Merkel cell carcinoma (MCC) is a rare and aggressive type of skin cancer that arises from Merkel cells, which are located in the upper layer of the skin and are responsible for the perception of touch. The main manifestations of this disease may include painless skin nodules that can quickly enlarge. The skin may often take on a reddish or bluish tint. It is important to note that MCC has a high tendency to metastasize, making early diagnosis and treatment especially critical to increase patient survival. Factors that contribute to the development of carcinoma include exposure to ultraviolet rays from the sun, immunosuppression, and infections caused by the herpes simplex virus and Epstein-Barr virus.
History of the disease and interesting historical facts
Merkel cell carcinoma was first described in 1972 when unique neoplastic cells were found in two patients suffering from an aggressive form of skin cancer. Named after German pathologist Hans Merkel, the carcinoma received its name due to its association with Merkel cells. Interestingly, the disease was initially considered rare and was often misdiagnosed, which contributed to its less accurate research. In the 2000s, research confirming the link between the disease and HPV (human papillomavirus) attracted significant attention to MCC, changing the approach to diagnosis and treatment. Research shows that Merkel cell carcinoma is highly invasive and is associated with a very poor prognosis if not treated early.
Epidemiology
The epidemiology of Merkel cell carcinoma indicates its relative rarity. According to the latest analysis, the incidence in the general population is approximately 0.3-1 case per 100,000 persons per year. Studies have shown that the disease is most common in older people, especially those over 65 years of age, and presumably more common in men. Geographical differences in incidence are also observed; for example, significantly more cases of MCC are recorded in regions with high levels of solar radiation. In addition, a significant increase in the incidence has been observed in recent decades, which is associated with the aging of the population, increased life expectancy, and changes in environmental ecology.
Genetic predisposition to this disease
It has now been established that genetic predisposition plays an important role in the development of Merkel cell carcinoma. In most cases, an association with mutations in the TP53 and Rb genes is observed. Molecular understanding suggests that, in addition to the above mutations, genes responsible for the immune response and cell proliferation may also be involved. Recent studies have identified a specific mutation in the gene encoding a protein associated with HPV, which also confirms the role of viral infections in the pathogenesis of carcinoma. It should be noted that even in patients without an obvious genetic predisposition, immunosuppression may be a significant risk factor.
Risk factors for the development of this disease
Major risk factors for developing Merkel cell carcinoma include:
- Exposure to ultraviolet radiation, both solar and artificial;
- Immunosuppression associated with organ transplantation or HIV infection;
- Previous skin diseases such as cutaneous lymphoma or other skin cancers;
- Disorders caused by HPV, especially types 16 and 18;
- Older age, especially after 65 years.
These factors together play an important role in the development of this aggressive type of cancer.
Diagnosis of this disease
The diagnosis of Merkel cell carcinoma involves several key components:
Diagnosis begins with a clinical examination, where the doctor pays attention to the main symptoms, such as:
- Painless nodules on the skin;
- Change in skin color around the tumor;
- Rapid growth of formations;
- Systemic manifestations such as weight loss or general weakness.
Laboratory tests may include blood tests for tumor markers such as neurotensin or CA 19-9. Radiological tests such as CT or MRI can evaluate for lymph node or internal metastases. Other diagnostic tests may include biopsy of the lesion, which allows histological examination to confirm the presence of carcinoma. Differential diagnosis includes ruling out other forms of skin cancer such as basal cell carcinoma or melanoma.
Treatment
Treatment for Merkel cell carcinoma depends on the stage of the disease and may include the following approaches:
- Surgery, which is the main method of treatment, is aimed at removing the primary tumor while capturing healthy tissue;
- Pharmacological treatment, including chemotherapy and targeted therapy, may be prescribed in the presence of metastases;
- Radiation therapy is used as an additional method or when surgical treatment is unavailable;
- Immunological drugs are becoming increasingly relevant in clinical practice, especially for patients with metastatic form.
The effectiveness of treatment depends on the stage of the disease at the time of diagnosis and the presence of metastases.
List of medications used to treat this disease
Medicines used to treat Merkel cell carcinoma include:
- Cisplatin;
- Doxorubicin;
- Paclitaxel;
- Immuno-oncology drugs such as nivolumab and Pembrolizumab.
The choice of a specific treatment regimen should always be based on the individual patient characteristics and the stage of the disease.
Disease monitoring
Monitoring for Merkel cell carcinoma includes regular check-ups:
- Every three to four months during the first year after treatment;
- Semi-annual assessment of the state for the second and third years;
- One-year follow-up after three years if there are no signs of relapse.
It is important to remember that the prognosis in the absence of metastases in the first years is 60-80%, but in the presence of metastases these indicators are significantly reduced. Possible complications include relapses of the disease and side effects from the treatment.
Age-related features of the disease
Merkel cell carcinoma is usually more common in older people, although cases have been observed in younger patients. In older people, the disease may develop against the background of other chronic diseases, which complicates diagnosis and treatment. In younger people, this disease may manifest itself in a more aggressive form. In addition, different age groups also respond differently to treatment, which requires a personalized approach.
Questions and Answers
- What are the main features of Merkel cell carcinoma? The main signs include painless nodules on the skin that can quickly enlarge and change color.
- How is this disease diagnosed? Diagnosis includes clinical examination, biopsy, laboratory and radiological studies.
- What are the major risk factors for developing Merkel cell carcinoma? Major risk factors include exposure to solar radiation, immunosuppression, and age over 65 years.
- How is Merkel cell carcinoma treated? Treatment includes surgery, chemotherapy, radiation therapy and immunotherapy.
- What is the prognosis of the disease with early diagnosis? The prognosis with early diagnosis can reach 60-80% survival in the first years.
