Systemic treatment of advanced clear cell sarcoma: results from a retrospective international series from the World Sarcoma Network

Background

Clear cell sarcoma (CCS) is a translocated aggressive malignancy with a high incidence of metastases and poor prognosis. There are few studies describing the activity of systemic therapy in CCS. We report a multi-institutional retrospective study of the outcomes of patients with advanced CCS treated with systemic therapy within the World Sarcoma Network (WSN).

Materials and methods

Patients with molecularly confirmed locally advanced or metastatic CCS treated with systemic therapy from June 1985 to May 2021 were included. Baseline demographic and treatment information, including response by Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, was retrospectively collected by local investigators. Descriptive statistics were carried out.

Results

Fifty-five patients from 10 institutions were included. At diagnosis, the median age was 30 (15-73) years and 24% (n = 13/55) had metastatic disease. The median age at diagnosis was 30 (15-73) years. Most primary tumours were at aponeurosis (n = 9/55, 16%) or non-aponeurosis limb sites (n = 17/55, 31%). The most common fusion was EWSR1–ATF1 (n = 24/55, 44%). The median number of systemic therapies was 1 (range 1-7). The best response rate was seen for patients treated with sunitinib (30%, n = 3/10), with a median progression-free survival of 4 [95% confidence interval (CI) 1-7] months. The median overall survival for patients with advanced/metastatic disease was 15 months (95% CI 3-27 months).

Conclusions

Soft tissue sarcoma-type systemic therapies have limited benefit in advanced CCS and response rate was poor. International, multicentre prospective translational studies are required to identify new treatments for this ultra-rare subtype, and access to early clinical trial enrolment remains key for patients with CCS.

•

This is the largest reported series of advanced CCS patients treated with systemic therapy.

•

The activity of sarcoma-type systemic therapy is poor and modest responses were seen only with sunitinib.

•

Effective therapies are needed to improve outcomes for patients with this ultra-rare sarcoma type.

Is the BRAF mutation still an unfavorable risk factor in patients with metastatic melanoma in the era of modern therapies?

e21544

Background: BRAF-mutated (MUT) melanoma is characterized by specific clinical features including more aggressive biological behavior than BRAF wild-type (WT) melanoma. BRAF mutations are historically known as negative prognostic factor for to shorter overall survival (OS) in patients with stage IV disease with melanoma. Methods: Consecutive patients with unresectable or metastatic melanoma started treatment with BRAF inhibitors (BRAFi), BRAFi and MEK inhibitors (MEKi) or IT (anti-PD-1 antibody) between 1/Jan/2013 and 31/Dec/2020. Clinical factors including age, gender, primary location of melanoma, ECOG performance status, baseline LDH level, and location of metastases, response to treatment were analyzed. Survival analyses were performed using the Kaplan-Meier method, Log-rank and chi-square tests were used for comparison between groups. Data cut-off was 31/Dec/2021. Results: In total 1456 patients were enrolled. BRAF mutation was found in 723 (49.7%) patients and 733 (50.3%) patients were BRAF WT. All BRAF WT patients received first-line IT, while BRAF MUT patient received first-line treatment with BRAFi (n = 134/723, 18%), BRAFi and MEKi (n = 426, 58%) or anty-PD-1 (n = 173, 24%). BRAF MUT patients were significantly younger (median 60 vs 69; p < 0.0001), had worse ECOG (p = 0.0008), elevated LDH (p < 0.0001), had higher number of metastatic sites (p < 0.0001) and brain metastases (p < 0.0001). The estimated median OS (mOS) in BRAF WT group was 17.3 month while in BRAF MUT - 14.8 months (p = 0.33; HR = 0.94, Cl 95% 0.8-1.1). mOS in BRAF MUT group treated with BRAFi was - 10.0, while with BRAFi and MEKi combination - 14.9. BRAF WT and BRAF MUT groups treated with IT did not differ significantly in baseline characteristics. BRAF MUT group treated with IT achieved mOS of 26.2 months, while in BRAF WT 17.3 months. Conclusions: The analysis showed no differences in the median OS between BRAF MUT and BRAF WT patients with unresectable or metastatic melanoma treated with novel therapies (BRAFi-MEKi combination or IT), despite unfavorable prognostic factors in the BRAF MUT group. Moreover mOS was significantly prolonged in the BRAF MUT patients treated with IT.

