One of the most dreaded diseases of the century, skin cancer has become a matter of concern with the rising number of people becoming a victim to its symptoms. Researches are going on to find ways to stop the occurrence as well as spread of the disease.
Photodynamic therapy is one such treatment that is used to stop the cancerous cells from growing. Before we try to understand what this treatment is all about and how has it proven to be an affective measure in treating Skin cancer, let us first introduce ourselves to the symptoms and causes of Skin cancer.
Symptoms and Causes of Skin Cancer
The Symptoms of skin cancer are divided in two groups- the Non melanoma and the melanoma group. The non melanoma symptoms are less dangerous than the melanoma symptoms. It is only when the melanoma symptoms are ignored and kept untreated that they convert in to melanoma symptoms of skin cancer. The symptoms are easy to understand.
The symptom begins with small moles or lumps which are smooth, shiny, firm and pale in colour. Sometimes sores become crusty with blood oozing out of them and do not heal. Uneven patches on the skin those become scaly later on can also be symptoms of skin cancer. Flaked areas of the skin, that do not get cured easily and reappear frequently also need medical attention immediately.
While some cases of skin cancer have been found to be genetic and keeps propagating from one generation to another, the main reason that triggers the cancerous cells of the skin are the harmful UV rays. The invisible UV rays are responsible for causing skin tans and sun burns. They are the part that causes the sun rays to become hot. These UV rays when get absorbed by the unprotected skin destroys the genetic materials that are needed for the healthy maintenance of the skin. This results in the unnatural growth of the skin cells triggering off skin cancer.
What is Photodynamic Therapy?
As the name Photodynamic therapy suggests, this therapy combines special drugs called photo sensitizers which are photosensitizing agents with certain wave lengths of light to kill the cancerous cells. Since the skin is easily reachable to photon based therapies therefore use of photodynamic therapy with general and topical agents has proved to be very affective in treating cutaneous disorders.
The process produces a type of Oxygen that inhibits the further growth of the carcinogen cells on the skin. The photosensitizing are wavelength specific and the degree of skin infection and the type of photosensitizing agents used determine the wavelength which will prove effective in triggering the sensitizers.
Action of the Photosensitizing agents and corresponding wavelengths of light to kill the cancer cells.
When using the photosynthesizing agents in killing the cancer cells, the agents have a two fold effect on the cancer cells. Firstly, as the agents get injected in to the body, they are absorbed by all the cells but stay longer in the cancer cells. At a predetermine time, which is usually 24-72 hour after the injection has been applied, the affected portion of the skin is exposed to a light of particular wavelength. This triggers the agents to produce a kind of active oxygen that has an inhibiting effect on the cancer cells.
Other than directly acting on the cancerous tumours, the photosensitive agents attack the blood supply mechanism of the tumour and prevent the tumour from getting essential growth nutrients for its development. This gradually shrinks the size of the tumour. The other effective manner in which the agents work is by triggering the body’s immune system to produce antibodies which will fight the colonization of the cancer cells within the body.
As discussed earlier the photosensitizing agents get triggered when they receive a particular wavelength of light. For example, red light triggers phototoxic reactions of delta-ALA, Protoporphyrin IX gets triggered by Violet light. In clinical treatment, lasers are usually used as a source of this light. For skin cancer treatment, LED’s or Light Emitting Diodes are used to trigger the sensitive agents that have been injected on the surface of the skin.
The photosensitive agents vary as per the cancer colonization. In skin cancers, PDT-ALA is one of the common Photodynamic therapies that use Levulan as a photosensitive agent. The component is a 20%solution of Aminolevulinic acid, commonly known as ALA, which is a precursor of haemoglobin synthesis and is found in all humans. ALA has been found to be affective in curing severe acne and even cystic formations on the skin.
The advantages of ALA treatments have been ascertained to three main points. The side effects which are associated with this Photodynamic Therapy are almost negligible or at least curable. Secondly, PDT-ALA therapy allows simultaneous treatment of multiple carcinogenous skin infections and also controls bleeding, pus formation and scaling of the affected area.
Thirdly, ALA allows greater depth of light penetration and therefore higher efficiency in being effective on the cancer cells. Prior to the development of the PDT ALA treatment of skin cancer, Accunate was vastly used as a PDT agent. Although effective but Accunate was responsible for triggering off hormonal misbalance in the body that may cause depression and birth defects.
Topical PDT has been found to be effective in treating non melanoma skin cancer, nodular basal carcinoma cells, skin lymphomas and other cutaneous disorders with no side effects associated with them. Moreover, three to four sessions of systematic treatment has been able to cure patients totally of the disease. It is because of the following reasons that PDT is becoming popular as an alternative treatment to skin cancer other than chemotherapy.
With two simple steps of administrating the Photodynamic therapy, the risk factors associated with the exposure of the skin to radiation and chemicals is reduced to a large extent. This increases the efficiency of the treatment while causing little or no side effects. There are historical evidences to suggest that photodynamic therapy is not new to the treatment of skin cancer. With more than hundred years of usage, the accuracy and competence of the therapy in the field of oncology cannot be ignored.
Photo Credit: Bestacne.net