Salpingo-oophorectomy is one of the main components in thepurposeful reduction of the risk of development of gynecologic cancer and breastcancer in female patients who suffer from mutations in the genes known as BRCA1and BRCA2. There are at least 17 to 39 percent of BRCA mutation carriers who have a mutation in the BRCA2 gene. No studies have evaluated the efficacy ofthe risk reducing salpingo-oophorectomy for the prevention of primaryperitoneal cancer, fallopian tube cancer, ovarian cancer or breast cancer. Thisis mainly due to the fact that the mutation carriers of the two aforementionedgenes are quite different from one another.
One of the most ambitious studies which dealt with suchmedical problems and issues took 10 years to be fully conducted. The study included participation of 1,079 women. There were certain rules andexpectations regarding the aforementioned participants. All those women had tohave documented evidence of deleterious mutations in the BRCA1 and BRCA2 genes.It was also of utmost importance that they had at least one ovary in situduring the period in which the genetic testing took place. One other importantcondition was that all those women should not have had any personal history ofgynecologic cancer associated with the BRCA genes prior to the genetic testing.The study could have only included women who were older than 30 at the time ofthe genetic testing, mostly due to the fact that most different types ofovarian cancer risk reduction strategies are not really the most recommendedmedical interventions for women younger than 30. It may also be important tonote that women who had some breast cancer history which was not involved withother distant metastatic diseases were also allowed to enroll. Those who hadbilateral salpingo oophorectomy were included in the risk reducing salpino-oophorectomy group. The surveillance group involved all those women who refusedto undergo the risk reducing salpino-oophorectomy process. They were advised toundergo a screening combination of serum CA-125, transvaginal ultrasound with other means of ovariancancer screening. These two distinct groups were involved with differentcalculations of the follow-up, as well.
In all different types of analyses performedduring the study, breast cancer was clearly defined as an invasive type of cancer,regardless any of its hystologic subtype or perhaps ductal carcinomain situ. Different types of gynecologic cancer were treated much moredifferently and the definition was also more versatile. The cancer was defined asinvasive epithelial carcinoma which could have affected the peritoneum, thefallopian tubes or the ovaries. Certain other types of cancer such as tumors ofthe cervix, tumors of the uterine corpus, non-eepithelial ovarian tumors,ovarian tumors of low malignant potential and lobular carcinoma in situ werenot actually included as significant events in the final analysis. Theevaluation of breast cancer end points did not include any patients whounderwent a risk reducing mastectomy but still suffered from bilateral breastcancer. The only similar type of cancer which was considered to be associatedwith a significant risk was a contralateral breast cancer, confirmed in somepatients. There were also certain participants in the study who needed to beexcluded from the analysis so that the biases could be limited properly. Thosepatients carried BRCA1 or BRCA2 mutations and suffered from unsuspected occulttype of gynecologic cancer. A small number of participants diagnosed eitherwith certain types of gynecologic cancer or breast cancer within 6 months ofthe initiation of the genetic testing also needed to be excluded from theanalysis. Patients from certain other small scale studies were included inthe evaluation and the analysis of the cancer end points as well. Some of them wereonly included in the analysis of the impact that risk reducing salpino-oophorectomy has on the subsequent types of breast cancer. Out of all theparticipants in the rather large scale study there were 597 of them whowere followed up for a mean of 35 months for breast cancer events and also another792 participants who were followed up for a mean of 39 months for different types ofgynecologic cancer events.
According to the final results there were 498 carriers ofthe mutations in the BRCA1 gene and they were assessable for gynecologic cancerend points. Out of all those there were 325 of them or 65 percent of them whounderwent risk reducing salpino-oophorectomy a median of 5.5 months afterreceiving the results of the genetic tests. There were also 294 carriers of themutations in the BRCA2 gene and they were too assessable for gynecologic cancerend points. Out of all those there were 184 of them or 63 percent of them who underwentrisk reducing salpino oophorectomy a median of 4.1 months after they receivedthe results of the genetic tests.