Sequential treatment with targeted and immune checkpoint inhibitor therapies in patients with BRAF positive metastatic melanoma: Real-world data

e21539

Background: The use of targeted therapies (TT) and checkpoint inhibitors (IT) significantly prolonged survival in patients with metastatic melanoma, especially in patients with BRAF mutation-positive melanoma. Optimal sequence of therapies use is still a matter of debate. The aim of this study was to evaluate real-life practice and outcomes in melanoma patients treated sequentially. Methods: Consecutive patients with BRAF mutation-positive unresectable or metastatic melanoma started treatment with TT (BRAF and MEK inhibitors) and/or IT (anti-PD1) between 1/Oct/2016 and 31/Dec/2020. Clinical factors including age, gender, ECOG performance status, baseline LDH level, and location of metastases, response to treatment and irAEs occurrence were analyzed. Survival analyses were performed using the Kaplan-Meier method, Log-rank and chi-square tests were used for comparison between groups. Data cut-off was 31/Dec/2021. Results: In total 585 patients were enrolled. 170 (29%) patients were treated with IT and 415 (71%) with TT in the first line. 331 patients (56%) received only one line of treatment – 247/415 (59%) patients only TT and 84/170 (49%) patients received only IT (anti-PD1). Disease progression was found in 175 (71%) patients in the only TT group and in 43 (51%) in the only IT group. 254 patients qualified for sequential treatment 168 (29%) patients received TT then IT (TT-IT), 64 (11%) IT then TT (IT-TT), and 22 (4%) IT-IT (anti-PD-1 then anti-CTLA-4). Patients with brain metastases and elevated LDH were statistically more often treated with first line TT and more patients with normal LDH level received IT-IT therapy. No other statistically significant differences in baseline characteristics was found for IT-TT, TT-IT and IT-IT groups. The estimated median OS (mOS) was not reached in patients treated with only one line of IT treatment, while for TT only it was only 11.8 months. Estimated mOS for patients treated in the first line with IT or TT was significantly different (p = 0.02; HR = 0.74, Cl 95% 0.6-0.9) and reached 25.6 and 15.3 months, respectively; although no statistically significant mOS differences was found in the subgroups without brain metastases (p = 0.56) and with normal LDH (p = 0.36). For sequential treatment groups mOS for IT-TT, TT-IT, and IT-IT was 19.6, 19.9 and 35.9 months, respectively. There was no statistically significant difference in OS between IT-TT and TT-IT treated groups (p = 0.56), and between IT-TT, TT-IT and IT-IT groups (p = 0.19). Conclusions: Patients who were treated with IT in the 1st line had better OS than patients treated TT in the 1st line in real-world data but this may be related to better prognostic factors in the IT group. Selected patients receiving IT in the first line achieve long OS, which is a result of a long-term response to IT. Novel predictive biomarkers factors of IT response should be incorporated in prospective trials.

Treatment of Locally Advanced Merkel Cell Carcinoma-A Multi-Center Study

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer with a high risk of recurrence and poor prognosis. The treatment of locally advanced disease involves surgery and radiotherapy. To analyze real-life treatment patterns and clinical outcomes, we conducted a retrospective analysis of data from 161 MCC patients treated with curative intent in four oncological centers in Poland. The median age at diagnosis was 72 years (30-94); 49.7% were male. Lymph node (LN) involvement at diagnosis was found in 26.9% of patients. Sentinel lymph node biopsy (SLNB) was performed in 36.5% of patients (positive in 10.5%), and 51.9% of patients received perioperative treatment. The relapse rate was 38.3%. With the median follow-up of 2.3 years, the median disease-free survival (DFS) was not reached, and the 1-year rate was 65%. The negative independent risk factors for DFS were male gender, metastases in LN at diagnosis, no SLNB in patients without clinical nodal metastases, and no perioperative radiotherapy. The estimated median overall survival (OS) was 6.9 years (95% CI 4.64-9.15). The negative independent risk factors for OS were male gender, age above 70, metastases in LN at diagnosis, and no SLNB in patients without clinical nodal metastases. Our results confirm that the MCC treatment should be conducted in an experienced multidisciplinary team; however, the outcomes are still unsatisfactory.

