Increasing evidence for a human breast carcinoma virus with geographic differences.
BACKGROUND
An early immunologic study suggesting that a virus similar to the mouse mammary tumor virus (MMTV) was associated highly with breast carcinoma in Tunisian patients, compared with patients in the United States, led the authors to examine different breast carcinoma populations by using more current molecular techniques.


METHODS
Thirty-nine paraffin blocks were selected for sequencing of the 250-base pair segment of the MMTV from patients with breast carcinoma who were seen and treated at the Institut Salah Azaiz in Tunisia. Fifteen of those blocks were examined under code by a second laboratory, which used a different methodology and was blinded to the results of the first laboratory, and 14 blocks were analyzed successfully.


RESULTS
The comparison of Tunisian patients and patients from other countries clearly showed a significantly higher proportion of tumors with MMTV-like sequences in the Tunisian series of patients. There was complete reproducibility of data between the two laboratories. Using the results from the first laboratory and similar studies from the literature, detection of the MMTV-like env gene sequence showed an important geographic pattern with a significantly higher percentage of positive patients with breast carcinoma in Tunisia (74%) compared with patients with breast carcinoma in the United States (36%), Italy (38%), Australia (42%), Argentina (31%), and Vietnam (0.8%)


CONCLUSIONS
The findings provided increased evidence for a human breast carcinoma virus with geographic differences in prevalence. The geographic differences were compatible with studies of MMTV in wild mice; thus, the data were plausible biologically.
Levine
Paul H
PH
Department of Epidemiology and Biostatistics, The George Washington University School of Public Health and Health Services, Washington, DC 20037, USA. sphphl@gwumc.edu
Pogo
Beatriz G-T
BG
Klouj
Afifa
A
Coronel
Stephanie
S
Woodson
Karen
K
Melana
Stella M
SM
Mourali
Nejib
N
Holland
James F
JF
D000818:Animals; D000835:Animals, Wild; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000821:virology*; D002277:Carcinoma / Q000453:epidemiology* / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis*; D005260:Female; D005843:Geography; D006801:Humans; D015674:Mammary Neoplasms, Animal / Q000821:virology*; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics* / Q000472:pathogenicity*; D051379:Mice; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012376:Rodent Diseases / Q000821:virology; D017422:Sequence Analysis, DNA; D014416:Tunisia / Q000453:epidemiology
D004279:DNA, Viral