Predictive markers in lung cancer: a few hints for the practicing pathologist.

This review article highlights some important points in the evolving area of predictive biomarkers determination in non-small-cell lung cancer toward standardization of testing practices, including EGFR mutations, ALK and ROS1 rearrangements and immunohistochemical expression of PD-L1. Considerations for selecting appropriate populations for molecular testing, and emergence of other targetable molecular alterations are also discussed.

Identification of microRNAs 758 and 33b as potential modulators of ABCA1 expression in human atherosclerotic plaques.

BACKGROUND AND AIM: Adenosine triphosphate (ATP)-binding cassette (ABC) transporters A1 and G1 are the main transporters involved in macrophage cholesterol efflux. The understanding of the molecular mechanism(s) of their regulation in atherosclerosis is crucial for potential therapeutic approaches. Preclinical studies support a role for microRNAs in the posttranscriptional regulation of these transporters; however, no evidence is still available on human atherosclerosis. Thus, the aim of this study was to investigate the modulation of the ABCA1 and ABCG1 pathway in human atherosclerotic plaques and microRNA involvement in its modulation. METHODS AND RESULTS: Thirty-one human atherosclerotic plaques were obtained from patients undergoing carotid endarterectomy for high-grade (>70%) vessel stenosis, and divided into normocholesterolemic (n = 15) and hypercholesterolemic groups (n = 16) according to the presence/absence of hypercholesterolemia. Both ABCA1 and ABCG1 messenger RNAs (mRNAs) were significantly upregulated in carotid plaques from hypercholesterolemic patients as assessed by real-time polymerase chain reaction (RT-PCR). Despite this result, no difference was found at the protein levels analyzed by Western blot, thus suggesting a strong posttranscriptional modulation. MicroRNA microarray and subsequent validation by RT-PCR showed a significant upregulation of ABCA1-linked miR-758 and miR-33b in plaques from hypercholesterolemic patients. CONCLUSION: We provide evidence of a strong posttranscriptional regulation of ABCA1 and ABCG1 expression in human atherosclerotic plaques from hypercholesterolemic patients. This effect is potentially due to the concomitant increase of miR-33b and miR-758, two well-established regulators of ABCA1 and ABCG1 expression. The identification of miR-33b and miR-758 as putative key regulators of ABCA1 protein expression within human atherosclerotic plaques provides further data for the realization of new anti-atherosclerotic drugs with specific targets based on anti-miRNA technologies.

Activating c-KIT mutations in a subset of thymic carcinoma and response to different c-KIT inhibitors.

BACKGROUND: To analyze a multi-institutional series of type C thymic carcinomas (TCs) (including neuroendocrine tumors), focusing on the expression and mutations of c-KIT. MATERIALS AND METHODS: Immunohistochemical expression of c-KIT/CD117, p63, CD5 and neuroendocrine markers, as well as mutational analysis of c-KIT exons 9, 11, 13, 14, 17 by direct sequencing of 48 cases of TCs. Immunohistochemical and molecular data were statistically crossed with clinicopathological features. RESULTS: Overall, 29 tumors (60%) expressed CD117, 69% were positive for CD5 and 85% (41 cases) for p63. Neuroendocrine markers stained all six atypical carcinoids and five poorly-differentiated thymic squamous cell carcinomas. Overall, six CD117-positive cases (12.5%) showed c-KIT mutation. No mutation was detected in CD117-negative tumors and carcinoids. All the mutations were found in poorly-differentiated thymic squamous cell carcinomas expressing CD117, CD5, p63 and lacking neuroendocrine markers (6 of 12 cases with these features). Mutations involved exon 11 (four cases: V559A, L576P, Y553N, W557R), exon 9 (E490K) and exon 17 (D820E). CONCLUSIONS: All TCs need an immunohistochemical screening with CD117, while c-KIT mutation analysis is mandatory only in CD117-positive cases, particularly when coexpressing CD5 and p63, lacking neuroendocrine differentiation. The finding of c-KIT mutation can predict efficacy with different c-KIT inhibitors.