Systemic treatment of patients with inoperable and metastatic Merkel cell carcinoma: A multicenter study

e21521

Background: Merkel cell carcinoma (MCC) is an uncommon, aggressive neuroendocrine skin cancer. The prognosis in the unresectable and metastatic setting is very poor. Distant metastases develop in more than 30%. Chemotherapy (CHT), the previous mainstay of treatment, is associated with the high response rates (RR) of limited duration. The main cytotoxic drugs have been platinum derivatives, taxoids, anthracyclines, and etoposide. The standard systemic treatment for this disease has changed in the last few years. Immunotherapy (IO) is currently the basis of systemic therapy in the metastatic setting. This study aimed to analyze outcomes for unresectable and metastatic MCC pts treated in routine clinical practice, mostly before the era of IO availability. Methods: We conducted the retrospective analysis of data from 36 MCC pts in unresectable (n= 23) and metastatic (n=13) settings treated in three oncological centers, diagnosed between 01/2010 and 12/2019, with data cut-off on 31/12/2020. The data collected included epidemiological and clinical information. Survival analyses were performed using the Kaplan-Meier method and log-rank test. Results: The median patient age at diagnosis was 72 years (57-88); 58.3% were male. The most common primary tumor (PT) locations were lower limbs (41.7%), head and neck (30.6%), and upper limbs (16.7%). In 63.9% the PT was located in the sun-exposed skin. The most common location of distant metastases were nonregional lymph nodes (n=9) and lungs (n=3). Thirty-six pts received 1st line CHT with the median progression-free survival (mPFS) of 5.3 months (95%CI 2.88-7.7) and objective response of 61.1%, with 13.9% complete responses (CR). The most commonly used regimens were platinum-based and anthracycline-based regimens (n=26). Disease progression (PD) was observed in 91.7% of pts treated with 1st line CHT. Twenty-one pts received 2nd line therapy, IO (n=14), or CHT (n=7), with PD in 19 pts (90.6%), mPFS 2.83 months (95% CI 0.59-5.06) and RR of 33.3% (0% CR). 13 pts were treated with avelumab (AVE), all in the 2nd line, with RR of 38.5% (0% CR). The mPFS in the 2nd line was 5 months (95%CI 0-11.46) on AVE compared to 2.82 (95%CI 0.46-5.19) on CHT (HR 0.65, 95%CI 0.25-1.70, p=0.378). During 1st line systemic therapy, 16 pts underwent palliative surgery (n=7, 19.4%) or received radiation therapy (RT) (n=9, 25%), and during 2nd line, one patient was treated with surgery, and five pts received RT. The median overall survival was 10.38 months (95% CI 2.90-17.87). Local treatment did not improve the treatment outcomes in the 1st (p=0.119) nor 2nd line (p=0.821). Conclusions: Our results confirm the poor prognosis of pts with unresectable and metastatic MCC. The response rates and median PFS for CHT in the 1st and 2nd line setting are consistent with historical data. The treatment with AVE in the 2nd line allows achieving better results, similar to the results reported in the clinical trials.

