PCR-based detection of EGFR, ALK, KRAS and BRAF mutations in Russian patients with lung adenocarcinoma: a single-center experience.

In contrast to other countries with predominantly white populations, Russian smoking-related lung cancers (LC) are mainly squamous cell carcinomas and approximately half lung adenocarcinomas (AdCa) are not related to tobacco consumption. Given that smoking significantly influences the probability of presence of actionable mutations in LC, one would expect that Russian lung AdCa patients would differ from other white populations in distribution of EGFR, ALK, KRAS and BRAF mutations. Herein, 2,336 consecutive lung AdCa cases, including 1,203 patients with known smoking status, were subjected to sequential testing for the above mutations. One quarter of lung AdCa patients carried either EGFR or ALK mutation with combined prevalence of 42% in those who had never smoked but only 8% in smokers. There was only a moderate difference in KRAS mutation frequency between ever- and never-smokers in EGFR/ALK-negative cases (31% vs. 23%), and this was mainly attributed to increased prevalence of G12C substitution in the former group. The occurrence of BRAF V600E mutation was 1.7% and 4% in EGFR/ALK/KRAS mutation-negative ever- and never-smokers, respectively. ALK testing of 470 EGFR-mutated tumors revealed only 1 (0.2%) instance of translocation. Similarly, KRAS testing identified 1 (1.25%) mutation in 80 EGFR-mutated AdCa and none in 48 ALK-rearranged AdCa. Therefore, concurrent actionable mutations in lung adenocarcinoma are exceptionally rare and sequential gene testing can be regarded as a reliable option.

Spectrum of APC and MUTYH germ-line mutations in Russian patients with colorectal malignancies.

Distribution of cancer-predisposing mutations demonstrates significant interethnic variations. This study aimed to evaluate patterns of APC and MUTYH germ-line mutations in Russian patients with colorectal malignancies. APC gene defects were identified in 26/38 (68%) subjects with colon polyposis; 8/26 (31%) APC mutations were associated with 2 known mutational hotspots (p.E1309Dfs*4 [n = 5] and p.Q1062fs* [n = 3]), while 6/26 (23%) mutations were novel (p.K73Nfs*6, p.S254Hfs*12, p.S1072Kfs*9, p.E1547Kfs*11, p.L1564X and p.C1263Wfs*22). Biallelic mutations in MUTYH gene were detected in 3/12 (25%) remaining subjects with polyposis and in 6/90 (6.7%) patients with colorectal cancer (CRC) carrying KRAS p.G12C substitution, but not in 231 early-onset CRC cases negative for KRAS p.G12C allele. In addition to known European founder alleles p.Y179C and p.G396D, this study revealed a recurrent character of MUTYH p.R245H germ-line mutation. Besides that, 3 novel pathogenic MUTYH alleles (p.L111P, p.R245S and p.Q293X) were found. Targeted next-generation sequencing of 7 APC/MUTYH mutation-negative DNA samples identified novel potentially pathogenic POLD1 variant (p.L460R) in 1 patient and known low-penetrant cancer-associated allele CHEK2 p.I157T in 3 patients. The analysis of 1120 healthy subjects revealed 15 heterozygous carriers of recurrent MUTYH mutations, thus the expected incidence of MUTYH-associated polyposis in Russia is likely to be 1:23 000.

[Pharmacoeconomic analysis of gefitinib therapy in patients with non-cell cell lung cancer].

We performed a treatment efficacy analysis for non-small cell lung cancer (NSCLC) patients' population with EGFR mutation aimed at optimization of pharmacoeconomic factors. The employment of gefitinib leads to an increase in patients' life expectancy for a median of 1.05 years. The average cost-effectiveness of this therapy is 934.8 thousand rubles per additional year (903.9-1100.5 thousand rubles for each year). If gefitinib therapy is given only to patients with proved EGFR mutation it can decrease the average expenses by 211.6-251.8 thousand rubles per patient in comparison to undiagnosed patients's population receiving gefitinib without a decrease in clinical effect. Comparison of selective gefitinib administration with isolated chemotherapy (CT) yields an incremental cost-effectiveness ratio of 960.7 to 1010.0 thousand rubles per additional year. Therefore, the strategy of EGFR gene mutations testing in patients with inoperable NSCLC with consequent gefitinib therapy administration in patients positive for mutation lead to an increase in life expectancy and is characterized by acceptable cost-effectiveness.