AKT1(E17K) in human solid tumours.

The serine-threonine kinase AKT1 is a central player in the oncogenic pathway controlled by PI3K. Recently, a somatic mutation in AKT1 (E17K) has been detected in breast, colorectal, lung and ovarian cancers. The E17K change results in constitutive AKT1 activation and induces leukaemia in mice. We determined the occurrence of the E17K variant in a panel of 764 tumour samples. These included breast, lung, ovarian, colorectal and pancreatic carcinomas as well as melanomas and glioblastomas. Despite the fact that these tumours are known to bear alterations in genes involved in the PI3K signalling pathway, AKT1(E17K) was detected only in breast (16/273), colorectal (1/88) and lung (1/155) cancers. Within the neoplasms of breast origin, the AKT1(E17K) variant was mutually exclusive with respect to the PIK3CA(E454K or H1047R) alleles and was present only in ductal and lobular histotypes. Our results, showing that AKT1 mutations seem to occur in a tissue-specific fashion have basic and clinical implications. First, the activity of mutated AKT1 in oncogenic PI3K signalling could be strictly dependent on the cell and tissue milieu. Second, therapeutic efforts aimed at selective targeting the AKT1(E17K) variant could be effective mainly in specific cancer types.

The effects of acute passive smoke exposure on endothelium-dependent brachial artery dilation in healthy individuals.

Passive smoking has both short-term and long-term vascular effects. It is not clear whether impairment of endothelial function reflects the acute effects of passive smoke exposure or the chronic effects. The purpose of this study was to assess the hypothesis that short-term exposure to passive smoke impairs endothelium-dependent vasodilation in healthy nonsmokers. Eighteen healthy young never smokers (12 men, 6 women) 21 to 55 years old (mean +/- SD: 34 +/-9 years) underwent ultrasonography measuring baseline brachial-artery diameter and brachial-artery diameter during hyperemia and after sublingual administration of nitroglycerin, twice: in a smoke-free environment, and then in the same environment polluted by 30 to 35 ppm carbon monoxide. Each subject served as his/her control. Carboxyhemoglobin was measured in blood samples of subjects tested. Mean value of carboxyhemoglobin was 0.6 +/-0.5% in a smoke-free environment and 1.4 +/- 0.5% in a smoking environment (p <0.02). Mean values of flow-mediated dilation (FMD) were 12.6% +/- 7.8% in a smoke-free environment versus 6.8 +/- 7.8% in a smoking environment (p <0.01). On the contrary, nitroglycerin-induced vasodilation did not show any statistical difference (21 +/- 9.8% versus 23 +/-1.4%). Finally, the increase of carboxyhemoglobin was related statistically to the impairment of flow-mediated dilation (r = 0.51; p <0.002). Passive smoking impaired flow-mediated vasodilation in healthy never smokers in a smoking environment. The impairment was strongly related to carboxyhemoglobin level.

Is transcutaneous oxygen and carbon dioxide monitoring indispensable in short- and long-term therapeutic management of non-reconstructable lower critical limb ischemia?

