Based on the analysis of modern literature, surgical approaches to the treatment  of chronic pain syndrome in cancer patients are presented. The definition and classification of chronic pain syndrome is given, its pathophysiology is described. The frequency of occurrence in the population and its dependence on the stage and localization of malignant neoplasm is shown. For practical use, an algorithm for the diagnosis of chronic pain syndrome and the basic principles of its therapy are presented.  As the 4th step of the World Health Organization pain relief ladder, surgical methods for the treatment of chronic pain syndrome are separately considered. Three main types of surgical interventions (neuromodulating, neurodestructive and anatomical) are described, indications and contraindications to their use are indicated.

Regional recurrences are one of the most common first manifestations of progression of clinically localized cutaneous melanoma. They are caused by subclinical metastases in the lymph nodes. Biopsy of the sentinel lymph nodes is the most effective method of detection of hidden regional metastases. It allows to appropriately increase the volume of surgical treatment  prior to dissection of the affected lymph collector and perform adjuvant therapy with the most effective drugs. This, in its turn, allows for significant improvement of regional and systemic control of the disease and long-term treatment outcomes.

Data obtained in several randomized trials on the effectiveness of lymph node dissection in patients  with sentinel lymph node metastasis showed that this procedure significantly improves regional control of the disease but does not affect long-term treatment outcomes. Additionally, some studies showed that assignment of responsibility for regional control to adjuvant therapy does not meet the expectations. Therefore, the most effective method of regional control of cutaneous melanoma is surgery. All of these studies show that it is necessary to develop criteria for identification of patients with high risk of metastases in the non-sentinel lymph nodes who require lymph node dissection for regional disease control and creation of the best conditions for adjuvant systemic therapy. This requires identification of predictors of multiple involvement of regional lymph nodes justifying indications for radical lymph node dissection. Studies in this area are being performed but their results are ambiguous and sometimes contradictory.

Aim. To evaluate the effectiveness of lymph node biopsy and radical lymph node dissection in patients with cutaneous melanoma and subclinical involvement of the sentinel lymph node.

Introduction. In patients with local recurrences of melanoma or with transit metastases of this tumor located distal to the axilla and inguinal region, the use of isolated regional limb perfusion is considered as one of the effective treatment options.

Aim. To evaluate the long-term results of treatment extremities melanoma using the method of isolated regional perfusion of the extremities.

Materials and methods. An analysis of the treatment and observation results of 72 patients (12 men and 60 women) with melanoma of the extremities was carried out, the median age was 56.7 years (from 25 to 78 years). All patients underwent isolated regional perfusion with hyperthermia using melphalan at doses of 10 mg/l volume for the lower limb and 13 mg/l volume for the upper limb. Patient survival for 5 years, the incidence of relapses and metastases of melanoma, as well as the frequency of limb amputation were assessed.

Results. The rate of complete response to treatment was 13.9 %, in the vast majority of cases there was a partial regression – in 72.2 % of cases. There was no response to treatment in only 13.9 % of patients.

Recurrence of transit metastases within 5 years developed in 52 (72.2 %) patients.  Amputation was performed only in 11.1 % of cases. The 1-year survival rate was 91.7 %, the 5-year survival rate for melanoma patients who underwent isolated regional perfusion was 55.6 %.

Сonclusion. Isolated regional perfusion under conditions of hyperthermia with melphalan is an effective and safe method of treatment  in terms of long-term results of melanoma treatment,  providing a 5-year patient  survival rate of 55.6 %, a low rate of amputations and metastasis.

Introduction. It is generally accepted that dedifferentiated  chondrosarcomas are a result of transformation of low-grade (grade I and II) malignant chondrosarcomas into sarcoma with marked signs of cellular and tissue anaplasia with more aggressive clinical progression. Morphological examination of dedifferentiated  chondrosarcomas allows to detect presence of pre-existent low-grade malignant chondrosarcoma tissue. Dedifferentiated chondrosarcomas comprise about 10 % of all chondrosarcomas. Most frequently, this tumor is located in the femur, pelvic bones, and humerus. A common clinical complication of dedifferentiated chondrosarcomas is pathological fracture. This disease is characterized by more aggressive progression with unfavorable prognosis compared to conventional types of chondrosarcomas.

Aim. To study in detail  the  data  of laboratory,  clinical, radiological and morphological examinations of patients with different chondrosarcoma types for refinement of the algorithm of dedifferentiated chondrosarcoma examination and diagnosis.

Materials and methods. Between 2008 and 2022, data of 160 patients  with chondrosarcomas of varying locations and differentiation were analyzed. Diagnosis of “cartilaginous tumor” was made in all patients after clinical and radiological exams, as well as preoperative biopsy. Diagnosis of “dedifferentiated chondrosarcoma” was made in 30 patients. Radiological exam included several methods (X-ray, X-ray computed tomography, and magnetic resonance imaging) and modes of patient  examination.  Morphological diagnosis included routine  techniques  of histological analysis with gentle decalcification and subsequent immunohistochemical (PD-L1, PU-1, CD8, CD20, Ki67, CD34) and genetic analyses (IDH1/IDH2).

