Biomarkers of treatment benefit with atezolizumab plus vemurafenib plus cobimetinib in BRAFV600 mutation-positive melanoma.

BACKGROUND: The phase III IMspire150 study (NCT02908672) demonstrated significantly improved progression-free survival (PFS) with atezolizumab, vemurafenib, and cobimetinib (atezolizumab group) versus placebo, vemurafenib, and cobimetinib (control group) in patients with BRAFV600-mutated advanced melanoma. We report exploratory biomarker analyses to optimize targeting of patients who are more likely to benefit from triplet combination therapy. PATIENTS AND METHODS: Five hundred fourteen patients were randomized to atezolizumab (n = 256) or control (n = 258). Outcomes were evaluated in subgroups defined by key biomarkers, including programmed death-ligand 1 (PD-L1) expression, lactate dehydrogenase (LDH) level, tumor mutational burden (TMB), and interferon-γ (IFN-γ) gene signature. Exploratory recursive partitioning analysis was then used to model associations between PFS and baseline covariates, including key biomarkers. RESULTS: PFS benefit for atezolizumab versus control was greater in patients with high TMB [≥10 mutations/Mb; hazard ratio (HR) 0.73; 95% confidence interval (CI) 0.52-1.02; P = 0.067] versus low TMB (<10 mutations/Mb; HR 0.92; 95% CI 0.65-1.30; P = 0.64) and similar between patients with strong IFN-γ (≥median; HR 0.76; 95% CI 0.54-1.06) versus weak IFN-γ (

Cobimetinib plus atezolizumab in BRAFV600 wild-type melanoma: primary results from the randomized phase III IMspire170 study.

BACKGROUND: Emerging data suggest that the combination of MEK inhibitors and immunotherapeutic agents may result in improved efficacy in melanoma. We evaluated whether combining MEK inhibition and immune checkpoint inhibition was more efficacious than immune checkpoint inhibition alone in patients with previously untreated BRAFV600 wild-type advanced melanoma. PATIENTS AND METHODS: IMspire170 was an international, randomized, open-label, phase III study. Patients were randomized 1 : 1 to receive cobimetinib (60 mg, days 1-21) plus anti-programmed death-ligand 1 atezolizumab (840 mg every 2 weeks) in 28-day cycles or anti-programmed death-1 pembrolizumab (200 mg every 3 weeks) alone until loss of clinical benefit, unacceptable toxicity, or consent withdrawal. The primary outcome was progression-free survival (PFS), assessed by an independent review committee in the intention-to-treat population. RESULTS: Between 11 December 2017, and 29 January 2019, 446 patients were randomized to receive cobimetinib plus atezolizumab (n = 222) or pembrolizumab (n = 224). Median follow-up was 7.1 months [interquartile range (IQR) 4.8-9.9] for cobimetinib plus atezolizumab and 7.2 months (IQR 4.9-10.1) for pembrolizumab. Median PFS was 5.5 months [95% confidence interval (CI) 3.8-7.2] with cobimetinib plus atezolizumab versus 5.7 months (95% CI 3.7-9.6) with pembrolizumab [stratified hazard ratio 1.15 (95% CI 0.88-1.50); P = 0.30]. Hazard ratios for PFS were consistent across prespecified subgroups. In exploratory biomarker analyses, higher tumor mutational burden was associated with improved clinical outcomes in both treatment arms. The most common grade 3-5 adverse events (AEs) were increased blood creatine phosphokinase (10.0% with cobimetinib plus atezolizumab versus 0.9% with pembrolizumab), diarrhea (7.7% versus 1.9%), rash (6.8% versus 0.9%), hypertension (6.4% versus 3.7%), and dermatitis acneiform (5.0% versus 0). Serious AEs occurred in 44.1% of patients with cobimetinib plus atezolizumab and 20.8% with pembrolizumab. CONCLUSION: Cobimetinib plus atezolizumab did not improve PFS compared with pembrolizumab monotherapy in patients with BRAFV600 wild-type advanced melanoma.

Prognostic impact of baseline tumour immune infiltrate on disease-free survival in patients with completely resected, BRAFv600 mutation-positive melanoma receiving adjuvant vemurafenib.