[Effectiveness of gefitinib (Iressa) as first-line therapy for inoperable non-small-cell lung cancer with mutated EGFR gene (phase II study)].

Tumor regression was reported in 20-30% of patients with inoperable non-small-cell lung cancer (NSLC) following standard first-line chemotherapy. Clinical trials with second-line gefitinib (Iressa) showed a strikingly high response in patients with mutated EGFR. However, clinical experience with gefitinib as first-line therapy had been limited to small-scale trials mostly among subjects of Asian origin. Our study was not associated with the drug manufacturer and included 25 chemotherapy-naive patients with mutated EGFR inoperable lung adenocarcinoma. Standard dose was 250 mg/day. Complete response was observed in 1 patient (4%), partial--11 (44%), sustained stabilization--13 (52%); median time until tumor progression--186 days. Median overall survival failed to be registered within the duration of the study. Among most frequent side-effects were skin rash (19; 76%) and diarrhea (14; 56%): marked side-effect -toxicity grade III (4; 16%). Gefitinib appeared highly efficient and tolerable and may be recommended as first-line treatment of mutated EGFR inoperable NSLC.

Hereditary breast-ovarian cancer syndrome in Russia.

Hereditary breast-ovarian cancer syndrome contributes to as much as 5-7% of breast cancer (BC) and 10-15% of ovarian cancer (OC) incidence. Mutations in the "canonical" genesBRCA1andBRCA2occur in 20-30% of affected pedigrees. In addition toBRCA1andBRCA2 mutations, germ-line lesions in theCHEK2,NBS1, andPALB2genes also contribute to familial BC clustering. The epidemiology of hereditary breast-ovarian cancer in Russia has some specific features. The impact of the "founder" effect is surprisingly remarkable: a single mutation,BRCA15382insC, accounts for the vast majority ofBRCA1defects across the country. In addition, there are two other recurrentBRCA1alleles:BRCA14153delA andBRCA1185delAG. BesidesBRCA1, in Russia breast cancer is often caused by germ-line alterations in theCHEK2andNBS1genes. In contrast toBRCA1andBRCA2, theCHEK2andNBS1heterozygosity does not significantly increase the OC risk. Several Russian breast cancer clinics recently started to investigate the efficacy of cisplatin in the therapy ofBRCA1-related cancers; initial results show a unique sensitivity ofBRCA1-associated tumours to this compound.

[Allelic distribution of the CYP1A1 in lung cancer patients, middle-aged tissue donors and in elderly people without cancer]. / Raspredelenie allelei gena CYP1A1 u bol'nykh rakom lëgkogo, donorov srednego vozrasta i pozhilykh liudei bez onkologicheskoi patologii.

The genetic polymorphism of metabolizers of tobacco smoke carcinogens can influence individual susceptibility to lung cancer. The study was concerned with the Mspl-polymorphism of the CYP1A1 gene responsible for encoding aryl hydrocarbon hydroxylase. It also plays a role in the activation of polycyclic aromatic hydrocarbons (PAH). The CYP1A1 alleles and genotype distribution in 146 lung cancer patients was compared with that in 230 healthy donors. Another control group consisted of 259 "cancer-resistant" subjects, i.e. tumor-free smokers and non-smokers aged 75 and more. The CYP1A1 allele incidence (19%) in patients with squamous lung cancer was significantly higher than in the control cohorts (11%) which is consistent with the leading role of PAH in the etiology of this pathology.

Distinct prevalence of the CYP19 Delta3(TTTA)(7) allele in premenopausal versus postmenopausal breast cancer patients, but not in control individuals.

