Cancer Incidence following Expansion of HIV Treatment in Botswana.
BACKGROUND
The expansion of combination antiretroviral treatment (ART) in southern Africa has dramatically reduced mortality due to AIDS-related infections, but the impact of ART on cancer incidence in the region is unknown. We sought to describe trends in cancer incidence in Botswana during implementation of the first public ART program in Africa.


METHODS
We included 8479 incident cases from the Botswana National Cancer Registry during a period of significant ART expansion in Botswana, 2003-2008, when ART coverage increased from 7.3% to 82.3%. We fit Poisson models of age-adjusted cancer incidence and counts in the total population, and in an inverse probability weighted population with known HIV status, over time and estimated ART coverage.


RESULTS
During this period 61.6% of cancers were diagnosed in HIV-infected individuals and 45.4% of all cancers in men and 36.4% of all cancers in women were attributable to HIV. Age-adjusted cancer incidence decreased in the HIV infected population by 8.3% per year (95% CI -14.1 to -2.1%). However, with a progressively larger and older HIV population the annual number of cancers diagnosed remained constant (0.0% annually, 95% CI -4.3 to +4.6%). In the overall population, incidence of Kaposi's sarcoma decreased (4.6% annually, 95% CI -6.9 to -2.2), but incidence of non-Hodgkin lymphoma (+11.5% annually, 95% CI +6.3 to +17.0%) and HPV-associated cancers increased (+3.9% annually, 95% CI +1.4 to +6.5%). Age-adjusted cancer incidence among individuals without HIV increased 7.5% per year (95% CI +1.4 to +15.2%).


CONCLUSIONS
Expansion of ART in Botswana was associated with decreased age-specific cancer risk. However, an expanding and aging population contributed to continued high numbers of incident cancers in the HIV population. Increased capacity for early detection and treatment of HIV-associated cancer needs to be a new priority for programs in Africa.
Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, United States of America; Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana; Department of Immunology and Infectious Diseases, Harvard School T.H Chan School of Public Health, Boston, Massachusetts, United States of America; Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America.
Scott
S
Dryden-Peterson
Department of Public Health, Botswana Ministry of Health, Gaborone, Botswana.
Heluf
H
Medhin
Department of Public Health, Botswana Ministry of Health, Gaborone, Botswana.
Malebogo
M
Kebabonye-Pusoentsi
Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
George R
GR
Seage
Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
Gita
G
Suneja
National Health Laboratory, Botswana Ministry of Health, Gaborone, Botswana.
Mukendi K A
MK
Kayembe
Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana.
Mompati
M
Mmalane
Department of Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
Timothy
T
Rebbeck
Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
Jennifer R
JR
Rider
Department of Immunology and Infectious Diseases, Harvard School T.H Chan School of Public Health, Boston, Massachusetts, United States of America.
Myron
M
Essex
Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital, Boston, Massachusetts, United States of America; Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana; Department of Immunology and Infectious Diseases, Harvard School T.H Chan School of Public Health, Boston, Massachusetts, United States of America; Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America.
Shahin
S
Lockman
D000970:Antineoplastic Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D001902:Botswana / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology*
D000970:Antineoplastic Agents