Results. Among 160 patients, preoperative biopsy verified the diagnosis of “dedifferentiated chondrosarcoma” only in 6 patients. In 4 patients, the possibility of chondrosarcoma transformation into poorly differentiated sarcoma of non-cartilaginous structure was suspected. At the stage of postoperative material examination, diagnosis of “dedifferentiated chondrosarcoma” was confirmed in 4 patients with suspicion of more malignant tumor transformation and newly made in 20 more patients.  Female patients were a little more common (19/11).  Mean patient  age was 59 years. Pathological fracture at the preoperative stage was observed in 6 patients. In almost one third of the cases (36 %), decreased differentiation of chondrosarcoma compared to preoperative biopsy was observed. It is important for management of these patients that in approximately 13 % of chondrosarcoma cases, recurrence with decreased tumor differentiation is observed.

Conclusion. Radical surgical resection remains the standard treatment of chondrosarcoma as the effectiveness of radio- and chemotherapy is limited though it remains important in dedifferentiated type of the disease. These circumstances lead to the use of tumor immunotherapy targeted at the search for potential use of the immune response for recognition and killing of various malignant cells including dedifferentiated chondrosarcoma. Consequently, a promising research direction is determination of the significance of tumor-associated macrophages, as well as tumor-infiltrating lymphocytes as antitumor factors and biomarkers affecting clinical and morphological characteristics of oncological diseases.

Introduction. Giant cell tumor of bone is a relatively rare, locally aggressive osteolytic skeletal neoplasm with uncertain behavior: recurrence rates up to 70 % and distant metastases occur 2–6 % of cases. Nowadays denosumab is the choice of therapy for patients  with unresectable  or advanced disease. However,  the efficiency,  duration or administration and most of all safety of continuous denosumab are not established.

Materials and methods.  Fourty advanced or unresectable giant cell tumor cases were observed from 2005 till 2020 in N.N. Blokhin National Medical Research Center of Oncology. The average age of pts was 33,6 ± 13,1 years (18–64), and the women and men ratio was about 2,1 : 1. The most commonly affected sites were long bones of the lower extremities (22,5 %), sacrum (22,5 %), long bones of the upper extremities (17,5 %), spine (17,5 %), pelvis (10 %) and others. 70 % of cases were anatomically compounded due to tumor localization and 27,5 % of cases were primary disease. 37,5 % of cases were with pulmonary metastases. Patients underwent computed tomography / magnetic resonance imaging every 3 months during the first three years and then once every six months. Patient received subcutaneous denosumab 120 mg every 4 weeks with a loading dose of 120 mg subcutaneous on study days 8 and 15. After 2 years monthly therapy and confirmed stabilization  effect patient  then  received maintenance  therapy: once in three  months injection. All patients received daily calcium and vitamin D supplement.

Results. Median follow-up was 52,8 ± 41,3 months (3–219 months). The average denosumab injections were 25 ± 16 (4–85). Clinical and radiographically stabilization of the effect occurred on average at 12 ± 8 (4–32) injections. Hypocalcemia was registered in one case (2.5 %). There was significant improvement of Karnofsky scale, Visual analogue scale (VAS) and Watkins scale (p <0.001). 5-year progression-free survival for was 70.1 % (95 % confidence interval 55.7–88.0), the median was not reached. Progression of disease was observed only in subgroup with violations in denosumab administration or its cancellation (32,5 %). 3-year progression-free survival in subgroup with violations in denosumab administration or its cancellation was 10 % (95 % confidence interval 15.5–64.1). In subgroup with continuous denosumab and once in three months injection after 2 years monthly therapy there was no signs of progression.

Conclusions. In this study we showed evidence of safety and effectiveness of continuous denosumab for unresectable or advanced giant cell tumor even with once in three months injection therapy. Denosumab for advanced giant cell tumor of bone became a choice of treatment, but we need further investigation for observation long term denosumab effectiveness and complications.

Ollier disease is a rare non-hereditary disorder of the bone tissue characterized by development of multiple benign bone tumors – enchondromas. One of the dangerous complications of this pathology is tumor transition into chondrosarcoma. Currently, there are no drug therapies for Ollier disease. Surgical treatment is performed in case of complications (chondrosarcoma, pathological fracture).

The article presents a clinical case of chondrosarcoma treatment  in a 42-year-old male with Ollier disease diagnosed when the patient was 8 years old. Since 2021, the patient noted intensive tumor growth on the right foot and left calf. In August of 2022, the patient sought medical help at the Republican Clinical Oncological Dispensary of the Bashkortostan Ministry of Health. Examination showed synchronous malignant transformation of enchondromas of the right foot and left calf confirmed by histological exam. Due to tumor advancement, surgical treatment  was performed. Other enchondroma lesions are being watched.