BACKGROUND: We conducted a retrospective exploratory analysis to evaluate the effects of baseline tumour immune infiltrate on disease-free survival (DFS) outcomes in patients with fully resected stage IIC-IIIC melanoma receiving adjuvant vemurafenib monotherapy or placebo in the BRIM8 study. PATIENTS AND METHODS: BRIM8 was a phase III, international, double-blind, randomised, placebo-controlled study. Eligible patients with BRAFV600 mutation-positive, completely resected melanoma were randomly assigned to oral vemurafenib (960 mg twice daily) or matching placebo for 52 weeks. The primary end point was DFS. The association of CD8+ T-cell infiltration and programmed death ligand 1 (PD-L1) expression with DFS, as measured by immunohistochemistry, was explored retrospectively. RESULTS: Four hundred ninety-eight patients were randomly assigned to receive adjuvant vemurafenib (n = 250) or placebo (n = 248); tumour samples were available for biomarker analysis for approximately 60% of patients. In the pooled biomarker population, placebo-treated patients with <1% CD8+ T cells in the tumour centre had shorter median DFS than those with ≥1% CD8+ T cells (7.7 versus 47.8 months). DFS benefit from vemurafenib versus placebo was greater in patients with <1% CD8+ T cells [hazard ratio (HR) 0.56; 95% confidence interval (CI) 0.34-0.92) than in patients with ≥1% CD8+ T cells (HR 0.77; 95% CI 0.48-1.22). Likewise, median DFS was shorter among placebo-treated patients with <5% versus ≥5% PD-L1+ immune cells (IC) in the tumour (7.2 versus 47.8 months). A greater DFS benefit with vemurafenib versus placebo was observed in patients with <5% PD-L1+IC (HR 0.36; 95% CI 0.24-0.56) than in patients with ≥5% PD-L1+IC (HR 0.99; 95% CI 0.58-1.69). CONCLUSIONS: The presence of CD8+ T cells and PD-L1+IC are favourable prognostic factors for DFS. Treatment with adjuvant vemurafenib may overcome the poor DFS prognosis associated with low CD8+ T-cell count or PD-L1 expression. CLINICALTRIALS. GOV IDENTIFIER: NCT01667419.

[Impact of СD8/FoxP3 T lymphocyte ratio in the peritumoral area of primary cutaneous melanoma on the prognosis of the disease]. / Vliyanie sootnosheniya CD8/FoxP3 T-limfotsitov v peritumoral'noi zone pervichnoi melanomy kozhi na prognoz techeniya zabolevaniya.

UNLABELLED: Cutaneous melanoma (CM) is a malignant tumor characterized by typical histological features, one of which is tumor-infiltrating lymphocytes (TIL) that reflect the state of local immunity and determines the course of the disease. AIM: to study a correlation of the ratio of CD8/Foxp3 T lymphocyte subpopulations infiltrating primary cutaneous melanoma (PCM) with the clinical and morphological factors and prognosis of the disease. MATERIAL AND METHODS: The CD8+ and FoxP3+ T-lymphocyte subpopulations infiltrating PCM were investigated in 180 cases by immunohistochemical staining with anti-CD8 and anti-FoxP3 antibodies. RESULTS: The predominant type of TIL was CD8+ cytotoxic T lymphocytes (80.1 cells in the field of vision); FoxP3+ T lymphocytes averaged 34.9 cells in the field of vision. There was a statistically significant correlation of a high ratio of CD8/FoxP3 T cells with disease stage, ulceration and regression segments in PCM, a low disease progression rate, and higher 5-year overall and relapse-free survival. CONCLUSION: The findings may be used in researches and in the practical work of pathologists and clinicians.

[ Spectrum of oncogene mutations is different in melanoma subtypes].

Melanoma is the most lethal malignancy of skin, which is comprised of clinically relevant molecular subsets defined by specific "driver" mutations in BRAF, NRAS, and KIT genes. Recently, the better results in melanoma treatment were obtained with the mutation-specific inhibitors that have been developed for clinical use and target only patients with particular tumor genotypes. The aim of the study was to characterize the spectrum of "driver" mutations in melanoma subtypes from 137 patients with skin melanoma and 14 patients with mucosal melanoma. In total 151 melanoma cases, the frequency of BRAF, NRAS, KIT, PDGFRA, and KRAS mutations was 55.0, 10.6, 4.0, 0.7, and 0.7%, respectively. BRAF mutations were found in 69% of cutaneous melanoma without UV exposure and in 43% of cutaneous melanoma with chronic UV exposure (p=0.045), rarely in acral and mucosal melanomas. Most of melanomas containing BRAF mutations, V600E (92%) and V600K (6.0%) were potentially sensitive to inhibitors vemurafenib and dabrafenib. NRAS mutations were more common in cutaneous melanoma with chronic UV exposure (26.0%), in acral and mucosal melanomas; the dominant mutations being Q61R/K/L (87.5%). KIT mutations were found in cutaneous melanoma with chronic UV exposure (8.7%) and mucosal one (28.6%), but not in acral melanoma. Most of KIT mutations were identified in exon 11; these tumors being sensitive to tyrosine kinase inhibitors. This is the first monitoring of BRAF, NRAS, KIT, PDGFRA, and KRAS hotspot mutations in different subtypes of melanoma for Russian population. On the base of data obtained, one can suppose that at the molecular level melanomas are heterogeneous tumors that should be tested for "driver" mutations in the each case for evaluation of the potential sensitivity to target therapy. The obtained results were used for treatment of melanoma patients.

