Mainstream therapies

MAINSTREAM THERAPIES

Please note: all information on this page is lay-gathered.You may want to verify its accuracy with your health care givers.

Watch and wait

Watch and wait means no treatment at present. Since for some lymphomas, particularly of the low-grade variety, current treatments have not demonstrated a capability to prolong life, more and more doctors and patients opt for this modality. Long term studies have shown that beginning treatment only when necessary for medical reasons does not compromise the patients' survival odds. Watch and wait is also used for those patients whose disease has recurred but remains stable or slow-growing.

Surgery

Surgery is used to extract nodes for biopsies. It is also used to extract organs such as the lacrimal glands or spleen when the cancer is localized in them and they can be missed, or when the spleen is massively enlarged. Surgery can also be helpful in cases where the lymphoma has penetrated parts of the gastrointestinal tract. Since most lymphomas are disseminated by definition, surgical removal of the cancer is not really an option.

Radiation

Radiotherapy uses high dose radiation to kill cancerous cells and shrink nodes and masses. Usually, external beam radiation is used in lymphoma, which can range from local to regional to total lymph irradiation to total body irradiation. It is sometimes used along with chemotherapy, and is frequently a part of the high dose treatment preceding a transplant.

Radiation is curative for some cases of early stage lymphomas, and can be used as a less toxic local control of a large node. The effects of radiation continue up to 6 months after treatment.

For a good basic description of radiotherapy, check out
www.cansurvive.org.uk/treat/radio1.html

Chemotherapy

Chemotherapy involves the use of cytotoxic (cell-killing) drugs. The effect is systemic, and there are many risks connected with the use of these agents. There are a number of agents capable of killing the lymph cells, and some are curative for the faster growing lymphoma types. These agents often bring about profound node shrinkage of the low-grade lymphomas but do not prevent a recurrence.

Light(er) chemo: Oral alkylating agents are used alone or in combination with steroids. The agents commonly used are chlorambucil, cyclophosphamide, and etoposide. A steroid such as prednisone can also be used alone but is not typically employed in first-line treatment.

Medium chemo: Several agents are administered together via IV drip on an outpatient basis, with or without oral steroids. Commonly used combinations are CHOP, CVP, CHOP-B, ESHAP, EPOCH and others.

Heavy chemo: High dose therapy is used either as a prelude to transplants, or as a salvage regimen for resistant (refractory) lymphomas. High dose therapy also involves combinations of agents, but in very high doses.

For good basic info on chemo, as well as explanation of many of the combination regimens, see
medweb.bham.ac.uk/cancerhelp/public/ specific/lymphoma/treat/chemo/about.html
www.cansurvive.org.uk/treat/chemo1.html

This page provides good basic info about steroids.
medweb.bham.ac.uk/cancerhelp/public/ specific/lymphoma/treat/steroid.html

Transplants

Bone marrow transplants, and more increasingly stem cell transplants, are used in many centers for lymphoma treatment. They are used usually at relapse, but also as first line therapy. Marrow is harvested from the hip bones, whereas stem cells are harvested from the blood.

Transplants are preceded by high dose radiation and/or chemotherapy which destroys the bone marrow. The patient is then rescued by the infusion of the previously harvested marrow or stem cells.

Transplants come in three varieties. Autologous transplants use the patient's own marrow or stem cells. This is the safest transplant but also one with the most risk of recurrence because the reinfused cells are likely to be contaminated with lymphoma cells. Allogeneic transplants are those which use another person's marrow or stem cells. In this way, clean cells are used, and the risk of relapse is lessened. The cells usually come from a matched sibling, but in some cases can come from a parent or a matched stranger. These transplants have a high mortality rate.

A much safer subspecies of an allogeneic transplant is one that used the cells from an identical twin. This type of transplant is called syngeneic.

An excellent link page for transplant info:
www.alumni.caltech.edu/~mike/lymphoma/bmt.html

Anti-microbial treatment

In some cases, where the lymphoma is caused by a known microbe, such as Helicobacter pylori for MALToma, a course of antibiotics may completely and permanently eliminate the lymphoma. This seems to work best in the early stages when the body can repair the genetic abnormalities. An anti-viral approach is being tested in lymphomas caused by herpesviruses.

Immunotherapies

Immunotherapies constitute the most hopeful frontier of lymphoma-related oncology at present. So far, only two agents have been approved by the FDA, but several others are in the works.

RITUXIMAB (Rituxan) is a monoclonal antibody which is infused into the body via an IV drip. Typically, the treatment is done once a week for 4 weeks. Side effects are usually minimal. The response (node shrinkage) usually lasts about 10-12 months, and can be repeated for most patients.

Rituxan consists of genetically engineered protein bits, partly human and partly mouse, which attach themselves to all or most B-cells in the body (both healthy and cancerous). The immune system then mounts a reaction which kills these B cells. Progenitor cells are not affected, and the immune system regenerates new B cells within a few months.

Rituxan only works for patients whose cancerous B cells show a specific antigen, the CD20. Not all B cell lymphomas have enough CD20 to be vulnerable to Rituxan. Rituxan was approved for relapsed or refractory lymphomas but is commonly used "off-label" for first line therapy.

A good basic file on rituximab:
www.tirgan.com/rituxan.htm

INTERFERON ALPHA (Intron A, Roferon A) is a cytokine, a protein that regulates cell processes. Interferon can stimulate an immune reaction against cancerous cells, inhibit their growth, or promote their normal maturation.

Interferon can be taken at home via subcutaneous injection. It can be added to a chemo regimen, or can be used as maintenance therapy after the chemo is finished. There is evidence that interferon prolongs remissions but does not improve survival in most cases (there is some indication that it will improve survival in large cell follicular NHL). Toxicities of interferon vary depending on dosage and patient sensitivity. The agent can make the patient feel as though they have the flu for the duration of the treatment, and it can also cause profound depression.

A page of info on Intron A:
www.pslgroup.com/dg/44636.htm

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