A new technology will soon be available in Brazil for the noninvasive treatment of patients with nonmelanoma skin cancer, the most frequent type of skin cancer worldwide.
In recent years, a device developed by a group of researchers at the University of São Paulo’s São Carlos Physics Institute (IFSC-USP) for the diagnosis and optical treatment of nonmelanoma skin cancer has achieved promising results, especially in the elimination of early-stage tumors. The procedure is currently being evaluated for use by the Brazilian national health service (SUS).
Created at the Center for Research in Optics and Photonics (CEPOF), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by FAPESP, the technique was presented during the São Paulo School of Advanced Science on Modern Topics in Biophotonics held at IFSC-USP on March 20-29, 2019.
The event was supported by FAPESP through its São Paulo Schools of Advanced Science Program (SPSAS) and attended by graduate students and young researchers from Brazil and abroad. The discussions focused on advanced topics in biophotonics, a multidisciplinary research area that utilizes light-based technologies in medicine and the life sciences.
“The device was developed in Brazil with totally national technology,” Cristina Kurachi, a professor at IFSC-USP and one of the creators of the technique, told Agência FAPESP.
Made by MM Optics, a São Carlos-based startup, the device uses optical fluorescence to recognize and measure tumoral lesions in minutes. Lesions are then treated with a methyl aminolevulinate (MAL) cream developed by PDF-Pharma, another startup based on Cravinhos, São Paulo State. MAL is a derivative of 5-aminolevulinic acid (5-ALA).
After two hours of contact with the skin, the compound is absorbed and, inside the tumor cell mitochondria, gives rise to protoporphyrin, a photosensitizing pigment that is a precursor of chlorophyll.
The cream is removed from the lesion, and the region is irradiated for 20 minutes with a 630 nanometer red light source coupled to the device. The light activates the protoporphyrin and triggers a sequence of reactions in the tumor cells, generating reactive oxygen species capable of eliminating the lesions while leaving healthy tissue intact.
The device produces fluorescence images after the procedure to ensure total irradiation of the lesions. Two sessions are required for the treatment, with a one-week interval between sessions. After 30 days, the lesions are reappraised, and a biopsy is performed to confirm elimination of the tumors.
As part of a project supported by the Brazilian government via BNDES, the national development bank, and FINEP, the Brazilian Innovation Agency, clinical trials were held to validate the technique at 72 health centers nationwide. The multicenter study was led by Vanderlei Salvador Bagnato, Full Professor at IFSC-USP and coordinator of CEPOF.
For example, more than 2,000 lesions were treated with the new technique, and 40 groups of physicians were trained to use it at Hospital Amaral Carvalho in Jaú, São Paulo State. Clinical trials were also conducted in nine other Latin American countries. Their results showed that the treatment is capable of eliminating 95% of the tumors treated without scarring or side effects except for minor redness at the site.
“Although we work at a physics institute, we’ve been doing translational medicine. In other words, we’ve succeeded in transferring the results of basic research to clinical applications that benefit the public, especially the poor,” said Kurachi, one of the organizers of the SPSAS in Biophotonics.
The translational nature of the research conducted by the group at IFSC-USP was one of the factors that aroused the interest of researcher Fleury Augustin Nsole Biteghe in coming to Brazil to attend the SPSAS in Biophotonics.
Biteghe is a postdoctoral fellow in chemical biology at the University of Cape Town in South Africa, where his main research interest is the application of photodynamic therapy to treat skin cancer. He heard about the event while in Germany last year to participate in a conference on photodynamic therapy where some of the scientists affiliated with IFSC-USP presented their results.
“I was impressed and very interested in being part of the research done by this group in Brazil. They’ve shown that it’s possible to do translational research resulting in novel treatments for skin cancer,” Biteghe said. “I plan to apply for a postdoctoral fellowship with this research group to learn from them and take the experience back to South Africa, where we’ve faced obstacles in developing technology that enables photodynamic therapy to be used in clinical practice.”
The SPSAS in Biophotonics was attended by 138 graduate students and early-career researchers, 48 of whom came from other countries, including Argentina, Canada, Finland, Norway, Poland, Russia and the United States. The other 90 were Brazilians from different parts of the country.
The program consisted of poster sessions, lectures and courses led by some of the foremost experts in fields such as tissue optics, neurophotonics and biosensors.
One of the speakers was Gang Zheng, a professor at the University of Toronto and Senior Scientist at Princess Margaret Cancer Center, also in Toronto, Ontario (Canada). In 2011, Zheng and colleagues at his laboratory discovered the first all-organic nanoparticle possessing intrinsically multimodal biophotonic properties, which was obtained from porphyrin.
More recently, Zheng’s group developed larger porphyrin microbubbles that burst on exposure to low-frequency ultrasound and form smaller nanoparticles with the same optical properties as the original microbubbles.
“These nanoparticles can be used simultaneously to obtain images of tumors and deliver drugs for cancer treatment,” Zheng explained during his presentation.
The School was also attended by researchers from Israel, Spain, Portugal and the United Kingdom.
“We invited researchers from a range of countries so that the students could get a broad overview of biophotonics research in progress in different parts of the world,” Kurachi said.