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Cancer Treatment Types

Overview of Cancer Therapies

The arsenal of cancer therapies is growing and expanding every day. In this section we will provide brief and rather limited descriptions of treatment strategies as well as internet links for more detailed review. We want you to have all the information you need and will be happy to answer any additional questions about systemic therapy of cancer using chemotherapy, targeted therapies, hormonal therapy and biotherapy. Detailed questions about local therapies should best be addressed to you surgeon, radiation oncologist or intervention radiologist.

Cancer therapies could be roughly divided into two big groups: local and systemic.

Local Therapies

The goal of Local Therapies is to remove or destroy cancer cells in one specific location. This could be achieved by Surgery, Radiation therapy and Tumor Ablation and Embolization. Novel approaches to local cancer treatment are currently being tested.

Surgery

 Surgical procedures can be used to achieve different goals:

• Preventive or prophylactic surgery is sometimes done to remove tissues which have a high likelihood to turn into cancer, either because they have already developed some abnormalities (pre-cancerous lesions), or because genetic tests indicate that risk of cancer is very high.
  
• Staging surgery is sometimes necessary to determine cancer spread more accurately. For example, patients with lung cancer might need evaluation of the lymph nodes in the chest and patients with cancer of the stomach might need a closer look at the inner lining of their abdomen. Limited surgical procedure might also be necessary to obtain a biopsy when lesions, suspicious for metastatic disease, are too small or are located in the areas which are hard to reach with other approaches.
  
• Curative surgery is done when cancer appears to be confined to one area. It is most often performed on tumors which have not spread to other organs; in selected cases, however, removal of tumor metastases from distant organs could still achieve a cure.
  
• Debulking (or cytoreductive) surgery is performed in some types of cancer when complete removal of the tumor is not possible. The aim is to decrease the tumor bulk, which could improve efficiency of non-surgical therapies, for example chemotherapy or biotherapy. The benefit of cytoreductive surgery has so far been demonstrated only in a limited number of cancer types.
  
• Palliative surgery is occasionally used to alleviate symptoms and problems caused by advanced disease and is not intended for cure.
  
• Restorative (or reconstructive) surgery is used to restore person’s image and/or functional abilities which where impaired during primary surgery. Examples include breast reconstruction surgery after mastectomy and the use of bone grafts and artificial prosthetic materials after surgery for cancers of oral cavity.

Links to Surgical Oncology Information sites:
National Cancer Institute – Training site for cancer data collectors http://training.seer.cancer.gov/module_cancer_treatment/surgery.html

Radiation therapy

Like surgery, radiation therapy has many uses in cancer treatment.

• Curative and Definitive Radiation Therapy may be used, alone or in combination with chemotherapy, to cure or control some types of cancer instead of surgery.
  
• Neoadjuvant Radiation Therapy is sometimes given before surgery to kill cancer cells that might have escaped the main tumor and lodged in its vicinity. It is also given to shrink the tumor so it is easier to remove without damage to the function of surrounding organs.
  
• Adjuvant Radiation Therapy is used after surgery for certain cancers to “clean the area” which surrounded the removed tumor. This is done to destroy cancer cells that might have escaped the tumor before surgery and have not been removed because of it.
  
• Prophylactic Radiation Therapy is directed to a normal-looking organ when from past experience we know that it is very likely to harbor occult cancer cells. To date, the only example of this strategy is prophylactic brain radiation for certain types of lung cancer.
  
• Palliative Radiation Therapy is widely used to treat complications of advanced disease and to control symptoms like pain and swelling.

There are several ways to deliver radiation therapy:

• External Beam Radiation (EBRT) delivers beams of radiation which are focused on the tumor from outside your body.
  
• 3-Dimentional Conformal Radiation Therapy (3D-CRT) is a more precise form of EBRT. It uses computer simulation process to produce an image of a tumor and surrounding organs in three dimensions. Based on this image, multiple radiation beams can be directed to hit the tumor and to spare normal tissues as much as possible.
  
• Intensity Modulated Radiation Therapy (IMRT) utilizes a computer which changes intensity of multiple radiation beams during treatment session based on tumor size, shape and location. This allows to deliver higher radiation doses to the tumor while sparing more of the surrounding healthy tissue.
  