Patient perception of the benefit of a BRAF inhibitor in metastatic melanoma: quality-of-life analyses of the BREAK-3 study comparing dabrafenib with dacarbazine.

BACKGROUND: In a randomized phase III study (BREAK-3), dabrafenib showed prolonged progression-free survival (PFS) (median 5.1 versus 2.7 months; hazard ratio = 0.30; 95% confidence interval 0.18-0.53; P < 0.0001) compared with dacarbazine (DTIC) in patients with BRAF V600E metastatic melanoma. Assessing how these results are transformed into a real health benefit for patients is crucial. METHODS: The EORTC QLQ-C30 questionnaire assessed quality of life (QoL) at baseline and follow-up visits. RESULTS: For DTIC, all functional dimensions except role dimension worsened from baseline at follow-up. For dabrafenib, all functionality dimensions remained stable relative to baseline or improved at week 6; mean change in seven symptom dimensions improved from baseline, with appetite loss, insomnia, nausea and vomiting, and pain showing the greatest improvement. In the DTIC arm, symptom dimensions were unchanged or worsened from baseline for all symptoms except pain (week 6), with the greatest exacerbations observed for fatigue and nausea and vomiting. Mixed-model-repeated measures analyses showed significant (P < 0.05) and/or clinically meaningful improvements from baseline in favor of dabrafenib for emotional and social functioning, nausea and vomiting, appetite loss, diarrhea, fatigue, dyspnea, and insomnia at weeks 6 and/or 12. After crossing over to dabrafenib upon progression (n = 35), improvements in all QoL dimensions were evident after receiving dabrafenib for 6 (n = 31) to 12 (n = 25) weeks. CONCLUSIONS: This first reported QoL analysis for a BRAF inhibitor in metastatic melanoma demonstrates that the high tumor response rates and PFS superiority of dabrafenib over DTIC is not only a theoretical advantage, but also transforms in a rapid functional and symptomatic benefit for the patient. ClinicalTrials.gov Identifier: NCT01227889.

Functional and symptom impact of trametinib versus chemotherapy in BRAF V600E advanced or metastatic melanoma: quality-of-life analyses of the METRIC study.

BACKGROUND: In a randomized phase III study, trametinib prolonged progression-free survival and improved overall survival versus chemotherapy in patients with BRAF V600 mutation-positive melanoma. PATIENTS AND METHODS: Patients' quality of life (QOL) was assessed at baseline and follow-up visits using the European Organisation for Research and Treatment of Cancer Core QOL questionnaire. RESULTS: In the primary efficacy population (BRAF V600E+, no brain metastases) from baseline to weeks 6 and 12, patients' global health status scores worsened by 4-5 points with chemotherapy but improved by 2-3 points with trametinib. Rapid and substantive reductions in QOL functionality (e.g. role functioning, 8-11 points at weeks 6 and 12) and symptom exacerbation (e.g. fatigue, 4-8 points; nausea and vomiting, 5 points, both at weeks 6 and 12) were observed in chemotherapy-treated patients. In contrast, trametinib-treated patients reported small improvements or slight worsening from baseline at week 12, depending on the functional dimension and symptom. The mean symptom-scale scores for chemotherapy-treated patients increased from baseline (symptoms worsened) for seven of eight symptoms at week 6 (except insomnia) and six of eight symptoms at week 12 (except dyspnea and insomnia). In contrast, at weeks 6 and 12, the mean symptom-scale scores for trametinib decreased from baseline (symptoms improved) for pain (11-12 points), insomnia (10-12 points), and appetite loss (1-5 points), whereas those for diarrhea worsened (15-16 points). Mixed-model repeated-measures analyses showed significant (P < 0.05) and/or clinically meaningful improvements (small to moderate) from baseline in favor of trametinib for global health; physical, role, and social functioning; fatigue; pain; insomnia; nausea and vomiting; constipation; dyspnea; and appetite at weeks 6 and/or 12. QOL results for the intent-to-treat population were consistent. CONCLUSIONS: This first QOL assessment for a MEK inhibitor in metastatic melanoma demonstrated that trametinib was associated with less functional impairment, smaller declines in health status, and less exacerbation of symptoms versus chemotherapy.