Comparison of the efficacy and toxicity of anti-PD-1 monoclonal antibodies (nivolumab versus pembrolizumab) in treatment of patients with metastatic melanoma

e21514

Background: Anti-programmed cell death-1 antibodies (anti-PD-1) have become a standard treatment option for melanoma patients. Currently, two anti-PD-1 antibodies are registered in the treatment of melanoma patients: nivolumab and pembrolizumab. Nivolumab is a human monoclonal antibody, while pembrolizumab is a humanized antibody. Unfortunately, there are very few clinical data comparing the efficacy and toxicity of nivolumab and pembrolizumab in routine practice. Methods: Consecutive patients treated in the first line with anti-PD-1 (nivolumab or pembrolizumab) for unresectable or metastatic melanoma in comprehensive cancer centers between 03/2016 and 09/2020 were enrolled in the analysis. Baseline factors (age, gender, primary location of melanoma, BRAF mutation status, ECOG performance status, baseline LDH level, and location of metastases) were evaluated to identify predictors of overall survival (OS). Data on response to treatment and the occurrence of irAEs were collected prospectively during anti-PD-1 treatment. OS were assessed using Kaplan–Meier and Cox models. The Chi-Square statistic was used for testing relationships between categorical variables. Median follow up for nivolumab and pembrolizumab group was 12.6 (range 0.2-52.1) and 10.7 (range 0.03-53.5) months, respectively. Results: Overall, 736 patients were included in the present analysis (443 nivolumab, 293 pembrolizumab). There were no statistically significant differences in baseline factors (age, gender, primary location of melanoma, BRAF mutation status, ECOG performance status, baseline LDH level (normal vs elevated), brain metastasis and TNM stage) between the groups. Median OS for patients treated with nivolumab and pembrolizumab was 22 and was 17.3 months, respectively. There was no statistically significant difference in OS between the nivolumab and pembrolizumab groups (p = 0.12, HR = 1.2, Cl 95% 0.9-1.4). At multivariate analysis normal LDH levels, no brain metastases, and ECOG 0 or 1 were positive prognostic factors for OS both in nivolumab and pembrolizumab groups. In the nivolumab and pembrolizumab groups, 6% and 5% CR (complete response), 33% and 31% PR (partial response), 25% and 24% SD (stable disease), respectively, were observed. There was no statistical difference between the groups in the response to treatment (p = 0.65). There was no statistical difference between the groups in occurrence of the irAEs (p = 0.97) as well as in the type of irAEs. Conclusions: Our analysis in melanoma patients treated in routine practice with nivolumab or pembrolizumab confirmed no statistical differences in OS and treatment responses between these two anti-PD-1 antibodies. There were also no differences in toxicity between the two drugs. The choice of treatment should be based on the preferences of the patient and the physician.

Treatment of patients with locally advanced Merkel cell carcinoma: A multicenter study

