The island of Principe, part of the archipelago of São Tomé and Príncipe, in the Gulf of Guinea, suffers the problems inherent to its double insularism. Its 7.000 inhabitants have very limited access to health care. In 2014, the privately funded NGO Ascedere started a cervical cancer screening program. A previous report has shown that this island has a unique HPV genotype distribution: HPV prevalence is high (36.7%%), but HPV16 and 18 are very rare (0 and 2%, respectively)1.
Retrospective evaluation of the records of the women screened between January 2014 and September 2016.
During this time period 972 women were screened, with a mean age of 35.5±10.04 years old (21-83 years old). Out of these, 968 (99.6%) had a satisfactory Pap test; 150 (15.5%) had an abnormal Pap test: ASC-US 58 (6.0%), LSIL 56 (5.8%), LSIL-H 2 (0.2%), ASC-H 9 (0,9%), HSIL 23 (2.4%), carcinoma/adenocarcinoma 2 (0.2%). Colposcopy was indicated in 111 (11.4%) women; 31 (27.9%) of them did not show up for evaluation. An histologic diagnosis of HSIL (CIN2 p16+/CIN3) was made in 35 women (3.6%) and of invasive carcinoma in 2 (0.2%). Of the women with HSIL, 33 (94.3%) had an excision of the transformation zone.
The mean age of women with a final histological diagnosis of HSIL/invasion was similar to those without evidence of it (36.5±11.59 vs. 35.5±9.97 years, p=0.542). Only one case was detected in a woman younger than 25 years old. There were no differences in contraception use, parity, use of alcohol, menopause status, existence of co-infections (C. trachomatis, N. gonorrhoea and T. vaginalis), age of sexual debut, menarche, age of first delivery, or number of sexual partners in women with and without HSIL/invasion. There were no differences in HIV status or smoking, but the occurrence of both risk factors is very rare in this setting.
Strategies most be implemented to reduce the number of women lost to follow-up. Despite the low prevalence of HPV16 and 18, still there is an elevated risk of HSIL, which justifies the maintenance of a cervical cancer screening program and the introduction of the nonavalent vaccine.
1Svitrigaile G, Vieira-Baptista P, Bellen G, Sousa C, Machado AP, Vanden Broeck D, Donders G. Prevalence of sexually transmitted diseases among women in Principe Island. Poster presentation. 19th ESSM Congress, Nice 2017