User login
SAN DIEGO - A remedy that has been used for nearly 2 centuries is still a valuable adjuvant therapy for melanoma, according to Dr. Norman Brooks.
Zinc chloride paste not only penetrates and kills even thick melanomas, it appears to stimulate a strong immune reaction that decreases the likelihood of metastasis and recurrence, Dr. Brooks said at the meeting sponsored by the American Society for Mohs Surgery.
"I believe chemosurgery with zinc chloride paste, followed by wide excision, is a better way to remove a melanoma than fresh tissue surgery," said Dr. Brooks, a dermatologist in Encino, Calif., who specializes in skin cancers. "It not only kills the tumor locally but stimulates total body resistance and immunity, supporting the idea that surgery actually enhances melanoma tumor growth and metastatic spread. That’s why I believe it's so important to use zinc chloride when treating melanoma."
History of Zinc Chloride
Zinc chloride was first used as a cancer treatment in 1815. In 1858, a U.S. physician added a powdered form of the bloodroot plant (Sanguinaria canadensis), which contains the anticancer alkaloid sanguinarine; the compound was used to treat breast cancer. The current paste, formulated by Dr. Frederic E. Mohs, is a compound of naturally occurring ingredients: the mineral stibnite, which forms the inert paste-like vehicle; powered root of the bloodroot plant, which has been shown to induce apoptosis in several types of cancer; and a saturated zinc chloride solution, which destructively penetrates tissue.
A 1997 study explored the idea that surgery can liberate atypical melanocytes and predispose a patient to metastatic disease, Dr. Brooks said (Dermatol. Surg. 1997;23:1043-6). The epidemiologic study of 1,224 primary melanomas concluded that surgery of primary melanoma may enhance tumor growth at metastatic sites.
Chemosurgery with zinc chloride paste, therefore, helps avoid this phenomenon, Dr. Brooks said. The paste not only destroys tissue where it is applied, it also fixes the tissue into a firm mass. A delayed excision allows the specimen to be removed en bloc and examined histopathologically to determine margins. However, leaving a portion of the fixed tissue in place for several more days causes a strong vaccine-like reaction on the skin surface, indicating, according to Dr. Brooks, the beginning of a systemic immunologic response.
The Evidence
According to Dr. Brooks, he and his colleagues published the only piece of objective evidence on this phenomenon in 1998 (Dermatol. Surg. 1998;24:1021-5).
The study involved mice that were injected with two different melanoma types: a poorly immunogenic (B16) type and a more immunogenic type (K1735p). The resultant tumors were freshly excised in some mice, or excised 24 hours after the application of zinc chloride paste. A week later, all the mice received a second injection of melanoma cells at a different site. K1735p tumors developed at the challenge sites in significantly fewer of the mice pretreated with zinc chloride (32% vs. 69%, respectively). The paste did not alter the development of B16 melanomas. The authors concluded: "Zinc chloride fixation of the more immunogenic K1735p melanoma increased resistance to subsequent tumor challenge, suggesting that zinc chloride fixative paste acts as an immune adjuvant."
Treatment Application
At the meeting, Dr. Brooks presented his most recent article describing a simplified method for using the paste (Dermatol. Surg. 2010;36:237-40).
His process begins with a fresh tissue biopsy to confirm melanoma. He recommended a shaved saucerized excision with a margin of 1-2 mm beyond the suspected tumor edge carried at least through the mid-dermis, or below the suspected thickness of the lesion.
After melanoma is histopathologically confirmed, he applies the Mohs paste. Since the compound will not penetrate an intact keratin layer, it must only be applied to the excised area. "If the biopsied area has developed a crust or eschar, this must also be removed," Dr. Brooks said.
He applies a 1-mm thick layer of paste with a cotton-tipped swab. More can be applied for thicker lesions, but less if the lesion overlies an important anatomic structure. If the biopsy is a small excisional one, a swab of 50% bi- or trichloracetic acid can remove the outer keratin layer and allow the paste to penetrate.
The next step is to apply a sterile cotton ball and cover the dressing with bio-occlusive tape for 24 hours – the time it takes the paste to achieve full penetration. After 24 hours, the patient can return for a conventional, wide excision with standard vertical or bevelled Mohs margins, followed by closure.