The CYP19 gene encodes the enzyme aromatase, which plays a key role in the conversion of androgens to oestrogens. A polymorphism in CYP19 in intron 4 (TTTA)n has been reported to be associated with breast cancer (BC) risk, although conflicting evidence has also been published. Here, we employ a non-traditional, highly demonstrative design of a molecular epidemiological study, where the comparison of BC cases and healthy middle-aged female donors was supplemented by an analysis of groups with extreme characteristics of either BC risk (bilateral breast cancer (biBC) patients) or cancer tolerance (tumour-free elderly women aged >or=75 years). None of the (TTTA)n polymorphic variants was significantly overrepresented among the affected women compared with any of the control groups. However, a 3-bp deletion/insertion CYP19 polymorphism, which is located in the same intron approximately 50 bp upstream to the (TTTA)n repeat, was evidently associated with the menopausal status in both the BC and biBC cohorts. In particular, the Delta3(TTTA)(7) allele occurred significantly more frequently in premenopausal than in postmenopausal BC patients (65/172 (38%) versus 67/310 (22%); P=0.0001; Odds Ratio (OR)=2.20 (95% Confidence Interval (CI) 1.46-3.32)), while the perimenopausal cases demonstrated an intermediate value (9/34 (26%)). In the biBC cohort, women who developed both tumours during their premenopausal period had a significantly higher prevalence of the Delta3(TTTA)(7) allele than patients with a postmenopausal onset of bilateral disease (16/46 (35%) versus 8/50 (16%); P=0.035; OR=2.80 (1.08-7.23)); those biBC patients, whose tumours were diagnosed before and after the cessation of menses, displayed an intermediate occurrence of the Delta3(TTTA)(7) allele (7/32 (22%)). Similar tendencies in the Delta3(TTTA)(7) allele distribution in BC and biBC patients suggest that its association with the menopausal status of the patients is truly non-random and thus this observation deserves further detailed investigation.

[Genetic polymorphism of steroid 17 alpha-hydroxylase/17,20-lyase (CYP17) and hyperinsulinemia in endometrial carcinoma]. / Polymorfism gena steroid-17-al'fa-gidroksilazy/17,20-liazy (CYP17) i giperinsulinemiia pri rake tela matki.

Initiation and/or promotion of endometrial carcinoma is considered to be associated with estrogens and androgens (androstendione) excess as well as hyperinsulinemia and resistance to insulin. It is possible that certain polymorphisms of the genes involved in steroidogenesis or steroid metabolism contribute to carcinoma susceptibility. In the current study, we compared the role of CYP17 biallelic MspA1) polymorphism in 114 endometrial carcinoma patients and 182 healthy women. According to our data, A2/A2 CYP17 genotype traditionally regarded as "unfavorable" was less frequent in cancer patients than in control which confirmed the results of two previous publications. For the first time, carriers of the genotype were shown to have relatively low levels of blood insulin and C-peptide. No significant difference was found between mean concentrations of testosterone, dehydroepiandrosterone sulfate and those of estradiol in the carriers of various CYP17 genotypes with endometrial cancer. Hence, CYP17 polymorphism which is represented by the "normal" A1/A1 genotype might be a factor of risk for endometrial carcinoma. Since this genetic variety may develop through an unconventional (nonsteroid) pathway, taking relevant preventive measures in high-risk groups should be recommended.

Tissue transglutaminase expression in breast carcinomas.

Tissue transglutaminase (tTG) is known to participate in multiple cellular processes, including apoptosis, cellular adhesiveness etc. Alterations of tTG expression could contribute to the development of several categories of diseases, including AIDS, cancer etc. The aim of the study was to test the pattern and relevance of tTG expression in a subset of breast carcinomas. RT-PCR has detected tTG-specific RNA message in 11 out of 25 (44%) breast cancer samples. tTG message was detected in 6/8 (75%) breast carcinomas with high apoptotic index, but only in 5/17 (29%) with the low one (p = 0.03). Immunohistochemical analysis revealed that only 15% of breast carcinomas displayed tTG protein in tumor cells, while the staining of the stromal components occurred in approximately one-half of the tumours tested. Surprisingly, there was no significant association between tTG RNA expression and protein positivity. Moreover, there was no evident relationships between tTG immunostaining and apoptotic index or clinical parameters of breast neoplasms. There are at least 2 alternative explanations for the poor concordance between RNA and protein data. It is likely that the sensitivity of immunohistochemistry is not sufficient to detect functionally relevant tTG enzyme in all breast cancer sections. Otherwise, tTG RNA expression does not always lead to accumulation of its product in the tumor cells, but reflects the transcriptional activation of other pro-apoptotic genes due to common triggering mechanisms.

