Zinc Paste May Enhance Mohs Surgery Success

SAN DIEGO — The use of zinc chloride fixative paste may be controversial, but its judicious application can increase the melanoma-clearing properties of Mohs surgery, Dr. Norman A. Brooks said at a meeting sponsored by the American Society for Mohs Surgery.

"Zinc chloride fixative paste is an amazing substance; it has the ability to cure cancer right out of the bone," said Dr. Brooks, a Mohs surgeon in private practice in Encino, Calif.

Application of the paste has been shown to freeze melanomatous tissue in place. This process kills the tissue, which can then be removed using Mohs surgery.

Dr. Frederic Mohs did not invent the paste, but he did fine-tune the standard formula, which is still in use today.

The use of zinc chloride fixative paste for the treatment of skin conditions has not been approved by the Food and Drug Administration, and patients should not apply it themselves or buy it online. The paste is powerful, toxic, and potentially scar causing, and it must be handled carefully, Dr. Brooks said.

It does, however, appear to work. Studies have shown higher cure rates in melanoma patients when the paste was used prior to excision of the cancer with Mohs surgery, he noted.

The application of zinc chloride fixative paste is a two-step process. The paste can't penetrate the outer keratin layer of the skin, so it's necessary to apply a saturated dichloroacetic or trichloroacetic acid solution to the area. When the area turns white, that means the acid has dissolved the keratin and the paste can be applied. The paste is applied in a layer 1- to 2-mm thick, with a narrow margin around the clinical melanoma that includes subclinical extensions. A dry, sterile cotton ball is then applied with clear plastic adhesive tape as an occlusive dressing to hold the paste in place.

Approximately 24 hours later, the killed tissue is excised and a wall of white, fixed tissue will be visible, Dr. Brooks said. The excised specimen can be preserved in formaldehyde, embedded in paraffin, and sectioned for examination.

The use of zinc chloride paste is not a substitution for Mohs surgery, but it can be a supplement to it. "If used preoperatively, after a biopsy, it can cure patients even more effectively than surgery alone," Dr. Brooks said.

Zinc chloride paste does not get the publicity of cancer treatments such as interferon because it is not FDA approved, Dr. Brooks noted. Companies that might consider seeking FDA approval balk at the multimillion-dollar cost of a toxicity study. Although the paste is made of naturally occurring ingredients, the toxicity study is cost prohibitive and no company has been willing to put up the money.

"I don't blame them. That would be financially insane," Dr. Brooks said. But that doesn't mean Mohs surgeons can't use the paste if they get informed consent from patients.

"You need to tell the patient that this is not an FDA-approved drug; it is a naturally occurring substance, and it can improve the outcome of the surgery by reducing the risk of recurrence," Dr. Brooks said.

The formula for zinc paste perfected by Dr. Mohs has been published and can be found in the Mohs surgery literature.

Many patients with cancer are now receiving preoperative treatments such as chemotherapy, and the use of zinc chloride fixative paste prior to excision of the cancer can be another effective strategy when properly applied, Dr. Brooks said.

A biopsy was performed on a 1.8-mm-thick amelanotic melanoma of the left arm.

Zinc chloride fixative paste was applied to the fresh tissue site with a 2- to 3-mm margin.

A dressing held the zinc chloride paste in place for 24 hours before Mohs excision.

Conventional excision of a deep wide margin was done a week after applying paste.

No sentinel node involvement was seen on this patient at time of fresh tissue excision. Photos courtesy Dr. Norman A. Brooks

SAN DIEGO — The use of zinc chloride fixative paste may be controversial, but its judicious application can increase the melanoma-clearing properties of Mohs surgery, Dr. Norman A. Brooks said at a meeting sponsored by the American Society for Mohs Surgery.

"Zinc chloride fixative paste is an amazing substance; it has the ability to cure cancer right out of the bone," said Dr. Brooks, a Mohs surgeon in private practice in Encino, Calif.

Application of the paste has been shown to freeze melanomatous tissue in place. This process kills the tissue, which can then be removed using Mohs surgery.

Dr. Frederic Mohs did not invent the paste, but he did fine-tune the standard formula, which is still in use today.

The use of zinc chloride fixative paste for the treatment of skin conditions has not been approved by the Food and Drug Administration, and patients should not apply it themselves or buy it online. The paste is powerful, toxic, and potentially scar causing, and it must be handled carefully, Dr. Brooks said.

It does, however, appear to work. Studies have shown higher cure rates in melanoma patients when the paste was used prior to excision of the cancer with Mohs surgery, he noted.

The application of zinc chloride fixative paste is a two-step process. The paste can't penetrate the outer keratin layer of the skin, so it's necessary to apply a saturated dichloroacetic or trichloroacetic acid solution to the area. When the area turns white, that means the acid has dissolved the keratin and the paste can be applied. The paste is applied in a layer 1- to 2-mm thick, with a narrow margin around the clinical melanoma that includes subclinical extensions. A dry, sterile cotton ball is then applied with clear plastic adhesive tape as an occlusive dressing to hold the paste in place.