However, to take advantage of the paste's immunologic properties, the block of tissue should be left in place for a week or longer, or the main block can be removed, leaving a rim of the fixed tissue in place to stimulate the immune response. Dr. Brooks said the fixed tissue can then be histologically examined to confirm negative margins. For patients with raised lesions, he recommended debulking to create a flat tissue plane and they applying the paste as described.
He also stressed that the Mohs paste does not interfere in any way with conventional melanoma treatment. "About half of my patients end up going to [a cancer center] for excision, sentinel nodes, or other treatment," including interferon, he said. But some patients, after reviewing the comparatively small survival benefit interferon offers and its significant side effects, elect to have the fixed tissue excised and then continue with the practice of node palpation and regular ultrasounds to identify any early disease spread.
Dr. Brooks reported having no relevant financial disclosures.
"Mohs paste is a tried and true compound that does what it's purported to do," said Dr. Kenneth Gross.
"The first patient I [used the paste on] developed a sentinel node that was swollen and large, and I thought it was a metastatic, but it turned out to be clearly an immune response. On the flip side – I don't paste everyone. But if I have a high-risk patient who is well balanced and capable of understanding the implications, I do offer to paste them."
It is important to get informed consent and explain that zinc chloride is not an approved therapy; however, assure the patient it will not interfere with any other therapy they might want to pursue. Consider reserving it for high-risk patients, many of whom have melanoma that extends to the bone. "If you do your Mohs down to the periosteum and want to know if the bone is clear, you can paste it and a day or so later the bone will decalcify and a little chip will come out and you can examine that."
Mohs paste has fallen out of use over the years as fresh-tissue surgery has gained popularity. "Fresh-tissue replaced it because it allows immediate closure, while the paste causes a lot of inflammation and, the way Dr. Mohs did it, it left a wound that healed by secondary intention. It heals well but people won’t stand for that these days." Younger physicians, he said, "want to use what’s new, and what they were taught to use."
For many years, Dr. Mohs got the paste from just one pharmacist, who retired long ago. "Then there was just no reliable place to get the stuff. But recently we've been able to work with Delasco, [a medical supply company] that can compound it very reliably. It's cheap and a small amount will last virtually forever at room temperature."
Because Mohs paste is composed of natural ingredients and has been in use for so long, it is an unpatentable therapy. Therefore, it will probably always remain on the fringes of medicine.
"You will never find any large head-to-head studies with other therapies, and no pharmaceutical company is ever going to research it. It would cost millions of dollars to do the kind of studies you’d need to get approval and then what would you have at the end? Nothing you could make money off of. So it won't happen."
Aside from some slight discomfort and the inflammatory reaction, however, there are few down sides to using the paste. "If you look at it from a perspective of what can I do that won't hurt my patients, probably helps them, and won’t interfere with definitive, modern therapy, I would say Mohs paste is a shining example."
Kenneth Gross, M.D., was a course
director at the meeting, and is a surgical dermatologist in San Diego.
He reported having no relevant conflicts of interest.
"Mohs paste is a tried and true compound that does what it's purported to do," said Dr. Kenneth Gross.
"The first patient I [used the paste on] developed a sentinel node that was swollen and large, and I thought it was a metastatic, but it turned out to be clearly an immune response. On the flip side – I don't paste everyone. But if I have a high-risk patient who is well balanced and capable of understanding the implications, I do offer to paste them."
It is important to get informed consent and explain that zinc chloride is not an approved therapy; however, assure the patient it will not interfere with any other therapy they might want to pursue. Consider reserving it for high-risk patients, many of whom have melanoma that extends to the bone. "If you do your Mohs down to the periosteum and want to know if the bone is clear, you can paste it and a day or so later the bone will decalcify and a little chip will come out and you can examine that."
Mohs paste has fallen out of use over the years as fresh-tissue surgery has gained popularity. "Fresh-tissue replaced it because it allows immediate closure, while the paste causes a lot of inflammation and, the way Dr. Mohs did it, it left a wound that healed by secondary intention. It heals well but people won’t stand for that these days." Younger physicians, he said, "want to use what’s new, and what they were taught to use."
For many years, Dr. Mohs got the paste from just one pharmacist, who retired long ago. "Then there was just no reliable place to get the stuff. But recently we've been able to work with Delasco, [a medical supply company] that can compound it very reliably. It's cheap and a small amount will last virtually forever at room temperature."
Because Mohs paste is composed of natural ingredients and has been in use for so long, it is an unpatentable therapy. Therefore, it will probably always remain on the fringes of medicine.
"You will never find any large head-to-head studies with other therapies, and no pharmaceutical company is ever going to research it. It would cost millions of dollars to do the kind of studies you’d need to get approval and then what would you have at the end? Nothing you could make money off of. So it won't happen."
Aside from some slight discomfort and the inflammatory reaction, however, there are few down sides to using the paste. "If you look at it from a perspective of what can I do that won't hurt my patients, probably helps them, and won’t interfere with definitive, modern therapy, I would say Mohs paste is a shining example."
Kenneth Gross, M.D., was a course
director at the meeting, and is a surgical dermatologist in San Diego.
He reported having no relevant conflicts of interest.
"Mohs paste is a tried and true compound that does what it's purported to do," said Dr. Kenneth Gross.
"The first patient I [used the paste on] developed a sentinel node that was swollen and large, and I thought it was a metastatic, but it turned out to be clearly an immune response. On the flip side – I don't paste everyone. But if I have a high-risk patient who is well balanced and capable of understanding the implications, I do offer to paste them."
It is important to get informed consent and explain that zinc chloride is not an approved therapy; however, assure the patient it will not interfere with any other therapy they might want to pursue. Consider reserving it for high-risk patients, many of whom have melanoma that extends to the bone. "If you do your Mohs down to the periosteum and want to know if the bone is clear, you can paste it and a day or so later the bone will decalcify and a little chip will come out and you can examine that."
Mohs paste has fallen out of use over the years as fresh-tissue surgery has gained popularity. "Fresh-tissue replaced it because it allows immediate closure, while the paste causes a lot of inflammation and, the way Dr. Mohs did it, it left a wound that healed by secondary intention. It heals well but people won’t stand for that these days." Younger physicians, he said, "want to use what’s new, and what they were taught to use."
For many years, Dr. Mohs got the paste from just one pharmacist, who retired long ago. "Then there was just no reliable place to get the stuff. But recently we've been able to work with Delasco, [a medical supply company] that can compound it very reliably. It's cheap and a small amount will last virtually forever at room temperature."
Because Mohs paste is composed of natural ingredients and has been in use for so long, it is an unpatentable therapy. Therefore, it will probably always remain on the fringes of medicine.
"You will never find any large head-to-head studies with other therapies, and no pharmaceutical company is ever going to research it. It would cost millions of dollars to do the kind of studies you’d need to get approval and then what would you have at the end? Nothing you could make money off of. So it won't happen."
Aside from some slight discomfort and the inflammatory reaction, however, there are few down sides to using the paste. "If you look at it from a perspective of what can I do that won't hurt my patients, probably helps them, and won’t interfere with definitive, modern therapy, I would say Mohs paste is a shining example."
Kenneth Gross, M.D., was a course
director at the meeting, and is a surgical dermatologist in San Diego.
He reported having no relevant conflicts of interest.
SAN DIEGO - A remedy that has been used for nearly 2 centuries is still a valuable adjuvant therapy for melanoma, according to Dr. Norman Brooks.
Zinc chloride paste not only penetrates and kills even thick melanomas, it appears to stimulate a strong immune reaction that decreases the likelihood of metastasis and recurrence, Dr. Brooks said at the meeting sponsored by the American Society for Mohs Surgery.
"I believe chemosurgery with zinc chloride paste, followed by wide excision, is a better way to remove a melanoma than fresh tissue surgery," said Dr. Brooks, a dermatologist in Encino, Calif., who specializes in skin cancers. "It not only kills the tumor locally but stimulates total body resistance and immunity, supporting the idea that surgery actually enhances melanoma tumor growth and metastatic spread. That’s why I believe it's so important to use zinc chloride when treating melanoma."
History of Zinc Chloride
Zinc chloride was first used as a cancer treatment in 1815. In 1858, a U.S. physician added a powdered form of the bloodroot plant (Sanguinaria canadensis), which contains the anticancer alkaloid sanguinarine; the compound was used to treat breast cancer. The current paste, formulated by Dr. Frederic E. Mohs, is a compound of naturally occurring ingredients: the mineral stibnite, which forms the inert paste-like vehicle; powered root of the bloodroot plant, which has been shown to induce apoptosis in several types of cancer; and a saturated zinc chloride solution, which destructively penetrates tissue.
