goal of surgery may be to:
- Diagnose cancer – A surgical biopsy may remove part of a tumor, or a cancer may be removed entirely, in order to determine a precise diagnosis.
- Stage cancer – Staging a cancer—determining how large a cancer is and how far it has spread—is extremely important in choosing the best treatments for cancer. Many factors go into staging a cancer, but measuring the size of a tumor after surgery is one of these factors. Surgery may also be one to look for the spread of the cancer for the purpose of staging, for example, via an axillary lymph node dissectionwith breast cancer or mediastinoscopy with lung cancer.
- Cure cancer – When solid cancers are caught at an early stage, surgery may be used in an attempt to cure the cancer. This may be followed by other treatments such as chemotherapy or radiation therapy in order to reach any cancerous cells that were not removed at the time of surgery.
- Debulk a tumor – You may wonder why surgery is not used more often for large cancers which have spread. After all, isn’t it a good idea to at least reduce the size of a tumor as much as possible? With most advanced tumors, such as stage IV breast cancer, surgery is not recommended, as treatments such as chemotherapy are more effective. There are exceptions in which “debulking” or cytoreduction surgery may have more benefits than risks. For example, with some ovarian cancers, debulking surgery may reduce the amount of tumor present, allowing chemotherapy to be more effective before the tumor becomes resistant to these drugs.
- Palliate cancer – Surgery may be done for palliative reasons as well. For example, surgery may remove part of a tumor which is causing pain, an obstruction, or interfering with other processes in the body.
- Prevent cancer – For cancers which have a precancerous stage or if it’s thought that someone may develop a cancer in a region of the body, surgery may be done to remove the organ before cancer can develop. For example, some people who have a very high genetic risk for developing breast cancer may elect to have a preventive mastectomy.
Risks and Side Effects of Surgery for Cancer – As with other treatments for cancer, surgery carries risks, and it’s important to make sure these risks are outweighed by the possible benefits of treatment. These risks vary considerably depending on the type of tumor and location, but may include bleeding, infection, and complications of anesthesia.
Special surgical techniques – Advances in surgical techniques, such as the option of lumpectomy versus the radical mastectomy of the past, are allowing surgeons to remove tumors with fewer complications and a faster recovery time. The term minimally invasive surgery is used to describe these techniques which offer the same ability to remove a tumor, but with less damage to normal tissue. An example is the use of video-assisted thoracoscopic surgery to remove lung cancer, in contrast to the thoracotomies done routinely in the past. Robotic surgery is another example of a special surgical technique that may be used. There are many other special surgical techniques. Laser surgery entails the use of high-energy radio waves to treat cancer. Electrosurgery is done with the use of high energy electron beams, and cryosurgery uses a cold source like liquid nitrogen to freeze tumors.
Chemotherapy refers to the use of chemicals (medications) to rid the body of cancer cells.These drugs work by interfering with the reproduction and multiplication of rapidly growing cells, such as cancer cells.
Since these drugs are designed to treat rapidly growing cells, they are most effective for rapidly growing—or aggressive—tumors. The forms of cancer which were historically the most aggressive and rapidly fatal are sometimes now the most treatable and possibly curable with the use of chemotherapy. In contrast, chemotherapy is less effective for slow-growing, or “indolent” tumors.
This mechanism of action also accounts for the well-known side effects of chemotherapy. There are several “normal” types of cells in the body which grow rapidly as well, such as those in the hair follicles, digestive tract, and bone marrow. Since chemotherapy attacks any rapidly growing cells, this accounts for the well-known side effects of hair loss, nausea, and bone marrow suppression.
The goal of chemotherapy may be:
- To cure cancer – With blood-related cancers such as leukemias and lymphomas, chemotherapy may be used with the intent to cure the cancer.
- Adjuvant chemotherapy – Adjuvant chemotherapy is chemotherapy given after surgery in effect to “clean up” any cancer cells that have traveled beyond the tumor but are not yet detectable on imaging tests we now have. These wayward cells which are too small to be detected are referred to as micrometastases. Adjuvant chemotherapy is designed to lower the risk of recurrence of a cancer.
- Neoadjuvant chemotherapy – Neoadjuvant chemotherapy may be given prior to surgery to decrease the size of a tumor. If a tumor is unable to be operated on due to its size or location, chemotherapy in this setting may decrease the size of the tumor enough so that surgery is possible.
- To extend life – Chemotherapy may be used to prolong life.
- Palliative chemotherapy – Palliative chemotherapy refers to the use of chemotherapy to decrease the symptoms of cancer, but not to cure cancer or extend life.
There are several different types of chemotherapy medications, which differ in both their mechanisms of action and the part of the cell cycle they disrupt. Most often chemotherapy drugs are used in combination—something termed combination chemotherapy. Individual cancer cells are all at different points in the process of reproducing and dividing. Using more than one drug helps to treat cancer cells at whichever point they are at in the cell cycle.