• Stereotactic Radiosurgery is primarily used to treat primary brain tumors and metastatic disease to the brain. These techniques do not really remove the tumor; instead it allows delivery of a high dose of radiation to a small area, thus killing cancer cells.
  
• Brachytherapy, unlike EBRT, places radioactive material inside or in close proximity to the tumor. Brachy in Greek means “short distance”. This technique allows to achieve high radiation doses in the tumor, while surrounding normal tissues receive little radiation exposure. MammoSite, a sub-type of brachytherapy, is used in patients who have undergone lumpectomy for breast cancer. This technique introduces an inflatable balloon, containing radiation source, into the space previously occupied by cancer.

General Radiation Oncology links:
National Cancer Institute
http://www.nci.nih.gov/cancertopics/factsheet/Therapy/radiation

National Cancer Institute: Radiation Therapy and You: Support for People With Cancer http://www.cancer.gov/cancertopics/radiation-therapy-and-you

American Cancer Society http://www.cancer.org/docroot/ETO/radiation_therapy_guide_for_patients_and_families.asp

National Cancer Institute – Training site for cancer data collectors http://training.seer.cancer.gov/module_cancer_treatment/unit2_radiation1_intro.html

New York Times articles on Radiation http://topics.nytimes.com/top/news/health/diseasesconditionsandhealthtopics/radiation/index.html

RadiologyInfo
http://www.radiologyinfo.org/en/sitemap/category.cfm?category=onco

IMRT:
http://www.radiologyinfo.org/en/info.cfm

Radiosurgery:
http://www.radiologyinfo.org/en/info.cfm?pg=stereotactic

MammoSite
http://www.mammosite.com/?src=aw

International Radiosurgery Association
http://www.irsa.org/index.html

Tumor ablation and embolization

Tumor ablation refers to non-surgical, non-radiation methods for killing cancer cells locally. Multiple strategies have been developed for this purpose, including, but not limited to, microwave, laser, cryotherapy (local freezing of the tissue), targeted ultrasound and injection of chemicals into the tumor. Currently, the most frequently used technique is Radiofrequency Ablation (RFA) . It employs an electrode which is inserted into a tumor under ultrasound or CT scan guidance. The energy released at the tip of the electrode leads to production of heat which basically “cooks” the tumor. In carefully selected patients, this procedure is safe, effective and fast. RFA has been most commonly used on primary and metastatic tumors of the liver; it is also employed for killing cancer lesions in the bones, kidneys, lungs and other organs.

Another approach for killing primary and metastatic tumors in the liver is Trans-Arterial Chemoembolization (TACE) . The rational behind this technique is that cancer cells receive most of their blood supply from hepatic artery, while normal liver cells are supplied by portal vein. Occlusion of hepatic artery branches and simultaneous delivery of chemotherapy into the occluded area interrupts blood supply to the tumor and exposes cancer cells to higher doses of medications.

Links to information about tumor ablation and embolization:
National Institute of Health
http://www.cc.nih.gov/drd/rfa/frame-patient.html

RadiologyInfo
http://www.radiologyinfo.org/en/info.cfm

Tumor Ablation Clinic
http://www.diagnosticimaging.com/ablation/patient/ablation.jhtml

Johns Hopkins Medicine
http://www.hopkinsmedicine.org/vascular/procedures/chemoembolization/

Systemic Cancer Therapy

Systemic cancer therapy uses medications which are either administered into the veins or absorbed after swallowing and are thus spread by blood flow to multiple organs and tissues in the body. Systemic therapies, like all other cancer therapies, can benefit patients at different times during their fight with cancer.

