The age of the DES-exposed patients has varied from 7 to 34 years with the highest frequency from 14 to 22 years. The risk among the exposed is small and is on the order of 1 per 1,000.
Factors that may increase the risk are maternal history of prior miscarriage, exposure to DES in early gestation, a fall season of birth, and prematurity. Pregnancy does not appear to influence adversely the tumor characteristics or prognosis of patients who have developed these malignancies.
Criteria for appropriate local therapy of small clear cell adenocarcinomas of the vagina are presented. Recurrent CCA has been observed as long as 20 years after primary therapy emphasizing the importance of prolonged follow-up..
Sources and more information
Clear cell adenocarcinoma of the vagina and cervix secondary to intrauterine exposure to diethylstilbestrol, Herbst AL, Anderson D, Semin Surg Oncol. 1990;6(6):343-6. NCBI PMID: 2263810.
Diethylstilbestrol, teratogenesis, and carcinogenesis: medical/legal implications of its long-term sequelae, including third generation effects
1990 Study Abstract:
The spectrum of teratogenic and carcinogenic effects which can be exerted when the unborn child is exposed to diethylstilbestrol (DES) has been shown to be broad. Animal work indicates the need for vigilance as regards genetic susceptibility to DES sequelae. The emergence of third generation sequelae has been demonstrated in mice, and has been postulated to occur in humans. Given the emergent data establishing problems of infertility in men and women and of relatively late onset cancer, and the possibility that in utero exposure to DES may prime a variety of tissues to noxious environmental influences there is an urgent need for measures to provide just coverage for those harmed by the drug. The DES disaster also raises important ethical and reserch questions which demand attention.
Diethylstilbestrol, teratogenesis, and carcinogenesis: medical/legal implications of its long-term sequelae, including third generation effects, NCBI, PMID: 23511655, 1990;1(3):171-93. doi: 10.3233/JRS-1990-1301.