Chemotherapy may be given by vein (intravenous chemotherapy) orally, via a pill or capsule, directly into the fluid surrounding the brain, or into the fluid present in the abdominal cavity.
Risks and side effects of chemotherapy – Most people are familiar with the common chemotherapy side effects, such as hair loss. Thankfully, in recent years treatments have been developed for managing many of these side effects. For example, many people now have minimal or no nausea or vomiting relative to in the past. These side effects vary depending on the drug’s use, the dosages, and your general health, but may include:
Most of these side effects resolve shortly after your final chemotherapy session, but there are sometimes long-term side effects of chemotherapy. Examples include heart damage with some of these drugs and a slightly increased risk of secondary cancers (such as leukemia) with others. The benefits of therapy often far outweigh any of these potential concerns, but having an awareness may help you discuss all options thoroughly with your doctor.
Radiation therapy is a treatment which uses high-energy x-rays (or proton beams) to destroy cancer cells. Significant improvements have been made in these therapies in recent years, minimizing the damage to normal tissues around a cancer.
Radiation may be given externally, in which radiation is delivered to the body from an outside similar to an x-ray machine, or internally (brachytherapy) in which radioactive material is either temporarily or permanently injected or implanted in the body.
As with other cancer treatments, radiation therapy for different reasons and with different goals. These goals may be:
- To cure the cancer – Stereotactic body radiotherapy (SBRT) may be used, for example, in an attempt to cure a small cancer that can otherwise not be reached with surgery, or to completely remove an isolated metastasis.
- As adjuvant therapy – Radiation therapy may be used after surgery to treat any cells that are left over after surgery. This may be done either externally or internally. An example is the use of radiation therapy to the chest wall after a mastectomy.
- As neoadjuvant therapy – Radiation therapy may be combined with chemotherapy to reduce the size of a tumor before surgery. For example, radiation therapy—usually combined with chemotherapy—may be used to decrease the size of an inoperable lung cancer so that surgery can then be done.
- Preventively – An example of preventive therapy is giving radiation therapy to the brain to prevent brain metastases in people with small cell lung cancer.
- Palliative radiation therapy – Palliative radiation therapy refers to the use of radiation to address the symptoms of cancer but not to cure a cancer. It may be used to decrease pain, reduce pressure, or relieve obstructions caused by a cancer.
Radiation therapy may be given in several different ways as well:
- External beam radiation therapy – External beam radiation is used often and involves directing a beam of radiation locally to the site of a tumor.
- Intensity-modulated radiation therapy (IMRT) – IMRT is a method of more precisely directing radiation to a site, allowing a higher amount of radiation to be given with less damage to surrounding cells.
- Brachytherapy – Brachytherapy, or internal radiation, is a method in which radioactive seeds are placed in the body either temporarily or permanently.
- Stereotactic body radiotherapy (SBRT) – SBRT, also known as cyber knife or gamma knife, is not a surgery, but actually a method of directing a high dose of radiation to a small area of tissue, with the intent to completely destroy an early stage cancer much as surgery would. It may be used to treat “oligometastases”—isolated or few metastases to an area such as the lung, liver, or brain from another cancer.
- Proton therapy – Proton therapy uses proton beams—atomic particles that are more easily controlled than x-rays—to treat irregularly shaped tumors which are difficult to treat with conventional radiation.
- Systemic radiation therapy – Systemic radiation is a method in which radiation is delivered throughout the body through the bloodstream. An example is the use of radioactive iodine to treat some types of thyroid cancers.
Risk and side effects of radiation therapy – The risks of radiation therapy depend on the specific type of radiation as well as the location where it is delivered and the doses used. Short-term side effects of radiation therapy often include redness (like a sunburn), inflammation of the area which receives radiation, such as radiation pneumonitis with radiation to the chest, and fatigue. Cognitive symptoms are also common in people who receive whole brain radiation. Long-term side effects of radiation therapy may include scarring in the region where it is used as well as secondary cancers.
Targeted therapies are medications that are designed to target cancer cells specifically, and in such are often less harmful to normal cells. Many of the recently approved drugs for cancer are targeted therapies, and more are being evaluated in clinical trials. In addition to being called targeted therapies, these treatments may also be referred to as “molecularly targeted drugs” or “precision medicine.”
Targeted therapies differ from chemotherapy in a few important ways. Unlike chemotherapy which attacks any rapidly dividing cells whether normal or cancerous, targeted therapies specifically target cancer cells. Chemotherapy drugs are also usually cytotoxic, meaning that they kill cells, whereas targeted therapies are often cytostatic, which means they stop the growth of cancer but do not kill the cancer cells. There are two basic types of targeted therapies: