The prognosis of women diagnosed with synchronous tumors is unclear: do they follow along the lines of the more advanced primary? Is it worse?
We who treat gynecologic cancers may run encounter a woman who has synchronous tumors. Frequently this scenario occurs in a woman with a suspected ovarian or uterine cancer who after surgery is found to have a primary cancer in both places. Typically medical therapy is aimed at the more advanced stage or higher risk histology. Still, the prognosis of women diagnosed with synchronous tumors is unclear: do they follow along the lines of the more advanced primary? Is it worse?
A team lead by Lorna Rodriguez a from the Cancer Institute in New Jersey sought to address this issue and the report was published in Obstetrics & Gynecology (M Williams, E Bandera, et al. Obstet & Gynecol 2009; 113:783-789). Using data from the Surveillance, Epidemiology, and End Results (SEER) Program taken from 1973 through 2005 they compared the risk of death from ovarian cancer for women diagnosed with synchronous primaries of the ovary and endometrium compared to those with single ovarian cancer. They were able to adjust this risk based on factors available through SEER: demographics, prognostic, and treatment variables.
Their results indicate that women with synchronous primaries represented 3% of ovarian cancers identified through SEER. Compared to the cohort with ovarian cancer, they found that women with synchronous primaries had a 25% reduction in their risk of dying from ovarian cancer, which was statistically significant (HR 0.75, 95%CI, .66-.85); this represented an adjusted risk accounting for multiple factors including age, stage, treatment and prognostic factors. Of note, when analysis looked at stage, women diagnosed with advanced disease had a 30% reduction in risk (HR 0.70, 95%CI .60-.81); those with localized disease had a 27% reduction (HR 0.63, 95%CI, .42-.95).
These results are provocative, but likely not conclusive. First, their definition of synchronous tumors was defined as "cancers of the endometrium and ovary within two months of each other" and were based on proper coding using ICD (International Classification of Diseases), version 3.0. Simultaneous diagnosis of synchronous tumors was identified in 64% of their cases. It is difficult to imagine that in 36% of cases a TAH-BSO was not carried out at the same operative procedure for a cancer diagnosis (either for endometrial or ovarian cancers). That this many cases were synchronous but not simultaneously diagnosed raises the question of accuracy of diagnosing as true primaries versus metastatic. Only a prospectively designed study with histologic confirmation would be able to address this particular issue.
In addition, the analysis as performed restricted outcome to death from an ovarian cancer. Still, one would need to question what the risk was of death from uterine cancer as well. Endometrial carcinomas are prognostically different from ovarian cancer: far more curable given its propensity to present as abnormal uterine bleeding. Still, adenocarcinomas of the uterus have different biologic behaviors with endometrioid tumors doing far better than other histologies, such as clear cell and papillary serous. Therefore, knowing more about the uterine cancers and the intended risks of dying from them is still unknown. Such a question may be very hard to tease out, particularly in the presence of advanced ovarian cancer, where the risk of death was reduced for those with synchronous tumors according to this study.
Still, a valiant attempt to answer an important question about prognosis of women with synchronous tumors is helped by this study. It is not likely to change treatment paradigms for women who find themselves in this situation, but the fact their prognosis is not worse can provide some reassurance.