Human Papillomavirus Detection Strategies in Retinoblastoma

HPV infections in retinoblastoma: a systematic review

BACKGROUND

Retinoblastoma is the most common primary intraocular malignancy in children less than 4 years. Retinoblastoma (RB) contains about 3%-5% of all childhood cancers. Recent studies demonstrated that interacting between RB tumor suppressor and oncoproteins of DNA tumor viruses such as human papillomavirus (HPV). The objective of the current systematic review study was to present conducted studies in the field of HPV infection and its possible role in retinoblastoma.

METHODS

For this systematic review, all relevant original research studies were assessed by searching in electronic databases include PubMed, Embase, Scopus, Google Scholar, and Web of Science by using relevant keywords. The study was designed based on the PRISMA criteria. All publications with English literature and original researches are considered for screening.

RESULTS

Conducted search results lead to 4070 studies. The title and abstract screening lead to 11 studies. Data extraction was performed on 8 included studies. The prevalence of the HPV was ranged from 0 to 69%, and HPV genotype 16 and 18 were the most detected types. The most used method for the detection of the viruses was PCR, and the most assessed sample was formalin-fixed, paraffin-embedded tissue blocks.

CONCLUSION

The association between HPV and retinoblastoma is still inconsistent. The prevalence of the HPV in RB was ranged from 0 to 69%, which indicates a wide range and highlights the importance of further investigation for more accurate statistical of HPV prevalence in RB. Thus, further worldwide studies of larger sample sizes of cohorts should be investigated to clarify this uncertainty.

Molecular evidence of human papillomaviruses in the retinoblastoma tumor

Retinoblastoma tumor (RB) is one of the most prevalent ocular cancers among children. RB may be caused by inherited mutations in RB1 gene as well as some environmental risk factors. Human papillomaviruses (HPV) are suspected as a risk factor of RB due to their pRb inactivating protein. This study evaluated the molecular prevalence of HPV among the RB tumor specimens in Iran. The RB tumor samples were tested for detection of HPV-L1 gene using a nested-PCR approach, and then followed by sequencing and phylogenetic analysis to reveal HPV types. Overall, there were 61 RB tumor samples; 54/61 (88.5%) had unilateral and 7/61 (11.5%) bilateral RB; 55/61 cases (90.2%) had sporadic non-familial RB tumor. HPV-DNA was detected in 6/61 (9.8%) of patients' tumors; the HPV positive RB cases all had unilateral and unfamiliar sporadic RB tumor. HPV type 16 was the most prevalent type identified across the RB tumor samples (3/61, 4.9%). The rate of detected HPV among the RB specimens seems to be considerable. Further investigations are required to elucidate the exact association between HPV and progression to RB.