Phase I-II study of plitidepsin and dacarbazine as first-line therapy for advanced melanoma.

BACKGROUND: This phase I-II trial compared plitidepsin 1-h infusion alone or combined with dacarbazine (DTIC) 1-h infusion as front-line therapy for advanced melanoma. METHODS: The recommended dose (RD) for plitidepsin/DTIC was defined in the first stage. In the second stage, patients were randomised to receive single-agent plitidepsin 3.2 mg m(-2) (n = 20) on days 1, 8 and 15 every 4 weeks (q4wk) or plitidepsin 2.4 mg m(-2) on days 1, 8 and 15 q4wk combined with DTIC 800 mg m(-2) q4wk (n = 38). RESULTS: The overall response rate with plitidepsin/DTIC was 21.4%; all responders had normal serum lactate dehydrogenase (LDH) levels and performance status ≤ 1 at baseline. Median progression-free survival (PFS) with plitidepsin/DTIC was 3.3 months in all patients, and 4.3 months in those with baseline normal LDH. No responses occurred with single-agent plitidepsin and median PFS was 1.5 months. Both regimens were well tolerated. Haematological abnormalities were more common and transaminase increases more severe with plitidepsin/DTIC. Treatment-related transaminase increases leading to infusion omission on day 8 were relatively common. No drug-drug pharmacokinetic interactions were found. CONCLUSION: This plitidepsin/DTIC schedule has antitumour activity and manageable toxicity in advanced melanoma. Further evaluation of plitidepsin 2.4 mg m(-2) fortnightly and DTIC 800 mg m(-2) q4wk is recommended.

[Use of sunitinib in metastatic renal cell carcinoma patients with poor prognosis].

We evaluated overall and relapse-free survival in patients with metastatic renal cell carcinoma (MRCC) with poor prognosis. The study involved 92 patients (median age 54.1 years, male 63%, female 29%), retrospectively; 48.9% had poor prognosis. They received oral sunitinib 59 mg/day in 6 cycles (4 weeks on, 2 weeks off). Median overall survival was 17.6 months, relapse-free--10.8 months. Risk of progression in the poor and good prognosis groups was identical (HR=09). Overall response was 29% in poor prognosis and 40%--in good one (p = 0.07). Drug tolerability was acceptable in both groups. Sunitinib was effective in both groups of MRCC patients.

Neoadjuvant talimogene laherparepvec plus surgery versus surgery alone for resectable stage IIIB-IVM1a melanoma: a randomized, open-label, phase 2 trial.

Talimogene laherparepvec (T-VEC) is a herpes simplex virus type 1-based intralesional oncolytic immunotherapy approved for the treatment of unresectable melanoma. The present, ongoing study aimed to estimate the treatment effect of neoadjuvant T-VEC on recurrence-free survival (RFS) of patients with advanced resectable melanoma. An open-label, phase 2 trial (NCT02211131) was conducted in 150 patients with resectable stage IIIB-IVM1a melanoma who were randomized to receive T-VEC followed by surgery (arm 1, n = 76) or surgery alone (arm 2, n = 74). The primary endpoint was a 2-year RFS in the intention-to-treat population. Secondary and exploratory endpoints included overall survival (OS), pathological complete response (pCR), safety and biomarker analyses. The 2-year RFS was 29.5% in arm 1 and 16.5% in arm 2 (overall hazard ratio (HR) = 0.75, 80% confidence interval (CI) = 0.58-0.96). The 2-year OS was 88.9% for arm 1 and 77.4% for arm 2 (overall HR = 0.49, 80% CI = 0.30-0.79). The RFS and OS differences between arms persisted at 3 years. In arm 1, 17.1% achieved a pCR. Increased CD8+ density correlated with clinical outcomes in an exploratory analysis. Arm 1 adverse events were consistent with previous reports for T-VEC. The present study met its primary endpoint and estimated a 25% reduction in the risk of disease recurrence for neoadjuvant T-VEC plus surgery versus upfront surgery for patients with resectable stage IIIB-IVM1a melanoma.

