Molecular subtyping offers better prognostic information
Cervical cancer can be caused by at least 12 different ‘high-risk’ HPV types, and there have been conflicting reports as to whether the HPV type present in a cervical cancer influences the prognosis for the patient. CSCCs can now also be categorized into two subtypes, C1 and C2, the authors explained, among which C1 tumors have a more favorable outcome.
“Although HPV16 is more likely to cause C1 tumors and HPV18 C2 tumors, HPV type is not an independent predictor of prognosis, suggesting it is the tumor type rather than the causative HPV type that is critical for the disease outcome,” they highlighted.
“Intriguingly, the C1/C2 grouping appeared to be more informative than the type of HPV present,” they added. “While certain HPV types were found more commonly in either C1 or C2 tumors, prognosis was linked to the group to which the tumor could be assigned, rather than the HPV type it contained.”
The reason that HPV16 and other alpha-9 HPV types have been associated with more favorable outcomes was possibly that these viruses are “more likely to cause C1-type tumors”, the authors suggested. Although larger numbers are needed for robust within-stage comparisons of C1 and C2 tumors, “we observe a clear trend in the survival rates between C1 and C2 by stage”, they said.
Taking molecular (C1/C2) subtyping into account may allow for more “accurate prognostication” than current staging and potentially different clinical management of patients with C1 versus C2 tumors, the authors said. This could include the identification of patients at risk of relapse who may require further adjuvant therapy after completion of up-front therapy.
New therapeutic targets
Dr. Fenton highlighted that the study findings suggested that determining whether a patient has a C1 or a C2 cervical cancer could help in planning their treatment, since it appeared to provide “additional prognostic information beyond that gained from clinical staging”. Given the differences in the antitumor immune response observed in C1 and C2 tumors, this classification might also be useful in predicting which patients are likely to benefit from emerging immunotherapy drugs, he said.
The study findings also found that CSCC can develop along “two trajectories” associated with differing clinical behavior that can be identified using defined gene expression or DNA methylation signatures, and this may guide “improved clinical management of cervical cancer patients”, they said.
“This collaborative multidisciplinary research is a major step forward in our understanding of cervical cancer,” said Dr. Chester. “Through careful molecular profiling and genetic analysis of cervical cancer tumors we have gained valuable new insight into the tumor microenvironment and factors potentially making the cancer less aggressive in some patients.”
The authors expressed hope that their study findings will stimulate functional studies of genes and their role in cervical cancer pathogenesis, potentially enabling identification of new therapeutic targets.
The study was funded by Debbie Fund (a UCL postgraduate research scholarship), Rosetrees Trust, Cancer Research UK, the Biotechnology and Biosciences Research Council, the Royal Society, and the Global Challenges Doctoral Centre at the University of Kent, MRC, PCUK, BBSRC, TUF, Orchid, and the UCLH BRC. The authors declared no competing interests.
A version of this article first appeared on Medscape UK.