The absence of high-risk human papillomavirus in Czech non-small cell lung cancer cases

The emerging role of human papillomavirus in lung cancer

Lung cancer stands as one of the most lethal diseases and is the foremost cause of cancer-related mortalities worldwide. The pathophysiology of lung cancer is multifaceted, and it includes multiple cell signaling pathways and other complex factors such as oxidative stress and genetics. The association of HPV with lung carcinogenesis was first proposed in 1979, and since then, scientists worldwide have been putting forward several hypotheses to establish a relationship between this virus and lung cancer. Although studies have reported the presence of HPV in lung cancer, the exact mechanism of entry and the route of transmission have not been elucidated clearly till date. Numerous studies across the globe have detected differentially expressed HPV oncoproteins in lung cancer patients and found their association with the critical cell signaling pathways that leads to the development and progression of lung cancer. Many reports have also provided evidence stating the involvement of HPV in determining the survival status of lung cancer patients. The present review recapitulates the studies evincing the association of HPV and lung cancer, its route of transmission and mechanism of action; the detection of the virus and treatment opportunities for HPV-positive lung cancer; and the severity associated with this disease. Therefore, this will provide an explicit idea and would help to develop preventive measures and specific as well as effective treatment for HPV-associated lung carcinogenesis.

Infection with human cytomegalovirus, Epstein-Barr virus, and high-risk types 16 and 18 of human papillomavirus in EGFR-mutated lung adenocarcinoma

AIM

To assess the frequency of human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), and high-risk types of human papillomavirus (HPV16 and HPV18) infections in lung adenocarcinoma samples.

METHODS

Lung adenocarcinoma cytological smears and their DNA isolates were obtained from patients hospitalized at the Department for Lung Diseases Jordanovac, Zagreb, in 2016 and 2017. Overall, 67 lung adenocarcinoma samples were examined: 34 with epidermal growth factor receptor gene (EGFR) mutations and 33 without EGFR mutations. The EGFR mutation status and virus presence were assessed with a polymerase chain reaction, and random samples were additionally tested for EBV with Sanger sequencing. HCMV, EBV, HPV16, and HPV18 infections were evaluated in relation to EGFR mutation, smoking status, and sex. A meta-analysis of available data about HPV infection in non-small cell lung cancer was performed.

RESULTS

More frequent HCMV, EBV, HPV16, and HPV18 infections were observed in lung adenocarcinoma samples with EGFR mutations than in samples without these mutations. Coinfection of the investigated viruses was observed only in lung adenocarcinoma samples with mutated EGFR. In the group with EGFR mutations, smoking was significantly associated with HPV16 infection. The meta-analysis showed that non-small cell lung cancer patients with EGFR mutations had a higher odds of HPV infection.

CONCLUSION

HCMV, EBV, and high-risk HPV infections are more frequent in EGFR-mutated lung adenocarcinomas, which indicates a possible viral impact on the etiology of this lung cancer subtype.

High-Risk Human Papillomavirus Infection in Lung Cancer: Mechanisms and Perspectives

Lung cancer is a very prevalent and heterogeneous group of malignancies, and most of them are etiologically associated with tobacco smoking. However, viral infections have been detected in lung carcinomas, with high-risk human papillomaviruses (HR-HPVs) being among them. The role of HR-HPVs in lung cancer has been considered to be controversial. This issue is due to the highly variable presence of this virus in lung carcinomas worldwide, and the low viral load frequently that is detected. In this review, we address the epidemiological and mechanistic findings regarding the role of HR-HPVs in lung cancer. Some mechanisms of HR-HPV-mediated lung carcinogenesis have been proposed, including (i) HPV works as an independent carcinogen in non-smoker subjects; (ii) HPV cooperates with carcinogenic compounds present in tobacco smoke; (iii) HPV promotes initial alterations being after cleared by the immune system through a "hit and run" mechanism. Additional research is warranted to clarify the role of HPV in lung cancer.

