Integrity of plasma cell-free DNA as a prognostic factor for vaccine therapy in patients with endometrial cancer

Endometrial cancer is the most prevalent gynecological cancer in developed countries. Although the prognosis of endometrial cancer is better than that of other gynecological cancers, the prognosis of advanced endometrial cancer is still poor and thus new therapeutic modalities, such as immune therapies, are urgently required. For the further development of new modalities, exploration of new biomarkers is important. The present study investigated the circulating cell-free DNA (cfDNA) integrity as a ratio of the necrotic tumor cell-derived long cfDNA fragments to the total dead cell-derived short cfDNA fragments from genomic Alu elements in patients with advanced endometrial cancer during peptide vaccination treatment. The results demonstrated that: i) The plasma cfDNA integrity was decreased during the first cycle of vaccination in patients with endometrial cancer treated with the personalized peptide vaccination, and ii) the post-vaccination cfDNA integrity levels were correlated with good prognosis. Some of these findings have been confirmed in other cancers, and thus cfDNA integrity might be an important marker for future cancer vaccine therapies in general, and might also be applicable for other immune therapies.