A 1997 study explored the idea that surgery can liberate atypical melanocytes and predispose a patient to metastatic disease, Dr. Brooks said (Dermatol. Surg. 1997;23:1043-6). The epidemiologic study of 1,224 primary melanomas concluded that surgery of primary melanoma may enhance tumor growth at metastatic sites.
Chemosurgery with zinc chloride paste, therefore, helps avoid this phenomenon, Dr. Brooks said. The paste not only destroys tissue where it is applied, it also fixes the tissue into a firm mass. A delayed excision allows the specimen to be removed en bloc and examined histopathologically to determine margins. However, leaving a portion of the fixed tissue in place for several more days causes a strong vaccine-like reaction on the skin surface, indicating, according to Dr. Brooks, the beginning of a systemic immunologic response.
The Evidence
According to Dr. Brooks, he and his colleagues published the only piece of objective evidence on this phenomenon in 1998 (Dermatol. Surg. 1998;24:1021-5).
The study involved mice that were injected with two different melanoma types: a poorly immunogenic (B16) type and a more immunogenic type (K1735p). The resultant tumors were freshly excised in some mice, or excised 24 hours after the application of zinc chloride paste. A week later, all the mice received a second injection of melanoma cells at a different site. K1735p tumors developed at the challenge sites in significantly fewer of the mice pretreated with zinc chloride (32% vs. 69%, respectively). The paste did not alter the development of B16 melanomas. The authors concluded: "Zinc chloride fixation of the more immunogenic K1735p melanoma increased resistance to subsequent tumor challenge, suggesting that zinc chloride fixative paste acts as an immune adjuvant."
Treatment Application
At the meeting, Dr. Brooks presented his most recent article describing a simplified method for using the paste (Dermatol. Surg. 2010;36:237-40).
His process begins with a fresh tissue biopsy to confirm melanoma. He recommended a shaved saucerized excision with a margin of 1-2 mm beyond the suspected tumor edge carried at least through the mid-dermis, or below the suspected thickness of the lesion.
After melanoma is histopathologically confirmed, he applies the Mohs paste. Since the compound will not penetrate an intact keratin layer, it must only be applied to the excised area. "If the biopsied area has developed a crust or eschar, this must also be removed," Dr. Brooks said.
He applies a 1-mm thick layer of paste with a cotton-tipped swab. More can be applied for thicker lesions, but less if the lesion overlies an important anatomic structure. If the biopsy is a small excisional one, a swab of 50% bi- or trichloracetic acid can remove the outer keratin layer and allow the paste to penetrate.
The next step is to apply a sterile cotton ball and cover the dressing with bio-occlusive tape for 24 hours – the time it takes the paste to achieve full penetration. After 24 hours, the patient can return for a conventional, wide excision with standard vertical or bevelled Mohs margins, followed by closure.
However, to take advantage of the paste's immunologic properties, the block of tissue should be left in place for a week or longer, or the main block can be removed, leaving a rim of the fixed tissue in place to stimulate the immune response. Dr. Brooks said the fixed tissue can then be histologically examined to confirm negative margins. For patients with raised lesions, he recommended debulking to create a flat tissue plane and they applying the paste as described.
He also stressed that the Mohs paste does not interfere in any way with conventional melanoma treatment. "About half of my patients end up going to [a cancer center] for excision, sentinel nodes, or other treatment," including interferon, he said. But some patients, after reviewing the comparatively small survival benefit interferon offers and its significant side effects, elect to have the fixed tissue excised and then continue with the practice of node palpation and regular ultrasounds to identify any early disease spread.
Dr. Brooks reported having no relevant financial disclosures.
SAN DIEGO - A remedy that has been used for nearly 2 centuries is still a valuable adjuvant therapy for melanoma, according to Dr. Norman Brooks.
Zinc chloride paste not only penetrates and kills even thick melanomas, it appears to stimulate a strong immune reaction that decreases the likelihood of metastasis and recurrence, Dr. Brooks said at the meeting sponsored by the American Society for Mohs Surgery.
"I believe chemosurgery with zinc chloride paste, followed by wide excision, is a better way to remove a melanoma than fresh tissue surgery," said Dr. Brooks, a dermatologist in Encino, Calif., who specializes in skin cancers. "It not only kills the tumor locally but stimulates total body resistance and immunity, supporting the idea that surgery actually enhances melanoma tumor growth and metastatic spread. That’s why I believe it's so important to use zinc chloride when treating melanoma."
