Monitoring of the presence of EGFR-mutated DNA during EGFR-targeted therapy may assist in the prediction of treatment outcome.

The aim of our trial was to evaluate the prognostic significance of qualitative ctDNA analysis on different stages of EGFR mutated non-small cell lung cancer (NSCLC) treatment. We included 99 patients amendable for the first line treatment with either gefitinib/erlotinib (n = 87), afatinib (n = 10) or osimertinib (n = 2). Sequential qualitative analysis of ctDNA with cobas® EGFR Mutation Test v2 were performed before first dose, after 2 and 4 months of treatment, and on progression. Our analysis showed clinically significant heterogeneity of EGFR-mutated NSCLC treated with 1st line tyrosine kinase inhibitors (TKIs) in terms of progression-free and overall survival. When treated with conventional approach, i.e. monotherapy with TKIs, the patients falls into three subgroups based on ctDNA analysis before and after 2 months of treatment. Patients without detectable ctDNA at baseline (N = 32) possess the best prognosis on duration of treatment (PFS: 24.07 [16.8-31.3] and OS: 56.2 [21.8-90.7] months). Those who achieve clearance after two months of TKI (N = 42) have indistinguishably good PFS (19.0 [13.7 - 24.2]). Individuals who retain ctDNA after 2 months (N = 25) have the worst prognosis (PFS: 10.3 [7.0 - 13.5], p = 0.000). 9/25 patients did not develop ctDNA clearance at 4 months with no statistical difference in PFS from those without clearance at 2 months. Prognostic heterogeneity of EGFR-mutated NSCLC should be taken into consideration in planning further clinical trials and optimizing the outcome of patients.

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.

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.