AIM: The aim of this study was to evaluate the capacity of transcutaneous partial pressure of O(2) (TCpO(2)) and CO(2) (TCpCO(2)) to predict clinical response to pharmacological treatment in short- and long-term follow-up of unreconstructable critical limb ischemia (CLI) treated with prostanoids; to suggest a diagnostic and therapeutic algorithm able to define the possibility of prostanoid therapy in unreconstructable CLI at high risk of limb loss. METHODS: Twenty-six consecutive patients with CLI (21 with distal trophic lesions, 31 symptomatic limbs) considered unreconstructable after peripheral angiography and with a history of type 2 diabetes mellitus underwent daily parenteral Iloprost treatment for 2-3 weeks. RESULTS: Transcutaneous gas-analytic monitoring (TGM) in non-reconstructable CLI treated with Iloprost divided patients into 2 groups: early responders (ER) with increased TcpO(2) and normalization of TcpCO2, and non responders (NR) with unchanged TcpO(2) and TcpCO(2) parameters. In the NR who underwent a second cycle of Iloprost within a few months of the first, TGM further divided the patients into another subgroup of late responders (LR) with TcpO(2) and TcpCO(2) similar to the ER group and a subgroup of NR, who, after pharmacological treatment failure, should undergo eventual surgical re-timing and/or spinal cord stimulation in a final attempt to save the limb. CONCLUSIONS: In the short-term follow-up of CLI, a marked reduction in supine/dependent TcpO(2) and a marked increase in supine TcpCO(2) at the symptomatic forefoot proved to be significant predictors of major amputation risk. In the long-term follow-up period, TGM showed that, in ER and in LR, the favourable effect of pharmacological therapy observed in the first 6 months will disappear over the next 6 months, suggesting an algorithm of 2- to 3-week cycles of prostanoid therapy repeated every year. In NR treated with surgical and/or alternative therapies who did not undergo major amputations, prolonged instrumental TGM will provide a constant evaluation of metabolic parameters, thus providing the possibility to save the limb with additional pharmacological therapy.

mRNA markers of breast cancer nodal metastases: comparison between mammaglobin and carcinoembryonic antigen in 248 patients.

Histological detection of axillary lymph node metastases is still the most valuable prognostic parameter for breast cancer, but about 30% of node-negative patients relapse within five years, suggesting that current methods are inadequate for identifying metastatic disease. More sensitive, PCR-based methods for the detection of metastatic cells are now available, enabling the amplification of cancer cell-specific mRNA messages by the RT-PCR assay. An ideal tumour marker, consistently expressed in tumour samples and not at all in normal lymph nodes, remains to be identified. The present study first investigated the expression of seven mRNA markers, CEA, CK19, c-Met, mammaglobin, MUC-1, beta1-->GalNAc-T and p97, selected on the basis of their previously reported specificity for breast cancer cells. Eighteen lymph nodes were examined from patients without tumours. Only mammaglobin mRNA and CEA mRNA were not expressed in normal nodes. All of the other markers showed a band of expression in 17%-55% of cases, indicating that they are not breast cancer-specific. CEA mRNA and mammaglobin mRNA expression could be detected in 15/20 (75%) and 19/20 (95%) primary breast carcinomas, respectively. The expression of mammaglobin mRNA and CEA mRNA was then compared in axillary lymph nodes from 248 consecutive breast cancer patients, 89 with histologically documented lymph node metastasis and 159 without histological evidence of metastatic disease. Ninety-seven per cent of the patients with histologically involved nodes showed expression of mammaglobin mRNA, whereas CEA mRNA was expressed in 79% of these cases. In the group of patients with histologically negative lymph nodes, 46 (29%) and 32 (20%) were found to be positive for mammaglobin and CEA expression, respectively, indicating the presence of metastases not detected by routine histological examination of one lymph node section. These results show that both mammaglobin RT-PCR and CEA RT-PCR are useful tools for the detection of breast cancer metastases in axillary lymph nodes. The detection sensitivity of the mammaglobin RT-PCR is far superior to that of the CEA RT-PCR, allowing the diagnosis of occult metastases in nearly one-third of cases.

Reduced expression of INT-6/eIF3-p48 in human tumors.