History of Zinc Chloride
Zinc chloride was first used as a cancer treatment in 1815. In 1858, a U.S. physician added a powdered form of the bloodroot plant (Sanguinaria canadensis), which contains the anticancer alkaloid sanguinarine; the compound was used to treat breast cancer. The current paste, formulated by Dr. Frederic E. Mohs, is a compound of naturally occurring ingredients: the mineral stibnite, which forms the inert paste-like vehicle; powered root of the bloodroot plant, which has been shown to induce apoptosis in several types of cancer; and a saturated zinc chloride solution, which destructively penetrates tissue.
A 1997 study explored the idea that surgery can liberate atypical melanocytes and predispose a patient to metastatic disease, Dr. Brooks said (Dermatol. Surg. 1997;23:1043-6). The epidemiologic study of 1,224 primary melanomas concluded that surgery of primary melanoma may enhance tumor growth at metastatic sites.
Chemosurgery with zinc chloride paste, therefore, helps avoid this phenomenon, Dr. Brooks said. The paste not only destroys tissue where it is applied, it also fixes the tissue into a firm mass. A delayed excision allows the specimen to be removed en bloc and examined histopathologically to determine margins. However, leaving a portion of the fixed tissue in place for several more days causes a strong vaccine-like reaction on the skin surface, indicating, according to Dr. Brooks, the beginning of a systemic immunologic response.
The Evidence
According to Dr. Brooks, he and his colleagues published the only piece of objective evidence on this phenomenon in 1998 (Dermatol. Surg. 1998;24:1021-5).
The study involved mice that were injected with two different melanoma types: a poorly immunogenic (B16) type and a more immunogenic type (K1735p). The resultant tumors were freshly excised in some mice, or excised 24 hours after the application of zinc chloride paste. A week later, all the mice received a second injection of melanoma cells at a different site. K1735p tumors developed at the challenge sites in significantly fewer of the mice pretreated with zinc chloride (32% vs. 69%, respectively). The paste did not alter the development of B16 melanomas. The authors concluded: "Zinc chloride fixation of the more immunogenic K1735p melanoma increased resistance to subsequent tumor challenge, suggesting that zinc chloride fixative paste acts as an immune adjuvant."
Treatment Application
At the meeting, Dr. Brooks presented his most recent article describing a simplified method for using the paste (Dermatol. Surg. 2010;36:237-40).
His process begins with a fresh tissue biopsy to confirm melanoma. He recommended a shaved saucerized excision with a margin of 1-2 mm beyond the suspected tumor edge carried at least through the mid-dermis, or below the suspected thickness of the lesion.
After melanoma is histopathologically confirmed, he applies the Mohs paste. Since the compound will not penetrate an intact keratin layer, it must only be applied to the excised area. "If the biopsied area has developed a crust or eschar, this must also be removed," Dr. Brooks said.
He applies a 1-mm thick layer of paste with a cotton-tipped swab. More can be applied for thicker lesions, but less if the lesion overlies an important anatomic structure. If the biopsy is a small excisional one, a swab of 50% bi- or trichloracetic acid can remove the outer keratin layer and allow the paste to penetrate.
The next step is to apply a sterile cotton ball and cover the dressing with bio-occlusive tape for 24 hours – the time it takes the paste to achieve full penetration. After 24 hours, the patient can return for a conventional, wide excision with standard vertical or bevelled Mohs margins, followed by closure.
However, to take advantage of the paste's immunologic properties, the block of tissue should be left in place for a week or longer, or the main block can be removed, leaving a rim of the fixed tissue in place to stimulate the immune response. Dr. Brooks said the fixed tissue can then be histologically examined to confirm negative margins. For patients with raised lesions, he recommended debulking to create a flat tissue plane and they applying the paste as described.
He also stressed that the Mohs paste does not interfere in any way with conventional melanoma treatment. "About half of my patients end up going to [a cancer center] for excision, sentinel nodes, or other treatment," including interferon, he said. But some patients, after reviewing the comparatively small survival benefit interferon offers and its significant side effects, elect to have the fixed tissue excised and then continue with the practice of node palpation and regular ultrasounds to identify any early disease spread.
Dr. Brooks reported having no relevant financial disclosures.
EXPERT ANALYSIS FROM A MEETING SPONSORED BY THE AMERICAN SOCIETY FOR MOHS SURGERY