Increased cancer prevention, screening, and treatment are needed for people living with HIV both before and after an initial cancer diagnosis due to the increased risk for first and second primary cancers, according to data published in The Lancet HIV.
The San Francisco HIV/AIDS case registry was used to conduct this population-based study. People age >16 who were diagnosed with HIV/AIDS in San Francisco, California, between January 1, 1990 and December 31, 2010 were identified. Of these 22,623 cases, 4545 incident primary cancers, comprising 4144 first primary cancers; 372 second primary cancers; 26 third primary cancers; and 3 fourth or later primary cancers were included in the study.
Standardized incidence ratios in first primary cancers in patients with HIV were elevated in a number of cancers:
1. Kaposi sarcoma (127; 95% CI, 121-132),
2. non-Hodgkin lymphoma (17.2; 95% CI, 16.1-18.4),
3. invasive cervical cancer (8.0; 95% CI, 4.1-11.9),
4. anal cancer (46.7; 95% CI, 39.7-53.6),
5. vulvar cancer (13.3; 95% CI, 6.1-20.6),
6. Hodgkin lymphoma (10.4; 95% CI, 8.4-12.5),
7. eye and orbit cancer (4.2; 95% CI, 1.4-6.9),
8. lip cancer (3.8; 95% CI, 1.3-6.2),
9. penile cancer (3.8; 95% CI, 1.4-6.1),
10. liver cancer (3.0; 95% CI, 2.3-3.7)
For secondary primary cancer, the standardized incidence ratios were increased for Kaposi sarcoma (28.0; 95% CI, 20.2-35.9), anal cancer (17.0; 95% CI, 10.2-23.8), non-Hodgkin lymphoma (11.1; 95% CI, 9.3-12.8), Hodgkin lymphoma (5.4; 95% CI, 1.1-9.7), and liver cancer (3.6; 95% CI, 1.4-5.8).
Lower first primary cancer standardized incidence ratios were observed for prostate cancer (0.6; 95% CI, 0.5-0.7), colon cancer (0.6; 95% CI, 0.4-0.8), and pancreatic cancer (0.6; 95% CI, 0.3-1.0). The same was observed in secondary primary cancer for testicular cancer (0.3; 95% CI, 0.0-0.9), kidney cancer (0.4; 95% CI, 0.0-0.9), and prostate cancer (0.6; 95% CI, 0.2-0.9). Over time, first and second primary AIDS-defining cancer incidence declined while incidence of second primary non-AIDS-defining cancer increased.
Investigators list several study limitations. One of which was their inability to exclude in situ anal cancers from the reference population used to calculate standardized incidence ratios for second anal cancers, so that these ratios for second primary anal cancers were likely underestimated. Further, the incidence ratios for rectal cancers were probably overestimated while those for anal cancers were likely underestimated as a result of recent research showing misclassifications of rectal cancers in HIV and cancer registries. There were also similar misclassification issues in distinguishing the AIDS-defining non-Hodgkin lymphoma types from non-AIDS-defining non-Hodgkin lymphoma types for the standardised incidence ratio analyses. Also, the study population may not be representative as the numbers of women with HIV/AIDS in San Francisco are low and the study population was mainly men who have sex with men. Also, investigators noted that information regarding viral co-infections was lacking.
Despite the limitations, according to the investigators, this study “is the first study to distinguish the risk of first and second primary cancers among people living with HIV, and provides important data to address practices to prevent cancer development or reduce morbidity and mortality before and after cancer diagnosis and treatment.” The investigators also recommend that additional research into improved prevention, early detection, and treatment of cancer in this vulnerable population is of increasing importance.
Hessol NA, Whittemore H, Vittinghoff E, et al. Incidence of first and second primary cancers diagnosed among people with HIV, 1985-2013: a population-based, registry linkage study [published online September 20 2018]. Lancet HIV. doi:10.1016/S2352-3018(18)30179-6