GSTM1 genotypes in elderly tumour-free smokers and non-smokers.

Cancer is known to be an extremely common disease, with the life-time risks reaching close to 0.5 for men and to 0.4 for women. Hence those individuals, who succeeded to achieve a reasonably old age without a history of malignancy, represent a distinct group of interest, which apparently can be defined as 'tumour-tolerant'. Focus on the genetic features of these subjects may significantly facilitate the research of cancer-predisposing polymorphisms: first, a fundamental understanding of molecular mechanisms conferring the phenomena of cancer resistance appears to be outstandingly important; second, it is promising to involve non-affected geriatric cohorts in the molecular epidemiological studies as a tumour-free control of especial value. Here we analysed the GSTM1 genotype frequencies in the individuals with seemingly different degrees of resistance or susceptibility to neoplasms, such as elderly tumour-free smokers and non-smokers (> or = 75-years-old), healthy middle-aged donors, and lung cancer patients. The proportion of GSTM1-deficient individuals gradually increased from elderly controls (70/157; 45%) to middle-aged ones (77/140; 55%) to lung cancer sufferers (34/58; 59%), showing the minimal estimates in elderly non-affected smokers (35/81; 43%) and the maximal ones in the affected non-smokers (7/7, 100%). These data have led to the two groups of conclusions. First, the broad protective role of GSTM1 has been confirmed in this report. In particular, GSTM1-deficiency appeared to reduce the chances of entering an elderly age without a history of malignancy (OR=0.66 (0.42-1.04); P=0.073). Second, the efficiency of 'tumour patients versus elderly donors' comparative analysis has been exemplified. Indeed, the long-debated fact of overrepresentation of GSTM1(-) genotypes among lung cancer sufferers was clearly demonstrated by comparison of the affected individuals to the geriatric controls (OR=1.76 (0.96-3.23); P=0.068), whereas the same patients failed to produce any convincing deviations towards the middle-aged donors (OR=1.16 (0.63-2.14); P=0.641).

[A polymorphism study of the CYP19 gene in endometrial cancer patients]. / Izuchenie polimorfizma gena CYP19 u bol'nykh rakom éndometriia.

A strong connection is known to exist between initiation/promotion of endometrial cancer and excess of estrogens. Therefore, participation of certain alleles of genetic polymorphisms in steroid biosynthesis or metabolism may be responsible for predisposition to the disease. The present study, comparing CYP19 (aromatase) gene polymorphism in 85 patients and 110 healthy females, pointed to a more frequent occurrence of relatively longer alleles (A6 and A7) of the CYP19 gene in the former group. Furthermore, precisely those genotypes co-occurred more frequently with elevated blood levels of estradiol and testosterone in postmenopausal patients. Hence, CYP19 gene polymorphism may be regarded as a factor of genetic risk for endometrial carcinoma.

L-MYC and GSTM1 polymorphisms are associated with unfavourable clinical parameters of gliomas.

L-MYC and GSTM1 genotypes were analysed in glioma patients (GP) and healthy donors (HD). None of these genes appeared to influence the risk of this disease, however both polymorphisms correlated with unfavourable clinical parameters of gliomas. In particular, S allele of the L-MYC was overrepresented in the relapsed patients (P < 0.05), and GSTM1-null genotype was associated with the advanced tumour grade (P < 0.05). Patients, but not donors, demonstrated frequent combination of SS L-MYC homozygosity with GSTM1(-) variant (P < 0.01 ), as well as a correlation between LL L-MYC homozygosity and GSTM1 (+) genotype (P < 0.05).

