Identification of G2607A mutation in EGFR gene with a significative rate in Moroccan patients with nasopharyngeal carcinoma

The epidermal growth factor receptor (EGFR) is involved in the regulation of several cellular processes and in the development of many human cancers. Somatic mutations of EGFR at tyrosine kinase domain have been associated with clinical response to tyrosine kinase inhibitors (TKIs) in lung cancer patients. In this study, we evaluated the frequency of point mutations in EGFR for future use of TKI in clinical treatment of nasopharyngeal carcinoma (NPC). Sixty Moroccan patient specimens of NPC were analysed for EGFR mutations in the region delimiting exons 18 and 21 by direct sequencing. Our results showed the absence of mutations in the EGFR kinase domain in these exons in all 60 analysed specimens. Sequence analysis of the EGFR—TK domain, revealed the presence of (G2607A) polymorphism at exon 20. The genotypes AA and GA were found respectively in 39 (65%) and 16 (26.6%) cases. Statistical analysis showed no difference between the polymorphism and either gender or age of patients. Mutations in EGFR kinase domain are rare events in NPC biopsies, suggesting, that treatment of NPC patients with TKI may not be effective. However, EGFR G2607A polymorphism at exon 20 is frequent in NPC cases and could be associated to clinical response to TKI therapy.

Antibody responses to recombinant Epstein-Barr virus antigens in nasopharyngeal carcinoma patients: complementary test of ZEBRA protein and early antigens p54 and p138

Serological tests based on the antibodies directed against the Epstein-Barr virus early antigen (EA) and viral capsid antigen (VCA), which have been recognized as tumor markers for nasopharyngeal carcinoma (NPC), are routinely used to help in the diagnosis of this malignancy. The detection of these antibodies reveals very low titers, found only in a small proportion of young compared with older NPC patients. This is a problem for the diagnosis of NPC, especially among Maghrebians, among whom young people are also affected, and emphasizes the necessity to search for more reliable markers. The present study reports results of immunoglobulin G (IgG) and IgA responses of NPC patients to recombinant EA antigens p54 (BMRF1) and p138 (BALF2), VCA complex antigens p18 (BFRF3) and p23 (BLRF2), and EBNA antigen p72 (BKRF1). Our results show that IgA-EA-p54 and -p138 (IgA-EA-p54+138) antibodies have a diagnostic value for detection of NPC (70%), compared with IgA-VCA-p18+23 and IgA-EBNA-p72, which have limited diagnostic value, especially in young patients. It is also noteworthy that IgA-EA-p54+138 can detect a high percentage (64%) of NPC cases negative by immunofluorescence. These results, however, clearly show that a single test cannot achieve the objective of detecting all NPC patients, and it seems advisable to combine different tests for the diagnosis of NPC. The combination of IgG-ZEBRA with IgA-EA-p54+138 improved the sensitivity of detection of NPC to 95% in the overall NPC population. The use of IgA-EA-p54+138 in combination with IgG-ZEBRA will facilitate detailed studies on the pattern of antibody response, which may result in the development of useful serological markers to guide the treatment of NPC.

A rare case of angiosarcoma of the breast in a man: case report

This is a case report of a 57-year-old man who had primary angiosarcoma of the left breast. Five months after detecting a mass in his breast, he underwent mastectomy with biopsy of the ipsilateral axillary lymph nodes. Three years later, he is still alive without any recurrence. Angiosarcoma of the female breast is rare and exceptional in males. It is a condition with a poor prognosis and there are as yet no established chemotherapeutic regimens.

Primary malignant lymphoma of the ovary: an unusual presentation of a rare disease

Because the outcome of patients with primary ovarian non-Hodgkin's lymphoma (NHL) is controversial, we present the incidental finding of a primary malignant lymphoma of the ovary in a 50-year-old patient. Three and a half years following ablative surgery and adjuvant chemotherapy, the patient is alive and disease free. Ovarian lymphoma is a disease of reportedly poor prognosis. However, many previously reported cases of ovarian lymphoma actually represented ovarian involvement by a more diffuse lymphomatous process. If stringent criteria are used for case selection, true primary ovarian lymphoma is a very rare disease and usually carries a favorable prognosis.