e21566

Background: Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer with a high risk of recurrence and poor prognosis. The treatment of locally advanced disease includes surgery (SUR) and radiotherapy (RTH) to achieve high locoregional control rates. The sentinel lymph node biopsy (SLNB) is recommended procedure in cases without clinical nodal involvement. In selected cases, chemotherapy (CHT) may also be considered, but its role is not confirmed. This study aimed to analyze outcomes for locally advanced MCC pts treated in routine clinical practice. Methods: We conducted the retrospective analysis of data from 156 MCC pts treated with curative surgery in four oncological centers, diagnosed between 01/2010 and 12/2019, with data cut-off on 31/12/2020. The data collected included epidemiological and clinical information. Survival analyses were performed using the Kaplan-Meier method, log-rank test and multivariate Cox regression. Results: The median patient age at diagnosis was 72 years (30-94); 50.6% were male. The primary tumor (PT) locations were lower limbs (33.3%), upper limbs (30.1%), and head and neck (28.2%). MCC with no PT was diagnosed in 3.9%. In 62.0% the PT was located in the sun-exposed skin. The median tumor size was 25 mm (4-170). Lymph node (LN) involvement (clinical or positive SLNB or LND) at diagnosis was found in 26.9% (n = 42). The scar excision was done in 50.0% (positive in 16.6%), SLNB in 36.5% (positive in 10.5 %), 51.9% of pts received perioperative treatment, including RTH- 86.4%, CHT- 21%. The relapse rate was 38.3% (35.8% local-regional, 11.1% distant). With the median follow-up of 2.2-years, the median disease-free survival (DFS), local relapse-free survival (LRFS), and distant metastases-free survival (DMFS) were not reached. The 1-year DFS, LRFS and DMFS rates were 65%, 68%, and 90%. The negative independent risk factors for DFS were male gender (HR 1.42, 95%CI 1.06-3.01), metastases in LN at diagnosis (HR 5.41, 95%CI 2.39-12.26), no SLNB in pts with no clinical metastases in LN (HR 5.45, 95%CI 2.41-12.3), and no perioperative RTH (HR 2.19, 95%CI 1.29-3.76). The median overall survival (OS) was 6.9 years (95%CI 4.64-9.15). The negative independent risk factors for OS were male gender (HR 1.95, 95%CI 1.16-3.27), age above 70 (HR 2.0, 95%CI 1.15-3.48), metastases in LN at diagnosis (HR 3.15, 95%CI 1.49-6.68), and no SLNB in pts with no clinical metastases in LN (HR 2.30, 95%CI 1.10-4.82). PT location, UV-exposure, and perioperative CHT or RTH were not independent risk factors for OS. Conclusions: Our results confirm that the MCC treatment should be done in an experienced multidisciplinary team. Male gender, nodal involvement at diagnosis, and no SLNB in pts without clinical metastases in LN are associated with poor prognosis in DFS and OS. The perioperative RTH improves the treatment outcomes and reduces disease progression risk but does not impact OS. Perioperative CHT does not affect pts survival.

Treatment beyond progression with immune checkpoint inhibitors in advanced melanoma

e21541

Background: Immunotherapy (ITH) holds the possibility of tumor burden decrease after initial RECIST defined progression (PD). Clinical concept of treating of selected patients (pts) beyond PD is supported by this pseudoprogression phenomenon. The aim of this study was to evaluate real-life practice and outcomes related to treatment beyond progression (TBP) in melanoma patients. Methods: We evaluated advanced melanoma pts who started anti-PD1 treatment between 12/2015 and 12/2018 and identified pts who received TBP and had subsequent imaging to evaluate the tumor burden. Survival analyses were performed using the Kaplan-Meier method, Log-rank, chi-square and Fisher exact tests were used for comparison between groups. Data cut-off was 02/2021. Results: Of 399 subsequent melanoma pts treated, 57 (14%) patients received TBP. Anti-PD1 was 1st line treatment in 61.4% and 2nd line - in 38.6% of patients. 71.9% patients were diagnosed with skin, 7.0% - mucosal and 21.1% with FPI melanoma and 47.4% were BRAF mutated, 56.1% were male and 12.3% had 3 or more metastatic sites at treatment initiation. In this cohort median time to 1st PD (TTFP) was 4.43 months(m), while to 2nd PD (TTSP) – 8.01 m. On TBP 26.3% pts achieved objective response (OR), and next 42.1% - SD. 1st PD was reported most often as increase in 3 or more targets or one new lesion – both 22.8%; and in 24.6% cases involved central nervous system. In 56.8% second PD was observed in the same targets as 1st PD. 61.4% patients received multimodal treatment of ITH combined with radiation therapy – in 49.1%, surgery - 5.3% and both - 7.0%. There was no correlation of TTSP with gender, ECOG, initial disease stage or TNM, BRAF mutation, number of metastatic sites or pattern of progression. Multimodal treatment resulted in 13.6 m TTSP, while ITH alone - 8.0 m (p = 0.056). 1st line OR correlated with DCR on TBP while TTFP > 6 m correlated with TTSP (HR = 0.53, 95%CI 0.28-0.99). Patients with 1st line CR – had median TTSP 16.4 m, with PR – 23.5 m, while those with PD – 5.1 m. Median OS after 1st PD was 26 months and correlated with OR on TBP. Conclusions: Selected clinically fit melanoma patients despite evidence of first radiographic progression may benefit from continued treatment with PD-1 inhibitors. Multidisciplinary treatment should be offered to these patients including radiosurgery or stereotactic radiotherapy of progressing loci. Molecular biomarkers of TTSP should be analyzed in prospective studies.

