Year : 2021 | Volume
: 7 | Issue : 2 | Page : 79--80
Liquid biopsy in ovarian carcinoma
Department of Gynecologic Oncology, Editor in Chief, Journal of Indira Gandhi Institute of Medical Sciences, Patna, Bihar, India
Academic Section, Second Floor, Journal of Indira Gandhi Institute of Medical Sciences, Sheikhpura, Patna, Bihar
|How to cite this article:|
Pankaj S. Liquid biopsy in ovarian carcinoma.J Indira Gandhi Inst Med Sci 2021;7:79-80
|How to cite this URL:|
Pankaj S. Liquid biopsy in ovarian carcinoma. J Indira Gandhi Inst Med Sci [serial online] 2021 [cited 2022 May 26 ];7:79-80
Available from: http://www.jigims.co.in/text.asp?2021/7/2/79/331755
Ovarian cancer (OC) is the leading cause of gynecological cancer-related mortalities among females with an estimated burden of 313,959 new cases and 207,252 deaths worldwide. If diagnosed at early stages, the 5-year survival rate for Stage I and II ovarian carcinoma is 89% and 71%, respectively. However, due to the lack of early symptoms, physical signs, and effective screening tests, most of the OC cases are diagnosed in advanced stages and associated with poor survival rate despite cytoreductive surgery and adjuvant chemotherapy with cisplatin and paclitaxel or targeted therapies (Bevacizumab/PARPi). Therefore, effective tumor markers and screening approaches are requiredfor early diagnosis and better prognosis of OC patients.
Currently, tumor markers such as CA 125, HE4, and TVS are the conventional tools for diagnosing OC. However, a number of large prospective studies reported that these tests are not sensitive and specific enough to diagnose OC in the early stage and is not recommended in the general population for screening purpose. There are also few supplementary algorithms like Risk of Ovarian Malignancy Algorithm (ROMA), Risk of Ovarian Cancer Algorithm, etc., used in clinical practice to predict the likelihood of malignancy in patients presenting with adnexal mass. However, none of these is found appropriate for early diagnosis of OC.
In recent years, liquid biopsy is a trending diagnostic concept and has been considered for the early diagnosis of cancer, detection of minimal residual disease, in decision-making for adjuvant therapies as well as it carries prognostic value also. Liquid biopsy refers to the molecular analysis of tumor components like circulating tumor nucleic acids (ctDNA and cfmiRNA)), circulating tumor cells (CTCs), and exosomes which are released from tumor into the peripheral circulation. This novel technology offers a valuable alternative to standard biopsy. Contrast to invasive biopsy procedure which is associated with risks such as pain, bleeding, or even upstaging of cancer, liquid biopsy has the advantages of being noninvasive, dynamic, and presents intra-tumoral heterogeneity. Therefore, it can help for real-time monitoring of the disease course. It may offer novel insights on cancer prevention and treatment by detecting any targetable genomic alteration and guide corresponding targeted therapy. During the course of treatment or in nonresponder to chemotherapy, regular monitoring of ctDNA can explicate drug resistance acquired from genetic alterations, which are not detectable by routine conventional approaches. Therefore, genomic-based drug response prediction can bring new perspective for better management of cancer patients.
This technology has shown promising results in the management of different types of cancers including hepatocellular Ca, NSCLC, Colorectal Ca and Ca breast, etc.
At present, Liquid biopsies have not been implemented in clinical practice for OC and the studies done so far are mostly research based. The studies related to OC are mostly focused on CTCs, circulating tumor DNA, and cfmiRNAs. The detection rate of CTCs in patients of ovarian Ca is dependent on its various isolation methods.
There are studies demonstrating significant association between the number of CTCs and tumor stage in patients with advanced disease. Early stage (I and II) and late stage (III and IV) of OC had 8.4 and 16.9 times the number of CTCs, respectively, in comparison of benign ovarian pathology. As advanced stages of the OC have a higher tumor burden in comparison to early-stage disease, higher numbers of CTCs are shed into the circulation and establishing metastatic colonies at different sites. This may be an explanation of the high incidence of recurrence and worst survival outcomes in cases of advanced staged OC patients despite maximal efforts at debulking surgery.
Uterine Cavity Lavage Biomarkers is another diagnostic technique for the detection of endometrial and ovarian cancer in which fluid from the endometrial cavity is obtained allowing the collection and detection of cancer cells close to the anatomical site of the tumor's origin. The combined approach of uterine lavage and DNA sequencing technology can detect mutational changes.
However, none of the studies presently available in support of Liquid biopsy to be offered in the general population for screening purposes due to unacceptable sensitivity and specificity. Several prospective clinical studies are ongoing in quest of promising biomarkers for ovarian cancer diagnosis and prognosis.
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