The int-6 gene, originally identified as a common integration site for the mouse mammary tumor virus (MMTV) in mouse mammary tumors, encodes the p48 component of the eukaryotic translation initiation factor-3 (eIF3-p48). Int-6/eIF3-p48 is expressed in all adult tissues which have been tested and early in embryonic development. Int-6/eIF3-p48 has been highly conserved throughout evolution and the deduced amino acid sequence of the human gene product is identical to the mouse protein. Viral insertions at the Int-6/eIF3-p48 locus in mouse mammary tumors result in production of chimeric Int-6/eIF3-p48/MMTV products that may act as dominant negative oncoproteins. Int-6/eIF3-p48 has also been identified as a human protein that binds to the human T-cell leukemia virus type I Tax oncoprotein. The role of Int-6/eIF3-p48 in human carcinogenesis is unknown at the present time. In this study we have examined Int-6/eIF3-p48 gene status and expression in two of the most common forms of cancer in humans, breast and lung tumors. Sixty-two breast carcinomas and 78 non-small cell lung carcinomas (NSCLC) were investigated. LOH at the Int-6/eIF3-p48 locus was observed in 5 (21%) of 24 informative breast tumors and 10 (29%) of 34 informative lung tumors. A reduced expression of Int-6/eIF3-p48 was seen in 23 (37%) of breast cancer samples and 24 (31%) of NSCLC samples. An association between Int-6/eIF3-p48 expression and LOH at the Int-6/eIF3-p48 locus was observed. Int-6/eIF3-p48 expression was not related to commonly used pathological parameters in breast cancer patients, while in NSCLC patients int-6/eIF3-p48 expression was mainly seen in adenocarcinomas (P<0.0001). In conclusion, our data show for the first time a decreased expression of Int-6/eIF3-p48 in a consistent portion of human breast and lung carcinomas, frequently associated with LOH at the Int-6/eIF3-p48 locus. Additional studies on larger series of tumor specimens with long-term follow-up are needed to determine whether Int-6/eIF3-p48 expression may represent a new prognostic or predictive marker.

Usefulness of carotid intima-media thickness measurement and peripheral B-mode ultrasound scan in the clinical screening of patients with coronary artery disease.

Previous observational studies have shown a relationship between carotid intima-media thickness (IMT) and coronary artery disease (CAD). In this study the authors evaluated the accuracy of the common carotid IMT measurement in predicting the presence and severity of CAD and the additional information offered by the detection of carotid, iliac, and lower limb plaques. One hundred and fifty consecutive patients were subjected to coronary angiography and carotid, iliac, and lower limb ultrasound scan. The mean value of six IMT measurements of the far wall of the common carotid artery was calculated in each patient. The mean IMT was significantly correlated to the number of stenosed coronary vessels (r = 0.43, p<0.001), although the positive and negative predictive value of mean IMT in identifying patients with CAD was low (81% and 46%, respectively). The combined information offered by IMT measurements and peripheral (carotid, iliac, and lower limb) plaque detection was then used to obtain the best multivariate regression model able to predict CAD status. The multivariate model showed a highly significant multiple correlation coefficient (r = 0.60, p<0.0001) and a sharp improvement in the negative predictive value (92%) with respect to the univariable model. B-mode ultrasound scan including common carotid IMT measurement and peripheral plaque detection may be of clinical value in the screening of patients with CAD.

p53 status is neither a predictive nor a prognostic variable in patients with advanced ovarian cancer treated with a paclitaxel-based regimen.

BACKGROUND: The aim of this study was to assess the relationship between p53 status and the clinical outcome of patients with advanced ovarian cancer treated with a paclitaxel-based regimen. PATIENTS AND METHODS: The investigation was conducted on 38 patients with FIGO stage III-IV ovarian cancer from whom tumor tissue samples for p53 protein immunostaining were obtained during initial cytoreductive surgery. All these patients subsequently received six cycles of first-line combination chemotherapy with paclitaxel 175 mg/m2 (3-hour infusion) plus carboplatin AUC 6 with or without epidoxorubicin 75 mg/m2. RESULTS: Positive p53 immunostaining was detected in tissue samples collected from 24 (63.2%) ovarian cancers. A clinical complete response was obtained in 14 (58.3%) of the 24 patients with positive p53 immunostaining compared to 9 (64.3%) of the 14 patients with negative p53 immunostaining (p = 0.717). A pathological complete response was found in 6 (25.0%) of the former compared to 4 (28.6%) of the latter (p = 0.956). Similarly, survival did not correlate with p53 status (p = 0.1271). DISCUSSION: p53 status seems to be neither a predictive nor a prognostic variable in patients with advanced ovarian cancer treated with a paclitaxel-based regimen. These results are consistent with experimental data showing that paclitaxel cytotoxicity in ovarian cancer is likely to be mediated by a p53-independent pathway.