Correlation of immunity-related adverse events with survival and response to anti-PD-1 treatment in patients with metastatic melanoma

e15164

Background: Immunotherapy has become a standard treatment option for metastatic melanoma patients, and the use of anti-programmed cell death-1 monoclonal antibodies (anti-PD-1) has significantly improved the outcomes of this group of patients. Immune related adverse events (irAEs) during anti-PD-1 treatment may present a significant problem. However, irAEs' relationship with overall survival although suggested in single studies was not confirmed in real world data. Methods: Consecutive patients starting treatment between March 2016 and April 2019 with fist line anti-PD-1 (nivolumab or pembrolizumab) for unresectable or metastatic melanoma in 6 comprehensive cancer centers in Poland were enrolled in the study. Baseline patients characteristics and irAEs development during treatment were evaluated to identify predictors of progression-free (PFS) and overall (OS) survival in Cox model. PFS and OS were assessed using Kaplan–Meier method. Results: Overall, 410 patients were included in the present analysis and 107 patients experienced irAEs. Response rate (RR) and disease control rate (DCR) were 36% (148 pts) and 65% (267 pts) respectively. Median PFS and OS were 7.6 (2.8–21.6) and 21.6 (6.7–38.2) months, respectively. In univariate analysis normal LDH level, no brain metastases, ECOG 0 or 1, ≤ 2 number of metastases locations were positive prognostic factors for both OS and PFS. At the same time irAEs occurrence was correlated with longer PFS, OS, RR and DCR (all p < 0.001); moreover high LDH level correlated with irAEs (p = 0.027) development. There was no correlation between irAEs and the number of cycles of anti-PD-1 patients received. Conclusions: Our study showed an association between irAEs and longer survival on anti-PD1 therapy in patients with advanced or metastatic melanoma. An association with irAEs and response to therapy has also been demonstrated.

Prognostic and predictive factors for the outcomes of clear cell sarcoma (CCS) multidisciplinary treatment: The role of lymph node involvement

e23554

Background: CCS is a rare aggressive sarcoma with melanocytic differentiation and specific genetic background of EWSR1/ATF1 or EWSR1/CREB1 translocations. It typically localizes in the tendons, fascia, and aponeuroses. The role of lymph node dissection (LND) remains to be elucidated in this sarcoma, although it was indicated to have a high rate of clinically occult regional lymph node (LN) metastases. Methods: 23 consecutive patients (pts) (15 women and 8 men) were referred, diagnosed and underwent multidisciplinary treatment in our Institute between 07/2000 and 12/2019. Kaplan-Meier estimator was used in survival analysis and univariate Cox proportional hazard model was used to investigate prognostic and predictive factors. Cases for whom local relapsed were not noted or those not known to be dead were censored at last visit. OS was compared for nodal involvement, including both: clinically detected and treated with therapeutic LND and microscopic metastases evaluated in sentinel LN biopsy (SLNB). Local relapse and radiotherapy were analyzed. Results: The median age at diagnosis was 32y (range:20-72). The median tumor size was 3.5cm (2-15cm). 15 pts underwent surgery of the primary tumor and 8 - resection of local relapse after non-complete resection outside the reference center. In 11 cases SNLB was performed, while in 7 – therapeutic LND. SLNB was positive in 2 (18%) cases and was followed by completion LND. For pts treated due to primary tumor, R0 resection was achieved in 12 cases and R1 in 3. After median follow-up of 65.6 months (m) (95% confidence interval, CI 55.3–NR) 11 (48%) pts are alive. Median OS was 59m (95%CI: 39-NR). Clinically detectable LN were correlated with shorter DFS (HR: 6.6, 95%CI: 1.5-28.8, p = 0.01). The number of involved LN also correlated with DFS (HR 1.7 per 1 LN; 95%CI:1.1-2.6, p = 0.009). No such correlations were found for OS. 5-year LRFS rate was 72.5% (95%CI: 53.8-97.7). 15 pts underwent neoadjuvant radiotherapy and for these pts 5-year LRFS rate was 75.0% (95%CI: 50.3-100). There was no statistical difference for LRFS if radiation therapy was not applied, which may be due to the number of pts. Conclusions: CCS is a highly aggressive sarcoma with poor prognosis. High quality surgery remains the gold standard for these pts, with the increasing role of SLNB and LND. Multimodal treatment should be considered in all cases. There is unmet need for new therapies for advanced CCS pts.