Approximately 24 hours later, the killed tissue is excised and a wall of white, fixed tissue will be visible, Dr. Brooks said. The excised specimen can be preserved in formaldehyde, embedded in paraffin, and sectioned for examination.

The use of zinc chloride paste is not a substitution for Mohs surgery, but it can be a supplement to it. "If used preoperatively, after a biopsy, it can cure patients even more effectively than surgery alone," Dr. Brooks said.

Zinc chloride paste does not get the publicity of cancer treatments such as interferon because it is not FDA approved, Dr. Brooks noted. Companies that might consider seeking FDA approval balk at the multimillion-dollar cost of a toxicity study. Although the paste is made of naturally occurring ingredients, the toxicity study is cost prohibitive and no company has been willing to put up the money.

"I don't blame them. That would be financially insane," Dr. Brooks said. But that doesn't mean Mohs surgeons can't use the paste if they get informed consent from patients.

"You need to tell the patient that this is not an FDA-approved drug; it is a naturally occurring substance, and it can improve the outcome of the surgery by reducing the risk of recurrence," Dr. Brooks said.

The formula for zinc paste perfected by Dr. Mohs has been published and can be found in the Mohs surgery literature.

Many patients with cancer are now receiving preoperative treatments such as chemotherapy, and the use of zinc chloride fixative paste prior to excision of the cancer can be another effective strategy when properly applied, Dr. Brooks said.

A biopsy was performed on a 1.8-mm-thick amelanotic melanoma of the left arm.

Zinc chloride fixative paste was applied to the fresh tissue site with a 2- to 3-mm margin.

A dressing held the zinc chloride paste in place for 24 hours before Mohs excision.

Conventional excision of a deep wide margin was done a week after applying paste.

No sentinel node involvement was seen on this patient at time of fresh tissue excision. Photos courtesy Dr. Norman A. Brooks

SAN DIEGO — The use of zinc chloride fixative paste may be controversial, but its judicious application can increase the melanoma-clearing properties of Mohs surgery, Dr. Norman A. Brooks said at a meeting sponsored by the American Society for Mohs Surgery.

"Zinc chloride fixative paste is an amazing substance; it has the ability to cure cancer right out of the bone," said Dr. Brooks, a Mohs surgeon in private practice in Encino, Calif.

Application of the paste has been shown to freeze melanomatous tissue in place. This process kills the tissue, which can then be removed using Mohs surgery.

Dr. Frederic Mohs did not invent the paste, but he did fine-tune the standard formula, which is still in use today.

The use of zinc chloride fixative paste for the treatment of skin conditions has not been approved by the Food and Drug Administration, and patients should not apply it themselves or buy it online. The paste is powerful, toxic, and potentially scar causing, and it must be handled carefully, Dr. Brooks said.

It does, however, appear to work. Studies have shown higher cure rates in melanoma patients when the paste was used prior to excision of the cancer with Mohs surgery, he noted.

The application of zinc chloride fixative paste is a two-step process. The paste can't penetrate the outer keratin layer of the skin, so it's necessary to apply a saturated dichloroacetic or trichloroacetic acid solution to the area. When the area turns white, that means the acid has dissolved the keratin and the paste can be applied. The paste is applied in a layer 1- to 2-mm thick, with a narrow margin around the clinical melanoma that includes subclinical extensions. A dry, sterile cotton ball is then applied with clear plastic adhesive tape as an occlusive dressing to hold the paste in place.

Approximately 24 hours later, the killed tissue is excised and a wall of white, fixed tissue will be visible, Dr. Brooks said. The excised specimen can be preserved in formaldehyde, embedded in paraffin, and sectioned for examination.

The use of zinc chloride paste is not a substitution for Mohs surgery, but it can be a supplement to it. "If used preoperatively, after a biopsy, it can cure patients even more effectively than surgery alone," Dr. Brooks said.

Zinc chloride paste does not get the publicity of cancer treatments such as interferon because it is not FDA approved, Dr. Brooks noted. Companies that might consider seeking FDA approval balk at the multimillion-dollar cost of a toxicity study. Although the paste is made of naturally occurring ingredients, the toxicity study is cost prohibitive and no company has been willing to put up the money.

"I don't blame them. That would be financially insane," Dr. Brooks said. But that doesn't mean Mohs surgeons can't use the paste if they get informed consent from patients.

"You need to tell the patient that this is not an FDA-approved drug; it is a naturally occurring substance, and it can improve the outcome of the surgery by reducing the risk of recurrence," Dr. Brooks said.

The formula for zinc paste perfected by Dr. Mohs has been published and can be found in the Mohs surgery literature.

Many patients with cancer are now receiving preoperative treatments such as chemotherapy, and the use of zinc chloride fixative paste prior to excision of the cancer can be another effective strategy when properly applied, Dr. Brooks said.

A biopsy was performed on a 1.8-mm-thick amelanotic melanoma of the left arm.

Zinc chloride fixative paste was applied to the fresh tissue site with a 2- to 3-mm margin.

A dressing held the zinc chloride paste in place for 24 hours before Mohs excision.

Conventional excision of a deep wide margin was done a week after applying paste.

No sentinel node involvement was seen on this patient at time of fresh tissue excision. Photos courtesy Dr. Norman A. Brooks