CYP17 polymorphism in the groups of distinct breast cancer susceptibility: comparison of patients with the bilateral disease vs. monolateral breast cancer patients vs. middle-aged female controls vs. elderly tumor-free women.

The CYP17 gene encodes an enzyme involved in several critical steps of steroidogenesis. The promoter region of the CYP17 displays a single-nucleotide polymorphism, which is suspected to modulate the expression of the gene and thus may contribute in the interindividual variations of hormonal background. In agreement with this functional hypothesis, the MspA1+ allele (designated as A2) of the CYP17 was shown to render an increased risk of breast cancer (BC). However, the latter observation was disputed by a series of negative reports. Here, we re-evaluated the role of CYP17 MspA1 polymorphism in the BC susceptibility, using a non-traditional design of a case-control study. In addition to randomly selected 183 BC patients and 107 female middle-aged donors, we examined the groups with apparently extreme characteristics of either BC risk or BC resistance, namely the 57 bilateral breast cancer (biBC) patients and 75 elderly (>/=75 years old) tumor-free women. Neither BC nor biBC patients showed increased prevalence of 'unfavorable' A2 allele as compared with the non-affected cohorts. Moreover, the A2 variant was not significantly associated with the tumor size, nodal involvement and menopausal status in the patients either with the monolateral or bilateral disease. Thus, our data argue against the earlier reported role of the CYP17 in BC predisposition and progression. In addition, usual distribution of the CYP17 alleles in the elderly group indicates a neutral effect of this polymorphism on the longevity in females.

Evidence for microsatellite instability in bilateral breast carcinomas.

The molecular pathogenesis of various categories of breast cancer (BC) has been well described, but surprisingly few reports have appeared on analysis of somatic mutations in bilateral BC. We have performed a polymerase chain reaction (PCR)-driven investigation of chromosomal regions showing common loss of heterozygosity (LOH) in 23 cases (46 tumors) from patients diagnosed with bilateral BC. LOH was observed in 15/46 (33%) informative tumors for chromosome 1p, 5/32 (16%) for 5q, 12/44 (27%) for 11q, 15/40 (38%) for 13q and 4/24 (17%) for 17p. These values are within the range of interlaboratory variations reported for unilateral BC. There was no strong evidence for concordance of LOH within the same patient for any of the chromosomal loci tested. Atypical for breast carcinomas, 7/46 (15%) tumors accumulated a high frequency (ranging from 11 to 29%) of shortened dinucleotide CA repeats, implying microsatellite instability (MI). Further analysis with the highly informative BAT-26 marker allowed for the classification of two of these tumors as having a replication error positive (RER(+)/MSI-H) phenotype, whereas the remaining five carcinomas harbored so-called borderline MI. Thus an involvement of both RER(+) and borderline MI appears to be a distinct feature of bilateral breast carcinomas compared to unilateral lesions.

L-myc polymorphism in cancer patients, healthy blood donors and elderly, tumor-free individuals in Russia.

L-myc polymorphism was investigated in 95 breast cancer (BC), 63 colorectal cancer (CC) and 58 lung cancer (LC) patients, as well as in 122 healthy, middle-aged blood donors (HBDs) and 184 elderly, tumor-free individuals. The occurrence of the S allele in the BC cohort (57%) was significantly higher than that in middle-aged, healthy females (41%) and elderly, non-affected women (47%), implying involvement of the L-myc genotype in BC susceptibility (age-adjusted OR = 1.74, 95% CI 1.11-2.73, p = 0.016). L-myc allele distribution in CC and LC was similar to that in controls. Contrary to earlier reports, L:S allele frequencies ratio in elderly blood donors (EBDs) did not significantly differ from that in HBDs (0.49:0. 51 and 0.54:0.46, respectively). However, the S allele had a tendency to be over-represented among elderly compared with middle-aged smokers (55% vs. 44%; OR = 1.57, 95% CI 0.98-2.50, p = 0. 059), which implies that it may be linked with tolerance to smoking effects.

