Prevalence of Papillomaviruses,Polyomaviruses, and Herpesviruses in Triple-Negative and Inflammatory Breast Tumors from Algeria Compared with Other Types of Breast Cancer Tumors

Background

The possible role of viruses in breast cancer etiology remains an unresolved question. We hypothesized that if some viruses are involved, it may be in a subgroup of breast cancers only. Epidemiological arguments drove our interest in breast cancer subgroups that are more frequent in Africa, namely inflammatory breast cancer (IBC) and triple-negative breast cancer. We tested whether viral prevalence was significantly higher in these subgroups.

Materials and Methods

One hundred fifty-five paraffin-embedded malignant breast tumors were randomly selected at the pathology laboratory of the University Hospital of Annaba (Algeria) to include one third of IBC and two thirds of non-IBC. They were tested for the presence of DNA from 61 viral agents (46 human papillomaviruses, 10 polyomaviruses, and 5 herpesviruses) using type-specific multiplex genotyping assays, which combine multiplex PCR and bead-based Luminex technology.

Results

Viral DNA was found in 22 (17.9%) of 123 tumors. The most prevalent viruses were EBV1 and HPV16. IBC tumors carried significantly more viruses (any type) than non-IBC tumors (30% vs. 13%, p<0.04). Similarly, triple-negative tumors displayed higher virus-positivity than non-triple-negative tumors (44% vs. 14%, p<0.009).

Conclusions

Our results suggest an association between the presence of viral DNA and aggressive breast cancer phenotypes (IBC, triple-negative). While preliminary, they underline the importance of focusing on subgroups when studying viral etiology in breast cancer. Further studies on viruses in breast cancer should be conducted in much larger samples to confirm these initial findings.     

Nasopharyngeal carcinomas and Epstein-Barr virus: from epidemiology and detection to therapy

Nasopharyngeal carcinomas (NPC) challenge clinicians and biologists in various fields including epidemiology, genetics, virology and immunology. These tumours have a striking geographical distribution. They are constantly associated with the Epstein-Barr virus (EBV) and contain a massive lymphocytic infiltrate. Their study has major implications especially at this moment while a pathological role of EBV is suspected in several other human epithelial malignancies (for example gastric, mammary and thyroid carcinomas). The North-South Workshop on Nasopharyngeal Carcinoma was held at the Institut Gustave-Roussy in early December 2003. Its main goal was to support the exchanges between clinical research on NPC in the South and basic research in the North. With regard to epidemiology and genetics, the main information was the possible existence of several susceptibility genes (including two of them on the 4p and 5p chromosomes). In virology, participants have emphasized the selection of peculiar EBV variants within the malignant cells and the expression of novel oncogenic viral proteins : LMP2 and BARF1. Cellular gene alterations also contribute to NPC development, especially inactivation of tumor suppressor genes located on the 3p chromosome. Therapeutic research was not forgotten. Hope of higher rate of cure relies on improved ballistic processes in radiotherapy (IMRT) and on the development of targeted therapeutics : induction of the lytic/productive viral cycle, gene therapy with conditional replicative adenoviruses, antitumor vaccination directed against the viral protein LMP2.     

EBV-associated nasopharyngeal carcinomas: from epidemiology to virus-targeting strategies

Nasopharyngeal carcinoma is a human malignancy consistently associated with the Epstein-Barr virus. Exposure to non-viral carcinogens and genetic predisposition are other crucial etiologic factors. Tumor development appears to require the expression of a small subset of transforming viral RNAs and proteins with concomitant silencing of most other viral genes. Impairment of the interactions of viral proteins with cellular partners or disruption of viral latency might prove to be useful for novel therapeutic strategies.