New Nanosensor Developed for Ovarian Cancer Screening
Overview of Ovarian Cancer
A study published in April 2018 in Science Advances highlighted the development of a new nanosensor by researchers in the United States aimed at screening for ovarian cancer. This type of cancer ranks as the third most prevalent reproductive cancer among women in Canada, with 2,800 new diagnoses reported in 2017. Tragically, approximately 1,800 women succumb to the disease each year. Ovarian cancer occurs when cells undergo uncontrolled division and proliferation. While the precise causes are not fully understood, factors such as family history, advancing age, reproductive history, and obesity have been linked to the disease. Data from the International Cancer Benchmarking Partnership indicates that the five-year survival rate stands at 46%. However, if detected at stage 1, when the cancer has not spread beyond the ovary, the five-year relative survival rate can soar to 92%.
Limitations of Current Screening Methods
Current methods for screening ovarian cancer include the CA-125 blood test and transvaginal ultrasonography. The CA-125 test assesses the level of CA-125, a protein associated with ovarian cancer cells, in the blood of women at heightened risk. Transvaginal ultrasonography involves the insertion of an ultrasound tube into the vagina to examine the uterus, fallopian tubes, and ovaries. Unfortunately, these existing methods suffer from high false-positive rates and limited sensitivity in detecting small lesions.
Innovative Nanosensor Technology
In the aforementioned study, the team of doctors and medical experts from the US introduced a nanosensor designed to noninvasively detect ovarian cancer biomarkers within a living organism, with data wirelessly transmitted to an external detector. This nanosensor, which utilizes an antibody-functionalized carbon nanotube complex, can identify human epididymis proteins (HE4) in proximity to the fallopian tube, ovary, uterine cavity, and peritoneal cavity. The device is also activated using a near-infrared source for optical excitation and data collection.
Enhanced Sensitivity Through Functionalized Carbon Nanotubes
The researchers assessed the sensitivity of the nanosensors using biofluid samples from ovarian cancer patients. With only 10 microliters of fluid, the nanosensors demonstrated the ability to distinguish between patients with high-grade serous ovarian cancer and those without the disease.
Successful Testing in Live Subjects
The study further involved testing the nanosensors in live mice. These sensors were positioned within the peritoneal cavity, specifically on the interior of the parietal peritoneum above the intestines. Signals emitted from the sensors were successfully captured by placing an optical probe a few centimeters above the skin of the mice. The data collected from the mice with ovarian cancer significantly differed from that of those without the disease.
Implications for Ovarian Cancer Detection
The technique developed by the researchers is straightforward, non-invasive, and offers potential for patients at risk of ovarian cancer to monitor disease onset, recurrence, or treatment response effectively.
Reference
Williams, R.M. et al. 2018. Noninvasive Ovarian Cancer Biomarker Detection Via an Optical Nanosensor Implant. Science Advances, 4(4), eaaq1090. DOI 10.1126/sciadv.aaq1090.