Use of recombinant interleukin-2 for intrapleural therapy of tumor-associated pleurisy.

Clinical efficiency of low dose Roncoleukin was studied in 30 patients with metastatic exudative pleurisy. Intrapleural therapy proved to be highly effective (overall effect reached 84%), was well tolerated, and improved patients' quality of life.

[Cancer vaccinotherapy: from the experiment to clinical application].

Methods of cancer immunotherapy with dendritic cell-based vaccines, activated outside the organism, as well as techniques employing genetically modified whole-cell antitumoral vaccines, transfected by cytokine gens and stimulating the patient's dendritic cell stimulation in vivo, have been developed in Russian Oncological Research Center. Phase 1 clinical trials of dendritic cell vaccine in patients with disseminated melanoma and colon cancer have been carried out. The treatment is well-tolerated; significant adverse effects are absent. Moderate clinical efficacy and immune activation have been noted. Preclinical and phase 1 clinical studies of genetically modified vaccines also demonstrate the safety of this treatment and its ability to activate antitumoral immune response. Both vaccines are promising as subjects of rationally planned clinical trials of the efficacy of this treatment.

[Adoptive immunotherapy of malignancies].

The results of the studies show that mononuclear leukocytes isolated from human peripheral blood, malignant effusions, and surgically removed spleen can be generated into lymphokine-activated killers (LAK) characterized by high anti-tumor activity. LAKs may be used foradoptive immunotherapy of malignant effusions and the prevention of tumor recurrence in oncological patients after radical surgery.

FGFR2 overexpression predicts survival outcome in patients with metastatic papillary renal cell carcinoma.

BACKGROUND: Up to date, there are no data about FGFR2 expression and its predictive role in papillary RCC (pRCC) patients. The aim of the present study was to test FGFR2 expression and mutations for association with survival outcome in patients with pRCC. METHODS: Specimens of removed primary tumors from 214 untreated metastatic pRCC patients were evaluated by immunohistochemistry with FGFR2 antibody. FGFR2 mutations were assessed by PCR and direct sequencing, with DNA obtained from 62 paraffin-embedded pRCC samples. FGFR2 expression was tested for associations with progression-free survival (PFS), overall survival (OS) and best objective response. RESULTS: Expression of FGFR2 was observed in 23 % (49/214) of primary pRCC, mostly in cytoplasm of tumor cells. Expression of FGFR2 was significant lower in normal tissue of kidney (1 %, P = 0.001). FGFR2 S252W mutation was found in one patient (1.6 %), and no N549K mutation was detected. FGFR2 expression was strongly associated with a number of metastatic sites, type 2 of pRCC, lower nucleolar grade (P < 0.001). FGFR2-positive patients had significantly shorter OS and PFS (P < 0.05). On multivariate analysis, FGFR2 expression, MSKCC risk group and type of pRCC were found to be independent predictors of survival. CONCLUSIONS: In this study, we described immunohistochemical expression of FGFR2 in a large series of pRCC specimens. FGFR2 expression was found to be prognostic factor for survival in patients with metastatic pRCC. FGFR2 mutations are rare across papillary types of RCC.

More than 5000 patients with metastatic melanoma in Europe per year do not have access to recommended first-line innovative treatments.

BACKGROUND: Despite the efficacy of innovative treatments for metastatic melanoma, their high costs has led to disparities in cancer care among different European countries. We analysed the availability of these innovative therapies in Europe and estimated the number of patients without access to first-line recommended treatment per current guidelines of professional entities such as the European Society for Medical Oncology (ESMO), the European Organisation for Research and Treatment of Cancer (EORTC), the European Association of Dermato-Oncology (EADO), and European Dermatology Forum (EDF). MATERIALS AND METHODS: Web-based online survey was conducted in 30 European countries with questions about the treatment schedules from 1st May 2015 to 1st May 2016: number of metastatic melanoma patients, registration and reimbursement of innovative medicines (updated data, as of 1st October 2016), percentage of patients treated and availability of clinical studies and compassionate-use programmes. RESULTS: The recommended BRAF inhibitor (BRAFi) + MEK inhibitor (MEKi) combination was both registered and fully reimbursed in 9/30 (30%) countries, and in 13/30 (43%) (all from Eastern Europe) not reimbursed. First-line immunotherapy with anti-PD1 antibodies was registered and fully reimbursed in 14/30 (47%) countries, while in 13/30 (43%) (all from Eastern Europe) not reimbursed. It was estimated that in Europe 19,600 patients with metastatic melanoma are treated, and 5238 (27%) do not have access to recommended first-line therapy. Significant correlation was found between human development index (HDI, UNDP report 2015), (r = 0.662; p < 0.001), health expenditure per capita (r = 0.695; p < 0.001) and the Mackenbach score of health policy performance (r = 0.765; p < 0.001) with the percentage of patients treated with innovative medicines and a number of reimbursed medicines. CONCLUSIONS: Great discrepancy exists in metastatic melanoma treatment across Europe. It is crucial to increase the awareness of national and European policymakers, oncological societies, melanoma patients' associations and pharma industry.