Study of human leukocyte antigen class I phenotypes in Moroccan patients with nasopharyngeal carcinoma

Previous reports demonstrated an association between the human leukocyte antigen (HLA) and risk for nasopharyngeal carcinoma (NPC) among the Chinese in Singapore, a population with a high incidence of this malignancy. In our study, we assess the association between HLA and NPC in Morocco, a median-prevalence area for this cancer, where NPC presents the particularity of also affecting young individuals. Using the standard microlympho-cytotoxicity test, we typed a total of 154 Moroccan NPC patients and 257 unrelated healthy controls for their HLA-A and B antigens. The results of these analyses show that the frequencies of HLA-A10, HLA-B13 and HLA-B18 were found to be higher in the NPC group than in the control group, whereas HLA-A9 was associated with a decreased risk. After correction for the number of specificities tested, these differences were statistically significant only for HLA-B18 (corrected p value [pc] < 0.023, relative risk [RR] = 4.14) and HLA-A9 (pc < 0.023, RR = 0.45). The comparison of the distribution of the HLA antigens in younger and older cohorts of patients shows that the incidence of HLA-A10 and HLA- B18 was higher in the older group, whereas the frequencies of HLA-A19 and HLA-B13 were significantly higher in younger patients compared with controls. The presence of both HLA-A19 and HLA-B13 phenotypes correlated with an increased risk of developing NPC among overall patients compared with controls. According to the sex distribution, increased frequency of HLA-B18 was found in male and female NPC patients compared with controls, whereas the frequency of HLA-A10 was higher only in male NPC patients compared with controls.

Antibodies to the Epstein-Barr virus transactivator protein (ZEBRA) as a valuable biomarker in young patients with nasopharyngeal carcinoma

Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC) generally occurs in adults, especially in high-prevalence populations such as the Chinese and Eskimos. In Maghrebian populations, young patients affected with this malignancy represent 25% of the total NPC cases. In adults with NPC, relatively high titers of IgA antibodies to the EBV viral capsid antigen (VCA) and early antigen (EA) represent important markers. However, nearly 50% of young NPC patients are negative for IgA-anti-VCA and -EA or exhibit very low titers of these antibodies. We report here that 92% of sera from young NPC patients negative for IgA-EA and 89% of those negative for IgA-VCA were positive for IgG antibodies to the EBV transactivator protein (ZEBRA) at very high titers. Our results show that in young patients with NPC these antibodies represent the most reliable marker for diagnosis and prognosis, particularly when compared with conventional NPC markers, i.e., IgA-VCA (58%) and anti-EA (25%). The titers of IgG-ZEBRA antibodies increased along with lymph node involvement only in the young patient group, suggesting a prognostic value of this marker in this patient group.

Radiation therapy in Africa: distribution and equipment

BACKGROUND AND PURPOSE

Africa is the least developed continent as regards radiation oncology resources. The documented ASR of cancer is of the order of 1 to 2 per 1000. With improving health care this is becoming more significant. This review was undertaken to help develop priorities for the region.

MATERIALS AND METHODS

Radiation Oncology departments in Africa were identified and a survey of their equipment performed. These were compared to the reported situation in 1991. Population tables for the year 2000 were compared to available megavoltage machines.

RESULTS

Of 56 countries in Africa, only 22 are confidently known to have megavoltage therapy concentrated in the southern and northern extremes of the continent. The 155 megavoltage machines operating represents over 100% increase over the past 8 years. The population served by each megavoltage machine ranges from 0.6 million to 70 million per machine. Overall, only 50% of the population have some access to Radiation Oncology services.

CONCLUSION

Progress has been made in initiating radiation oncology in Ghana, Ethiopia and Namibia. There has been some increase in machines in Algeria, Egypt, Libya, Morocco and Tunisia. However, a large backlog exists for basic radiation services.

The viral origin of cervical cancer in Rabat, Morocco

In Northern Africa, cervical cancer is the second most common cancer among women. The diagnosis is usually made in advanced stages, and mortality is high, yet few studies have investigated the role of human papillomavirus (HPV) and other risk factors in the etiology of cervical cancer. A hospital-based case-control study was completed at the Institut National d'Oncologie (INO) in Rabat, Morocco. The study included 214 cases of invasive cervical cancer and 203 controls. A structured questionnaire was used to investigate known and suspected risk factors for cervical cancer. A GP 5+/6+ polymerase chain reaction system was used to detect the presence of HPV DNA and HPV type distribution. Probes for 30 HPV types were used in one research laboratory. HPV DNA was the central risk factor and accounted for the large majority of the cases. The adjusted odds ratio (ORa) for any HPV was 61.6 (95% CI, 29.2-130) and the corresponding HPV attributable fraction (AF) was 92%. Among cases of cervical cancer, HPV 16 was the most common type (67.7%) followed by HPV 18. The HPV type-specific prevalence was similar for squamous cell carcinomas and adenocarcinomas. In multivariate adjusted or HPV-stratified analyses, in addition to the strong effect of HPV, other risk factors identified were sexual intercourse with multiple partners before the age of 20 and low socio-economic status. Use of oral contraceptives for 5 or more years and high parity were also found to be related to cervical cancer. Screening was rare in this population but offered substantial protection against cervical cancer. In Morocco, cervical cancer is a late sequel of a viral infection with certain HPV types. Developing screening programs for preneoplastic cervical lesions is a public health priority. When available, HPV vaccination would offer a relevant alternative for preventing cervical cancer.