[Polymorphism of the GSMT1 gene in lung cancer resistance and susceptibility]. / Polimorfizm gena GSTM1 v gruppakh predraspolozhennosti i rezistentnosti k raku lëgkogo.

The published studies of onco-associated genetic polymorphisms are characterized by insufficient interlaboratory reproducibility. The inconsistency of the results can be partially attributed to some characteristics of patients and control groups, which are used for the comparison of allele frequencies. For instance, many investigations involve so-called "healthy donors" as a standard. However, the efficiency of such a comparison can be questioned; indeed, as an individual life-time risk of malignancy reaches as high as 40-50%, a significant part of "healthy donors" would soon or later become the oncological patients. Here we tested the advantage of using "true" oncologically tolerant individuals as an additional control, e.g. tumor-free people, who succeeded to achieve an elderly age without signs of any neoplastic disease. GSTM1 gene polymorphism was used as a "positive control" for this novel design of molecular epidemiological study, as the GSTM1-null genotype displays slight but reproducible association with lung cancer risk. In the present investigation, GSTM1-deficiency was detected in 45% elderly tumor-free individuals, 55% healthy middle-aged donors, and 59% lung cancer patients. The minimal frequency (43%) of GSTM1(-) genotype was detected in elderly tumor-free smokers, and the maximal one (100%) was found in never-smoking lung cancer patients. Thus, the comparison of lung cancer patients to the "true" oncologically tolerant cohort (elderly tumor-free individuals, especially smokers) revealed more demonstrative deviations for the unfavorable genotype, than the traditional comparative analysis between oncological patients and healthy donors.

[L-myc and GSTM1 polymorphism in cerebral glioma]. / Polimorfism genov L-myc i GSTM1 u bol'nykh gliomami golovnogo mozga.

L-MYC and GSTMI polymorphisms were studied in glioma patients. L-MYC allele frequency in patients (L: 61/114 (54%); S: 53/114 (46%)) and controls (L: 108/204 (53%); S: 96/204 (47%)) was identical. S allele was associated with certain unfavourable clinical features of the disease. In particular, its frequency was 26/42 (62%) in relapse vs. 26/68 (38%) in relapse-free disease (p < 0.05). GSTMI "null" genotype was identified in both patients and healthy donors (48%). GSTMI-deficient genotypes were significantly predominant in patients with grade III-IV gliomas as compared with grade I-II tumors (p < 0.05). Patients, but not donors, frequently revealed a combination of SS L-MYC homozygosity and GSTMI (-) variant (p < 0.01) as well as an association of LL L0-MYC homozygosity and GSTMI (+) genotype (p < 0.05).

[Search for Ki-ras codon 61 mutations in lung adenomas induced in neonatal BALB/c mice with 5-bromodesoxyuridine injection followed by urethane treatment]. / Poisk mutatsii v 61-m kodone onkogena Ki-ras v adenomakh lëgkikh, indutsirovannykh neonatal'nym vvedeniem 5-bromodezoksiuridina i posleduiushchim vozdeistviem uretana u myshei balb/c.

BALD/c mice were injected, s.c., 1 mg 5-bromodeoxyuridine (BDU) on days 1.3 and 7 after birth and/or 0.1 ml 5% solution of urethane, 5 times a day every fourth day, i.p., at the age of 3 months. Lung tumors, mostly adenomas, developed in 67% of males and 56% of females, treated with urethane alone. Tumor frequency in response to BDU + urethane rose to 91% in males and 56% in females; multiple neoplasia increased too. In BDU-treated animals, lung tumors appeared in 13% of males and 25% of females whereas in intact controls-3 and 11%, respectively. DNA isolated from paraffin mounts of tumor tissue was used to identify mutations in codon 61 of Ki-ras oncogene. Polymorphism studies of restriction fragment lengths in PCR products failed to detect CAA CTA and CAA CGA sequence changes in 7 samples of DNA. Our findings do not rule out other mutations of RAS oncogenes in our material. They also suggest that further research focus on Ki-ras codon 12 as well as Ha-ras "hot" triplets.