Safety and immunogenicity of the PRAME cancer immunotherapeutic in metastatic melanoma: results of a phase I dose escalation study.

PURPOSE: The PRAME tumour antigen is expressed in several tumour types but in few normal adult tissues. A dose-escalation phase I/II study (NCT01149343) assessed the safety, immunogenicity and clinical activity of the PRAME immunotherapeutic (recombinant PRAME protein (recPRAME) with the AS15 immunostimulant) in patients with advanced melanoma. Here, we report the phase I dose-escalation study segment. PATIENTS AND METHODS: Patients with stage IV PRAME-positive melanoma were enrolled to 3 consecutive cohorts to receive up to 24 intramuscular injections of the PRAME immunotherapeutic. The RecPRAME dose was 20, 100 or 500 µg in cohorts 1, 2 and 3, respectively, with a fixed dose of AS15. Adverse events (AEs), including predefined dose-limiting toxicity (DLT) and the anti-PRAME humoral response (ELISA), were coprimary end points. Cellular immune responses were evaluated using in vitro assays. RESULTS: 66 patients were treated (20, 24 and 22 in the respective cohorts). AEs considered by the investigator to be causally related were mostly grade 1 or 2 injection site symptoms, fatigue, chills, fever and headache. Two DLTs (grade 3 brain oedema and proteinuria) were recorded in two patients in two cohorts (cohorts 2 and 3). All patients had detectable anti-PRAME antibodies after four immunisations. Percentages of patients with predefined PRAME-specific-CD4+T-cell responses after four immunisations were similar in each cohort. No CD8+ T-cell responses were detected. CONCLUSIONS: The PRAME immunotherapeutic had an acceptable safety profile and induced similar anti-PRAME-specific humoral and cellular immune responses in all cohorts. As per protocol, the phase II study segment was initiated to further evaluate the 500 µg PRAME immunotherapeutic dose. TRIAL REGISTRATION NUMBER: NCT01149343, Results.

[Melanoma cell lines as the basis for antitumor vaccine preparation].

The aim of the study was to obtain cell lines from tumor samples, and to determine phenotypic cell characteristics in order to choose the optimal line for vaccine preparation. 15 cell lines with stable growth, varying in cultural growth character and cytomorphology, were obtained from samples taken from patients with metastatic skin melanoma. Immunofluorescense method was used to determine the expression of T- and B-lymphocyte markers, antigens of major histocompatibility complex (MHC) class I and II, and CD86 co-stimulating molecule in the cell lines. The expression of melanocyte differentiation antigens and cancer/testicular antigens was evaluated using immunocytochemical assay. The results allowed the authors to distinguish three types of melanoma cell lines according to the expression of MHC molecules: MHC-negative; MHC class I positive; MHC classes I and II positive.

Enhanced expression of 1p32 and 1p22 fragile sites in lymphocytes in cutaneous malignant melanomas.

Frequency and distribution of 5-fluorodeoxyuridine (5-FdU) plus caffeine-induced fragile sites on chromosomes of peripheral blood lymphocytes (PBL) from 10 patients with cutaneous melanoma were studied in comparison with 10 PBL samples from normal donors of corresponding sex and age. The total number of breaks showed a significant difference among individuals in both groups, however, the average frequencies of 5-FdU plus caffeine-induced, as well as spontaneous damages in PBL from melanoma patients, were higher than those from healthy volunteers. The analysis of the breakpoint distribution showed a statistically significant increase in the expression of several fragile sites. The highest enhancement was observed at 1p32 and 1p22 sites (p less than 0.001). Earlier, the increase in the expression of 1p32 fragile sites was reported for neuroblastoma patients. We believe that enhanced expression of fragile sites in 1p may play a yet-unknown pathogenetic role in the development of some neuroectodermal tumors.