Correlation between HPV PCNA, p16, and p21 Expression in Lung Cancer Patients

Purpose. Evaluate if human papillomavirus (HPV) infection in lung cancer patients might be helping cancer development by altering p16, p21, and PCNA, key human genes involved in cell proliferation and tumor development. Methods. 63 fresh-frozen (FF) and formalin-fixed paraffin-embedded (FFPE) samples from lung tumor patients were used to detect HPV by PCR, followed by genotype through sequencing. The host gene expressions of p21, p16, and PCNA were quantified by qPCR in both FF and FFPE samples, and the expression of viral oncogenes E5, E6, and E7 was also measured by qPCR in 19 FF samples. Results. 74.6% of samples were positive for HPV, 33/44 FFPE samples and 14/19 FF samples. HPV-16 and HPV-18 were detected in 31/33 and 7/33 FFPE, respectively, and HPV-16 was the only type in FF samples. E5, E6, and E7 were expressed in 10/19, 2/19, and 4/19 FF samples, respectively. The p16 RNAm expression was higher in FF HPV+ samples and FFPE+FF HPV+ samples, while p21 showed higher expression in all HPV- samples. In turn, the PCNA expression was higher in HPV+ FF samples; however, in FFPE and FFPE+FF samples, PCNA was higher in HPV- samples. In FF samples, PCNA, p16, and p21 showed a significant positive correlation as well as E5 and E7, and E5 was inversely correlated to p21. In FFPE, also, a positive correlation was observed between PCNA HPV+ and p21 HPV+ and PCNA HPV+ and p16 HPV. In FF+FFPE analysis, a direct correlation was found between PCNA HPV+ and p21 HPV+, p21 HPV+ and p16 HPV+, and PCNA HPV- and p16 HPV-, and an inverse correlation between PCNA HPV+ and p16 HPV+. Also, the p16 protein was positive in 10 HPV+ samples and 1 HPV-. Conclusions. Our data show that lung cancer patients from Northeast Brazil have a high prevalence of HPV, and the virus also expresses its oncogenes and correlates with key human genes involved in tumor development. This data could instigate the development of studies focused on preventive strategies, such as vaccination, used as a prognostic indicator and/or individualized therapy.

HPV and lung cancer: A systematic review and meta-analysis

BACKGROUND

Lung cancer has emerged as a global public health problem and is the most common cause of cancer deaths by absolute cases globally. Besides tobacco, smoke infectious diseases such as human papillomavirus (HPV) might be involved in the pathogenesis of lung cancer. However, data are inconsistent due to differences in study design and HPV detection methods.

AIM

A systematic meta-analysis was performed to examine the presence of HPV-infection with lung cancer.

METHODS AND RESULTS

All studies in all languages were considered for the search concepts "lung cancer" and "HPV" if data specific to HPV prevalence in lung cancer tissue were given. This included Journal articles as well as abstracts and conference reports. As detection method, only HPV PCR results from fresh frozen and paraffin-embedded tissue were included. Five bibliographic databases and three registers of clinical trials including MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov were searched through February 2020. A total 4298 publications were identified, and 78 publications were selected, resulting in 9385 included lung cancer patients. A meta-analysis of 15 case-control studies with n = 2504 patients showed a weighted overall prevalence difference of 22% (95% CI: 12%-33%; P < .001) and a weighted overall 4.7-fold (95% CI: 2.7-8.4; P < .001) increase of HPV prevalence in lung cancer patients compared to controls. Overall, HPV prevalence amounted to 13.5% being highest in Asia (16.6%), followed by America (12.8%), and Europe (7.0%). A higher HPV prevalence was found in squamous cell carcinoma (17.9%) compared to adenocarcinoma (P < .01) with significant differences in geographic patterns. HPV genotypes 16 and 18 were the most prevalent high-risk genotypes identified.

CONCLUSION

In conclusion, our review provides convincing evidence that HPV infection increases the risk of developing lung cancer.

Pitfalls of commercially available HPV tests in HPV68a detection

Background

Human papillomavirus 68 (HPV68) is a probable carcinogenic HPV genotype which is included in almost all HPV screening assays and exists as two genetically variable subtypes (HPV68a and HPV68b). Routine HPV sample testing has shown that the cobas 4800 HPV Test (Roche) provides higher false-negative rates for HPV68 status than PapilloCheck HPV-Screening (Greiner Bio-One). The aim of our study was to evaluate the efficacy of cobas 4800 in HPV68 detection.

Methods

A total of 2,145 cervical/cervicovaginal samples from women aged 17–88 were tested for HPV68 status using the cobas 4800 and PapilloCheck HPV tests. Viral load was assessed by quantitative PCR in all of the HPV68-positive cases. HPV68a/b subtyping was performed with real-time PCR followed by high resolution melting curve analysis, and was subsequently confirmed by Sanger sequencing.

Results

Cobas 4800 detected HPV positivity in only 13/33 HPV68 single-genotype infection cases. Viral load was comparable across both tested subgroups. HRM analysis and Sanger sequencing identified the HPV68a subtype in all of the 20 instances of cobas 4800 false negatives. HPV68a and HPV68b were detected in 3/13 and 10/13 cases identified as other HPV-positive by cobas 4800.

Conclusion

The HPV68a subtype was missed by cobas 4800 in more than 85% of all HPV68a-positive cases. Therefore, commercially available assays may underestimate HPV68 prevalence.