Browse the corpus

Cancer antigen 125 (CA125) is an antigenic tumor marker expressed by epithelial ovarian neoplasms and cells lining various organs such as the endometrium, fallopian tubes, pleura, peritoneum, and pericardium.[1][2] CA125 is used as one of the serological tests in cases when an ovarian neoplasm is suspected and for monitoring patients who have already been diagnosed with epithelial ovarian cancers.[2][3] However, due to its low sensitivity, the test has limited use in diagnosing early ovarian cancer. The specificity is particularly low in premenopausal women; thus, it is most useful in postmenopausal women.[4]

The inherent function of CA125 membrane protein is still not completely clear. The latest studies suspect that the oligosaccharides associated with CA125 might play a role in cell-mediated immunity.[12] CA125 may have a role in inhibiting cytotoxic responses of the natural killer cells.[13][14] Under physiological conditions, CA125 is expressed on the cell membrane. However, due to the presence of the cells' junctional complexes, it cannot cross into the bloodstream. Pathological states associated with the disruption of this membrane barrier lead to the antigen being shed into the blood and a consequent serological rise in the levels of CA125.[1] CA125 has been considered to play a role in promoting tumorigenesis and metastasis. This mechanism is believed to occur due to the binding between CA125 and mesothelin, a glycoprotein expressed on the mesothelial cells of the peritoneum.[15] Elucidating this role of CA125 in oncogenesis has proposed a potential therapeutic avenue through the creation of monoclonal antibodies targeting CA125.[15][16] In the case of ovaries, it appears that CA125 expresses when the ovarian epithelium undergoes metaplasia into a Müllerian-type endothelium or a neoplastic transformation.[1][2] Upon their malignant transformation, the tumor cells invade and disrupt the architecture to enter the bloodstream.[17] In benign ovarian cysts, although the antigen may be shed into the cystic fluid, it is not present in the bloodstream.[8]

CA125 serves a crucial role as a tumor marker in diagnosing patients suspected of having ovarian cancer and monitoring disease progression. According to guidelines, it is an essential criterion for referring patients with an adnexal mass suspicious of malignancy to a gynecological oncologist. Although it has a higher specificity when used in postmenopausal women, very high levels in premenopausal women require referral. In addition, patient outcomes have been observed to improve when treatment is provided by specialized gynecological oncologists and conducted in hospitals with necessary consult services and multidisciplinary collaboration.[51] Interprofessional team care involves multiple disciplines, such as primary care physicians, gynecological oncologists, nurses, and pathologists. Each of them has an essential role in providing care for individuals with suspected ovarian cancer or monitoring the disease status, thus influencing disease management. Clinicopathologic meetings involving discussions between pathologists and clinicians are a form of interprofessional care. Interprofessional team care has been shown to improve the accuracy of the diagnosis, achieve accurate staging and grading of the disease, and thus improve the management of the patient's disease. In addition to improving patient care, it provides a learning opportunity for the team members.[52] Nurses involved in the care of a patient with ovarian cancer are in a unique position to provide information and education to the patient and their family about the disease. In addition, they may be able to identify patients needing psychological support and counseling, thereby improving the quality of life for their patients by coordinating referrals with nutritionists, physiotherapists, and psychologists.[53] Evidence shows that patients treated under interprofessional team care involving clinicians and physicians from different specialties had a significant survival advantage.[54]