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Metastatic Melanoma
Neoplastic transformation of melanocytes gives rise to malignant melanoma, a form of skin cancer. Once histopathology confirms the diagnosis, the tumor is staged to determine prognosis and treatment.
Two staging systems are commonly used to identify the extent of the disease. Stages I and II describe local metastases, whereas Stages III and IV describe the presence of local and distant metastases.
Metastatis Melanoma Diagnosis/Prognosis
Once a patient develops distant metastatic disease, variables such as age, sex, primary site, level, thickness and ulceration have no bearing on outcome. The most significant factor associated with survival in patients with distant metastases is whether a single site, or two or more organ sites, of disease are present. The location of organ sites of disease is also an important factor; patients with visceral disease generally have a poor outcome. Even when these factors are considered, the median survival between poor prognosis and good prognosis patients varies only by months.
Patients with a single metastatic site have a better prognosis than patients with metastases at two or more organ sites. It should be noted that a metastasis to a single site does not imply a single metastasis; most patients will have multiple lesions within a site. The median survival time is seven months in patients with a single site (other than lung), four months with two organ sites and two months with more than two organ sites. The one-year survival rate is 36% with one metastatic site, 13% with two organ sites and less than 1% with more than two organ sites.
Once the number of organ sites of metastases have been determined, locations of distant metastases are an important factor. If a patient has only a single site of metastasis, metastases to the lungs, skin, subcutaneous tissues, or distant lymph nodes have a better survival rate than metastases to any other single site with visceral involvement. Patients with isolated pulmonary metastasis have the longest median survival (11 months), but pulmonary metastasis as the only site of disease occurs in only 11% of patients. The skin, subcutaneous tissues, and distant lymph nodes are the most common organ sites of relapse, but only 23% of patients have non-visceral metastases as the only manifestation. The median duration of survival with non-visceral metastasis is seven months with 25% alive at one year. Excepting the visceral/non-visceral classifications, there is no difference in outcome between any combination of organ sites, reiterating that more than one site of metastasis has a poor prognosis. If a patient has a combination of visceral and non-visceral metastases, he/she will have the same poor prognosis as a patient with visceral metastases alone.
Spontaneous regression of primary lesions in melanoma has been reported. Indeed, there is a subset of patients who present with unknown primary organ sites, implicating immune-mediated regression as the mechanism. Although spontaneous regressions of metastases have been reported for metastatic melanoma, the literature supports a complete spontaneous regression rate of less than 1.0% in melanoma patients with distant metastases.
Metastatic Melanoma Treatment
The prognosis of metastatic melanoma is dismal. Several large medical series have demonstrated five-year survival rates of 2-3% among all patients who presented. There are surgical series that have reported higher survival rates of 6%; however, the patient population referred for surgical treatment has a tendency to have good prognostic factors. These series have a higher proportion of patients with single organ sites of metastatic disease or pulmonary metastases that are surgically resectable. Long-term survival can be achieved by surgical resection of isolated metastasis. However, for those patients with multiple organ sites of disease and multiple lesions within the organ sites (the majority of patients with metastatic melanoma), surgery is not an option and long-term survival is uncommon.
Meaningful therapeutic options are limited in metastatic melanoma. The systemic treatment options for advanced melanoma include use of single-agent chemotherapy or combination chemotherapy. Very few chemotherapeutic agents have demonstrated anti-tumor activity. Dacarbazine (DTIC) remains the most active agent for the treatment of systemic melanoma. The response rate is in the range of 15-25%. The median duration of response is five to six months. Overall only 1-2% of patients treated with DTIC sustain long-term complete response. Other classes of chemotherapy including nitrosoureas, vinca alkaloids and platinum compounds have similar response rates, but few long-term survivors. Combination therapies have also been investigated with response rates below 20% and survival comparable to that of single agent DTIC.
Additional Resources
American Cancer Society: National
General information on cancer research/statistics, treatments and living with cancer.
http://www.cancer.org/
Cancer Care, Inc.
Information on a variety of cancers, treatment options and support groups.
http://www.cancercareinc.org/
OncoLink
FAQ's, global resource lists, general information on cancer causes, screening and prevention.
http://www.oncolink.com/
National Cancer Institute
A wide range of cancer information based on the latest research for patients, health professionals and basic researchers.
http://cancernet.nci.nih.gov/
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Information contained on the Hemispherx website other than historical information, should be considered forward-looking and is subject to various risk factors and uncertainties. For instance, the strategies and operations of Hemispherx involve risks of competition, changing market conditions, changes in laws and regulations affecting these industries and numerous other factors discussed on the Hemispherx website and in the Company's filings with the Securities and Exchange Commission. Accordingly, actual results may differ materially from those in any forward-looking statements. Additionally, all the referenced investigational drugs and associated technologies of the company are experimental in nature and as such are not designated safe and effective by a regulatory authority for general use and are legally available only through clinical trials with the referenced disorders. The forward-looking statements represent the Company's judgement as of the date of this website. The Company disclaims, however, any intent or obligation to update these forward-looking statements. |