• Neoadjuvant Therapy is administered to patients who are expected to have curative surgery. The goal is to reach and kill cancer cells which might have escaped from the primary tumor and are residing unseen in distant organs. Neoadjuvant therapies might also shrink the tumor so that a more limited surgery could be performed.
• Adjuvant therapy is administered to patients who have already undergone curative surgery and have no signs of residual or metastatic disease. It is usually given for a pre-defined period of time or number of cycles. As with neoadjuvant therapy, the goal is to kill “sleeper” cancer cells which might be present in distant organs, but can not be detected by imaging techniques. Adjuvant therapy decreases the likelihood, but does not completely eliminate, the risk of cancer recurrence. As there is no visible tumor left, it is not possible to say whether adjuvant therapy is working for you personally.
• Therapy for Advanced Disease utilizes a wide spectrum of anti-cancer medications. It could be administered continuously or intermittently. The length of treatment and the type of medications used depends on the characteristics of your tumor, your preferences and your general state of health.

There are several categories of systemic anti-cancer therapy:

• Chemotherapy
• Targeted Therapy
• Hormonal Therapy
• Biological Therapy

Chemotherapy

Chemotherapy employs chemicals that damage multiple molecules and structures which are crucial for multiplication and/or survival of cancer cells.

Some of these agents damage DNA, the store of all the “blueprint” genetic information necessary for proper cell functioning and growth. Other groups of drugs block production of DNA “building blocks” or interfere with DNA “copying” machinery and thus prevent cancer cell reproduction. Yet other groups of compounds attack microtubules or spindles, the cell “muscles” which are responsible for distribution of genetic material between “daughter” cells and their separation during cell division.

Because different groups of chemotherapy agents assault cancer cells in different ways, combinations of certain drugs may work more efficiently than the same medications used separately.

MedlinePlus
http://www.nlm.nih.gov/medlineplus/cancerchemotherapy.html

MedicineNet
http://www.medicinenet.com/chemotherapy/article.htm

National Cancer Institute
http://www.cancer.gov/cancertopics/chemotherapy-and-you

Scott Hamilton CARES Initiative - Chemocare
http://www.chemocare.com/whatis/what_is_chemotherapy.asp

USA Today Health scout
http://www.healthscout.com/ency/68/155/main.html

Targeted Therapy

Targeted therapy is a general term that refers to a medication that is directed against a specific molecule or a defined set of related molecules. The target molecules are known or suspected to play important role in the development and growth of a tumor. The majority of target molecules are not unique to cancer cells; similar molecules are usually present in some normal tissues. In tumors, however, these molecules usually are either modified, or produced in larger quantities than in normal cells. By attacking or blocking these molecules, the targeted drugs interfere with processes vital for cancer cells growth and survival.

National Cancer Institute
http://www.cancer.gov/cancertopics/factsheet/Therapy/targeted

Scott Hamilton CARES Initiative – Chemocare
http://www.chemocare.com/whatis/targeted_therapy.asp

American Cancer Society
http://pubs.acs.org/cgi-bin/sample.cgi/achre4.pdf

Hormone Therapy

Hormone therapy is used in cancers which are known to depend on hormones for their growth. Hormones are normally produced in your body and are carried via bloodstream to multiple organs and tissues, where they regulate important functions. When tumors arise in the organs which are normally regulated by hormones, quite often they continue to require those same hormones for growth. Blocking hormone production or activity in such cases may halt tumor expansion.

Hormone therapies are widely used in treatment of breast and prostate cancer.

WebMD
http://www.webmd.com/breast-cancer/hormone-therapy-overview

American Cancer Society
http://www.cancer.org/docroot/CRI/content/Hormone_Therapy.asp
http://www.cancer.org/docroot/CRI/content/Androgen_Suppression_Hormone_Therapy.asp

Breastcancer.org
http://www.breastcancer.org/treatment/hormonal/

Prostateinfo.com
http://www.prostateinfo.com/patients/treatment/hormone.asp

Biological therapy

Biological therapy, sometimes called biotherapy, immunotherapy or biological response modifier therapy, is designed to stimulate, modify or enhance your body’s own immune responses. Some cancers seem to be vulnerable to immune attack. Immunotherapy could stop, control, or suppress growth of these cancers.

National Cancer Institute
http://www.cancer.gov/cancertopics/biologicaltherapy#1
http://www.cancer.gov/cancertopics/factsheet/Therapy/biological
http://www.cancer.gov/cancertopics/treatment/types-of-treatment

American Cancer Society
http://www.cancer.org/docroot/CRI/content/Immunotherapy.asp