Risk for secondary cancers after Kaposi sarcoma has declined
Overall risk for secondary cancers after Kaposi sarcoma decreased over time; however, acute lymphocytic leukemia and cancers of the tongue and penis became new common secondary cancers, according to results of a longitudinal analysis.
Closer screening and monitoring for these cancers would be helpful, the researchers wrote.
“Having a second tumor complicates patient management, adds to health care cost and is associated with higher morbidity and mortality,” Fahad Mukhtar, MD, MPH, of the department of epidemiology and biostatistics at University of South Florida, told HemOnc Today. “If physicians are aware of the type of tumors that may potentially follow Kaposi sarcoma and other tumors, screening could be implemented to afford the patients a better chance of survival.”
Research from the 1980s and 1990s indicated patients with Kaposi sarcoma have greater risk for developing other secondary cancers, especially younger patients who had AIDS-associated Kaposi sarcoma. However, since these earlier studies, demographics of the population with Kaposi sarcoma and HIV/AIDS have changed, and those with HIV/AIDS have longer life expectancies due to new antiretroviral agents.
Mukhtar and colleagues evaluated how secondary cancers among patients with Kaposi sarcoma have changed over time.
Researchers used data from nine cancer registries in the SEER database to identify 14,905 cases of Kaposi sarcoma diagnosed between January 1973 and December 2013. They calculated standardized incidence ratios (SIR) for secondary cancers in the pre-AIDS era (1973-1979), in the pre-highly active antiretroviral therapy (HAART) era (1980-1995), and the HAART era (1996-2013).
The development of secondary cancers — or those diagnosed 2 months after Kaposi sarcoma diagnosis — served as the primary outcome.
Most patients with Kaposi sarcoma were aged younger than 65 years at diagnosis (92.1%) and were men (96.3%).
For the pre-HAART era, researchers reported SIRs of 2.01 (95% CI, 1-3.6) for cancer of the rectum; 49.7 (95% CI, 33.53-70.94) for cancer of the anus; 4.98 (95% CI, 2.79-8.22) for liver cancer; 13.7 (95% CI, 2.82-40.03) for cancer of the cervix; 6.4 (95% CI, 2.76-12.60) for Hodgkin lymphoma; and 48.97 (95% CI, 44.85-53.36) for non-Hodgkin lymphoma.
In the HAART era, cancer of the anus, Hodgkin lymphoma, non-Hodgkin lymphoma and liver cancer remained associated with Kaposi sarcoma. New significant SIRs in this era included cancer of the tongue (6.99; 95% CI, 3.20-13.27), cancer of the penis (10.28; 95% CI, 1.24-37.13) and acute lymphocytic leukemia (17.62; 95% CI, 3.63-51.49).
“We found a change in the type of tumors that develop in patients with a previous diagnosis of Kaposi sarcoma,” Mukhtar said. “This could be attributed to change in the demographics of patients affected with the disease, longer survival of patients with the disease, advances in therapy, patient management and the underlying immune response.”
The SIR for developing any tumor after Kaposi sarcoma decreased between the pre-HAART and HAART era (3.36 vs. 1.94).
“Future studies could explore the possible role of oncogenic viruses or genetic factors in predisposing patients with Kaposi sarcoma to develop some of these second tumors,” Mukhtar said. – by Melinda Stevens
For more information:
Fahad Mukhtar, MD, MPH, can be reached at Department of Epidemiology and Biostatistics, College of Public Health, University of South Florida, 13201 Bruce B. Downs Blvd, Bldg MDC56, Tampa, FL 33612; email: firstname.lastname@example.org.
Disclosures: The researchers report no relevant financial disclosures.