Clinicopathological prognostic and predictive factors of malignant peripheral nerve sheath tumors (MPNST) survival and treatment efficacy

e22537

Background: MPNST accounts for about 5% of soft tissue sarcomas. It is known to have high metastatic potential and poor prognosis, but reported long-term outcomes vary widely across published series. Our study aimed to determine factors affecting clinical outcome in a large cohort of patients (pts) with MPNSTs treated at reference sarcoma center. Methods: 289 consecutive pts (144 woman and 145 man) referred, diagnosed and treated between 03/1998 and 04/2018 were analyzed. Kaplan-Meier estimator and the log-rank test were used in survival analysis and multivariate Cox proportional hazards model was used to confirm the correlation. Results: Mean age at diagnosis was 50y (15-86). 39 (13.5%) pts were NF1 positive, 12 were primary diagnosed with metastatic disease. After median follow-up of 66.5 months (m) (95% confidence interval, CI 58.1 – 85.2) 151 pts continue treatment or follow-up. Median OS was 55.7m (39.3 - 148.9) in the whole group while 5y survival rate was 48.8% (CI: 42.8-55.7%). 37/167 pts with radical resection in reference center developed local recurrence, and 75/92 pts operated first in regional hospitals. Median DFS was 29.7m (CI: 16.1-58.3) in case of treatment in reference center and 4.1m (CI: 2.4-9.2) in case of regional hospital (p < 0.001).72 pts developed metastatic disease and were treated with chemotherapy. Median PFS on 1st line was 5.6m (CI: 3.3 - 8.1), There were no statistically significant differences in survival rates nor in response rates between doxorubicin- and ifosfamid-based regiments. Tumor size at diagnosis (HR:2.33, CI: 1.50-3.62), high grade (HR:3.31, CI:2.14-5.12) and R0 resection (HR:0.47, CI:0.30-0.72) were the strongest independent predictors of DFS and OS. (neo)adjuvant radiotherapy did not influenced LRFS in case of R0 resection but improved LRFS when complete resection was not feasible (HR: 0.22 CI: 0.08-0.58 p = 0.002). Conclusions: MPSNT is a highly aggressive tumor with poor prognosis. High quality surgery remains the mainstay of management for these patients, but multimodal treatment should be considered in majority of cases in MDT units. There is unmet need for new therapies in advanced/metastatic cases.

Insulin and IGFs in renal cancer risk and progression

Insulin and IGFs play a significant role in cancer development and progression, including renal cell carcinoma (RCC). RCC is the most frequent type of kidney cancer in adults and the tenth most common malignancy worldwide. Insulin is normally associated with metabolism control, whereas IGFs are defined as proliferation regulators. Today, there is convincing evidence of an association between obesity and the risk of RCC. Indicated risk factors together with type 2 diabetes are irreversibly connected with circulating insulin and IGF levels. The interplay between these molecules, their receptors, and IGF-binding proteins might be crucial for RCC cell biology and RCC progression. Given the potent activity IGF/IGF receptor 1 (IGF1R) inhibitors demonstrate against RCC in basic research, some type of combination therapy may prove to be beneficial clinically in the management of RCC. This review addresses not only molecular but also clinical associations between insulin and IGF1 signaling pathways and both RCC biology and clinical course. Revealing these interactions may improve our understanding of basic molecular oncology processes in RCC and improve treatment strategies.