Lung tumours from non-smoking subjects: A p53-related genetic instability in a subset of cases.

Tumours developed in non-smoking patients represent about 10% of all lung neoplasms and show peculiar morphologic and genetic features. In a previous study, we found a constant association between p53 gene alterations and loss of heterozygosity (LOH) at the FHIT locus in a subset of non-smoking tumours (7 cases out of 35 analyzed), so we hypothesized that a genomic instability associated with p53 mutations could be the cause of FHIT LOH in these neoplasms. To test this hypothesis, in the same panel of tumours, we investigated the presence of LOH at 7 other microsatellite loci located on different chromosomes. Interestingly we found that all of the tumours with p53 alterations and LOH at the FHIT locus showed loss of heterozygosity at all of the informative tested loci. This association was statistically significant (p=0.0001). Our data indicate the presence of a generalized genomic instability in this subset of lung tumours. Since p53 alterations were mostly G:C --> A:T transitions and frameshift deletions, we are tempted to hypothesize that the genomic instability observed in non-smoking patients could be caused by particular p53 alterations. In fact, other kind of p53 mutations (G:C --> T:A transversions), frequently found in a series of 35 tumours of smokers used as control, were not associated with LOH at microsatellites loci. However, we cannot exclude that p53 alterations are a consequence and not the cause of the genomic instability. In this case, we have to admit that a gene(s), upstream of p53, is implicated in genome destabilisation in a subset of lung adenocarcinomas developed in non-smoking patients.

Telomerase activity as a prognostic indicator in stage I non-small cell lung cancer.

Patients with stage I non-small cell lung cancer (NSCLC) are typically treated with surgical resection alone. However, about one-third of such patients develop disease recurrence and die within 5 years after complete resection. The ability to predict recurrence could represent an important contribution to treatment planning. This study evaluates the presence of telomerase activity in tumor cells as a predictor of disease recurrence and cancer-related death after operation for stage I NSCLC patients. The activity of the telomerase enzyme was investigated by telomeric repeat amplification protocol (TRAP) in tumors and matching normal lung tissue samples obtained from 107 consecutive operable patients with pathological stage I NSCLC. Telomerase activity was detected in 66 (62%) of the 107 tumors examined and in none of the corresponding adjacent noncancerous lung tissue samples. Correlation with pathological parameters showed that telomerase activity was associated with histopathological grade (P = 0.0135) but not with tumor size or histological type. Univariate survival curves, estimated using the method of Kaplan and Meier, defined a significant association between telomerase activity and both disease-free survival (P = 0.0115) and overall survival (P = 0.0129). In multivariate analyses, performed by Cox's proportional hazards regression models, the presence of telomerase activity was the only strong predictor of disease-free survival (P = 0.0173) and overall survival (P = 0.0187). Our data indicate that telomerase activity can be an important prognostic factor that should be considered in future prospective trials of adjuvant therapy for high-risk stage I NSCLC patients.

Assessment of the prognostic relevance of serum anti-p53 antibodies in epithelial ovarian cancer.

The objective of this study was to assess the prognostic relevance of preoperative serum anti-p53 antibodies in epithelial ovarian cancer. These autoantibodies were detected with a new generation enzyme-linked immunosorbent assay in blood samples preoperatively drawn from 86 patients with this malignancy. Serum anti-p53 antibodies were found in 3 (10.0%) of the 30 patients with stage I-II and 15 (26.8%) of the 56 patients with stage III-IV epithelial ovarian cancer (P = 0.09). We assessed in detail 44 patients with stage III-IV disease who underwent six cycles of first-line platinum-based chemotherapy. A pathological complete response at second-look was achieved by none of the 15 patients with serum anti-p53 antibodies compared to 24.1% of the 29 patients without autoantibodies (P = 0.09). However, the preoperative serum anti-p53 antibody status had no prognostic relevance for progression-free survival and survival. In conclusion, the assessment of preoperative serum anti-p53 antibodies seems to have a limited clinical value in the management of patients with advanced epithelial ovarian cancer.