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Purpose of chemotherapy
Chemotherapy Chemotherapy Treatment with drugs to kill cancer cells or to render them less active. May be given intravenously or orally depending on the drug and situation. targets cells that divide quickly, such as cancer cancer A term used to describe diseases in which abnormal cells continually divide without normal regulation. Cancerous cells may invade surrounding tissues and may spread to other regions of the body via blood and the lymphatic system. cells that multiply without control as well as healthy cells that divide rapidly. MCC is usually initially responsive to chemotherapy, leading to significant tumor shrinkage. However, MCC often quickly gains resistance, and the tumor can start to grow again despite receiving chemotherapy drugs.
Chemotherapy drugs may be given intravenously or orally on certain days of the week over a set number of weeks. For example, a patient may receive chemotherapy Monday, Wednesday and Friday on weeks 1, 4, 7, and 10.
Combination chemotherapy is when two or more drugs are given at the same time as they work better together than alone. MCC has similarities to other neuroendocrine neuroendocrine Neuroendocrine refers to the type of cells that make up Merkel cell carcinoma. "Neuro-" means that these cells have some sensory function related to the nervous system, while "endocrine-" refers to hormonal types of cells. Merkel cells have both such features. carcinomas, such as small cell lung cancer. For this reason, a medical oncologist medical oncologist A doctor who specializes in the diagnosis and treatment of cancer patients especially using chemotherapy. may use drugs that have shown effectiveness against small cell lung cancer. A combination of etoposide etoposide An anticancer drug used as a form of chemotherapy. It is often given intravenously or orally in combination with other drugs. Etoposide combined with carboplatin (or cisplatin) is a common therapy for Merkel cell carcinoma in its advanced stages. (VP16) and carboplatin carboplatin A "chemotherapy" drug in the class of DNA alkylating agents that is used to treat some types of cancer. It is closely related to cisplatin but has fewer side effects. (or cis-platin) is one such regimen that will shrink MCC tumors in more than half of cases. A study of 62 MCC patients who received chemotherapy to treat distant metastatic metastatic Having to do with the spread of cancer from a primary site of origin to distant areas beyond the draining lymph nodes. disease showed that nearly 60% of patients had their tumors shrink initially. On average, however, MCC tumors began to grow again by only 90 days after the chemotherapy was first started (Iyer et al. 2016). When MCC returns after chemotherapy, there are two problems that make controlling it more challenging: the immune system is somewhat suppressed by the chemotherapy and the MCC tumor cells have learned how to evade the effects of chemotherapy drugs. For patients who do not have problems with their immune system (no auto-immune disease and no major immunosuppressive medications), it is typically recommended to first try an immunotherapy, prior to using chemotherapy.
Adjuvant chemotherapy is not typically indicated in treating Merkel cell carcinoma
The following are reasons that adjuvant chemotherapy is not be routinely recommended. In the absence of definitive data, the decision to use chemotherapy should be customized to each situation and should be discussed with a medical team.
- Mortality: There is a 4 to 7% acute death rate due to adjuvant chemotherapy in MCC partly due to the fact that these patients are often over 70 years old (Voog 1999; Tai 2000).
- Morbidity: Neutropenia (low white blood count) occurs in 60% of patients with fever, and blood infections in 40%.1
- Decreased quality of life: This is quite severe in this older population, including fatigue, hair loss, nausea and vomiting.
- Resistance to chemotherapy: Merkel cell carcinoma Merkel cell carcinoma A skin cancer composed of cells that look microscopically similar to normal Merkel cells present in the skin. MCC was first described in 1972 and only in the 1990s was the CK20 antibody developed to make it easily identifiable by pathologists. Many doctors and patients are not aware of this cancer because of its recent description and relative rarity (~2,000 cases/year in the US--roughly 30 times less common than melanoma). About 40% of patients treated for MCC will experience a recurrence, making it far more aggressive than most other types of skin cancer, including melanoma. that recurs after chemotherapy is less responsive to later palliative palliative Relieving pain or decreasing the severity of a disease. Palliative therapy is usually contrasted with curative therapy (given with intent to cure the patient of cancer). chemotherapy.
- Immunity: Chemotherapy suppresses immune function and this is known in general to be very important in preventing and controlling MCC.
- Apparent poorer outcomes: In a study of 6908 patients captured in the National Cancer Database, there was no benefit (or detriment) of giving adjuvant chemotherapy to patients with high risk disease (MCC that had spread to the nodes).
Who this works for
MCC patients that have not responded to radiation or other treatments and who are not good candidates for immune stimulating therapy. Chemotherapy is generally reserved for later stages, when disease is more wide-spread.
Who this doesn’t work for
Patients who have an intact immune system and no auto-immune disease may benefit from being treated with an immune stimulating therapy prior to trying chemotherapy.
Side effects of chemotherapy include, but are not limited to: fatigue, nausea, pain, hair loss, and immune suppression.
Often used in conjunction with
Chemotherapy is usually used alone as it is often effective, although responses typically only last for a few months.
What to do next
Patients who no longer respond to chemotherapy, may benefit from Pazopanib (Votrient), an oral medication that has been reported to help control metastatic MCC in some cases. Please click here for more details on this drug which was developed for other types of cancers including kidney cancer.
Sandostatin is an agent which can be combined with pazopanib. It works in a different way than pazopanib, and can also sometimes slow or stop the growth of MCC.
Do I need chemotherapy?
In general, chemotherapy is reserved for late stages of MCC, when immune therapies are not an option. For disease that is not metastatic, good control can often be achieved with surgery and radiation alone.
Understand the Science
The following clinical publications and scientific research provide additional in-depth information about chemotherapy.