The regulation of clear cell renal cancer cells proliferation and tyrosine kinase inhibitors responsiveness by tumor micro-environmental factors

488

Background: Tumor microenvironment is a complex network of multiple cell types, paracrine and endocrine signaling molecules, ECM and physical factors, which orchestrate the fate of tumor progression. In the field of ccRCC little attention has been paid to non-immunologic factors in tumor niche. Objectives of this study include the analysis of hypoxia, triiodothyronine (T3), insulin, insulin-like growth factor-1 and -2 impact on ccRCC cells. The effect of above mentioned tumor niche factors on TKI activity on ccRCC cells was to be quantified. The study was initiated as ccRCC cells are known to harbor disrupted hypoxia response and TRbeta (TRβ) - T3 receptor - functions as a tumor suppressor with tissue hypothyroidism involved in maintaining a proliferative advantage, whereas hypothyroidisms was defined as biomarker of sunitinib treatment efficacy. Moreover obesity and diabetes (DM2) are considered risk factors for ccRCC and high IGF-I expression is associated with poor long-term patient survival. This research aims to find molecular background for clinically relevant observations. Methods: ccRCC cells from primary and metastatic tumors (ATCC, MSK collections) along with cancer progenitor cells (CD133+) were cultured in normoxic or hypoxic conditions; in defined media supplemented with T3, IN, IGF, TRβ inhibitor and TKIs (sunitinib, axitinib). Cell proliferation was evaluated using AlamarBlue and MTT. Colony formation potential was evaluated. TRβ gene expression was measured with RealTime-RT PCR and sequenced under standard protocol. Normal kidney proximal tube cells were used as negative control. Results: ccRCC TKI responsiveness is limited by hypoxia, at the same time tumor cell proliferation may be promoted by T3, IN and IGF. Colony formation potential of ccRCC cells under TKI treatment in hypoxic conditions is downregulated. Conclusions: Multiple micro-environmental factors modify the proliferation and/or differentiation of ccRCC cell populations. Understanding the complex molecular feedback loops between cancer cells and the surrounding microenvironment should aid the identification of novel targets for improving TKIs clinical management.

Mitochondrial DNA mutations in cancer--from bench to bedside

Mitochondria are cell organelles mostly known for their production of ATP through oxidative phosphorylation. As suggested over 70 years ago by O. Warburg and recently confirmed with molecular techniques, alterations in respiratory activity and mitochondrial DNA appear to be a common feature of malignant cells. Somatic mtDNA mutations have been reported in many types of cancer cells. MtDNA mutation pattern may enhance the specificity of cancer diagnostics, detection and prediction of tumor growth rate and patients' outcome. Therefore it may be used as a molecular cancer bio-marker. Nevertheless recently published papers list a large number of mitochondrial DNA mutations in many different cancer types, but their role in cell pathophysiology remains unsummarized. This review covers the consequences of mitochondrial genes mutations for human cell physiology and proliferation. We underline effects of mtDNA mutation-resulting amino acid changes in the respiratory chain proteins' structure, and propose changes in mitochondrial protein function. Mutations are critically evaluated and interpreted in the functional context and clinical utility of molecular mitochondrial research is summarized and new perspectives for 'mitochondrial oncology' suggested.

The value of immunohistochemical research on PCNA, p53 and heat shock proteins in prostate cancer management: a review

This review addresses the significance of the expression of proliferating cell nuclear antigen (PCNA), p53 and some heat shock proteins (Hsps) in prostate carcinoma (PC). In fact, PCNA and p53 are two widely discussed tools in PC diagnosis, mainly because of the controversy regarding the significance of their expression during prostate cancer development and progression. At the same time, only few studies have shown the potential role of Hsps in carcinogenesis and their overexpression in pre-neoplastic and neoplastic lesions of the prostate. We briefly describe the physiological roles of Hsps in normal cells, and the significance of their immunohistochemical detection in PC as well as in pre-cancerous lesions of the prostate. We will also discuss the possible functional interactions of these molecules in both dysplastic and neoplastic cells.