Mukhtar F, et al. – Analysts presumed that the secondary cancers developing in patients with Kaposi sarcoma (KS) have changed in recent years, as well as, they explored the risk of secondary cancers after KS in different periods. This study noticed a significant decline in the overall risk of secondary cancers after KS. As compared with the pre–HAART era, certain cancers, including acute lymphocytic leukemia, cancer of the tongue, and cancer of the penis, were increasingly becoming more common in the HAART era. These outcomes suggested to closely monitor and screen these secondary cancers in patients with KS.

Methods

• They employed longitudinal data from 9 cancer registries in the Surveillance, Epidemiology, and End Results (SEER) database to identify cases of KS diagnosed from January 1973 to December 2013.
• November 2016 to February 2017 were the dates of the analysis.
• The development of secondary cancers in individuals with KS was the primary outcome.
• Moreover, secondary cancers were considered only if diagnosed 2 months after a diagnosis of KS.
• They estimated standardized incidence ratios (SIRs) for the development of new secondary cancers in the pre-AIDS era (1973-1979), pre–highly active antiretroviral therapy (HAART) era (1980-1995), and HAART era (1996-2013).
• In addition, they regulated stratified analysis on a subset of the cases diagnosed from 1996 to 2013 based on age at diagnosis (<65 and ≥65 years), latency period between KS and the development of secondary cancers (1 year, 2-5 years, >5 to 10 years, and >10 years), and registries with higher vs lower reported rates of HIV/AIDS.

Results

• 13721 (92.1%) were younger than 65 years at the time of diagnosis, and 14356 (96.3%) were male, among 14905 individuals with diagnosed KS.
• SIRs were 2.01 (95% CI, 1.00-3.60) for cancer of the rectum, 49.70 (95% CI, 33.53-70.94) for cancer of the anus, 4.98 (95% CI, 2.79-8.22) for cancer of the liver, 13.70 (95% CI, 2.82-40.03) for cancer of the cervix, 6.40 (95% CI, 2.76-12.60) for Hodgkin lymphoma, and 48.97 (95% CI, 44.85-53.36) for non-Hodgkin lymphoma, from 1980 to 1995.
• Cancer of the anus, Hodgkin lymphoma, non-Hodgkin lymphoma, and cancer of the liver remained associated with KS, with the addition of the following significant SIRs: 6.99 (95% CI, 3.20-13.27) for cancer of the tongue, 10.28 (95% CI, 1.24-37.13) for cancer of the penis, and 17.62 (95% CI, 3.63-51.49) for acute lymphocytic leukemia, from 1996 to 2013.
• From the pre-HAART era to the HAART era, the SIR of developing any tumor after KS decreased significantly from 3.36 to 1.94.